The overall ROC AUC comparison between ROC in ELISA and ROC in CLEIA confirmed a more accurate ROC AUC with the new automatic method: T-tau AUC ELISA = 0.94  vs. AUC CLEIA = 0.95 , and P-tau181 AUC ELISA = 0.91  vs. AUC CLEIA = 0.98 . The performance of the new CLEIA method in automation is comparable and, for tau and P-tau181, even better, as compared with standard ELISA. Hopefully, in the future, automation could be useful in clinical diagnosis and also in the context of clinical studies.Recently, a fully automated instrument for the detection of the Cerebrospinal Fluid (CSF) biomarker for Alzheimer’s disease (AD) (low concentration of Amyloid-beta 42 (Aβ42), high concentration of total tau (T-tau) and Phosphorylated-tau (P-tau181)), has been implemented, namely CLEIA. We conducted a comparative analysis between ELISA and CLEIA methods in order to evaluate the analytical precision and the diagnostic performance of the novel CLEIA system on 111 CSF samples. Results confirmed a robust correlation between ELISA and CLEIA methods, with an improvement of the accuracy with the new CLEIA methodology in the detection of the single biomarkers and in their ratio values. For Aβ42 regression analysis with Passing–Bablok showed a Pearson correlation coefficient r = 0.867 (0.8120; 0.907% 95% CI  Several studies report the usefulness of cerebrospinal fluid (CSF) biomarkers in the diagnostic setting of Alzheimer’s disease (AD)  and receThe biomarker pattern, commonly referred to as the “AD signature”, typically displays decreased concentration of Aβ42 and increased concentration of total tau (T-tau) and Phosphorylated-tau (P-tau181). In particular, by combining CSF Aβ42, T-tau and P-tau181, a higher diagnostic accuracy for identification of AD from non-AD dementia, as well as the prediction of progression to AD in patients with Mild Cognitive Impairment (MCI), can be reached . MoreoveIn the last few years, enzyme-linked immunosorbent assays (ELISA) were mostly used for the quantification of Aβ42, T-tau and P-tau181 ,8,9,10. Recently, a fully automated instrument for the detection of these biomarkers has been implemented, aiming to further improve the reproducibility and the sensitivity of the measurements. The Fujirebio Lumipulse system is a complete automatic instrument based on Chemiluminescent Enzyme Immuno Assay (CLEIA). The importance of the automation with the Lumipulse system has recently been considered from the Biofluid Based Biomarkers Professional Interest Area (BBB-PIA) working group of the Alzheimer’s Association. It was highlighted that 76.5% of participants used the Lumipulse system and overall, 88.2% of experimenters took advantage of automated platforms .This technology has been already used in clinical routine in non-neurological settings and it has shown consistent inter-assay measures in serum ,13. NeveIn this framework, we conducted a comparative analysis between ELISA and CLEIA methods in order to evaluate the analytical precision and the diagnostic performance of the novel CLEIA system. In particular, we measured, with both methods, Aβ42, T-tau and P-tau181 levels in a large set of CSF samples in order to compare the two analytical methods. Furthermore, we evaluated, in a fraction of samples, the clinical performance to establish an optimal threshold of discrimination of the categories with Lumipulse assay.The population consisted of 111 subjects  who were admitted to the Neurodegenerative Diseases Unit of the Fondazione Ca’ Granda, IRCCS Ospedale Maggiore Policlinico, University of Milan  between July 2019 and December 2020. The clinical workup included detailed past medical history, general and neurological examination, routine blood tests, formal neurocognitive assessment, CSF biomarkers Aβ42, T-tau and P-tau181 determination, brain computed tomography (CT) scan or magnetic resonance imaging (MRI), and, if needed, [18F]-fludeoxyglucose positron emission tomography. The presence of significant vascular brain damage was excluded (Hachinski Ischemic Score < 4). Lumbar punctures were performed after one night of fasting. Thirty one patients were diagnosed with AD according to the criteria of the International Working Group (IWG)-2 guidelines , 49 patiThis study was approved by the Institutional Review Board of the Fondazione Ca’ Granda, IRCCS Ospedale Maggiore Policlinico . All patients and or their caregivers gave their written informed consent.The demographic data of patients are described in CSF samples were collected into 15 mL polypropylene tubes by LP in the L3/L4 or L4/L5 interspace. The LP was conducted between 8 and 10 a.m. after one-night fasting. Following LP, CSF samples were centrifuged at 2000 r/min for 10 min at 4 °C. The supernatants were aliquoted in polypropylene tubes and stored at −80 °C until use.In the morning, one aliquot of CSF was thawed at room temperature for each sample. Aβ42, T-tau and P-tau181 were measured using, respectively, three commercially available sandwich enzyme-linked immunosorbent assay (ELISA) kits, INNOTEST Amyloid-beta 42, Tau and P-Tau 181 assays  according to the instructions of the manufacturer. A dedicated microplate and relative calibrators, two Run Validation Controls (RVC) as High and Low Controls, specific antibodies (two IgG specific antibodies labelled to biotin) for each analyte and relative working diluent solutions, wash, substrate and stop buffers were provided for each ELISA assay. In particular, for the calibration, 6 points levels were used in a targeted concentration range between 62.5–4000 pg/mL for Aβ42, 50–2500 pg/mL for Tau, 15.6–1000 pg/mL for P-tau181 and, together with RVC and samples, were uploaded in duplicates wells in the microplate. A specific IgG labelled with biotin in phosphate buffer called Conjugate 1 was also added. after time of incubation, a cycle of washing to remove any unbound substances. Another IgG biotin-conjugated specific antibody called Conjugate 2, that detected the first antigen-antibody complex by a Peroxidase-labeled Streptavidin, was added. Then, after other incubation and washing, a Substrate solution Tetramethyl benzidine (TMB) was uploaded. The color developed was in proportion to the amount of protein bound in the initial step: the reaction was stopped with Stop Solution and the intensity of the color was measured using a microplate reader set to a wavelength of 450 nm so protein’s levels were calculated by an interpolated standard curve. The Limit of Detection (LoD) was 65 pg/mL for Aβ42, 34 pg/mL for T-tau and 13 pg/mL for P-tau181 according to the manufacturer’s instructions.The new automated chemiluminescence enzyme immunoassay (CLEIA) method  was used for the measurement of Aβ42, Aβ40, T-tau and P-tau181 in the CSF samples, using respective Lumipulse assays . All measures were performed in the same batch of samples in run and single of reagents, calibration and three different internal controls  were processed at the beginning to ensure that all measured values testing the correct immunoassay functionality and were in the right range.For the calibration, a three-point master curve was used with a range respectively between 0 and 3409 pg/mL for Aβ42 and between 0 and 30,000 pg/mL for Aβ40, a range between 0 and 2250 pg/mL for T-tau and between 0 e 400 pg/mL for P-tau181. All reagents and samples were uploaded on the roundabout of the automatic platform and results of the assay were provided on touchscreen in real-time at the end of each sample’s assays, after transferable on printer and/or USB system. The LoD was 7.17 pg/mL for Aβ42, 2.78 pg/mL for Aβ40, 141 pg/mL for T-tau, 0.282 pg/mL for P-Tau181 according to the manufacturer.