Background and Objectives: The management of acute postoperative pain (APP) following major abdominal surgery implies various analgetic strategies. Opioids lie at the core of every analgesia protocol, despite their side effect profile. To limit patients’ exposure to opioids, considerable effort has been made to define new opioid-sparing anesthesia techniques relying on multimodal analgesia. Our study aims to investigate the role of adjuvant multimodal analgesic agents, such as ketamine, lidocaine, and epidural analgesia in perioperative pain control, the incidence of postoperative cognitive dysfunction (POCD), and the incidence of postoperative nausea and vomiting (PONV) after major abdominal surgery. Materials and Methods: This is a clinical, observational, randomized, monocentric study, in which 80 patients were enrolled and divided into three groups: Standard group, C (n = 32), where patients received perioperative opioids combined with a fixed regimen of metamizole/acetaminophen for pain control; co-analgetic group, Co-A (n = 26), where, in addition to standard therapy, patients received perioperative systemic ketamine and lidocaine; and the epidural group, EA (n = 22), which included patients that received standard perioperative analgetic therapy combined with epidural analgesia. We considered the primary outcome, the postoperative pain intensity, assessed by the visual analogue scale (VAS) at 1 h, 6 h, and 12 h postoperatively. The secondary outcomes were the total intraoperative fentanyl dose, total postoperative morphine dose, maximal intraoperative sevoflurane concentration, confusion assessment method for intensive care units score (CAM-ICU) at 1 h, 6 h, and 12 h postoperatively, and the postoperative dose of ondansetron as a marker for postoperative nausea and vomiting (PONV) severity. Results: We observed a significant decrease in VAS score, as the primary outcome, for both multimodal analgesic regimens, as compared to the control. Moreover, the intraoperative fentanyl and postoperative morphine doses were, consequently, reduced. The maximal sevoflurane concentration and POCD were reduced by EA. No differences were observed between groups concerning PONV severity. Conclusions: Multimodal analgesia concepts should be individualized based on the patient’s needs and consent. Efforts should be made to develop strategies that can aid in the reduction of opioid use in a perioperative setting and improve the standard of care. According to the latest available World Health Organization global survey on surgery volume from 2014, at least 312 million surgeries are performed globally every year .Among these patients, up to 10% suffer from severe chronic postoperative pain that persists 6 months after surgery—therefore, appropriate pain management is a critical aspect of surgical care ,8,9. SucAlthough acute postoperative pain (APP) in major abdominal surgery is managed with a variety of drugs, e.g., systemic non-steroidal anti-inflammatory drugs, acetaminophen, ketamine, lidocaine, cyclooxygenase-2 inhibitors, α2-agonists, and/or epidural local anesthetics, opioids remain a cornerstone of every analgesia protocol. In addition to their addictive profile, opioids have a slew of side effects, such as respiratory depression, decreased gastrointestinal motility, and postoperative nausea and vomiting (PONV) ,14. To aThe objectives of this study were to analyze if opioid-sparing analgesic strategies such as epidural analgesia (EA) and a ketamine–lidocaine co-analgetic regimen could impact postoperative pain, as the primary outcome, and to compare the intraoperative fentanyl dose, total postoperative morphine dose, intraoperative sevoflurane concentration, the incidence of POCD, and the severity of PONV, as quantified by postoperative ondansetron dose in the above-mentioned analgetic strategies, as secondary outcomes. The study was conducted in accordance with the Declaration of Helsinki and approved by the Local Ethics Committee (protocol code 8999/10 February 2021) for studies involving humans. Informed consent was obtained from all subjects included in the study.This is a comparative, monocentric, observational, randomized clinical study including patients proposed for major abdominal surgery. We used a convenience sample size of the data. We excluded the patients with inherited or acquired coagulopathies, local inflammation/infection at the epidural punction site, major arrhythmias, heart failure with reduced ejection fraction, chronic pain, and severe dementia.The patients received balanced anesthesia consisting of inhalative sevoflurane  and one of the following intravenous analgesia regimens: (1) Standard analgesia consisting of intraoperative fentanyl   and postoperative acetaminophen  (3 g/day) and metamizole  (4 g/day); (2) ketamine–lidocaine co-analgesia consisting of lidocaine 1%  1 mg/kg at induction followed by 1 mg/kg/h during surgery, and ketamine  0.5 mg/kg at induction followed by 0.5 mg/kg/h during surgery additionally to standard intraoperative analgesia regimen. Postoperatively, the patients received ketamine 0.5 mg/kg/h, acetaminophen (3 g/day), metamizole (4 g/day), and (3) EA with ropivacaine 0.5%  , followed by 8–10 mL/h ropivacaine 0.5% intraoperatively additionally to standard intraoperative analgesia regimen. Postoperatively, the patients received EA with 0.2 mg/kg/h ropivacaine 0.2% and fentanyl 0.1 microg/kg/h additionally to acetaminophen (3 g/day) and metamizole (4 g/day). All patients received morphine  as rescue therapy for pain management after surgery.Postoperatively, we used the visual analogue scale (VAS) as the primary outcome to quantify pain, both at rest and movement. We considered the following secondary outcomes: Total intraoperative fentanyl dose, total dose of morphine, intraoperative end-tidal sevoflurane concentration, confusion assessment method for intensive care units (CAM-ICU) score for POCD at 1 h, 6 h, and 12 h postoperatively, and the total dose of ondansetron as a marker for the intensity of PONV. We considered the POCD present in any patient who exhibited positive CAM-ICU test at least once during the testing time.The responsibility of data collection for each patient was assumed by the case-designated anesthesiologist one day prior to surgery. The VAS score at 1 h, 6 h, and 12 h after surgery, as the primary outcome, was documented by the ICU nurse, in accordance with the patients’ response. In the intraoperative setting, the designated anesthesiologist considered additional analgesic doses of fentanyl mandatory if any indirect signs of pain appeared, such as tachycardia, hypertension, sweating, reactive mydriasis, patient movement during surgery, and/or unsynchronized breathing patterns. Morphine was administrated postoperatively by the ICU nurse, titrated at a dose of 0.1 mg/kg, in accordance with the local protocol by a VAS score greater than 6 points at rest. The target of the intraoperative end-tidal sevoflurane concentration was at the discretion of the designated anesthesiologist in accordance with the above-mentioned patients’ indirect signs of pain or inadequate anesthesia depth and documented accordantly. The CAM-ICU scoring was assessed by the ICU nurse at the time points considered, based on a specific flowsheet, and quantified by the designated anesthesiologist on the second day. Ondansetron was administrated by the ICU nurse if any sign of nausea and vomiting occurred, not exceeding 32 mg/day, in accordance with the local protocol. Statistical analysis of the data and graphical representations were performed using GraphPad Prism 6.00 . We evaluated the groups for normal distribution using the D’Agostino–Pearson omnibus normality test and the Shapiro–Wilk test. For comparative analysis, we considered VAS at 1 h, 6 h, and 12 h after surgery and, fentanyl dose (µg/kg/h), morphine dose (mg/kg), sevoflurane (% in expired air), POCD (binary data), and ondansetron dose (mg/day) as markers for PONV severity.The VAS scores at 1 h, 6 h, and 12 h were considered discrete quantitative data and were expressed as the median and IQR. The medians of the groups were compared using the Kruskal–Wallis test. p-value < 0.05 was considered statistically significant. For categorical data , we used the Chi-squared test.For quantitative data, we used a one-way ANOVA followed by the Bonferroni correction technique for interactions between groups. The fentanyl, morphine, sevoflurane, and ondansetron doses were expressed as quantitative continuous variables and were compared as the mean ± SEM. A two-sided n = 32), co-analgesia , and EA . A further 19 patients were excluded from the statistical analysis because they encountered complications during surgery and remained intubated for more than 24 h, required early reintubation, or the epidural catheter was dislocated. The data are displayed in We enrolled 109 patients between February 2021 and January 2022. Of the enrolled patients, 29 refused to participate and 80 patients were assigned to one of the three treatment branches using an urn randomization technique: Standard analgesia  and C-8 (IQR 6–8) vs. EA-3 (IQR 2–5) (p < 0.0001). Moreover, the pain intensity was even lower in the EA group when compared to the Co-A group: EA-3 (IQR 2–5) vs. Co-A-6 (IQR 4–7) (p = 0.036) The same tendency was also observed at 6 and 12 h. At 6 h, the following VAS scores were recorded: C-8 (IQR 7–9) vs. Co-A-4 (IQR 2–5) (p = 0.0003), and C-8 (IQR 7–9) vs. EA-2 (IQR 2–4) (p < 0.0001). At 12 h, the following VAS scores were observed: C-5 (IQR 3–7) vs. Co-A-3 (IQR 2–4) (p = 0.02), and C-5 (IQR 3–7) vs. EA-2 (IQR 2–4) (p = 0.001).  vs. Co-A-6 (IQR 4–7) ( 0.001). A–C.p = 0.0027), C vs. EA . No statistically significant difference was observed between Co-A and EA groups , C vs. EA   B.p = 0.042) and between the Co-A and EA groups   C.p = 0.0085) (p = NS), C vs. EA  (The highest incidence of POCD was observed in the C group (24%), followed by the Co-A group (16%) and the EA group (8%). The difference was, however, statistically significant between the C and EA groups only ( 0.0085) A. The co p = NS) B.All major surgical procedures are associated with APP, which, if not managed properly, can not only increase comorbidity burden but also progress to chronic postsurgical pain . FurtherCurrently, conclusions are not yet robust enough to definitively alter prescription practices, as studies examining APP management via alternative opioid-sparing or opioid-free analgesia regimens continue to report results that are heterogeneous or lack scope . In thisThe effect estimates of pain at early time points in this study (1–6–12 h) indicate that patients undergoing major elective abdominal surgery who received an individualized multimodal analgesic strategy, either through epidural analgesia or co-analgesics, experienced less pain than patients receiving the standard analgesia protocol. The group receiving the intraoperative systemic ketamine–lidocaine analgesic regimen, followed by systemic postoperative lidocaine, reported less pain, coupled with a reduction in cumulative intra- and postoperative opioid consumption. We consider such a reduction to be clinically significant—in select patient populations that require higher dosages of opioids , for adequate pain control, alternative analgesia regimens may be particularly beneficial.In a systematic review, Bell et al. found that 27 of 37 studies included in the meta-analysis reported clear benefits of a perioperative subanesthetic dose of ketamine administration and a positive correlation with a reduction in rescue analgesia requirements and/or pain intensity . HoweverSpecifically for major abdominal surgery, systemic ketamine administration has been evaluated in several studies, both as a single intravenous bolus and continuous systemic infusion ,25,26. DHowever, even when strictly within the scope of abdominal surgery, the parameters of drug delivery are ambiguous. Katz et al. compared preincisional ketamine to continuous infusions in male patients undergoing radical prostatectomy and found no differences in pain incidence or intensity . KetaminLikewise, systemic lidocaine use as a multimodal analgesic for postoperative pain is flanked by compelling evidence. A review of 2802 patients across 45 studies found that the use of intravenous lidocaine infusion reduced postoperative pain at early and intermediate time points, while also affording