Presented at the Neonatal Society 2005 Spring Meeting.
Singh J1, Sinha SK1, Donn SM2, Clarke P3, Byrne S3
1 The James Cook University Hospital, Middlesbrough, UK
2 Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
3 Hope Hospital, Manchester, UK
Background: Volume controlled ventilation (VCV) differs from pressure limited (PLV) ventilation in that the primary gas delivery target is tidal volume. This may have advantages in conditions such as surfactant treated respiratory distress syndrome (RDS) where lung compliance is changing rapidly.
Objective: To compare the efficacy and safety of Volume Control Ventilation against Pressure Limited Ventilation in low birth weight infants with RDS requiring exogenous surfactants and mechanical ventilation.
Methods: Ninety newborns weighing 600 to 1500 g and 24 to 32 weeks gestation with RDS, who required exogenous surfactant and mechanical ventilation, were randomized to either VCV or PLV and treated with a “standard” protocol. The efficacy of the two modes of ventilation was assessed according to the time taken from entry into the trial to reach a pre-determined ‘success’ criteria, based on either the Alveolar-arterial oxygen gradient [< 13 kPa / 100 torr] or the mean airway pressure [< 8 cm H2O]. Secondary outcomes included mortality, total duration of artificial respiratory support and complications associated with mechanical ventilation.
Results: Mean time to reach success criteria was 21 hrs in VCV group as compared to 34 hrs in PLV (p=0.068). This difference was more obvious in the subgroup of babies who weighed less than 1000g (18 vs. 36 hrs; p=0.012). However, there was no significant difference in mean duration of ventilation [VCV= 254 hrs versus PLV=308; p=0.82] or mean duration of artificial respiratory support (ventilation + CPAP) [23 days in VCV versus 27 days in PLV; p=0.66]. Three babies in VCV and 8 in PLV needed rescue treatment with HFOV. There were 3 deaths in the VCV group and 9 in PLV (p=0.064). The incidence of other complications was similar in the two groups.
Conclusions: Volume Controlled Ventilation appears to be both safe and efficacious in extremely low birth weight babies. This may also have advantages over the traditional Time Cycled Pressure Limited mode of ventilation.