® v. 5.90 . Non-parametric Passing-Bablok regression was used for ELISA and CLEIA methods comparison; it is a statistical procedure that allows a reliable estimation of analytical methods agreement and also of possible systematic bias between them. This method is robust, non parametric and non sensitive to distribution of errors and data outlier [All statistical analysis was performed by Excel Analyse-it  outlier . RegressDiagnostic performance of Lumipulse assays for the CSF biomarker’s ratio used to distinguish between AD patients and controls was assessed by means of a receiver operating characteristic (ROC) curve analysis. Optimal thresholds were determined by maximizing the Youden index and sensitivity, and specificity was calculated. The ROC curves were compared according to the area under the curve (AUC) comparison method of DeLong et al. .We performed ELISA and CLEIA on the same samples and on the same day, in order to avoid environmental bias. CSF Aβ42, T-tau and P-tau181 measurements by using both methods were completed successfully for all 111 subjects.p > 0.05), T-tau: 521 ± 40 vs. 552 ± 37 pg/mL (p > 0.05), P-tau181: 66 ± 3 vs. 88 ± 6 pg/mL (p > 0.05). No significant differences between concentrations obtained with the two methods for Aβ42, T-tau and P-tau181 were shown.Mean ± SEM levels of the three analytes detected with ELISA as compared with CLEIA were as follows: Aβ42 776 ± 32 vs. 763 ± 26 pg/mL  intercept =−59.47, slope 0.80  intercept = 55.62, slope = 0.97 , intercept = −33.56, slope = 1.81  vs. AUC CLEIA = 0.95 , and P-tau181 AUC ELISA = 0.91  vs. AUC CLEIA= 0.98 . On the contrary, for Aβ42, it was found an ELISA ROC Aβ42 AUC = 0.98  better than CLEIA Aβ42 ROC AUC = 0.92  but a relevant improvement was observed by the introduction of the Aβ42/Aβ40 ratio   A,B.In an effort to reach more accuracy, CLEIA ratios were considered also for T-tau/Abeta42 and P-tau181/Aβ42. Considering the former, ROC AUC was 0.98, whereas for the latter ROC AUC was 0.99, showing an improvement of the performance C. Then, Optimal thresholds were calculated for T-tau/Aβ42 and P-tau181/Aβ42 ratios: 0.75  and 0.13 , respectively, further increasing the accuracy. Herein, we demonstrated that there is a robust correlation between the ELISA and CLEIA methods, with an improvement of the accuracy with the new CLEIA methodology in the detection of the single biomarkers and in their ratio values. Significant correlations between the two different methodological procedures were demonstrated for Aβ42, T-tau and P-tau181 analyses. Regarding Aβ42 levels, we confirmed that the linear relationship is stronger for lower levels compared to higher ones, as previously observed . ConversWe also showed that ROC analysis suggested optimal thresholds applicable for almost all the biomarkers and for their ratio. In line with the existing literature ,22, withNowadays, CSF biomarkers tests are for use in routine clinical practice, CSF biomarker profile supports the diagnosis of AD in terms of amyloid and tau biomarkers; CSF ratio tests provide to improve the accuracy also better of an imaging test for early, rapid, easy detection and cheaper costs. Recent findings report different cases in which CSF biomarkers are useful at different stages of AD diagnosis and in different ages; in particular, CSF Aβ42 assays have good agreement with amyloid PET imaging, while Aβ42/Aβ40 and tau/Aβ42 ratios have superior performance to Aβ42 alone ,24.Here, we did not consider clustering approach  allowingOur results demonstrate the potential value of an automated method for CSF biomarker determination, that will reduce analytical errors from the operator intervention, thus increasing the diagnostic performance. Besides reference values for each biomarker, the Aβ42/Aβ40 together with other ratios increase the accuracy and would be of help for a matter of reproducibility among different centers ,27. In fRelevance of this advanced method remains above all the high-throughput, contemporary and full in automation analyzing of the biomarkers. Automation offers a higher level of standardization, combining multiple parameters in comparison to manual testing. Therefore, the novel CLEIA method allows to analyze, in automation and quickly, different biomarkers in each sample, therefore it reduces the variability due to the pre-analytical factors: it is also of strong relevance as a faster and easy management in clinical settings, with a reduction of costs and high-resolution method analysis. Lumipulse demonstrated indeed an outstanding performance in terms of precision, linearity, analytical and functional sensibility, intra-inter assay variability, so these peculiar hallmarks emphasize its better involvement to test reproducibility .CSF biomarkers determination has shown great utility in the prediction of AD pathology, however the standardization and simplification of biomarker determination methods still remains a fundamental issue in clinical practice. Despite with Lumipulse many limits are overcome, there are still some features to better refine.Pre-analytical and analytical variability of CSF biomarkers for the diagnosis of AD and related dementia hinder their diffusion in routine and clinical settings, as well as the definition of universally recognized threshold values. Therefore, it is necessary to examine laboratory procedures that potentially contribute to this variation together with the validation of new diagnostic values of biomarkers in large multi-center studies. CSF collection and handling potentially contribute to the existing variation in addition to validating the diagnostic value of biomarkers .Moreover, recent literature underlines an incipient role of peripheral biomarkers (in particular blood based biomarkers as plasma P-tau epitopes, P-tau181, P-tau217, P-tau231, NfL and GFAP  but alsoHerein, we showed that the performance of the new CLEIA method in automation is comparable and, for T-tau and P-tau181, even better, as compared with standard ELISA in our population. Thanks to Lumipulse, as only few data reported today, a significant increase in the linearity and reproducibility in the measures at first was assessed successfully as well as a better accuracy through ratio determination. Hopefully, in the future, automation could be useful in clinical diagnosis and also in the setting of clinical studies especially also with the introduction of the new promising peripheral blood-based biomarkers as prescreening tools in clinical trials and in large scale population of epidemiological studies.


