Use of Ultrasound to Assess Diaphragmatic Thickness as a Weaning Parameter in Invasively Ventilated Chronic Obstructive Pulmonary Disease Patients
Introduction: Predictive indices of weaning from mechanical ventilation are often inaccurate. Despite of the existence of many weaning protocols, often making a correct decision is difficult because the diaphragmatic function is not included in any of the weaning criteria. Objective: The aim of this study was to determine the value of diaphragmatic thickness fraction (DTF) measured by Bmode ultrasound as a predictor tool in weaning of invasively ventilated chronic obstructive pulmonary disease patients. Methods: A prospective observational study was conducted on 112 invasively ventilated patients with COPD. Demographic, clinical data and laboratory investigations were obtained on admission. Patients underwent a spontaneous breathing trial (SBT) after the reversal of the underlying cause for respiratory failure and when they met all the weaning criteria. Then Rapid shallow breathing index (RSBI) was performed. As RSBI 105, weaning process was continued for 30 to 120 minutes. During the trial, diaphragm was visualized in the zone of apposition on both sides using a 10 MHz linear ultrasound probe. Diaphragm thickness was recorded at end of inspiration and end of expiration, and the DTF was calculated. Weaning failure was defined as the inability to sustain spontaneous breathing without any form of ventilatory support, for at least 48 h. Results: DTF differed significantly between patients who succeeded weaning from mechanical ventilation and those who failed. A cutoff value >29% on the right side and a cut off value >24% on the left were associated with a successful weaning from mechanical ventilation with a 97%sensitivity, 73% specificity, 0.90 positive predictive value (PPV) 0.91 negative predictive value (NPV) and 91% accuracy on both sides. Confidence interval was calculated, and ranged from 0.8720.973 for the right side and 0.8050.933 for the left side. Conclusion: Diaphragmatic thickness fraction detected by B mode ultrasonography, is associated with high sensitivity, specificity, positive and negative predictive values to determine weaning outcome, in this cohort of COPD. [Fayed AM, Abd ElHady MA, Shaaban M Sand Fikry DM. Use of Ultrasound to Assess Diaphragmatic Thickness as a Weaning Parameter in Invasively Ventilated Chronic Obstructive Pulmonary Disease Patients. J Am Sci 2016;12(6):96 105] ISSN 1545 1003 (print) ISSN 2375 7264 (online) http:/www.jofamericanscience.org. 12. doi:10.7537/marsjas12061612.