A review of data from the U. of Michigan Holden NICU from 12/1/93 through 12/2/95 for inhaled nitric oxide (NO) was performed. NO was offered to 27 term/near term neonates with persistent pulmonary hypertension (PPHN) documented by echo and/or pre/post ductal pO2 gradients. Postductal pO2 increased >10 Torr in responders. ECMO was offered for intractable worsening hypoxemia (OI>25).

Of 27 infants, 11(41%) were responders not requiring ECMO (R-E), 8(29%) were responders requiring ECMO (R+E), 7(26%) were non-responders requiring ECMO (NR+E), and 1(4%) was a non-responder not requiring ECMO (NR-E). Differences in characteristics among groups emerged. 1.) R-E had higher baseline postductal pO2's (68±22 Torr) than R+E (40±20 Torr, p=0.01) and NR-E (44±18 Torr, p=0.03). 2.) The first postductal pO2 obtained 30 mins. after initiating NO was higher in R-E (136±61 Torr) than R+E (74±41 Torr, p<0.03). 3.) No infant with baseline pO2<39 Torr avoided ECMO. 4.) Seven infants had MAS, 4 infants with severe parenchymal disease on CXR required ECMO. 5.) Of 6 infants with CDH, 5 were responders. Three with baseline postductal pO2's <45 required ECMO. Conclusion: Limited data suggest that patient selection may be important in predicting NO response.