Postoperative fever is one of the common complications in neurosurgery, and intracranial aseptic inflammation and infection are important risk factors. Continuous drainage of cerebrospinal fluid (CSF) via lumbar drainage (LD) is often used in the treatment of postoperative intracranial infection or aseptic inflammation. Compared with the previously reported placement of LD after the onset of meningitis symptoms, we designed this randomized controlled trial (RCT) to evaluate the effectiveness and safety of early drainage (1st day postoperation) of CSF using the preset lumbar cistern to prevent delayed fever (fever occurred after the third day postoperation) or reduce its treatment time after cerebellopontine angle (CPA) tumour surgery.Patients suffering from CPA tumours and who underwent resection of the tumour with an intraoperative dura opening time > 4 h are recruited for this study. The study is a 2-arm RCT to compare the early LD group and the no early LD group. Postoperative duration and rate of delayed fever and postoperative length of stay (LOS), as the main outcomes, will be compared in the two groups.Here, we present the study design of a prospective RCT to evaluate the safety and efficacy of using preoperative preset LD to treat or reduce postoperative delayed fever.China Clinical Trial Registry ChiCTR2100049057. Registered on July 20, 2021. Postoperative fever is one of the common complications in neurosurgery , 2. In aIn the case of intracranial infection, intravenous antibiotics alone are not sufficient. Continuous LD of CSF can remove bacteria, toxins, and necrotic substances. Therefore, it can quickly relieve the symptoms of meningeal irritation, alleviate intracranial infection, and enhance the therapeutic effect in a short time. For aseptic inflammation, such as SAH, early preventive lumbar cistern drainage can also reduce the incidence of complications, such as fever, before the appearance of fever signs , 10. TheSurgery for CPA tumours located deeply and surrounding dense nerves and vasculature is very meticulous and requires a considerable amount of time, resulting in a significant increase in delayed postoperative fever. Coincidently, to reduce the traction of the cerebellum during the operation, a lumbar cistern catheter is often pre-set before the operation to release a certain amount of CSF intraoperatively –13. TherWe design this randomized controlled trial (RCT) to evaluate the effectiveness and safety of early drainage (1st day postoperation) of CSF using the preset lumbar cistern to prevent delayed fever or reduce its treatment time after cerebellopontine angle (CPA) tumour surgery.The study is a 2-arm RCT to compare an intervention group receiving postoperative early LD and a control group receiving standard postoperative care only Fig. . We hypoThe trial will be conducted in the Department of Neurosurgery, Tangdu Hospital, The Air Force Medical University.Age: 18–65 yearsFirst surgery for tumours in the cerebellopontine angle and dural opening time > 4 hInformed consent provided by the patient or his or her legal representativeSubject exclusion criteriaAbnormal inflammatory indicators before surgeryPatients with severe intracranial hypertension or hydrocephalusPatients with severe heart liver lung and kidney insufficiencyPatient with severe lumbar hyperostosis or intervertebral disc herniationPatient is the researcher or his consanguinity who may have improper informed consentPatients with the use of dexamethasone or other steroid medications or who have immunosuppressionThe attending doctor thinks it is inappropriate to participate in this trialAll subjects had the right to withdraw from the trial at any time. During the trial, the researcher also has the right to terminate the trial of the subjects who meet the following conditions:Withdrawal from informed consent (the subjects decide to withdraw for any reason).The dural opening time is less than 4 h.The researchers believe that clinical adverse events (AEs), laboratory abnormalities, or secondary diseases (other systemic infections) indicate that it is not in the best interests of the subjects to continue to participate in the trial.Subject compliance is poor.After participating in the trial, it is found that the subjects did not meet the inclusion criteria or that the subjects are lost to follow-up.Subjects are imprisoned or forced to be isolated for the treatment of mental or physical diseases (such as infectious diseases).Subjects with allergies to the antibiotics given (meropenem and vancomycin).The ethics committee or regulatory body requests to terminate the trial.Serious violation of the protocol during the test.The following are the subject inclusion criteria:Trained research staff will assess the eligibility criteria for all participants who will be performed the surgery of CPA tumour resection and ask potential participants for written informed consent for trial enrollment.Consent for study inclusion is sought after explanation and agreement to CPA tumour surgery. Thus, patients capable of consenting to CPA tumour surgery will be informed about the study details themselves and may or may not agree to participate. If a patient is incapable of consenting to the proposed treatment, the legal representative should be informed of the conditions of treatment choices and afterwards of the details of the study. A patient may be randomized if the legal representative provides informed consent to the study.N/A, no additional participant data and biological samples will be obtained to be stored for future studies.The explanation is in the “Patients with a tumour in the CPA are routinely treated with LD and tumour resection. Before opening the dura, the LD is turned on to release a certain amount of CSF slowly, and then the tumour is removed according to conventional procedures. If the dural opening time is greater than 4 h during the operation, these patients are randomly divided into the early LD group and the no early LD group. The patients’ LD is removed in the no early LD group and reserved in the early LD group.In the no early LD group, body temperature is monitored routinely. If there is no fever after the 3rd day postoperation, the patients could be discharged, excluding other systemic abnormalities after the 6th day postoperation. If the body temperature is greater than 37.4 °C within the 3rd day postoperation, absorption heat is considered and symptomatic management will be given without any other intervention. If the body temperature is greater than 37.4 °C after the 3rd day postoperation, a lumbar puncture is performed to test the CSF. If the number of cells and white blood cells (WBCs) in CSF is increased and other systemic infections are excluded by testing the blood, urine, sputum, and stool and scanning chest CT, lumbar puncture should be performed to release CSF, or LDs should be placed to continuously drain CSF. If the body temperature is greater than 38 °C, the WBC count in the cerebrospinal fluid is increased, CSF glucose is less than 2.2 mmol/L, or CSF glucose/serum glucose is less than or equal to 0.4, vancomycin  and meropenem  will be administered. After treatment, if the body temperature is normal for 3 consecutive days, the routine WBC count in the cerebrospinal fluid is less than 300 × 106/L , the sugIn the early LD group, the LD is placed at a safe height, and the CSF drainage is controlled at approximately 150 mL/day after eliminating CT abnormalities on the first day post-surgery. Routine, biochemical, and culture tests of CSF are performed every 2 days. In addition, body temperature is routinely monitored. If the body temperature is greater than 37.4 °C within the 3rd day postoperation, absorption heat is considered and symptomatic management will be given without any other intervention. If the body temperature is normal for 72 h after the 3rd day postoperation, the routine WBC count in CSF is less than 300 × 106/L, and the CSF glucose is normal, the lumbar cistern could be removed, and the discharge standard could be reached after excluding other system abnormalities. If the body temperature is greater than 37.4 °C after the 3rd day postoperation, lumbar cistern drainage is continued. If the body temperature is greater than 38 °C, the WBC count in cerebrospinal fluid is increased, CSF glucose is less than 2.2 mmol/L, and CSF glucose/serum glucose is less than or equal to 0.4, meropenem and vancomycin are administered. After treatment, if the body temperature is normal for 3 consecutive days, the routine WBC count in CSF is less than 300 × 106/L, and the CSF glucose is normal, the restricted antibiotics and LD can be ceased and LD can be ceased, and the discharge standard can be reached after excluding other system abnormalities. The patients will be followed up for 30 days after discharge.If the number of WBCs in CSF gradually decreases and then increases during LD drainage, the possibility of retrograde infection should be considered. In addition, LD should be removed, and lumbar puncture should be performed according to the need. If the time of LD exceeds 10 days, LD repositioning is needed in the next lumbar segment or continuous lumbar puncture is performed.When patients suffer serious complications related to LD, such as brain hernia or repeated wetness at the skin outlet of the LD tube, which increases the risk of retrograde infection, LD will be discontinued.Doctors, nurses, and patients’ families work together to reduce LD-related complications and improve adherence to LD.The LD tube is placed at a safe height, and the CSF drainage is controlled at approximately 150 mL/day. Moreover, a stopcock is not allowed to open when the patient got out of bed. If a patient had a serious headache induced by intracranial hypotension, the LD catheter could temporarily be closed or raised to decrease CSF drainage. The LD catheter is replaced if it is fractured or had frequent CSF leaks at the puncture site to prevent retrograde