Validity of Integrative Weaning Index of Discontinuation From Mechanical Ventilation in Iranian ICUs

Abstract

Background: Today, usage of weaning index is a controversial issue. Proper use of these indexes is beneficial for prevention of the losses caused by weaning failure, rapid and reliable identification of patients who are potentially ready for spontaneous breathing and accelerating the weaning of mechanical ventilation. Objectives: This study is to determine the validity of integrative weaning index as a mechanical ventilation discontinuation predictor in patients hospitalized in the Iranian intensive care units. Patients and Methods: This scale was evaluated on 124 adult patients who were on mechanical ventilation for more than 24 hours, in two 24-hour phases, in six ICUs (Surgery-Trauma-Medical-Poisoning) of selected hospitals in Tehran, totaling 60 beds, by the researcher as a single blind test. Inclusion criteria were: Patient 18 to 80 years old, none of them suffering from neurological and neuromuscular diseases, none or a minimal dose of sedative drugs being used (15 - 18 points based on Palma and Cook criteria), non-addict or heavy smokers, not admitted in ICU-OH. The study was conducted from November 2011 to December 2012. The ventilators used were from Rafael brand. Results: There were 80 successful and 44 unsuccessful as well as 72 successful and 8 unsuccessful weaning cases in the first and second phase of the study, respectively. The area under the ROC curves for IWI was 0.967, with standard error of 0.020, 95% Confidence interval of 0.899 to 0.993 and Significance level of P = 0.001, SE = 94.59, SP = 66.67, PPV = 97.22, NPV = 50, DA = 92.5 and likelihood ratio of positive test being 2.84 besides the lowest likelihood ratio of negative test equal to 0.08), with Diagnostic odds ratio being 97% and Confidence interval of 0.82 to 0.97. Conclusions: Integrative weaning index has appropriate predictive validity for weaning patients from mechanical ventilation in Iranian intensive care units.