faster gastrointestinal recovery, as compared to epidural anesthesia with opioids ,30. In bThe synergistic effect of lidocaine and ketamine in clinical trials on pain management in abdominal surgery is still debatable . Our resIn patients who received epidural analgesia, we observed that the intensity of the pain at 1 h after surgery was reduced even further, as compared to the ketamine–lidocaine regimen. At 6 and 12 h after surgery, the pain scores were similar. Moreover, perioperative systemic opioid doses were also reduced compared to control and were comparable between the two multimodal regimens. Our results are in accordance with El Sayed et al., who found that epidural analgesia in major abdominal surgery improves pain control . Thus, wConsidering the intraoperative hypnosis intensity in patients undergoing major abdominal surgery, as one of the secondary outcomes, we observed a reduction in sevoflurane concentration secondary to EA. Consistent with our findings, Panousis et al. reported reduced intraoperative hypnotic use. Moreover, further benefits such as better intraoperative fluid management and a reduction in the catecholamines requirement could contribute to the improvement of the anesthesia quality .Our data do not support the reduction in the intraoperative sevoflurane concentration when combined with ketamine/lidocaine. Conversely, some experimental studies identified the combined administration of ketamine and lidocaine as synergistic, where the minimum alveolar concentration of volatile anesthetics was reduced by up to 57% without affecting anesthesia quality or recovery times ,41. OtheEfforts should be made to reduce the incidence of POCD, especially in the elderly, as it could deteriorate the patients’ ability of social reintegration. Our study revealed a reduction in POCD incidence in patients receiving EA. The results are in accordance with Orhun et al., who concluded that the reduction of the POCD incidence could be secondary to better pain control . The exaFinally, we observed no difference in PONV severity among the groups, as revealed by ondansetron dose. Xie et al. reported that lidocaine infusion could accelerate recovery after surgery in patients with obstructive sleep apnea, in part due to a reduction in PONV incidence . ConsideThe primary outcome of our study was the VAS score. Consequently, the patients who developed postoperative respiratory failure, needed reintubation, experienced surgery-related complications, or needed reintervention were excluded because of their reduced ability to answer the investigator questions or the exceedance of the 24 h observational time.Although postoperative monitoring was performed by the case anesthesiologist, no double blinding protocol was used. The role of perioperative nociception monitoring with commercially available systems and/or integrated nursing information systems is still debatable. Thus, our study design did not include such pain management strategies, focusing on perioperative pain therapy concepts only.The low number of patients included in the study is based on the assumed statistical power of over 80% for the primary endpoint . Even if no further assumptions were made on the secondary outcomes, our results raise awareness about this original and controversial topic: Opioid-sparing anesthesia in major abdominal surgery.Multimodal analgesia concepts should be used in accordance with patient consent and needs. Local protocols should be issued to find an individualized approach of APP management, which considers surgery indication, the type of surgery required, and the potential contraindications for an invasive pain management strategy. Efforts should be made to reduce opioid consumption in a perioperative setting. Further clinical studies are required to improve various opioid-free or opioid-sparing pain management strategies.


Myocardial infarction (MI) patients presenting without chest pain are a diagnostic challenge. They receive suboptimal prehospital management and have high mortality. To elucidate potential benefits of improved management, we analysed expected outcome among non-chest pain MI patients if hypothetically they (1) received emergency ambulances/acetylsalicylic acid (ASA) as often as observed for chest pain patients, and (2) all received emergency ambulance/ASA.We sampled calls to emergency and non-emergency medical services for patients hospitalized with MI within 24 h and categorized calls as chest pain/non-chest pain. Outcomes were 30-day mortality and a 1-year combined outcome of re-infarction, heart failure admission, and mortality. Targeted minimum loss-based estimation was used for all statistical analyses.Among 5418 calls regarding MI patients, 24% (1309) were recorded with non-chest pain. In total, 90% (3689/4109) of chest pain and 40% (525/1309) of non-chest pain patients received an emergency ambulance, and 73% (2668/3632) and 37% (192/518) of chest pain and non-chest pain patients received prehospital ASA. Providing ambulances to all non-chest pain patients was not associated with improved survival. Prehospital administration of ASA to all emergency ambulance transports of non-chest pain MI patients was expected to reduce 30-day mortality by 5.3%  from 12.8% to 7.4%. No significant reduction was found for the 1-year combined outcome . In comparison, the observed 30-day mortality was 3% among ambulance-transported chest pain MI patients.Our study found large differences in the prehospital management of MI patients with and without chest pain. Improved prehospital ASA administration to non-chest pain MI patients could possibly reduce 30-day mortality, but long-term effects appear limited. Non-chest pain MI patients are difficult to identify prehospital and possible unintended effects of ASA might outweigh the potential benefits of improving the prehospital management. Future research should investigate ways to improve the prehospital recognition of MI in the absence of chest pain.The online version contains supplementary material available at 10.1186/s12872-022-03000-1. Despite advances in the treatment and survival of patients with myocardial infarction (MI) , 2, bothEffective treatment of MI requires timely intervention and potential life-saving efforts that can be implemented prior to hospitalization including the immediate dispatch of an ambulance to patients and provision of acetylsalicylic acid (ASA) upon arrival of the ambulance , 8. No rIn consequence, we have examined a large dataset of calls to an emergency and a non-emergency medical service in Copenhagen, Denmark, where prehospital care and emergency ambulance dispatches are recorded. We investigated whether MI patients without chest pain could be expected to benefit from increased emergency ambulance dispatch and prehospital ASA treatment.In Copenhagen, Denmark, citizens having a medical emergency should dial 1-1-2, equivalent to 9-1-1 in the United States, to receive assistance. At the 1-1-2 emergency number, the call takers are paramedics and nurses, and they assess the medical urgency and prioritize dispatching of the ambulances. Citizens with non-emergency medical conditions can contact their general practitioner or call 1813 to reach the regional 24-h medical helpline  which is intended to cover outside the working hours for general practitioners. Here, primarily nurses, but also medical doctors provide medical guidance, refer to emergency departments, and dispatch ambulances. The 1813-medical helpline and the 1-1-2 emergency number is a combined medical service operated by Copenhagen Emergency Medical Services, serving 1.8 million inhabitants, approximately one-third of the Danish population . AlthougIn Denmark, all citizens with permanent residency are assigned a unique civil registration number. This number is registered when calling for help at the 1813-medical helpline and 1-1-2 emergency number and in most other encounters with the public sector , 18.We retrieved information on age, sex, ethnicity (Danish and immigrant/descendant of immigrant), and country of emigration from the Danish Civil Registration System. From the Population Educational Registers  patientsAll contacts for patients above age 30 to the prehospital services in Copenhagen  between April 1st, 2015, and December 31st, 2018 were considered. We included calls regarding patients hospitalized with a confirmed MI no later than 24 h after the call. We defined MI as a primary diagnosis of ICD-10 I21 identified from the Danish National Patient Registry. The same patients can occur multiple times in the study population, given that the same patient could; have experienced more than one MI during the study period, or have more than one call to the Copenhagen Emergency Medical Service within the 24-h time span. We excluded patients who were terminal, living at nursing homes, suspected dead at the time of call, unconscious, and calls with missing criteria or criteria that were non-informative of the patient's condition. For the analysis of prehospital ASA assignment, only MI patients who received an emergency ambulance response were included. Additionally, we excluded patients with contraindications for ASA treatment, defined by occurrence of any of the following words in the electronic prehospital medical record: ‘blood’, ‘bleeding’, ‘aneurysm’, or ‘ulcer’, or notation of allergy to ASA.Health care professionals at the 1813-medical helpline and 1-1-2 emergency number choose one criterion (symptom/description) to describe the situation/symptoms of the patients using criteria-based systems. The criteria are used for registration but also for the assigning of vehicles. Notably, the two services use different protocols. A locally developed electronic decision support system is used at the 1813-medical helpline and Danish Index is used at the 1-1-2 emergency number . For thiThis study aims to investigate if the excess mortality observed among MI patients with non-chest pain could be reduced if we hypothetically intervened on two prehospital factors, (1) receiving an emergency ambulance and (2) receiving prehospital ASA treatment. Receiving an emergency ambulance was defined as the dispatch of an emergency ambulance with lights and sirens, which is a mobile intensive care unit of type A. The service aim of emergency ambulances in Copenhagen, Denmark is 90% arriving at the patient within less than 13 min. All other dispatches including non-emergency ambulances, self-transport to hospital, home visits were defined as no emergency ambulance. Further details of the remaining types of dispatches/non-dispatches are available , 26.Our secondary aim was to investigate the prehospital management of MI patients after they received emergency ambulances. Prior to data access, ASA was chosen as the intervention of interest, as ASA is recommended as the prehospital treatment of MI patients regardless of later in-hospital treatment , 27. PreThe primary outcome was 30-day all-cause mortality, and the secondary outcome was a 1-year combined outcome. We defined 30-day mortality from The Danish Civil Registration System , 18 and All analyses were repeated for both outcomes. We defined effect measures in a causal inference framework  in termsFour main analyses were performed as outlined in Table as chest pain-intervention). In the second analysis, we estimated the expected outcome risk if all MI patients recorded without chest pain had received an emergency ambulance, referred to as the all-intervention. Both hypothetical interventions were compared to the observed outcome risk in non-chest pain MI patients and our target parameter for each analysis was the expected reduction in outcome risk under the hypothetical intervention of interest. The third and fourth analyses considered only patients who received an emergency ambulance and did not have contraindications towards ASA. In this subgroup, the third analysis targeted the expected outcome risk had non-chest pain MI patients received ASA treatment with the same probability as observed for chest pain patients (as chest pain-intervention), and the fourth analysis targeted the expected outcome probability had all non-chest pain MI patients received ASA treatment . Similarly, these hypothetical interventions were compared to the observed outcome risk among non-chest pain MI patients who received an emergency ambulance and our target parameter was the expected reduction