Tidal volume delivery and peak inspiratory pressure in babies receiving volume targeted or time cycled,pressure limited ventilation: A randomized controlled trial

Abstract

Objective: To study the consistency of tidal volume delivery and the respiratory parameters in babies randomized to either volume-controlled ventilation (VCV) or time-cycled, pressure-limited ventilation (TCPLV).

Methods: 90 babies between 24 to 32 weeks' gestation who formed part of the original controlled trial comparing VCV vs TCPLV were studied. As a part of the study protocol, these babies were continuously monitored for key respiratory parameters. Hourly recording of these parameters was obtained for 78 hours or until extubation if it occurred earlier. Consistency of tidal volume delivery and other parameters such as PIP, PEEP, Paw, Cdyn, Ve & FiO $_{2}$ were compared using the Student's t-test with a two-tailed significance level of ⩽0.05.

Results: Complete datasets were available on 86 babies, 45 on VCV and 41 on TCPLV. The mean expired tidal volume was slightly higher, and the mean FiO $_{2}$ was lower in the VCV group compared to TCPLV. This was also associated with a higher PIP in VCV compared to TCPLV (16.9 cmH $_{2}$ O vs. 15.3 cmH $_{2}$ O, p = 0.033). However, VCV was associated with significantly higher variability of peak inspiratory pressure and significantly less variability of tidal volume delivery (0.87 mL/kg vs 1.12 mL/kg, p = 0.009).

Conclusions: Despite targeting identical exhaled tidal volumes, VCV was associated with consistent tidal volume delivery compared to TCPLV. This may have significance to clinical practice and future research.