infection of the lumbar subarachnoid. The lumbar catheter also needed to be replaced at the other lumbar space in patients who had a fever, whose lumbar catheterization lasted more than 10 days, and whose intracranial infection is not controlled completely.Dexamethasone or other steroid medications are prohibited during the trial.Necessary antipyretics can be permitted during the trial.After the trial, we will provide the participant 100 yuan and exempt the cost of online diagnosis and treatment on the good doctor application for compensation.The primary outcomes in the study are postoperative duration and rate of delayed fever and postoperative hospital LOS, which is designated from the date of surgery to the date of discharge. The rates of death, reoperation, and readmission caused by intracranial haemorrhage, CSF leakage, and intracranial infection at postoperative day 30 are also calculated in both groups. In addition, postoperative CSF leaks, including rhinorrhea, otorrhea, and incision leaks, are compared between the two groups according to postoperative clinical manifestations and MRI.The other outcomes included complications  related to LD and other systemic complications .The participant timeline is presented in Fig. 2α = 0.05 and β = 20, the sample size required for this trial is N1 = N2 = 56. If the loss of follow-up rate is 20%, 70 patients with N1 = N2 are included in each group. Therefore, 140 patients are included in the study. The sample size was calculated using SPSS (version 19.0).To test whether the early lumbar cistern drainage group is better than the nonearly lumbar cistern drainage group. The two groups are divided into two groups at a ratio of 1:1. According to the results of an earlier review of dural opening times of greater than 4 h, the descriptive statistical result of fever time in the early lumbar cistern drainage group is 7.76 ± 3.13 days, and the descriptive statistical result of the group without early lumbar cistern drainage is 11. 23 ± 4.93 days . The smaThe participant will be recruited from the inpatients of the department of neurosurgery at Tangdu Hospital, Air Force Medical University.The Department of Neurosurgery in Tangdu Hospital is the largest neurosurgery centre in Northwest China with about 4000 intracranial tumour surgeries per year, which would provide adequate quantity of CPA tumour patients.http://www.medresman.org.cn/login.aspx).Any patient meeting the inclusion criteria and not violating the exclusion criteria may participate in the study and be randomized to either receive a postoperative early LD or not, thus defining the two distinct groups: early LD and no early LD. Randomization is performed via a dedicated internet site accessible to the investigator  via the Internet site above before the initiation of the surgery. All members would be aware of the result after surgery.After the assignment to interventions, everyone is unblinded during the study.N/A. After the assignment to interventions, everyone is unblinded during the study.Work training will be held before the start of the project to provide detailed training and explanation of the trial protocol, standard operating procedures (SOPs) for study operations, and the content of case report forms (CRFs). Well-trained assessors will use CRFs to collect clinical data after participant discharging. The person in charge of CRFs checks the weekly completion and files the case report form in summary after standardization. Supervisors also should randomly check the CRFs at any time. Data will be recorded on the paper version of CRFs by designated outcome assessors and double-entered in the electronic CRFs. Any incomplete data will be recorded as unknown, missing, or not applicable.This trial mainly involved randomized group data, baseline data, post-intervention outcome data, follow-up data, and statistical analysis result data. Randomized group data are provided and managed by the investigator responsible for the random grouping of the trial. Baseline data, post-intervention outcome data, and follow-up data are collected by dedicated data collection researchers. Statistical analysis result data are collected and provided by the researcher in charge of data statistical analysis. In order to maximize the completeness of data collection, we will enhance communication with patients. The participant who accomplishes the trial and follow-up will receive some economic compensation.All study-related information, such as participants’ medical records, will be kept securely in locked file cabinets with limited access. All private subject data are encrypted and protected, visible only to the project’s principal investigators, and used only for the research of the project. Principal investigators will be granted access to the cleaned dataset. To ensure confidentiality, data dispersed to project team members will be kept confidential to any identifiable participant information.To ensure confidentiality, data dispersed to project team members will be kept confidential to any identifiable participant information.N/A, no additional biological specimens for genetic or molecular will be obtained in this study.t-test is used for continuous data with a normal distribution, and the Mann–Whitney U-test is employed for non-normally distributed data (e.g. duration of delayed fever). For categorical data, the chi-square test or Fisher’s exact test is performed . A significant difference was identified as a p value < 0.05. All data were analysed by means of SPSS (version 19.0).All data, including patient characteristics and intraoperative and postoperative outcomes, are obtained and assessed during the hospital stay and follow-up period (30 days). Student’s Interim analyses  will be performed by independent statisticians and reported to the data monitoring committee (DMC).N/A, there are no additional analyses.For missing data, we will use the last-observation-carried-forward method.http://www.medresman.org.cn/login.aspx) which will be accessible to the public via a certain account.At the end of the study, a completely de-identified dataset is scheduled to be delivered to the Internet site , Tianzhi Zhao, Yunze Zhang, Yingxi Wu, Yang Wu, Gang Zhu, and Yafei Xue. We discussed the test protocols and related materials together.In addition, an independent data monitoring committee (DMC) will be established to monitor the trial’s quality and compliance and ensure the safety of participating patients. The DMC will be composed of three experts with expertise in neurosurgery, statistics, and trial methodology, who will examine the data every 12 months and determine if a trial should be modified or discontinued. All of them are independent of the sponsor and have no competing interests. Interim analyses will be performed by independent statisticians and reported to the DMC, which can obtain these interim results and make the final decision to terminate the trial when the rate of SAEs is greater than 2%.The DMC will be composed of three experts with expertise in neurosurgery, statistics, and trial methodology, who will examine the data every 12 months and determine if a trial should be modified or discontinued. All of them are independent of the sponsor and have no competing interests. Interim analyses will be performed by independent statisticians and reported to the DMC, which can obtain these interim results and make the final decision to continue, modified, or terminate the trial.Definition of adverse events (AEs) and severe adverse events (SAEs).Complications related to lumbar drainage amountComplications related to the insertion of a lumbar drainageAny SAEsThe term AEs describes any sign symptom, syndrome, or any disease (1) occurring newly in a trial participant after consent to the trial and (2) being of particular interest for the assessment of the disease or the security of the therapeutic concept. In this trial, AEs include the following:The term AEs does not implicate a causal correlation with participation in the trial. AEs are classified into severe (SAEs) and non-severe (AEs) adverse events.DeathAny life-threatening conditionRehospitalization or prolongation of hospitalizationLong-term or severe restraint of the state of healthAn SAE is any AEs occurring during the trial that is related to the following:Expected and unexpected harms will be collected systematically using CTCAE v5.0, and we will report all harms.The audit committee, which is independent of the sponsor and has no competing interests, will audit the trial conduct every 12 months.If the protocol has changed with important amendments, we will notify ethical committees in writing and trial participants orally or by calling.We will communicate the trial results to participants, healthcare professionals, the public, and other relevant groups by publishing paper.Continuous drainage of CSF via LD is often used in the treatment of postoperative intracranial infection or aseptic inflammation , 5, 8. CThe literature reported that the infection rate after neurosurgery is 1–11%, and aseptic meningitis is more common after posterior fossa surgery with an incidence of up to 30%, leading to delayed postoperative fever , 15–17. The use of CSF drainage via a lumbar drain during cranial surgery is a common practice for reducing ICP and enhancing exposure. Despite its common practice, the use of a lumbar drain is not without complications, including headache, nausea, and vomiting , 21; abdThis protocol aims to evaluate the safety and efficacy of using preoperative pre-set LD to treat or reduce postoperative delayed fever. Moreover, in the case of encouraging results indicating that early LD could significantly reduce the duration of delayed fever postoperation and length of stay, a multicentre trial may be started.The trial is currently in the recruitment phase. This study protocol is version 2 made on June 7, 2021. Recruitment commenced in August 2021 at Tangdu Hospital and is expected to be completed in August 2023.