in outcome risk under the hypothetical interventions of interest.In the first and third analysis, we estimated the interventional disparity indirect effect  among noThe target parameters in all analyses were estimated using targeted minimum loss-based estimation (TMLE) . Initialhttps://github.com/amalielykkemark/tmleExposed). All analyses were performed in R version 4.0.3   and similarly for 1-year combined outcome ranging from 1.3% CI 95% (as chest pain-intervention) to 1.6% CI 95% .In the main analysis of the hypothetical intervention on emergency ambulance, 5418 MI patients were included of which 1309 (24.2%) were recorded without chest pain. The observed 30-day mortality among MI patients without chest pain with no hypothetical intervention was 11% and 1-year combined outcome was 31.6%. In comparison, the observed 30-day mortality without intervention among MI patients recorded with chest pain was 2.8% and the 1-year combined outcome was 18.5%. We found a small non-significant increase for both 30-day mortality and 1-year combined outcome, with 30-day mortality increases ranging from 1.5% CI 95%  were recorded without chest pain. The observed 30-day mortality without intervention among non-chest pain MI patients was 12.8% and 1-year combined outcome was 33.9%. Similarly, among MI patients with chest pain, the observed 30-day mortality and 1-year combined outcome without intervention was 3% and 18.7%, respectively. Under the hypothetical intervention where non-chest pain MI patients had the same probability of receiving ASA as those with chest pain, 30-day mortality was reduced with 3.3% CI 95%. The reduction increased to 5.3% CI 95% for the intervention where all non-chest pain MI patients hypothetically received ASA. No significant changes were found for the hypothetical intervention on ASA for the 1-year combined outcome.To investigate the impact of the type of MI on the results, we repeated the main analyses of the two hypothetical prehospital interventions; emergency ambulance and ASA in subpopulations of STEMI and NSTEMI patients. Additionally, subgroup analyses for calls to the 1-1-2 emergency number were performed to assess whether the effects of the prehospital interventions differed according to the choice of medical service.as chest pain-intervention) and 2.4% CI 95%  . In the subgroup analysis of the hypothetical intervention on prehospital ASA, we included only emergency ambulance transported MI patients without contraindication of ASA. Here, the subgroups consisted of 1442 STEMI patients, 1738 NSTEMI patients, and 3057 patients who had called the 1-1-2 emergency number  MI patients who were recorded without chest pain, the observed 30-day mortality and 1-year combined outcome to 11% and 31.6%, respectively. Large differences in the prehospital management of MI patients with and without chest pain exists, where 90% of chest pain versus 40% of non-chest pain patients received emergency ambulances, and 73% and 37% of chest pain and non-chest pain patients received prehospital ASA. We found no improvement in 30-day survival when hypothetically increasing chance of receiving emergency ambulance dispatch to all non-chest pain MI patients. Increasing prehospital administration of ASA to emergency ambulance transported non-chest pain MI patients was found to reduce 30-day mortality by 3.3% CI 95% to 5.3% CI 95% depending on the intervention. However, no significant reduction was found for the 1-year combined outcome when hypothetically increasing chance of receiving ASA in the prehospital setting. Despite the reductions found for the hypothetical interventions on ASA, 30-day mortality remained two to three times higher among non-chest pain MI patients compared to chest pain.Contrary to our hypothesis, the hypothetical intervention on the probability of receiving an emergency ambulance did not change the risk of 30-day mortality and 1-year combined outcome. In fact, increasing emergency ambulance dispatch seemed to increase outcome likelihood slightly. The finding could be explained by the fact that MI patients with more severe symptoms are more likely to receive an emergency ambulance. These patients are equally more likely to have a more severe or progressed MI probably affecting the chance of survival. Unfortunately, we do not have data that can help us differentiate the severity of the patient's infarct at the time of the call.We found a relatively large reduction in the risk of 30-day mortality among non-chest pain MI patients when hypothetically increasing prehospital ASA assignment. We cannot determine the exact cause of this reduction. It is possible that the reduction is at least partly caused by the effect of ASA, but we also expect that other factors such as early diagnostics influence the result. Providing ASA to a patient indicates that the ambulance rescue team has suspected MI and initiated a multi-faceted strategy including recording a prehospital electrocardiogram (ECG) and possibly consulting the cardiologist on duty at the invasive cardiac centre, which in addition increases the patient's chances of receiving timely in-hospital treatment. Non-chest pain MI patients are less likely to be referred directly to a cardiac centre and have previously been found to have a lower chance of receiving ASA as well as other medications within 24 h of hospitalization, indicating that they are likely to also experience in-hospital delays in treatment . SecondlWe found a small but not statistically significant reduction for 1-year combined outcome under the hypothetical interventions on ASA administration, and the expected 1-year combined outcome remained around 1.5 to 2 times higher among non-chest pain MI patients compared to chest pain MI patients. The differences in outcomes are expected to, at least partly, be explained by dissimilarities in age, comorbidities, and educational level. A larger comorbidity burden and lower educational level among non-chest pain MI patients was anticipated, as they were older. However, research have indicated that people’s knowledge of MI symptoms vary according to educational level , and we The Danish guidelines are in accordance with the international guidelines and advocate prehospital administration of ASA to all eligible patients suspected of acute coronary syndrome . In thisIn this study, the criterion recorded at the Copenhagen EMS was used as a proxy of the primary symptom. However, because patients can develop chest pain between the time of call and ambulance arrival, we do not know if the non-chest pain MI patients who were administered ASA received it because they developed chest pain or because of prehospital diagnosis with ECG.The study population, covariates, and outcomes were defined using data recorded in the Danish national registers. We cannot rule out that coding errors and imprecise or missing registrations can affect the validity of the data , 40. FurMI patients included in this study were diagnosed in-hospital. Thus, identification of these patients is not possible at the time of their call, and as a result, the hypothetical interventions of emergency ambulances and ASA treatment among MI patients examined in the present study cannot be identified in a real-world setting, hindering a direct causal interpretation of the results. Identification of MI patients based on symptoms alone is not sufficient, as non-chest pain MI patients present with a variety of symptoms. Broader use of ECG and point-of-care cardiac necrosis markers could possibly improve identification of MI patients during ambulance transport, and thus, be a tool for selecting patients for ASA administration, although we know very little about their effectiveness in patients presenting without chest pain.A real-world intervention of emergency ambulance dispatch and prehospital ASA administration to suspected MI patients would also include dispatching ambulances and administering ASA to many patients not suffering an MI. Administration of ASA to patients not suffering from an MI could lead to severe adverse events including increased risk of bleeding. Likewise, increasing emergency ambulance dispatch would be expected to have economic and administrative consequences. Neither of these adverse effects were assessed in the present study. If this study was to be investigated in a real-world setting adverse effects of both increased emergency dispatch and ASA administration should be investigated thoroughly to be able to assess the cost versus benefits of the suggested prehospital interventions. Nevertheless, this study aimed to provide information on whether there is an indication of a possible benefit of improved prehospital management among the target population, namely MI patients presenting without chest pain.Compared to MI patients with chest pain, MI patients without chest pain had three times higher 30-day mortality and twofold increased 1-year combined outcome, regardless of any of the hypothetical interventions considered in this paper. Although some potential reductions in 30-day mortality were found when improving prehospital management, overall, MI patients recorded without chest pain still have a very poor prognosis. MI patients without chest pain had a higher prevalence of severe diagnosis during their admission including heart failure, COPD, and cardiogenic shock. The high prevalence of COPD aligns with the differences in comorbidity before the MI, but given that MI patients with and without chest pain had a similar prevalence of heart failure prior to the MI, the difference in heart failure diagnoses during the admission is alarming. In combination, these findings indicate that MI patients without chest pain are truly high-risk patients.Non-chest pain MI patients are difficult to identify prehospital and real-world interventions would inevitably include many patients not suffering from an MI. Thus, one should carefully weigh the potential risk of adverse effects, including bleeding risk, when increasing prehospital ASA administration. Bleeding is a serious complication and bleeding risk assessment of patients in the prehospital setting is important but might be challenging, as accurate risk discrimination remains difficult .Additionally, one must consider the possible large increase in economic as well as human resources needed to increase emergency ambulance dispatch, ASA administration, and presumably prehospital diagnostics, given the absence of long-term benefits and the uncertainty of the true cause of the reduction in 30-day mortality discussed in this paper.We found large differences in the prehospital management of MI patients with and without chest pain. Non-chest pain MI patients have low chance of receiving an emergency ambulance dispatch when calling for help and do often not receive ASA during the ambulance transport, indicating a need for improved prehospital management of non-chest pain MI patients. We found that hypothetically increasing ASA administration could lead to reduced 30-day mortality among non-chest pain MI patients. Still, the potential effect of increasing ambulance dispatch and ASA administration appears limited as non-chest pain MI patients currently are very difficult to identify in the prehospital setting and possible unintended side effects of ASA (e.g. bleeding risk) might outweigh the benefits. Early diagnosis among those receiving ASA is expected to contribute to the magnitude of our results for increased ASA use and confounding cannot be ruled out. A randomized trial investigating the beneficial as well as adverse effects of prehospital administration of ASA is warranted. Additionally, further research is needed to determine whether identification of non-chest pain MI patients could be improved by alternative medical telephone consultation techniques or broader criteria for using prehospital ECG and point-of-care cardiac necrosis markers.Additional file 1: Table S1 ICD-10 codes for comorbidities registered prior to MI diagnosis and for diagnoses registered during MI admission. Table S2 ATC-codes for claimed prescribed medication used to define presence of disease and use of medication. Table S3 ICD-10 codes for MI diagnoses. Table S4 Subset of diagnosis registered during admission with MI (for which the patient was included in this study). Table S5 Minutes from call to hospital arrival for subgroups of chest pain and non-chest pain and emergency response.


