Abstract

Background: Volume support ventilation (VSV) is a dual controlled ventilatory mode designed to stimulate spontaneous breathing and reduce   weaning time. We aimed to evaluate the outcome of VSV as compared to pressure support ventilation (PSV) in weaning of mechanically ventilated COPD patients. Methods: Fifty mechanically ventilated COPD patients admitted to  the respiratory ICU were enrolled. After patient stabilization, assessment of weaning readiness was done and patients were randomized in a ratio of 1:1 using either PSV(25 patients) or VSV (25 patients).  In PSV group, the level of PS was set at 15 cmH2O then  evaluated every 30 min and gradually decreased to 8cmH2O. In VSV group, the spontaneous tidal volume was set at 6 ml/Kg from IBW, PEEP was set at 3-5 cm H2O,FiO2 =40 % with target SpO2 of 88–92%. The inspiratory trigger was set at 1-3 L/min, pressure limit was set at 35- 40 cm H2O. Patients were followed after 30, 60 min, and 24 h. Weaning and hospital outcomes were recorded. Results: Weaning was successful in 80% in VSV group compared to 76% in PSV group. Weaning duration was sig­nificantly shorter in the VSV group than in the PSV group (12.76 ± 8.02 vs. 18.56 ± 5.97 (h); p= 0.04). The total mechanical ventilation time  and stay in ICU were insignificantly lower with VSV group in comparison to those with PSV grou. Death rate and complications were comparable in both groups.

Conclusion: VSV mode was safe, reliable method and can be reasonably used for weaning trials in COPD patients and confers a potential benefit in decreasing weaning duration and shorter ICU length of stay compared with PSV mode.