Comparison of five weaning indices in predicting successful weaning from mechanical ventilation

Abstract

Introduction: Mechanical ventilation is a life-supporting modality used in patients with respiratory failure. Most patients are extubated early but weaning can be prolonged in some. Aim: Comparison of accuracy of prediction of success of a spontaneous breathing trial (SBT) using CORE, CROP, RSBI, RSBI rate and minute ventilation recovery. Methods: This is a prospective observational study. 62 adult patients admitted to Multidisciplinary Intensive Care Unit during April 2012 - January 2013 were studied. All patients, orotracheally intubated and mechanically ventilated for at least 24 hours and ready for weaning were enrolled. The patients underwent SBT using pressure support ventilation (5 – 8 cm H2O), PEEP of 5 - 8 cm H2O, and 40% oxygen. The weaning indices were measured at 30 min and correlated with weaning success. Results: The mean (± SD) age was 49.7 (± 18.3) years. There were 46 male and 16 female patients. The threshold values were as follows: CORE index: ≥ 6, CROP index: ≥ 13, RSBI < 105 b/min/L, RSBI rate ≤ 20%. The sensitivity (%), specificity (%) and AUC of ROC curve were as follows: CORE (96, 66, 0.74), CROP (95, 33, 0.61), RSBI (89, 46, 0.2), RSBI rate (85, 28, 0.52) and minute ventilation recovery (higher than baseline minute ventilation at 25 min of rest on initial ventilator settings after 30 min of SBT) (n = 26) (92.3, 100, 0.93). Conclusion: CORE and RSBI are moderately accurate while CROP and RSBI rate are inaccurate. Minute ventilation recovery predicted weaning failure accurately.