Comparison of patient-ventilator asynchrony during pressure support ventilation and proportional assist ventilation modes in surgical Intensive Care Unit: A randomized crossover study

Abstract

Background:The patient-ventilator asynchrony is almost observed in all modes of ventilation, and this asynchrony affects lung mechanics adversely resulting in deleterious outcome. Innovations and advances in ventilator technology have been trying to overcome this problem by designing newer modes of ventilation. Pressure support ventilation (PSV) is a commonly used flow-cycled mode where a constant pressure is delivered by ventilator. Proportional assist ventilation (PAV) is a new dynamic inspiratory pressure assistance and is supposed to be better than PSV for synchrony and tolerance, but reports are still controversial. Moreover, most of these studies are conducted in chronic obstructive pulmonary disease patients with respiratory failure; the results of these studies may not be applicable to surgical patients. Thus, we proposed to do compare these two modes in surgical Intensive Care Unit (ICU) patients as a randomized crossover study.Aims:Comparison of patient-ventilator asynchrony between PSV and PAV plus (PAV+) in surgical patients while weaning.Subjects and Methods:After approval by the Hospital Ethics Committee, we enrolled twenty patients from surgical ICU of tertiary care institute. The patients were ventilated with pressure support mode (PSV) and PAV+ for 12 h as a crossover from one mode to another after 6 h while weaning.Results:Average age and weight of patients were 41.80 ± 15.20 years (mean ± standard deviation [SD]) and 66.50 ± 12.47 (mean ± SD) kg, respectively. Comparing the asynchronies between the two modes, the mean number of total asynchronous recorded breaths in PSV was 7.05 ± 0.83 and 4.35 ± 5.62, respectively, during sleep and awake state, while the same were 6.75 ± 112.24 and 10.85 ± 11.33 in PAV+.Conclusion:Both PSV and PAV+ modes of ventilation performed similarly for patient-ventilator synchrony in surgical patients. In surgical patients with acute respiratory failure, dynamic inspiratory pressure assistance modalities are not superior to PSV with respect to cardiorespiratory function.

Minimizing Asynchronies in Mechanical Ventilation: Current and Future Trends

“…Comparing patient-ventilator asynchrony between PSV and PAV plus (PAVϩ) in 20 surgical subjects during weaning, Gautam et al 68 found that asynchrony was less common in PSV. The mean number of total asynchronous recorded breaths was 7.05 Ϯ 0.83 during sleep and 4.35 Ϯ 5.62 when subjects were awake in PSV versus 6.75 Ϯ 112.24 and 10.85 Ϯ 11.33, respectively, in PAVϩ, leading them to conclude that PAVϩ was not superior to PSV with respect to cardiorespiratory function.…”

Outcomes of ventilatory asynchrony in patients with inspiratory effort

“…Most studies on PVA have analyzed patients who were relatively stable or had only one respiratory disorder in a few ventilation modalities (sometimes including cases with neuromuscular blockade) and who were observed for a short period. ( 7 - 9 , 19 , 22 , 23 ) In this study, evaluations were performed for several consecutive days, which represents the real context of the clinical course (day to day) of critically ill patients; consequently, we had a greater probability of detecting PVA.…”

Ventilator dyssynchrony – Detection, pathophysiology, and clinical relevance: A Narrative review

“…[ 34 ] Finally, newer mode of ventilation such as proportional-assist ventilation (PAV) has theoretical benefits that may reduce ventilator dyssynchrony, but in small studies to date, similar rate of ventilator dyssynchrony has been seen between PSV and PAV. [ 58 59 ] Thus, there is no clear optimal mode of ventilation to manage ventilator dyssynchrony.…”