Limiting ventilator-associated lung injury in a preterm porcine neonatal model.

PURPOSE

Preterm infants are prone to respiratory distress syndrome (RDS), with severe cases requiring mechanical ventilation for support. However, there are no clear guidelines regarding the optimal ventilation strategy. We hypothesized that airway pressure release ventilation (APRV) would mitigate lung injury in a preterm porcine neonatal model.

METHODS

Preterm piglets were delivered on gestational day 98 (85% of 115day term), instrumented, and randomized to volume guarantee (VG; n=10) with low tidal volumes (5.5cmkg) and PEEP 4cmHO or APRV (n=10) with initial ventilator settings: P 18cmHO, P 0cmHO, T 1.30s, T 0.15s. Ventilator setting changes were made in response to clinical parameters in both groups. Animals were monitored continuously for 24hours.

RESULTS

The mortality rates between the two groups were not significantly different (p>0.05). The VG group had relatively increased oxygen requirements (FO 50%±9%) compared with the APRV group (FO 28%±5%; p>0.05) and a decrease in PaO/FiO ratio (VG 162±33mmHg; APRV 251±45mmHg; p<0.05). The compliance of the VG group (0.51±0.07L·cmHO) was significantly less than the APRV group (0.90±0.06L·cmHO; p<0.05).

CONCLUSION

This study demonstrates that APRV improves oxygenation and compliance as compared with VG. This preliminary work suggests further study into the clinical uses of APRV in the neonate is warranted.

LEVEL OF EVIDENCE

Not Applicable (Basic Science Animal Study).