Chronic pain is a highly prevalent health problem especially in rural regions. There is a dearth of comprehensive pain management programs particularly in rural areas.The objectives of this paper are to describe the evolution of an interprofessional chronic pain team employing a patient-centered model of care with a biopsychosocial approach, and health services metrics.This descriptive case study approach includes an overview of the Chronic Pain Management Program (CPMP) services at St. Joseph Care Group in Thunder Bay, NW Ontario; the process involved in the development of an interprofessional chronic pain team employing a patient-centered model of care with a biopsychosocial approach; and metrics of the program’s operations.Established in 1998, CPMP has evolved to become inter-professional, providing consultations and management, with partial funding by the Ontario Ministry of Health and Long term Care that has allowed expansion of services. The CPMP currently provides three distinct program streams as follows: a) Intensive 6-week, four half-days/week, outpatient program that offers an interdisciplinary team approach in groups and individual format; b) PACE-IT , 8-week long, half-day/ week, interprofessional treatment program, in person; and c) Individual format for one-on-one services for patients not fitting in either the 6-Week or PACE-IT programs. In addition, Additional services provide virtual consultations and didactic videoteleconference sessions on opioid stewardship and pain management to health providers. Health services outcomes, research, and educational opportunities across the Northwestern Ontario Region, challenges and future needs are discussed.The CPMP’s model of care can serve as a foundation for expert chronic pain care delivery across rural Canada, and as template for similar institutionally-based and publicly funded pain clinics. Taken together, the current CPMP and future goals are designed to address the gaps in pain management for patients in rural settings.Our goal is to transform the management of chronic pain by providing seamless care at the referral, continuing care throughout the intensive programs, and care of patients once they are discharged in the community.The important next steps are to determine the efficacy of the CPMP in preventing chronic pain and disability and to evaluate the extent to which the CPMP reduces overall costs to the healthcare systemChronic pain impacts 20% of people globally . It is gmultidisciplinary versus interdisciplinary pain management. While both programs use multimodal treatments and various clinicians, interdisciplinary pain management programs share common rehabilitation philosophy, have robust and ongoing communication between team professionals, and active patient involvement, and are considered superior to multidisciplinary pain programs [Pain medicine experts agree that the successful management of chronic non cancer pain (CNCP) requires a multidisciplinary approach . Systemaprograms .Canadian chronic non-cancer pain (CNCP) patients are treated in a number of clinical settings by various and diverse health professionals including primary care, secondary care, allied health care and dedicated pain specialists. Medical care costs , as well as, costs of interventional procedures (various types of injections) are covered by the provincial public health care systems, though differences may exist between provinces. In contrast, allied health care costs , are paid out of pocket, by Extended Health Benefits or private insurances, therefore inaccessible to most chronic pain patients. The existence of numerous and variable treatment options reflect different practitioner training and philosophy, heterogeneity of patients and diagnoses, financial considerations, distance from a given clinic, availability of specific treatments, and geographic differences.Access to chronic pain services is especially limited for vulnerable populations, such as those in rural and remote regions, indigenous populations, low income populations, and for those who have difficulties with social determinants of health .Northern and rural communities have their own set of health issues, economic concerns, demographic traits, resource shortages, and cultural practises, all of which combined affect the peoples’ health . In a st1 have chronic pain and little access to care. Developing integrated, patient-centered model of pain care in rural communities, however, is met with many challenges.Chronic pain is assumed to be more prevalent in rural areas . CurrentThe present paper specifically outlines the background of CPMP services at SJCG in NW Ontario, the implementation and development of an inter-professional chronic pain team approach in a community-based hospital in Thunder Bay, and the practical application of a patient-centered model of care with a biopsychosocial approach, as well as health service metrics. The CPMP is designed specifically to diagnose chronic painful conditions and offered treatments in a patient-centered whole-person approach  in a timely manner. Since this study just contains a description of the program and services, ethics approval is not necessary. However, we did receive approval from the executive team, who all reviewed the paper.The Chronic Pain Management Program (CPMP) was established on March 24, 1998, at St. Joseph’s Hospital in Thunder Bay. At inception, the chronic pain team included Psychometrist, Psychologist, Physiotherapist, Rehabilitation Assistant, Social Worker, and Recreation Therapist. This team developed a six-week program, five days per week, eight hours per day, eventually reduced to four days per week, five hours per day, to align with available resources, utilizing also four beds on a medical inpatient floor. In 2007, the team was tasked with developing a return-to-work program and subsequently moved to an off-site location. The chronic pain team continued to provide services funded through the Ontario Ministry of Health and Long Term Care (MOHLTC), but also generated revenue through referrals from the Workplace Safety and Insurance Board and other insurance companies. Ultimately low third party referrals led to discontinuation of the insurance-based service and relocation of the team back to St. Joseph’s Hospital site. In 2011, a family physician as a pain consultant began working with the team.In 2016 the chronic pain team partnered with two local primary care offices to provide in-house chronic pain consultation as an opportunity to build capacity within primary care and to introduce patients to the self-management model of care for chronic pain management. This outreach service increased awareness of the program but was short lived, and the team concentrated at the St. Joseph’s Health Centre site, a move that led to overall decrease in wait-time for service and increased participation in the program.Funding for the CPMP has been provided by MOHLTC since the beginning of the program. In 2016, funding enhancements allowed for expansion of the team to include an additional Physiotherapist, Occupational Therapist, Mental Health Clinician, Social Worker, and Kinesiologist, while in 2018 a Registered Nurse position was funded.physician consulting service.Additionally, a physiatrist  joined the team in July 2018; the latter enhanced services offered, by adding a The CPMP operates via a patient-focused, interprofessional, time-limited, goal-oriented team approach to address chronic pain via a biopsychosocial model of care. It aims to empower patients with chronic pain to improve their overall capacity and functioning in all parts of their lives by building coping skills and instill pain self-management principles through a patient-centred approach. Patients identify through goal setting what they would like to be able to do post-intervention and work towards achieving this with the support of the inter-professional team, they. Each patient seen in the CPMP completes a variety of questionnaires in order to determine both readiness for services and their goals for treatment.The CPMP uses a Decision Guide (DG) (an evidence based shared-decision-making model centred on the patient). The DG (who is a clinician) along with the patient, assesses readiness, goals, and most appropriate type of treatment/program.https://northwestaccesspoint.ca/) since May 2017, in partnership between St. Joseph’s Care Group, Thunder Bay Regional Health Sciences Centre, Alpha Court Community Mental Health & Addiction Services, and the Canadian Mental Health Association—Thunder Bay Branch. Referrals are accepted into the Central Intake Database (CID), an online database that stores patient referrals and manages waitlists. The database allows administrators and interprofessional team members to ‘move’ the patient through the stages of the program. When a referral is received, it proceeds through the following stages:New referral (screened for fit and appropriateness)Welcome WorkshopQuestionnaire SessionDecision Guide (DG) appointmentInternal referrals are made to appropriate discipline/service(s)Referrals to the program have been received through the Access Point Northwest system   6-week Program, 2) PACE-IT , and 3) Individual Care (see program details in the description of the program) for patients to enroll.Once the service is ready to accept a patient, an appointment slot is created and the patient is contacted. If the patient declines, their file is closed in CID. If the proposed service is accepted by the patient, the patient is moved through and remains on the service list until programming is complete. Once the patient has completed the service, the referral request is closed. In June 2019, the ability to see waitlist numbers and wait times was launched in CID-specific dashboards.This is an intensive 6-week, four half-days per week (Monday to Thursday) outpatient program that offers an interdisciplinary team approach in groups and individual format, both in person and virtually during the Covid-19 pandemic to allow continuation of service due to pandemic restrictions. Over the 6-week program, patients participate in psychoeducational group lectures that are delivered by all members of the team, take part in individual and group exercise training sessions, meet with individual team members  as agreed during the Decision Guide meeting to address treatment goals, and have a consultation with the pain physician. Each patient completing the program receives over 80 h of pain services learning self-management techniques through psychoeducational group lectures and individualized services. Each client’s schedule will be slightly different because they may have additional sessions with a particular discipline and decide that they don’t need to see another discipline. Also, they have breaks in their schedules, time that they can use for going for a walk, or additional sessions with someone, relaxing, reading etc. On average, each client attends three group sessions per day  and between two and three individual sessions with therapists.This is an 8-week long, half-day-per week, interdisciplinary treatment program, both in person and virtually during the Covid-19 pandemic to allow continuation of service due to pandemic restrictions. This program used to be 12 weeks, but it was reduced to 8 weeks, offering one more program each year in order to decrease wait times. During the PACE-IT program, patients are learning self-management techniques, mainly through psychoeducational group lectures delivered by all members of the team, as well as group exercise sessions. They are also meeting with