Background and aims Meta-analysis of randomised trials (RCTs) demonstrated that volume-targeted ventilation (VTV) in comparison to pressure-limited ventilation (IPPV) reduces BPD/death, pneumothorax, hypocarbia and PVL/grade 3–4 IVH in prematurely born infants. Certain RCTs, however, employed different ventilators in the two arms and, overall, a range of VT levels were used. Our aim was to undertake an RCT in prematurely born infants with acute respiratory distress comparing IPPV with VTV, using a VT level of 5ml/kg, which has been shown to reduce the work of breathing.
Methods Infants < 34 weeks of gestational age and < 24 hours of age were recruited. The primary outcome was the time taken to achieve pre-specified weaning criteria. Secondary outcomes included the occurrence of PDA, pneumothorax, IVH, PVL and hypocarbia; hypocarbia was defined as a PaCO 2 of < 4.5 kPa on any blood gas in the first 72 hours after birth. Infants met failure criteria if they required HFO, peak pressures >26 cm H2O or had a pulmonary haemorrhage. Analysis was by intention-to-treat.
Results The planned sample size of 40 infants was achieved, with no significant differences in the two groups’ demographics. The time taken to achieve weaning criteria was similar in the two groups [14 hours (VTV) versus 23 hours (IPPV); hazard ratio=0.82 (95% CI 0.42, 1.58)], p=0.55. Five “VTV” and three “IPPV” infants met failure criteria, p=0.69. Fewer “VTV” than “IPPV” infants had hypocarbia (8 versus 19), p<0.001.
Conclusion VTV was associated with a significantly lower incidence of hypocarbia.