However, high variability in the sEMG signals of untrained users degrades the performance of gesture recognition algorithms. In this study, the hand posture recognition algorithm and radar plot-based visual feedback training were developed using multichannel sEMG sensors. Ten healthy adults and one bilateral forearm amputee participated by repeating twelve hand postures ten times. The visual feedback training was performed for two days and five days in healthy adults and a forearm amputee, respectively. Artificial neural network classifiers were trained with two types of feature vectors: a single feature vector and a combination of feature vectors. The classification accuracy of the forearm amputee increased significantly after three days of hand posture training. These results indicate that the visual feedback training efficiently improved the performance of sEMG-based hand posture recognition by reducing variability in the sEMG signal. Furthermore, a bilateral forearm amputee was able to participate in the rehabilitation training by using a radar plot, and the radar plot-based visual feedback training would help the amputees to control various electric prostheses. Surface electromyography (sEMG) records the electrical biosignals generated by the action potentials that occur during the contraction of muscle fibers . VariousElectric prostheses have been developed to improve patients’ quality of life following a limb amputation with the importance of their control . An sEMGMany studies have been performed to recognize hand gestures using multichannel sEMG sensors. Emayavaramban et al. developed a recognition algorithm for twelve hand gestures by using five sEMG sensors on the forearm . sEMG siPrevious clinical research used two types of rehabilitation training for amputees: (1) mirror therapy, which trains both the amputated side and the intact side at the same time; and (2) mental imagery, in which the amputee imagines movements without actually moving the residual limb . HoweverSC) were used to analyze changes in the variability of the sEMG signals during posture training. In addition, classification accuracy was determined according to the type of feature vector and the hand postures. The classification accuracies of the healthy adults and a forearm amputee increased by the visual feedback training and optimized feature vectors. In particular, the visual feedback training was more effective than the optimization of the feature vectors to improve the classification performance of the forearm amputee.In this study, sEMG-based ANN classifiers were developed to recognize the hand postures for the control of myoelectric prostheses. In addition, the radar plot-based visual feedback training was suggested to improve the performance of hand posture recognition considering the bilateral forearm amputee. The sEMG signals of healthy adults and a bilateral forearm amputee were measured by multichannel sEMG sensors. Radar plot-based visual feedback training, which can be applied to bilateral amputees, was performed by the healthy adults for two days and by the forearm amputee for five days, respectively. Those sEMG signals were then used to develop ANN classifiers that could be used with two types of feature vectors. t-distributed stochastic neighbor embedding (t-SNE) and the silhouette coefficient  and one bilateral forearm amputee  were recruited to participate in this study. The healthy adults had no neurological or musculoskeletal disorders. The amputee had no cognitive problems and had lost both his left and right forearms 21 years before participation in this study. The forearm amputee used a cosmetic prosthesis on the right forearm, which was shorter than the left side, and an electric prosthesis on the left forearm. At the time of this study, he had used a three-finger electric prosthesis with two degrees of freedom (DoFs) for 20 years and a five-finger electric prosthesis with multiple DoFs for 18 months. All participants were fully informed of the risks associated with the experiments, and they gave their written consent to participate in this study. The experimental procedures for healthy adults and a forearm amputee were approved by the Yonsei University Mirae Institutional Review Board (1041849-202002-BM-018-02) and the Institutional Review Board of the Korea Orthopedics & Rehabilitation Engineering Center (RERI-IRB-210915-2), respectively.A commercial sEMG system, Delsys Trigno wireless sEMG system , was used to measure sEMG signals at a sampling rate of 1926 Hz with the amplification factor of 909 in the analog mode a 18]. B. B18]. BThe forearm muscles used for sEMG-based hand posture recognition were selected from previous studies ,22,23,24A graphic user interface (GUI) was developed using LabVIEW  for real-time monitoring and recording of the sEMG signals. The GUI was designed with a radar plot , and theTwelve hand postures  were sugsEMG signals were filtered using the fourth-order Butterworth bandpass filter with a bandwith of 10–500 Hz, and the filtered sEMG signals were used to calculate the feature vectors. As suggested in a previous study , the meaThe ANN classifiers were developed using the Matlab software . Ten session data of each participant were divided into the training sessions and the testing sessions. The ANN classifiers were trained and validated using the automatically partitioned data within the training session data  to reduce the dimensions of the data or feature vectors [SC was calculated to quantify changes in the sEMG signal clusters according to the visual feedback training.t-SNE and the  vectors ,45,46,47 vectors . However vectors . For the vectors . t-SNE iSC quantifies data clustering by comparing inter- and intracluster similarity [SC is as follows:Ith cluster, and ith data point and the jth data point. Jth cluster. The SC was defined as the maximum Silhouette value in each cluster. A high SC indicates good clustering, with high intracluster similarity and low intercluster similarity, and the SC range is from −1 to 1.The milarity . In thismilarity . The calp < 0.05) between the classification performance results were statistically analyzed using the Kruskal–Wallis H test and pairwise comparison in IBM SPSS Statistics .The performance of sEMG-based hand posture recognition in healthy adults and a forearm amputee was evaluated using classification accuracy and confusion matrixes. Significant differences .The izations . Most ofThe radar plot-based visual feedback training effectively increased the classification accuracy of all participants . In the In the forearm amputee, only the hand postures of rest  and spherical grasp  were well-recognized with either feature vector on Day 1, which was the experiment before visual feedback training. The classification accuracies of each hand posture were improved by the visual feedback training, and most of the hand postures were recognized with a classification accuracy of higher than 70.0% on Day 4. In the data from Day 5, the last day of visual feedback training, MAV only showed many misclassifications of scissor sign vs. tip pinch  increased the classification accuracy by 4.8% more in trained healthy adults and 7.7% more in a trained forearm amputee, respectively. t-SNE and the These findings could be used to improve the performance of sEMG-based hand posture recognition, not only in rehabilitation and the control of electric prostheses for amputees, but also in HCI systems for healthy adults. In future work, the measurement of sEMG signals and visual feedback training will be performed with various forearm amputees, and the number and positions of the sEMG sensors will be analyzed to develop an efficient sEMG-based hand posture recognition algorithm.


