Association of high ventilator pressures with the development of chronic pulmonary hypertension in congenital diaphragmatic hernia patients requiring ECMO.

PURPOSE: Congenital diaphragmatic hernia (CDH) patients requiring extracorporeal membrane oxygenation (ECMO) were examined to determine, if aspects of their complex ventilatory management were associated with the development of chronic pulmonary hypertension (cPH).
METHODS: CDH patients requiring ECMO from 1992 to 2007 were retrospectively reviewed. cPH was defined as pulmonary hypertension at 3 months of age. Demographic and clinical variables including peak ventilatory pressures (PVP) and mean airway pressures (MAP) were tabulated.
RESULTS: 10/31 (32 %) patients developed cPH. Gestational age, birth weight, inborn status, CDH side and liver position were not different between cPH and non-cPH patients. Pre-ECMO, both groups required statistically similar ventilatory support, though there was a trend toward higher oxygenation index and higher PVP for cPH patients. While ECMO duration was similar between groups, cPH patients required significantly higher PVP (30.0 vs. 25.0 cmH(2)O, p = 0.01) and MAP (11.5 vs. 9.0 cmH(2)O, p = 0.02) for ECMO decannulation. Post-ECMO, maximum PVP (50.0 vs. 26.0 cmH(2)O, p < 0.001), MAP (18.1 vs. 12.0, p = 0.001), HFV requirement (90 vs. 10 %, p < 0.001), and ventilator time (35.7 vs. 20 days, p < 0.001) increased significantly for cPH patients.
CONCLUSION: Not until after ECMO decannulation do we see clinical differences separating patients who ultimately develop cPH. Although the degree of pulmonary hypoplasia may ultimately dictate ECMO decannulation criteria, perhaps greater physiologic optimization before decannulation could decrease the incidence of cPH.