Validation of Combined Index during Weaning from a Mechanical Ventilator in Chronic Obstructive Pulmonary Patients: An Observational Prospective Multi-center Triple-blinded Study in Military Hospitals in Iran

The weaning process from mechanical ventilation in chronic obstructive pulmonary diseases (COPD) is a time-consuming process required for the care of these patients. This study aimed to: 1. decide cut-off points of combined and common indices RSBI, P0.1, NIF, CROP, and IWI in the population of COPD patients; and 2. compare different weaning factors from the mechanical ventilator of combined, RSBI, P0.1, NIF, CROP, and IWI indices in the population of COPD patients.
This observational, prospective multi-center triple-blinded study was conducted from January 2013 to March 2014 in the population of hospitalized COPD patients in the critical care units of selected Military hospitals in Tehran, Iran. Patients were divided into two groups with cut-off points determining the first group (n = 90) and different predictive weaning factors from the mechanical ventilator determining the second group (n = 90). The process of weaning from the mechanical ventilator was performed in the same way in both groups and was based on the defined protocol. ROC analysis was used to determine cut off points in the first group and predictive factors in the second group.
Six indices combined, RSBI, IWI, P0.1, NIF, and CROP were compared from different predicting weaning factor's view. Generally, RSBI, combined, IWI, P0.1, NIF, and CROP indices were devoted the most favorably factors to itself, respectively. The highest area under the curves were devoted to RSBI (0.927) and combined (0.891) indices.
Although the proposed index has more components than other common indices in weaning process from mechanical ventilator, the RSBI index in addition to simplicity, provided the most desirable characteristics of predictive weaning from mechanical ventilator. It is also suggested that corrected RSBI index (RSBI application alongside tight subjective and objective signs and symptoms of respiratory distress) be used in the population of chronic obstructive pulmonary patients.