Using the orbital-free quantum crystallography approach, we have disclosed the quantitative trends in electronic features for bonds of different strengths formed by tetrel (Tt) atoms in stable molecular complexes consisting of electrically neutral tetrahedral molecules and halide anions. We have revealed the role of the electrostatic and exchange-correlation components of the total one-electron static potential that are determined by the equilibrium atomic structure and by kinetic Pauli potential, which reflects the spin-dependent electron motion features of the weak and strong bonds. The gap between the extreme positions in the electrostatic and total static potentials along the line linking the Tt atom and halide anion is wide for weak bonds and narrow for strong ones. It is in very good agreement with the number of minima in the Pauli potential between the bounded atoms. This gap exponentially correlates with the exchange-correlation potential in various series with a fixed nucleophilic fragment. A criterion for categorizing the noncovalent tetrel bonds (TtB) based on the potential features is suggested. By the analogy with IUPAC definitions , with respect to the electron density. A Lagrange multiplier µ, an electronic chemical potential, follows from the condition ∫ρ(r)dr = N. A static potentials[ρ] is presented as a sum of the contributions:Orbital-free density functional theory  allows emolecule ,45,46. Ir), which are in the hypothetical “bosonic” ground state, where all particles are in the same lowest energy state , is introduced. It describes the excess in the total electronic kinetic energy over the energy of the noninteracting “spinless” particles. The Weizsäcker (1935) kinetic energy rinciple . It arisgy state . Howeveri energy ,50, TP[ρs[ρ] and supposing the proper homogeneity of the functionals in density scaling, the Euler equation for the stationary state is re-written via corresponding potentials asTaking the functional derivative of THere, the kinetic potential All terms in (3) have clear physical and chemical meanings. They determine the one-electron homotropic and heterotropic forces  acting ies(r), is linked to the total (electron plus nuclear) charge density by the Poisson equation; there are approximations for the exchange potential, υxc(r), and the Weizsäcker potential, υW(r), is read as  remains common for various Tt atoms .We have also made sure that the exponential nature of the ∆–…Tt bonds by the expression Vx = −δ/2R [–, Cl–, and Br–, is responsible for its own trend, which is not exponential  ,76, wheronential b. For veMost properties of the chemical bonds are strongly dependent on the sort of bound atoms. The accumulated observations of the quantum-topological characteristics of electron density  rather iP(r), reflects important kinetic features of electron pairing and can serve as the characteristic that allows us to find out the threshold between covalent and noncovalent bonds in our series. Let us compare the behavior of the υP(r) function along the bond line for strong and weak interactions of the same sort. As it turned out, the Pauli potential, υP(r), exhibits two (sometimes more) minima in the central part of the weak noncovalent bonds min1, is always deeper than the next neighboring minimum υP(r)min2 located at the side of the Tt atom, providing its local electrophilic region for bonding. While the enhanced local positive electrostatic potential favors the electron transfer to the electrophilic region of the Tt atom, the Pauli potential, υP(r), indicates the unfavorable regions for the entry of electrons into this region controlling the electron pair formation.It is clear that the switching of the bond type from covalent to noncovalent demands the transfer from the sharing of an electron pair by two atoms forming a strong bond to another bonding mechanism. The kinetic component of bonding can help to better understand the resulting picture. The Pauli potential, υnt bonds . Each of–…Tt bonds, the minima υP(r)min1 and υP(r)min2 are separated by a small barrier which apparently indicates that a common region for an sharing electron pair cannot yet be formed, and the electronic features of Hal– and Tt atoms still retain their originality. An important finding was that two or more minima of Pauli potential, υP(r), which were formed for weak Hal–…Tt interactions satisfied the condition (xst – xes) > (xρ – xst) or Δx > 0. At the same time, the positions of the electrostatic and total static potentials extremes, υes(r)min and υst(r)min, could not coincide with the υP(r)min1 or υP(r)min2 positions. In only two cases for the H2N–Sn(CH3)3…Cl– and F–Ge(CH3)3…Cl– complexes, for which Δx > 0, we observed the absence of the second minimum υst(r)min2.For weak Hal–…Tt, for which the condition ∆st-es < ∆ρ-st or Δx < 0 is satisfied, the Pauli potential forms only one minimum between the Hal– and Tt atoms. This fact can be interpreted as the presence of a common region in which electron pair formation is allowed; such a case indicates the covalent nature of the bond.In all cases of strong bonds of Halst(r), and electrostatic potential, υes(r), is in accordance with the behavior of the Pauli potential, υP(r), along the bond line, gives evidence that the threshold demarcation of the covalent and noncovalent bonds in the series of Hal–…Tt interactions has a physical basis.Thus, our finding that the gap widths between positions of extremes for the static potential, υ3…Hal– complexes with a gradual increase of Hal–…Tt bonds’ strength under the influence of various substituents. As a rule, the energy characteristics and quantum-topological features of electron density rather indicate the absence of a clear threshold between not very strong and not so weak chemical bonds. It might seem that in a series illustrating the smooth strengthening of bonds under the influence of various substituents it makes sense to talk about interactions of intermediate nature. Nevertheless, the summary of our observations of the electrostatic potential, υes(r), static potential, υst(r), and Pauli potential, υP(r), distributions between the Hal– and Tt atoms do not support this supposition.A need to determine the range of properties for typical TtB bonds prompted us to analyze the electronic properties in a series of Y–TtXP(r), along the bond line Hal–…Tt suggest that the balance of forces and the features of electron distribution between the Hal– and Tt atoms is different for strong bonds, approaching the covalent type, and for weak noncovalent bonds. One minimum of υP(r) favors the formation of a common electron pair, while two minima of υP(r) indicate the preservation of the specificity of atomic shells in a typical noncovalent bond. In addition, we did not observe noticeable differences in the behavior of the Pauli potential, υP(r), for weak interactions with a bond critical point and cage critical point between the atoms.One or two minima of the Pauli potential, υst-es between positions of extremes for electrostatic, υes(r), and static, υst(r), potentials along the Hal–…Tt line is wide for weak bonds and narrow for strong ones. It is in very good agreement with the number of minima of the Pauli potential, υP(r), at the middle of a bond. This observation allowed us to propose a criterion based on the comparison of the gap widths ∆st-es and ∆ρ-st, which can serve as an informative descriptor for the express establishment of the type of bond. For covalent bonds, ∆st-es < ∆ρ-st, whereas, on the contrary, for noncovalent TtB bonds, ∆st-es > ∆ρ-st. The gap width ∆st-es exponentially correlates with the exchange-correlation component of static potential in a series of the bonds Hal–…Tt with the fixed nucleophilic fragment Hal–.The gap ∆– and Tt atoms has made it possible to verify that a priori attribution of interactions to covalent or noncovalent bonds and their categorization according to the electrophilic region has all the physical grounds supported by quantitative data.Thus, the analysis of the electrostatic, static, and Pauli potentials along the line between the HalA preliminary check confirms the transferability of the suggested criteria to the series of complexes between the neutral molecules with strong and weak tetrel bonds. The results will be reported later.


