Comparison of pressure support ventilation and proportional assist ventilation plus for weaning from mechanical ventilation in critically ill patients

Abstract

Pressure support ventilation (PSV) is widely used for weaning patients from mechanical ventilation in ICU. In PSV chances of oversupport and patient-ventilator dysynchrony is commonly noticed. Proportional assist ventilation (PAV) is a weaning mode which has shown to improve these problems faced with PSV. But the complexity in setting up the mode for ventilation has declined the usage of this mode. A modified software update of PAV called Proportional assist ventilation plus (PAV+) has been introduced. PAV+ has simplified the mode and the complication with respect to PAV has been rectified. Objective: To compare length of weaning (in hours) on ventilator (840, Puritan Bennett, California), using Pressure support ventilation (PSV) and Proportional Assist Ventilation Plus (PAV+). Methods: 24 adult patients who were invasively ventilated via an endotracheal tube were included in the study after successfully completing SBT criteria. Patients on ventilator only for airway protection, neuromuscular disease, COPD were excluded. All included patients were randomized into 2 groups; PSV (n=10) mode group and PAV+ (n=14) mode group after passing 30 minutes of PSV trial. Both modes were continued unless the patients met failure criteria or for breathing without ventilator assistance. An extubation failure was assessed to determine failure of weaning mode. Results: An Independent ttest was used for comparing means. Mean Age was 47.19+16.67. Length of weaning (in hrs) was 3.98+1.9 for PAV+ &3.44+1.1 for PSV. In PAV+ mean &SD changes in ABG were, H+- 38.09+6.7, PaCO2-38.58+14.13, P/F ratio-323.45+75.58 and for respiratory mechanics were PIP-14.43+7.68, MAP-8.9+2.62. PSV mean &SD changes were H+- 39.52+9.37, PaCO2-34.45+7.05, P/F ratio- 323.44+50.92 and for respiratory mechanics were PIP-15+3.31, MAP-9.25+1.56.ICU Discharge (in days) was 11.86+6.188 and 12.6+7.9 in PAV+ &PSV respectively. Discussion: There was no statistical significance present. Clinically the duration of ICU stay was reduced to nearly a day in comparison. safety of percutaneous tracheostomy (PT) using the Ciaglia Blue Rhino technique under fiber-optic bronchoscopy guidance in Intensive Care Unit in a tertiary level Hospital. Method: An observational study to evaluate efficacy, safety and long term consequences of percutaneous tracheostomy done by CIAGLIA BLUE RHINO technique under bronchoscopy guidance performed over 66 patients during January 2within 12 months in our Multi disciplinary ICU. All procedures were done at the bedside with aseptic methods under ETCO2 monitoring. Demographic variables, days of mechanical ventilation after PT, decannulation, operative and post operative complications were recorded. Results: Of 66 patients studied 28 pts were decannulated successfully during the hospital stay. Total 9 pt had complication. Out of them only one was major, loss of airway, due to over pulling of endotracheal tube; which was promptly managed with re-intubation over the Fibreoptic scope. Others were minor like bleeding (2), transitory desaturation (3), hypotension (1), guide-wire kinking (1), and difficult dilatation (1). There were no deaths during or within 48 hours of percutaneous tracheostomy. None of the patients had posterior tracheal wall injury. Off the 28 patients decannulated, none had any evidence of local complications. Conclusion: Overall percutaneous tracheostomy using the Ciaglia Blue Rhino technique with fiber-optic bronchoscopy assistance is a safe procedure that can be per formed in the ICU by trained intensivist without any major complications. Fibreoptic Bronchoscope offers real time view of exact tracheal space punctured, also prevents posterior tracheal wall injury and also prevents accidental loss of airway.