individual team members  as decided during the Decision Guide meeting to address treatment goals, and have a consultation with the pain physician. This program was introduced in 2014 as a less intense form of treatment to accommodate patients who are not ready or cannot commit to a full 6-week program, or who have other barriers such as employment or childcare issues, among others.Each PACE-IT patient who completes the program receives a minimum of 20–24 h of pain services throughout their journey. Each day, the patients have at least two one-hour group education sessions and 30 min of exercise/movement. For those patients who have set goals with individual team members, the sessions are scheduled outside of the PACE-IT Tuesday afternoon. Depending on their goals, patients could meet with each discipline, one or multiple, as there is no limit, but typically, they attend individual sessions while they are currently attending PACE IT, and on average, they have 2–3 sessions with each discipline. If they need more time to work on their goals, after PACE-IT is over, they will move into the “individual care stream”.If a patient does not fit in either the 6-Week or PACE-IT programs, or does not feel they would benefit from either program at the time of their decision guide appointment, he/she can be referred to the individual care stream for one-on-one services. For instance, a patient can be referred to one or more members of the interprofessional team , without attending the psychoeducational group lectures or exercise sessions. They would still be offered coping strategies and learn self-management strategies catered to their individual needs.Communication between team members for all 3 programs, is frequent and includes formal team rounds, where all providers and physicians discuss patients from the 6-Week and PACE-IT programs, as well as select patients with complex pain issues from the individual care stream.In 2018, a new pain physician , joined the CPMP team as a consultant . This consultant created a physician consultation service for patients requiring medication review, diagnostic pain assessments, and further therapeutic recommendations. Because of this service, the program now receives an increasing number of referrals from family physicians or nurse practitioners requesting pain medication management including opiates, and clarification of the diagnosis. A registered nurse was hired in 2019 to support the work of the physician consultant with MOHLTC funding obtained in 2018.A breakdown of the interprofessional team can be found in Table The CPMP is located on the first floor of St. Joseph’s Health Centre North and includes a reception area, medical and administrative offices, treatment rooms, a gym, a boardroom, and a shared office space, with approximately 4600 square feet of space. Application for more funding has been submitted to MOHLTC in order to obtain additional office space. CPMP is now operating as a paperless facility with an electronic medical records system safeguarded by a cloud-based company.The CPMP services are funded as follows: a) Medical consultations and medical management are remunerated by OHIP; b) patients after motor vehicle or work related accidents are funded by third parties ; while c) interdisciplinary pain services and support staff are funded by MOHLTC.The CPMP has always functioned as an interprofessional team and overtime the team has expanded. Currently, the CPMP staff consists of a manager; two physicians ; and allied health professionals, namely one psychologist, one psychological associate, two physiotherapists, a dietitian, two occupational therapists, two exercise therapists, one registered nurse, one rehabilitation assistant, one recreation therapist, two social workers, one psychotherapist, a half time data analyst, and a program administrator.All of our physiotherapists and exercise therapists are strength trainers and have additional expertise in postural analysis, body mechanics, and rehab exercise training. The social workers place emphasis on social determinants of health and provide counselling and support for individuals. The dietitian places emphasis on nutrition, weight management, and life choices. The psychologist, psychological associate, psychotherapist, and MSW provide psychological consultation and support and a variety of psychological therapies, including mindfulness, and cognitive behavioural therapy.The CPMP staff members use a variety of therapeutic equipment in the gym located at St. Joseph’s Health Centre North to assess patient’s baseline function and measure improvement of physical functioning, while the Occupational Therapists’ equipment and supply needs relate mostly to assessing and prescribing assistive devices  as well as the manufacturing of splints and custom orthotics.All members of staff are offered access to CPMP-funded continuous health education, including presentations and attendance at our annual Canadian Pain Conference meetings. Additionally, in order to maintain a highly engaged and satisfied workforce, St. Joseph’s Care Group conducts employee and physician surveys every two years asking the staff to provide feedback and suggestions regarding their experience in their workplace.Referrals for medical consultation and requests for assessment and treatment are made through the Access Point Northwest website and reviewed in CID by medical and administrative staff to ascertain that basic information has been received.During the 2020/21 Covid-19 pandemic, patients were provided with an online Welcome Workshop and phone intake prior to placement on wait lists for admission to the program. Prior to the pandemic restrictions, a three step resource and time intensive process was utilized; however, the amount of in-person contact has been reduced substantially now with the online process. All referrals continue to be received and reviewed prior to the clerical staff contacting the patient and providing a link to the online Welcome Workshop. The online Welcome Workshop is a PowerPoint presentation with a voice recording which can be accessed in the privacy of the patient’s home; this presentation is identical to the previous in-person session. Subsequently, the Decision Guide explains the program expectations during their appointment, (in-person or over the telephone), where discussion about treatment goals, readiness for treatment, and a personalized treatment plan is developed. The Decision Guide then makes the referral to the most appropriate program  within the CID.Of note, this new process has substantially reduced the number of no-shows for Decision Guide appointments and the wait time for access to services, while it emphasizes timely discharge after completion of services, as more focused treatment goals are being determined at the Decision Guide appointments Fig. .Fig. 1CPPrior to 2020, Community Outreach was an extension of the chronic pain program in two communities, the Manitouwadge Family Health Team and Atikokan Hospital. These partnerships have since concluded, and their patients continue to be referred to the CPMP for services.Chronic pain services until 2018, offered a condensed program specifically for regional patients. Patients residing outside of Thunder Bay attended a condensed and intensive program model over 4 days offered at St. Joseph’s Health Centre. Prior to the pandemic, planning for this regional sessions was extremely resource-intensive, consuming many hours of clinician time coordinating schedules and appointments, and often resulted in a low attendance. Currently, the program continues to accept referrals from all of NW Ontario and provide services as best as possible in a hybrid model of care . Some of the challenges still facing patients referred from regional communities include: complex medical history and significant functional impairment impacting ability to travel, financial issues limiting access to travel and pay for lodging, lack of community supports, and continuity of care.https://sjcgecho.squarespace.com/) is located at St. Joseph’s Health Centre and is comprised of CPMP allied health clinicians and one MD who serve as consultants in the didactic presentations and share knowledge through case-based learning. This is followed by a discussion with registered participants of ECHO (learners) who connect virtually from communities across Canada, sharing knowledge and insights and are referred as the Community Partners.In 2013, St. Joseph’s Care Group became involved in the launch of the Extension for Community Healthcare Outcomes pilot project, known as “Project ECHO: St. Joseph’s Care Group—Chronic Pain & Opioid Stewardship”. The ECHO model consists of a Hub and Community Partners. The Thunder Bay Hub  will be the subject of subsequent papers, as the present paper focusses on the description and evolution of pain services at SJGG in NW Ontario.In regard to batteries of tests, before COVID, patients used to complete a number of specialized questionnaires as follows: After the Welcome Workshop and before the Decision Guide appointment, patients complete several validated measures such as: Brief Pain Inventory (BPI), Pain Catastrophizing Scale (PCS), Tampa Scale of Kinesiophobia, Pain Stages of Change Questionnaire, and Multidimensional Health Locus of Control. The patients fill out the same upon discharge. However, as the result of the Covid-19 pandemic, the number of outcome measures has been reduced temporarily, and St. Joseph’s Care Group has started to use RedCap to capture the data. Patients are now provided with a link at the time of booking their Decision Guide appointment and asked to complete only the Brief Pain Inventory (BPI) and the Tampa Scale of Kinesiophobia (TSK) online through RedCap. This information is then saved to the RedCap database, to facilitate outcome measure reporting to the MOHLTC and to guide CPMP’s future planning purposes.The Table The CPMP staff welcomes several learners through such institutions as the Northern Ontario School of Medicine medical students, Royal College Anesthesiology residents, Family Medicine residents, Ph.D. Psychology residents, Kinesiology students, Occupational Therapy students, and Psychotherapy students. In addition, we have had site visits from nurse practitioners and physiotherapists from a few regional communities to gain further knowledge in chronic pain education delivery and processes.In regards to research, CPMP has access to the research ethics board of St. Joseph’s Care Group and can make grant submissions to the Northern Ontario Academic Medicine Association (NOAMA). For current research projects, the data is extracted partially through the electronic medical records system and through separate databases maintained by various team members.Several abstracts (and posters) were presented at various conferences and meetings, such as the Canadian Pain Society in 2018, 2019 and 2020 –16. CPMPLong wait times: Currently wait time is 101.50 days from referral date to intervention initiation due to program processes and increases in the numbers of new patient accepted into the programs. A wait list challenge (once accepted in the program) is appointments with a clinician. For example, the waiting list for an appointment with the dietitian, is about 10 months for individuals wanting nutrition counseling.Coordinating patient care and programming. The no-show rate for patients residing in Thunder Bay, as well as outside Thunder Bay, is high. For example, the March 2019 regional session, had a No Show rate of 62.5%, due to significant functional impairment affecting