N. fowleri were detected by mNGS in the CSF sample and the blood sample, respectively. PCR results and pathological smear subsequently confirmed the mNGS detection. The patient was finally diagnosed as primary amoebic meningoencephalitis. Besides, in this article, 15 similar child infection cases in the past 10 years are summarized and analyzed to promote the early diagnosis of this rare disease.In China, a 9-year-old boy was transferred to the hospital with fever, vomiting, and headache. The disease rapidly deteriorated into vague consciousness. Applying conventional clinical examinations such as blood and cerebrospinal fluid (CSF) tests, the diagnosis of bacterial meningoencephalitis was first drawn, and expectant treatments were adopted immediately. However, the symptoms did not alleviate, adversely, this boy died 3 days after admission. Considering the skeptical points of the duration, such as the unknown infectious bacteria and the pathogen invasion path, blood and CSF samples were then sent for metagenomic next-generation sequencing (mNGS) to ascertain the cause of death. The 42,899 and 1,337 specific sequences of  Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri (N. fowleri), and Sappinia dialoidea , which was first reported in 1965  was admitted to the Third Xiangya Hospital, Changsha, China. His disease broke out on the 16th with fever and vomiting. Upon admission, the blood test showed leukocytosis of 18.24 × 109/L (92.1% neutrophils). He was treated with Ibuprofen and piperacillin-tazobactam, but the condition did not improve. At 12:00 that day, the child appeared with a headache and vague consciousness and was transferred into the pediatric intensive care unit (PICU) for further treatment immediately. Besides, the child exhibited repetitive high fever, hypertension (149/86 mm Hg), relatively slow heart rate (62/min), positive meningeal irritation signs, and neck stiffness. No positive findings were found in his personal history and contact history of infectious diseases. Therefore, the initial diagnosis was intracranial infection with intracranial hypertension. To ascertain the infection causes, several examinations were adopted, including CSF examination, head computed tomography (CT), and routine blood test. A lumbar puncture discovered that the CSF was purulent in appearance, and the CSF pressure was higher than 300 mmH2O. Elevated levels of white blood cells , the protein concentration of 2,606 mg/dL, glucose concentration of 0.9 mg/dL in the CSF, and the blood glucose was 127.8 mg/dL at the same time. MRI showed unremarkable T2 flair and T1 enhancement of the boy's brain leptomeningeal linear enhancement in the occipital lobe  and 1,337 (out of 3025) specific sequence reads belonging to N. fowleri genome, respectively  in Hugo-Biotech Company, Beijing. The DNA was extracted and purified from 200 uL CSF supernatant and 200 uL blood plasma according to the manufacturer's instruction of TIANGEN kit with DNA library constructed using QIAseqectively . As N. fd by NGS . As for nfidence . Moreovenfidence . In addiN. fowleri infection case in the Chinese mainland. The child was misdiagnosed as “acute bacterial meningoencephalitis” until the NGS results came out. Patients with N. fowleri infection also experienced a 1–7 day disease latency period, and then initial symptoms occurred such as fever, headache, and vomiting, which is not distinctive from bacterial meningitis  hematogenous spread from systemic infection foci, (2) spread from nearby infected mastoid, middle ear, or paranasal sinuses, (3) through the choroid plexus, (4) the superficial parenchymal abscess flowing into the subarachnoid space, and (5) penetrating trauma on the skull . If the 3 to 15,406/mm3) with neutrophil predominance, even six cases reported the appearance of RBC. Eight cases exhibited decreased CSF glucose level (≤40 mg/dL) and the CSF protein increased in 14 cases (out of 16) except two cases which did not mention the protein index. In addition, not displayed in the table, the main CT feature was edema including diffuse edema and focal edema. It was worth noting that in some cases CT results showed no obvious abnormality or mild manifestation at first, but manifested in advanced stages.To make an accurate diagnosis as soon as possible, we summarized the clinical features of this case and another 15 cases of children infected with PAM worldwide in the past 10 years  13, 18––18–26. AN. fowleri infection should be considered, especially when the CSF is purulent but the CSF culture is negative.Thus, when an acute headache, fever, and vomiting occur, with increased WBC amount (neutrophil predominance) and protein concentration, and decreased glucose level, meningoencephalitis due to N. fowleri include indirect immunofluorescence, PCR, CSF wet mount, and mNGS. Among these 16 patients, nine were diagnosed after death, while 6 patients were diagnosed as PAM within hospital days. Two patients successfully survived due to the early diagnosis and timely treatment with satisfactory recovery. CSF wet mount is the most immediate and fast method and is commonly used for a diagnosis before death. PCR testing, brain tissue immunofluorescent analysis (IF), and NGS were also applied but were more time-consuming. If the brain crest fluid looks purulent, do a wet mount test and smear as soon as possible while culturing. It is important that, if there are many doubts about the diagnosis of bacterial meningitis, PCR or NGS should be performed immediately to assist the diagnosis. We expect the improvement of NGS detection speed in the future to help doctors make a faster and more accurate diagnosis.The common detection methods of N. fowleri infection in China, which had rapid progress and high mortality. After reviewing pediatric PAMs worldwide, some clues and methods were found promising to diagnose the disease.In summary, we illustrated the first case of child The original contributions presented in the study are included in the article/The studies involving human participants were reviewed and approved by the Ethical Review Committee of Third Xiangya Hospital. Written informed consent to participate in this study was provided by the participants' legal guardian/next of kin. Written informed consent was obtained from the individual(s), and minor(s)' legal guardian/next of kin, for the publication of any potentially identifiable images or data included in this article.WZ and YO designed and wrote the report. SL and HL participated in drafting and revising the manuscript. CC and LZ reviewed the manuscript for its intellectual content and revised the entire work. All authors approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.This study was funded by the Project for Xiangya famous doctor in Central South University (2014 [68]).