Do we need new indications for ECMO in neonates pretreated with high-frequency ventilation and/or inhaled nitric oxide?

Abstract

Objective: High-frequency ventilation (HFV) and/or inhaled nitric oxide (iNO) has reduced ECMO in neonates. But, frequently, improvement with HFV/iNO is temporary and only prolongs lung injury without preventing ECMO. We tried to identify a threshold oxygenation index (OI) that predicts temporary or persistent improvement with HFV/iNO in neonatal ECMO candidates as early as possible. Design: Cohort study of all neonates with OI > 40 during intermittent positive pressure ventilation between and 1997. The first treatment was HFV; at an OI > 40 during HFV, iNO was added; at an OI > 40 during HFV+iNO, ECMO was initiated. Temporary improvement was defined as secondary need for ECMO or fatal chronic lung disease without ECMO. Setting: University hospital level III neonatal intensive care unit. Main results: Ten of the 34 neonates studied rapidly required ECMO despite HFV/iNO. Eleven neonates temporarily im, proved for 1-10 days before the OI was again > 40. Nine received ECMO, two were denied ECMO after mechanical ventilation > 14 days and died of chronic lung disease. Thirteen neonates persistently improved with HFV/iNO without ECMO. The OI before, at 24 h or 48 h of HFV/iNO did not predict temporary or persistent improvement. However, after 72 h of HFV/iNO, neonates with persistent improvement had lower OIS than those with temporary improvement [median OI 16 (4-24) vs 31 (20-40); P = 0.0004]. In all neonates with an O1>≥25 after 72 h, HFV/iNO eventually failed (positive predictive value 100 %, sensitivity 91%, specificity 100 %, positive likelihood ratio 91). Conclusion: For neonates pretreated with HFV/iNO, an OI > 40 is an inadequate ECMO indication. Based on our data we hypothesize that an OI ≥25 after 72 h of HFV/ iNO is a better ECMO indication that avoids prolonged barotrauma.