ability to travel, financial issues, and lack of community supports in sustaining treatment gains once returning home.Opioid medication management at CPMP is a challenge given serious opioid crisis in Thunder Bay and many communities in the region. Currently, the CPMP is not set up or aligned with opioid management or tapering, although the physiatrist is doing his best to take care of patients with no family physician or when the family physician is unable or unwilling to prescribe or address opioids .. Unfortunately, while inclusion of other allied health care professionals such as pharmacists, may help, it will not address the above cited problems.The following represent challenges to CPMP’s current function:The CPMP will continue to work on its present services, but plans to expand. The CPMP Physician consultant will initiate regional visits yearly, especially for those who have already started pain management services, in order to increase capacity in the region, in closer collaboration with regional partners, and possible satellite services. Additionally, the CPMP aims to build further links with community primary care providers and specialist groups to disseminate evidence-based knowledge on chronic pain diagnosis and management.A cross-sectional descriptive study regarding community populations that attend the CPMP in Thunder Bay;An Academic Health Sciences Centre Alternative Funding Plan project of MyPainMyRecord, to explore how to include the patient voice in person-centred care for greater autonomy, engagement, agency, and empowerment regarding their pain care;The physician consultant and allied health clinicians at CPMP are currently designing shared primary care models and to provide OTN services for regional support, as well as (in collaboration with academic managers at NOSM) teach medical students and residents multiple modules such as Structured Clinical Skills (SCS), Whole Group Sessions (WGC), and other relevant topics.In regard to future research endeavours, the CPMP expects to start two new research projects:This paper presented in detail the structure and evolution of a chronic pain management program in Northwestern Ontario. The CPMP offers multimodal and interprofessional care to chronic pain patients, coupled with educational and research output and fulfills nearly all of the following principles of the Ontario Ministry of Health comprehensive pain strategy as follows: It is interprofessional and multimodal; patient centred; operates within the chronic disease management framework; provides evidence-based and stepped-up care; accountable to MOHLTC in regard to the services paid by taxpayer’s funds and the outcomes of these services; provides education for both patients and health providers; shows continuous quality improvement; supports data information exchange and research; and offers reasonable access to the care continuum.The addition of a pharmacist to the program could facilitate some of the medication related issues with chronic pain patients and provide assistance to the pain physician in that regard.Attracting well trained pain physicians to the program  is key to the maintenance and expansion of all services as well as educational and research output.Hiring additional allied health practitioners would provide opportunities to extend services within Thunder Bay and regionally.Introduction of electronic consultations through OTN and support of shared care models will improve wait times. Additionally, the CPMP team can mentor professionals in small towns through virtual connections, in person visits, and ongoing support through ECHO, so that they can offer services to patients who cannot travel to Thunder Bay. OTN service expansion requires support for an OTN dedicated room with an exam bed, small table and chairs, OTN set-up and TV/camera, and dedicated technician for scheduling and technical supportRecruitment of research staff is very important to accelerate the creation of a Northern Ontario Chronic Pain Research group.In order to overcome existing challenges and improve further its services, the CPMP is in need of additional resources as follows:CPMP demonstrates the advantages of interprofessional pain management program in Northern Ontario and clearly demonstrates the feasibility of the model. However, none of the above could have materialized if it were not for sustainable funding and support provided by the Ministry of Health and St. Joseph’s Care Group.Detailed medical consultations can assist with diagnosis, provide proper pharmacology interventions, and offer advice to referring primary care providers.When it comes to treatment, our selection criteria place emphasis on patient goals and assessment of readiness during the Decision Guide appointment, leading to selection of those who are more likely to improve and capitalize on the interdisciplinary resources of pain management. Such selection is important since public funding is not unlimited.CPMP presents a model and a template for similar institutionally-based and publicly funded pain clinics in other parts of Northern Ontario to combat the burden of chronic pain. In particular, CPMP’s ability to provide effective pain care in Northern Ontario has wide implications for the MOHLTC policymakers who endeavour to fund community pain management clinics, in their efforts to reduce personal suffering and the economic burden of chronic pain. Our next step will be to determine the effectiveness of our program in treating chronic pain and reducing disability and health care costs.


The need for an efficient and feasible strategy to deal with neck pain has a high priority for many countries. Validated assessment tools like the Neck Disability Index (NDI) to evaluate the functional status of a neck pain patient are urgently needed to treat and to follow-up patients purposefully. A German version (NDI-G) was shown to be valid and reliable, but has so far not been tested for responsiveness. The aim of this study was to evaluate the NDI-G`s responsiveness.This was a prospective cohort study with a seven-week follow-up. Fifty chronic neck pain patients filled out NDI-G twice. Additionally, the Patients’ Global Impression of Change score (PGIC) was assessed at follow-up. Wilcoxon and Spearman tests were used to assess direction and strength of the association between the change in NDI-G and PGIC. The receiver operating characteristics method and the area under the curve (AUC) were calculated to assess sensitivity and specificity of the NDI-G change over time.S = -0.53, p = 0.01) at follow-up. AUC showed an acceptable discrimination [AUC = 0.78 ] of the NDI-G, with a cutoff score of 1.5, between clinically improved and clinically not improved patients, based on the PGIC.The Wilcoxon test showed statistically significant differences for NDI-G at baseline and follow-up in the total sample, the “clinically improved” and “clinically not improved” subgroups as indicated in the PGIC. Spearman test resulted in a moderate correlation between the NDI-G and the PGIC (rThe NDI-G is responsive to change in chronic neck pain. Together with the results of a previous study on its validity and reliability, the NDI-G can be recommended for research and clinical settings in patients with neck pain in German speaking countries.NCT02676141. February 8, 2016. Neck pain is one of the leading global causes of years lived with disability especially in the working population . Its preThe objective of this study was to evaluate the NDI-G`s sensitivity for change over time and the ability to distinguish between improved patients and non-improved patients, as assessed by the patients` impression of change.This study is a prospective cohort study with a seven-week follow-up. The study was performed in the Department of Chiropractic Medicine, Balgrist University Hospital, Zurich, Switzerland. The study was approved by the ethics committee of the canton of Zurich (BASEC 2015-00068) and registered at ClinicalTrials.gov (NCT0267614). All participants provided written informed consent.Participants were recruited from the Department of Chiropractic Medicine at Balgrist University Hospital and private practices. Inclusion criteria were chronic neck pain (neck pain > 12 weeks) .Diagnosis and medical history were assessed before filling out the questionnaires. NDI-G  , good (0.7–0.9), moderate (0.5–0.69), fair (0.3–0.5), and little or none (0.0–0.3) [Descriptive statistics were used to describe the characteristics of the patients in the total sample and the two sub-groups  Table . Missing0.0–0.3) . To stat0.0–0.3) , 31. Fur0.0–0.3) . SPSS StFifty participants were recruited. Their mean age was 48.2 years SD ± 15.1 years), 36 (72%) were female and 14 (28%) were male. Mean weight was 68.5 kg (SD ± 14.2 kg). Mean height was 171.7 cm (SD ± 9.4 cm). 50 patients completed baseline and 46 follow-up measurements. There were neither ceiling nor floor effects. All participants had chronic neck pain for more than 24 months except one patient who had neck pain for more than one year. 19 (38%) patients were complaining about frequent severe headaches, and 14 (28%) patients did not experience any headache. 39 (78%) patients did not take any pain medication, 11 (22%) took pain medication e.g., ibuprofen, paracetamol and triptan on a frequent basis. 31 (62%) had no other comorbidities, 19 (38%) had additional problems e.g., temporomandibular disorder, shoulder impingement syndrome, and cardiovascular impairments. At baseline, four participants did not answer one item . Two patients gave the reason of driving no car, two gave no reasons. At follow-up, two participants did not answer one question (driving), but did not give any reasons. All data sets were kept in the final analysis. Dichotomization according to PGIC resulted in 17 (37%) “clinically not improved” and 29 (63%) “clinically improved” participants (Table 5.1 yearsp = 0.04), the “clinically improved” sample (p < 0.001) and the “clinically not improved” sample (p = 0.05). There was a significant moderate negative correlation between NDI-G change scores and the total sample PGIC ratings . The ROC curve showed an AUC of 0.78  . The result of the Wilcoxon test stated a significant difference between the baseline and the follow-up NDI-G total scores in the total sample (91) Fig. . The cutThe aim of this study was to evaluate the NDI-G`s sensitivity to change over time and its ability to distinguish between chronic neck pain patients categorized as “clinically improved” and “clinically not improved”, as assessed by the PGIC. NDI-G and PGIC correlated moderately at seven weeks follow-up. The ROC using the PGIC as an external anchor resulted in an AUC value of 0.78 , which indicates moderate, but acceptable responsiveness .Several studies investigated the responsiveness of the NDI in different languages, patient cohorts and clinical settings –28. Six One important aspect that could have influenced the outcome in such responsiveness studies is the measurement tool which was used as an external anchor. Tools used were the functional rating index (FRI) , global The main limitation of the present study was its sample size of 50 patients at baseline, which is the minimal sample size recommended . NeverthNDI-G emerged from this study as sensitive to capture changes over time. Its responsiveness is acceptable and comparable to similar studies on the NDI in other languages. Together with the results of the previous study on the reliability and validity of the NDI-G, NDI-G can be recommended for research and clinical settings in neck pain in German speaking countries.