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Recipients were divided around the median into three groups regarding their donor LOS in the ICU: 0 to 3 days , 4 to 7 days , and ≥8 days . Donor LOS in the ICU ranged between 0 and 155 days . No association between the LOS in the ICU and survival after HTx was observed . Neither the Kaplan–Meier survival analysis up to 5 years after HTx (Log-Rank p = 0.789) nor group comparisons showed significant differences. Baseline recipient characteristics were comparable between the groups, while the donor baselines differed in some parameters, such as less cardiopulmonary resuscitation prior to HTx in those with a prolonged LOS. However, regarding the recipients’ peri- and postoperative parameters, the groups did not differ in all of the assessed parameters. Thus, in this retrospective analysis, although the donors differed in baseline parameters, the donor LOS in the ICU was not associated with altered recipient survival or outcome after HTx.Prolonged treatment of organ donors in the intensive care unit (ICU) may be associated with complications influencing the outcome after heart transplantation (HTx). We therefore aim to explore the potential impact of the donor length of stay (LOS) in the ICU on outcomes in our cohort. We included all patients undergoing HTx in our center between September 2010 and April 2022 ( The effect of donor parameters on outcome and survival after heart transplantation is crucial and is currently one of the most essential topics of organ acceptance ,4,5,6,7.This study conformed to the principles of the Declaration of Helsinki and Good Clinical Practices. All heart transplant recipients participated voluntarily and provided informed consent. The study was approved by our local ethics committee.n = 241), of which all had complete data on the length of donor stay in the ICU according to the corresponding donor report and were therefore included. The cohort was split into groups around the median dividing the recipients into three groups in regard to their donor LOS in the ICU: Group 1, 0 to 3 days ; group 2, 4 to 7 days ; and group 3, ≥8 days .We screened all patients undergoing HTx in our center between September 2010 and April 2022 . Figures were created using GraphPad Prism, Microsoft PowerPoint, and IBM SPSS.Association between the donor LOS and survival after HTx was investigated using receiver operating characteristics (ROC) analysis and the Kaplan–Meier survival method. Qualitative (dichotomous) variables were compared by Pearson’s chi-squared test or, when its application conditions were not met, by Fisher’s exact test. If one of the two groups contained a zero value for an event, Yates’ correction was added. Quantitative variables were compared using Student’s Baseline characteristics in recipients were comparable between the groups, including the parameters of size mismatch and comorbidities. Furthermore, no statistically relevant differences could be observed in the laboratory values, including recipient sodium and potassium levels as well as creatinine, bilirubin, and hemoglobin see .p = 0.003).The donor length of stay in the ICU ranged between 0 and 155 days . Donors with the highest duration in the ICU had less cardiopulmonary resuscitation (CPR) prior to organ retrieval, which was significant in comparison to those with a medium LOS . In those with a prolonged LOS, traumatic brain injury was less likely to be reported as a cause of death and thereby significantly different to those with a medium LOS . Regarding laboratory values, those with a medium duration in the ICU had significantly higher donor sodium levels  than those with short  and long  stays. Additionally, longer duration in the ICU was associated with decreasing hemoglobin levels, with 11 g/dL in the short and 9 g/dL in the long duration group, reaching significance between the short and prolonged LOS groups (p = 0.00011) and 2 vs. 3 (p = 0.025).Intracerebral bleeding (ICB) as a donor cause of death was less frequent in donors with a medium in comparison to a short and prolonged LOS , the likelihood of kidney failure with hemodialysis post-HTx, postoperative neurological complications, the frequency of re-sternotomy post-HTx, or the need for mechanical life support post-HTx.2 0.229, p = 0.79).No clear general association between donor stay in the ICU and survival after HTx was observed using receiver operating characteristic (ROC) analysis see A: AUC foOnly limited knowledge exists on the association of perioperative morbidity and mortality in heart transplant recipients and the duration of the donor ICU/IMC stay prior to organ removal. We therefore aimed to investigate the influence of different levels of donor LOS in the ICU/IMC on outcomes after heart transplantation, and thus retrospectively analyzed 241 HTx recipients in a 10-year study period.Here, our main finding is that despite differing in a few donor baseline characteristics, donor duration in the ICU/IMC did not influence midterm survival up to 5 years after heart transplantation.n = 4 in 2019 , and in the mentioned DONATE study, no heart transplantation was performed from DCD donors. Thus, the absolute potential influence of DCD vs. NDD for heart transplantation in our reference cohorts seems to be low.There is little data explicitly focusing on the influence of donor LOS in the ICU or IMC and the respective outcome of solid organ transplant recipients, especially for heart transplantation. Our study’s median donor LOS in the ICU/IMC was 4 days IQR 3–8 days). This is in line with the published data from Australia with a mean LOS in the ICU of 3 days  and a pe–8 days. Concerning baseline characteristics, recipients’ preoperative parameters were comparable between the groups. However, in the present study, donors with the longest duration in the ICU had less frequent CPR (16%) compared to the other groups . This can partly be explained by a combination of higher and earlier mortality under those patients with CPR in the ICU in general , leadingIn our cohort, donors with a medium LOS died from ICB less frequently, while in donors with prolonged ICU LOS, traumatic brain injury was less frequent. Unfortunately, with the donor reports’ underlying data, we cannot state the reasons for this phenomenon. However, it was recently shown that the donor cause of death could be associated with a reduced recipient survival rate after heart transplantation . AlthougRegarding donor laboratory values, two parameters differed between the groups. First, those with a medium LOS had slightly higher sodium levels . In general, the cut-off values for severity of hypernatremia range from >150 mmol/L  to >156 Increasing donor LOS was associated with lower hemoglobin levels in our cohort, from the shortest to highest LOS ranging from 11 g/dL over 10 g/dL to 9 g/dL. This goes in line with data from Misar et al. in a large pediatric liver transplant cohort , as theyn = 75 in total, suggest no impact on recipient survival, but longer donor LOS in the ICU was associated with increased biliary complication, one of the major complications after liver transplantation. Although biliary complications do not typically arise for heart transplant recipients, this shows that in other solid organ transplantations, a specific major complication was associated with a prolonged LOS in the ICU.Regarding peri- and postoperative morbidity, the groups did not differ in all parameters assessed in this study, including common postoperative morbidities. Concerning survival, no clear general association between donor stay in the ICU and survival after HTx was observed using receiver operating characteristic (ROC) analysis. Thirty-day and one-year survival was equally distributed between all three groups. Compared to the literature, the 30-day survival in our cohort (ranging from 87–94%) is comparable to that of larger HTx cohorts 89–93% ,32). The. The32])This study’s major and obvious limitation is that it is composed of a single center and only includes retrospective data. Additionally, this study is technically not able to investigate the possible pathomechanistical  reasons behind the reported association. Therefore, future studies with larger cohorts, preferably from the newest era of heart transplantation and potentially with a prospective design and relationship to basic science, are needed to confirm or deny associations of donor length of stay in the ICU on outcome and survival after heart transplantation.In this retrospective analysis, although differing in some baseline parameters, the donor length of stay in the ICU was not associated with altered survival or outcome after HTx. Future studies have yet to be performed to confirm these findings on a prospective and larger scale.