Randomised weaning trial comparing assist control to pressure support ventilation

Objectives To determine if the work of breathing was lower, respiratory muscle strength greater, but the degree of asynchrony higher during weaning by assist control ventilation (ACV) rather than pressure support ventilation (PSV) and if any differences were associated with a shorter duration of weaning. Design Randomised trial Setting Tertiary neonatal unit Patients Thirty-six infants, median gestational age 29 (range 24 to 39) weeks Intervention Weaning by either ACV or PSV. Main outcome measures At baseline, 24 hours after entering the study and immediately prior to extubation, the work of breathing (PTPdi), thoracoabdominal asynchrony (TAA) and respiratory muscle strength (Pimax) were assessed and weaning duration recorded. Results There were no significant differences in the median PTPdi, TAA and Pimax results at any time point. The inflation times during ACV and PSV were similar. The median duration of weaning was 34 (range 7-100) hours in the ACV group and 27 (range 10-169) hours in the PSV group (p=0.88). Conclusion No significant differences were found between weaning by PSV and ACV when similar inflation times were used.