Chronic pain is persistent pain lasting more than three months, impacting many aspects of a person’s life. 20-30% of UK adolescents experience chronic pain .The previous pathway through our service was unclear, which meant young people were not accessing all available resources or being seen promptly.We aimed to create a model that optimised available resources, including local networks and ensured equitable access to our service across the region. We wanted to target critical barriers such as mental health, school attendance and sleep, and delivering asset-based care.We followed the “plan, do, study, act” PDSA cycle for this quality improvement project (QIP).The initial evaluation involved multidisciplinary team (MDT) meetings, site visits, and the MDT experience using other models of care. Patient cases were reviewed for weaknesses in existing models. Discussions highlighted the need to match resources to needs instead of a “one-size-fits-all” approach.Changes include creating our own “model” for Chronic Pain, introducing a specialist physiotherapy Triage Clinic to the pathway, converting our Pain Education Workshop (PEW) to virtual and utilising local resources by expanding our network.PEW seeks to empower patients and families to understand their pain. It is also offered to local healthcare professionals to increase confidence in supporting patients.We adapted the Thrive Mental Health Model to create a Triaged Model for Chronic Pain. We needed to streamline the service, as some patients became lost within the original pathway, not attending PEW and being on long waiting lists. We needed to manage difficulties faced with an increased patient cohort and case complexity, including mental health. Feedback demonstrated some patients found it difficult coming to MDT appointments without knowing who would be present. Triage Clinic helped to mitigate this.Young people with a lower level of need can be assessed virtually, have symptoms validated, receive advice and be discharged to appropriate care. Those with pain not managed by this reassurance are assessed within our service including, One-Stop-Shop, Adolescent Clinic for Rheumatology patients and Biomechanical clinic. Those requiring more support are referred to the MDT for intervention and education for serial day-case rehabilitation or more intensive intervention (PRIME). Ongoing challenges, such as severe mental health difficulties, mean some may not be ready to access support. We liaise with local services such as CAMHS, and patients may be reintroduced to the team later if appropriate.Our model showed improved outcomes compared to our previous service. We looked at data from 2018-2019 and 2021, removing the years involving the initial waves of the pandemic as the service adapted to the changes this brought.The physiotherapy Triage Clinic utilised our new Triage Model for the service. Following this we can discharge a portion of our patients to other services, some remain under the physiotherapy team, and the majority are seen in the Chronic Pain MDT clinic. It has been an opportunity, on initial consultation, to engage YP and their families and validate their pain.22% of our patients had full school attendance on their initial review by our team. The average was a 59% attendance. There was an increase in 83% of those with initially reduced attendance following intervention with the chronic pain team. On average, attendance went from 44% to 71%.We saw a rise in the number of local services involved with young people under our care. Other services involved safeguarding teams, allied healthcare professionals and CAMHS teams. In 2018 on average, 1.4 services were involved; this increased to 1.8 in 2019 and 2.4 in 2021. This may be due to increased complexity of the cases we see or due to more local support requirements. Our plans following the MDT clinic increasingly show more specific goals and activities of daily living targets year on year, from 53% in 2018 to 80% having this as part of their plan in 2021.There have been regional development over the past three years of the service. We now have over 100 staff, including 43 local physiotherapists working collaboratively with our team in supporting the young people and their parents in our care. The Evelina team aims to lead regional meetings and communities of practice.With the limited available resources, our team is continuing to work towards managing a complex cohort of patients successfully. We were shortlisted for a British Society of Rheumatology Award for Best Practice following the changes made within our department.This QIP and our new model can be adapted to many other specialities and teams. Changes we have made are especially relevant following the impacts of the Covid-19 pandemic and continued pressure with reduced resources and increased demand.The virtual PEW allows for increased access for young people that previously struggled to attend face-to-face workshops in a timely fashion. The young people and their families benefit from improving their understanding of their pain and learning new strategies to manage it. Some patients find the virtual setting more practical as they miss less school and do not have to pay for costly transport to attend. Others miss the face-to-face interaction with peers who have similar difficulties. Both individual peer support and expert patients are areas we would like to explore as a service allowing the ripple effect of our model to continue. While improving the efficiency of some aspects of our service, we know that a further challenge is managing other ‘bottle necks’ created.From this conference, we hope our new model will be critically appraised and answer questions from our peers in other services. We look forward to learning from the experience of our colleagues who also work with this often complex cohort of patients.


There are few studies in the literature about the effect of obturation techniques on postoperative pain. Besides, GuttaFlow2 was used for the first time in this study regarding postoperative pain. This study aimed to compare the postoperative pain levels and incidence following single-visit root canal treatment with different canal filling techniques; cold lateral compaction (CLC), thermoplasticised solid-core carrier (GuttaCore) based filling and cold free-flow compaction (GuttaFlow2) technique.n = 93) having single-rooted teeth with a single canal diagnosed with asymptomatic irreversible pulpitis or single-rooted vital teeth with a single canal requiring endodontic treatment because of prosthetic reasons were enrolled in this study. Patients were randomized into three groups (n = 31) according to the obturation technique. A single operator performed all the treatments in a single visit. Data on obturation levels, postoperative pain and analgesic intake frequency were recorded at postoperative 6, 12 and 24 h and daily afterward until the 7th day. Postoperative pain was measured by visual analogue scale (VAS). The date were statistically analyzed with chi-squared tests , the nonparametric Kruskal-Wallis test (for the comparisons of VAS score) and with the Friedman test (for the assessments of the changes in VAS scores over time).The patients (p < 0.05), except at 12 h (p = 0.054). The patients in the CLC and GuttaFlow2 groups did not need to use the prescribed analgesic; however, one patient in the GuttaCore group used it once.The GuttaCore group recorded the higher pain levels, except first 12 h, on the other hand, the GuttaFlow2 group recorded the lower pain levels at all time periods. Significant differences occurred among the groups during the first 4 days (Postoperative pain levels following root canal therapy were affected by the obturation technique especially first 4 days following obturation. Following root canal treatment, 3% to 58% of patients report postoperative endodontic pain , which mRoot canal filling materials are in direct contact with vital tissues, making them true implant materials with specific biological, mechanical and chemical features. Cold lateral compaction (CLC) is the most common method of root canal obturation because of its simplicity, reliability, low cost, ease of dimensional control and retreatment procedures, and suitability for post-space preparation . HoweverIn warm vertical compaction techniques, the obturation material mass becomes more homogeneous and adapts better to root canal irregularities compared to CLC . ThermafIn this context, the present study aimed to evaluate the effects of three different root canal obturation techniques on postoperative pain following single-visit root canal treatment in patients with asymptomatic irreversible pulpitis or vital pulps. The null hypothesis of this study was that the type of obturation technique would not change the incidence and intensity of post-treatment endodontic pain.The minimum estimated sample size was calculated using the G*Power 3.1 software  based on previous research data . An alphClinicalTrials.gov database (NCT/04228913), and the study was approved by the Clinical Research Ethics Committee of Aydın Adnan Menderes University, Aydın, Turkey (Protocol ADUDHF2017/21). Informed consent was obtained from all participants included in the study.All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The research protocol was registered in the The patients were selected from those referred to the Hospital of Aydın Adnan Menderes University of Dental Faculty, for root canal treatment from January 2018 to January 2019. All patients meeting the inclusion criteria were invited to participate in the study. Ninety-three systematically healthy patients  aged between 18 to 65 years met the criteria and agreed to participate in the study. Patients presenting with single-rooted teeth with a single root canal diagnosed with asymptomatic irreversible pulpitis  or single-rooted vital teeth with a single root canal requiring root canal treatment due to prosthetic reasons were included. During the removal of caries in asymptomatic irreversible pulpitis teeth large pulpal exposure may occur. In some cases, adequate haemostasis may not be achieved in 2–3 min. . In thisTo prevent bias, all treatments were performed by the same clinician (A.K.) who has 5 years of clinical experience. Each root canal was treated in a single visit to minimize the number of procedures and potential pain-related effects of the intracanal medicaments. During the diagnostic examination, periapical radiographs were obtained by the long-cone paralleling technique using a phosphor plate system  under standard exposure conditions. Thermal  and electric pulp tests  were performed to verify the sensibility of the related tooth.http://www.random.org). To prevent bias, a dental assistant who was blinded to the study procedures performed the allocation. Root canal fillings were performed as follows:Anaesthesia was achieved with 4% articaine hydrochloride containing 1:100,000 adrenalin. None of the patients required additional anaesthesia. Then, the rubber dam  was applied for isolation. Following the access cavity preparation, pulpal bleeding was observed to confirm the vitality of the related tooth. Subsequently, working length was determined to be 1 mm shorter than the value (zero) indicated by the electronic apex locator  and confirmed radiographically. Apical patency was established with a size 10 K-file, and initial shaping was performed using up to a size 20 K-file. Then, the root canals were prepared using a nickel–titanium rotary instrument  with up to an X3 file  in a crown-down manner at the speed and torque settings recommended by the