Impact of delivered tidal volume on occurence of intraventricular haemorrhage in preterm infants during PPV in the DR

Delivery of unintentional high tidal volume during positive pressure ventilation (PPV) in the delivery room (DR) is common. In animal models, the delivery of high tidal volumes have been associated with heamodynamic brain injury. Delivery of excessive tidal volumes (Vts) potentially causes hypocarbia, which is associated with white matter injury including periventricular leukomalacia (PVL). 

In this study the authors examined if Vt delivery during PPV at birth is associated with brain injury in preterm infants <29 weeks’ gestation. 

A total of 165 infants were included, 124 (75%) infants (<29 weeks’ gestational age) were ventilated with a mean Vt>6mL/kg compared with 41 (25%) ventilated with a mean Vt<6mL/kg. 

Overall, IVH (Intraventricular haemorrhage) in infants receiving Vt>6 mL/kg during PPV was diagnosed in 63 (51%) infants compared with 5 (13%) infants receiving Vt<6mL/kg (P=0.008). Severe IVH (grade III or IV) developed in 33/124 (27%) infants in the normal Vt group and 2/41 (6%) in the normal Vt group (P=0.01). 

As a recent Cochrane review reported, volume-targeted ventilation in the NICU significantly reduces grade 3/4 IVH or PVL when compared with pressure-limited ventilation (relative risk 0.48 (95% CI 0.28 to 0.84), risk difference  -0.09 (95% CI-0.15 to -0.02)). The authors note that this has not been assessed during neonatal resuscitation in the delivery room. 

Conclusion

The authors conclude that high Vt delivered during mask PPV at birth was associated with brain injury. Strategies to limit Vt delivery during mask PPV should be used to prevent high Vt delivery.