Background: Adaptive support ventilation (ASV) is a closed loop mode of mechanical ventilation (MV) that provides a target minute ventilation by automatically adapting inspiratory pressure and respiratory rate with the minimum work of breathing on the part of the patient. The aim of this study was to determine the effect of ASV on total MV duration when compared with pressure assist/control ventilation.
Methods: Adult medical patients intubated and mechanically ventilated for > 24 h in a medical ICU were randomized to either ASV or pressure assist/control ventilation. Sedation and medical treatment were standardized for each group. Primary outcome was the total MV duration. Secondary outcomes were the weaning duration, number of manual settings of the ventilator, and weaning success rates.
Results: Two hundred twenty-nine patients were included. Median MV duration until weaning, weaning duration, and total MV duration were significantly shorter in the ASV group (67 [43-94] h vs 92 [61-165] h, P = .003; 2 [2-2] h vs 2 [2-80] h, P = .001; and 4 [2-6] days vs 4 [3-9] days, P = .016, respectively). Patients in the ASV group required fewer total number of manual settings on the ventilator to reach the desired pH and Paco2 levels (2 [1-2] vs 3 [2-5], P < .001). The number of patients extubated successfully on the first attempt was significantly higher in the ASV group (P = .001). Weaning success and mortality at day 28 were comparable between the two groups.
Conclusions: In medical patients in the ICU, ASV may shorten the duration of weaning and total MV duration with a fewer number of manual ventilator settings.
Trial registry: ClinicalTrials.gov; No.: NCT01472302; URL: www.clinicaltrials.gov.