manufacturer. Additional instrumentation was performed, if necessary, using X4 and X5 files . After each file, root canals were irrigated with 2 mL of 5% sodium hypochlorite (NaOCl) ; a total of 10 mL of 5% NaOCl was used for the irrigation of each canal. In all irrigation procedures, a 27-gauge notched-tip irrigation needle  was used, which was set to be 2 mm shorter than the working length. In the final irrigation, 3 mL of 17% EDTA (Sigma-Aldrich), 3 mL of 5% NaOCl and 3 mL of distilled water were used, respectively. Then, the root canals were dried with sterile paper points , and the participants were randomly assigned one of the three study groups by using online software (Group 1 (CLC technique): Control radiography was performed at the working length with a master gutta-percha cone . AH Plus was prepared according to manufacturer’s recommendations Next, the master gutta-percha cone was immersed in AH Plus root canal sealer  and placed in the root canal within the designated working length. Accessory gutta-perchas  were used until the 25# spreader penetrated no more than 1–2 mm from the root canal orifice. Excess gutta-percha cones were removed using a warm excavator.Group 2 (Cold free-flow compaction technique): Control radiography was performed with a master gutta-percha cone  fitted to the working length. Then, GuttaFlow2 was dispensed on the mixing paper as per the manufacturer’s recommendations. The master cone was immersed in this mixture and placed into the root canal to coat GuttaFlow2 to the root canal walls. Next, the master cone was recoated and applied with reciprocating movements to the root canal at the working length. Excess gutta-percha cone was removed using a warm excavator.Group 3 (Thermoplasticised solid-core carrier technique): A size verifier matching the last file was used to confirm the adaptability. Periapical radiography was performed to ensure its adaptation to the working length. Light coating of AH Plus was applied with absorbent sterile paper points which was inserted to the coronal half of the root canal system, the second sterile paper point, was placed to the root canal to remove any excess of sealer. After the root canal walls were lightly coated with the sealer, a GuttaCore Obturator were heated in a GuttaCore Obturator Oven  as recommended by the manufacturer. The heated GuttaCore obturator was placed in the canal at the previously determined working length by a single and slow movement without rotation and excessive pressure and held firmly with one finger. Then, the shaft and handle of the GuttaCore was severed at the cementoenamel junction using a diamond bur in a high-speed handpiece under copious water spray.Directly after the root canal obturation, the coronal access cavities were restored with direct adhesive build-up using a composite resin material  in all groups.After the treatment, two forms  were given to the patients. Patients were instructed on how to determine and mark the postoperative pain level on the VAS scale which was marked in every mm from 0 to 100, at postoperative 6, 12 and 24 h, and then daily until the 7th postoperative day. The VAS scale varies from 0 to 100 mm, where 0 mm corresponds to ‘no pain’, and 100 mm indicates ‘unbearable pain’ . BesidesTwo independent observers (experienced endodontists) examined the periapical radiographs to evaluate the root canal obturation levels. The obturation length at a distance of within 0–2 mm of the radiographic apex was considered ‘acceptable’, a distance of more than 2 mm from the radiographic apex was considered ‘short’ and an extension beyond the radiographic apex was considered ‘overfilled’ .p < 0.05. Descriptive statistics were given as percentages, numbers and means with standard deviations. The collected data were not normally distributed according to the Lilliefors-corrected Kolmogorov–Smirnov test. Chi-square tests were used for the analyses of the categorical data. Mann–Whitney U tests were performed to compare two independent samples, and the Wilcoxon test was used to compare two dependent samples. The Kruskal–Wallis H test was performed to compare three independent samples (VAS scores). In the post hoc analysis, the pairwise comparison module of SPSS was used. The Friedman test was conducted to evaluate the pain score during follow-up. Consistency between observer decisions was assessed by Cohen’s kappa test. The level of statistical significance was set to 5%.Statistical analysis was performed using SPSS 24.0  at p = 0.098) and gender distribution (p = 0.824) between the groups.One patient from each group was excluded from the study, as their endodontic treatment could not be completed in a single visit as a consequence of strong nausea or anxiety. In total, 90 root canal treatments were performed on 90 patients . The demp = 0.023) and 24 h (p = 0.004), as well as on the 2nd (p = 0.002), 3rd (p = 0.003) and 4th (p = 0.023) days, on the other hand, there were no significant differences at other time points (p > 0.05).The minimum and maximum postoperative pain scores of the patients during follow-up are displayed in p = 0.023). No significant difference in VAS scores was detected between the GuttaCore group and the other groups at postoperative 6 h (p > 0.05). At postoperative 24 h (p = 0.004), day 2 (p = 0.002) and day 4 (p = 0.029), the VAS scores in the GuttaFlow2 group were lower than those in the GuttaCore group and there was no significant difference in the VAS scores between the CLC group and the other groups (p > 0.05). On the 3rd day, VAS scores were higher in the GuttaCore group than in the GuttaFlow2 (p = 0.004) and CLC (p = 0.018) groups, but there was no significant difference between the CLC and GuttaFlow2 groups (p = 0.08).VAS scores in the GuttaFlow2 group at postoperative 6 h were lower than those in the CLC group  . However, in the CLC  and GuttaCore groups , differences existed in the VAS scores of each tested method over time. In the CLC group, there were significant differences at the postoperative 6th h (p = 0.194) and on days 2 (p = 0.009), 3 (p = 0.004), 4 (p = 0.004), 5 (p = 0.004), 6 (p = 0.004) and 7 (p = 0.004). In the GuttaCore group, there was significantly higher VAS scores at the postoperative 12th, 2nd, 3rd days compared to the postoperative 5th, 6th, 7th days (p < 0.05). No significant difference was found at the 4th postoperative day and between days 1 (p = 0.051), 2 (p = 0.241), 3 (p = 0.168), 5 (p = 0.276), 6 (p = 0.276) and 7 (p = 0.102).According to the Friedman test, no differences existed in the VAS scores of GuttaFlow2 group over time  and 12 h (40.0%) after obturation. These analyses showed that both the number of patients with pain and the pain severity decreased from postoperative 12 h. None of the patients declared pain after the 6th postoperative day. In the GuttaCore group, 56.7% of the patients reported no pain throughout the study. For the other patients in this group, the pain rates were calculated as 40.0%, 43.3% and 40.0% for postoperative 6 h, 12 h and day 1, respectively. In this group, both the number of patients with pain and the pain severity began to decline after the first postoperative day. Only one patient declared mild pain on the 7th postoperative day.At all time-points, GuttaFlow2 group recorded lower pain levels compared to the other groups. Besides, in the GuttaFlow2 group, 86.7% of the patients indicated no pain throughout the study. The remaining 13.3% experienced postoperative pain, which was highest at postoperative 6 h (10.0%) and 12 h (13.3%). None of these patients experienced pain after the 2p > 0.05).The patients in groups CLC and GuttaFlow2 did not need to use the prescribed analgesic. One patient in the GuttaCore group used it once, but there was no difference in terms of analgesic intake among the groups (p > 0.05). However, there was an inverse correlation between age and postoperative pain severity (p < 0.05). Analyses of the relationship between age and pain levels revealed a significant correlation at postoperative 6 h , 12 h , day 2  and day 3 ; less pain was observed with increasing age. At the other time points, there was an inverse but insignificant correlation between postoperative pain severity and increasing age.There was no relationship between gender and the postoperative pain among the tested groups  rate was significantly higher in the GuttaCore group, whereas the acceptable filling rate was significantly higher in the CLC group. Material overfilling led to increased pain severity on the 1st (p = 0.003) and 2nd (p = 0.005) postoperative days (There was a good correlation (Cohen’s kappa coefficient 0.738–0.854) among the intra-observers and inter-observers in assessing the root canal obturation lengths. In the CLC group, 26 (86.7%) teeth were considered acceptable, and four (13.3%) were overfilled. In group GuttaFlow2 group, the number of teeth classified as acceptable was 21 (70.0%), and nine (30%) were overfilled. The GuttaCore group had eight (26.7%) teeth regarded as acceptable, and 22 (73.3%) were overfilled . Post hoive days .One of the distressing problems in endodontics is postoperative pain. This pain is caused by acute inflammation due to chemical, mechanical or microbial injury in the periapical tissues  and may In the present study, health-compromised patients were excluded to eliminate the effects of any systemic health-related factors on postoperative pain . PatientThe existence of preoperative pain is a significant determinant of postoperative endodontic pain . ChronicAlthough age and general health of the patient have not been associated with root canal treatment success, they can affect the periapical tissue-healing process . Jabeen Herein, we evaluate the effects of different root canal obturation techniques following a single-visit root canal treatment on the manifestation of postoperative pain in patients with asymptomatic irreversible pulpitis or vital pulps. The null hypothesis of this study was that no difference in postoperative pain exists among the evaluated obturation techniques following a single-visit root canal treatment. Based on the results of this study, this hypothesis could be rejected. There were significant differences in the VAS scores among the groups at postoperative 6 h, 24 h and 2nd, 3rd and 4th days. Patients in the GuttaFlow2 group reported significantly lower VAS scores than those in CLC group during the 6 h post-treatment. Regarding other time points, however this difference was not significant. Higher pain level results in the CLC group at 6 h, would be an issue of the force applied by the spreader in the CLC technique, as reported by Wong et al. (2015)i.e., lower VAS scores) than the patients in the GuttaCore group. On the 3rd postoperative day, patients in the GuttaFlow2 and CLC groups reported significantly lower VAS scores compared with patients in the GuttaCore group. No difference was observed among the groups at postoperative 12 h and days 5, 6 and 7. In the first 12 h of the postoperative period, CLC resulted higher postoperative pain whereas in the later time periods GuttaCore demonstrated higher VAS scores. Besides, patients in the GuttaFlow2 group had significantly lower mean postoperative pain levels after at postoperative 24 h and days 2, 3 and 4  on postoperative pain. Further investigations on both single- and multi-rooted teeth are required to confirm its global effect on postoperative pain following root canal treatments.10.7717/peerj.13756/supp-1Supplemental Information 1Click here for additional data file.10.7717/peerj.13756/supp-2Supplemental Information 2Click here for additional data file.