Abstract 1828

Introduction. iNO is a very useful therapy for newborn infants with persistent pulmonary hypertension. However, if NO fails, ECMO is still an ultimate therapy for these patients. It is unknown what influence this iNO pretreatment might have on the ECMO course. Therefore, in this retrospective study we evaluated whether iNO pretreatment will result in a more complicated ECMO course.

Methods. Between 1992 and 1997 after exclusion of newborns with congenital diaphragmatic hernia, 59 newborns who were treated with ECMO were evaluated. Twenty-five newborns (GA 39.0 ± 2.4 wk, BW 3422 ± 586 g) were pretreated with iNO (NO group) and thirty-four newborns (GA 39.3 ± 2.5 wk, BW 3392 ± 626 g) were not treated with iNO (control group). The following variables were collected: primary diagnosis, lowest arterial pO2 and O2 saturation before ECMO, maximum AaDO2, postnatal age at starting ECMO, ECMO duration, drug treatment and complications during ECMO.

Results. There were no differences in GA, BW, primary diagnosis between the NO group and the control group. The postnatal age at starting ECMO was 59.3 ± 67.7 h in the NO group and 52.6 ± 62.6 h in the control group (p = 0.70). The ECMO duration was 173.2 ± 51.8 h in the NO group and 154.8 ± 73.5 h in the control group. However, stepwise regression analysis showed that the longer mean ECMO duration in the NO group was not related to the iNO pretreatment, but to the higher postnatal age in the NO group. There was a strong positive relationship between ECMO duration and postnatal age at starting ECMO. There were no statistical significant differences in the lowest arterial O2 saturation, the lowest arterial pO2 and the maximum AaDO2 before ECMO. A significantly more frequent use of epinephrine was found in the NO group (20% vs. 3% in the control group). The use of epinephrine is strongly related to the longer ECMO duration. In the NO group clot formation and/or disseminated intravascular coagulation (DIC) occurred more frequently (68 times vs. 26 times in the control group, p = 0.001). After correction for the primary diagnosis and ECMO duration the odds ratio for clot formation and/or DIC in the NO group was 5.9 (95% CI 1.7 - 20.4). There was no significant differences in the occurrence of hemorrhage between both groups, but after correction for primary diagnosis, medication and ECMO duration the odds ratio for hemorrhage in the NO group was 3.2 (95% CI 0.5 - 22.1).

Conclusion. The ECMO duration is positively correlated with the postnatal age at starting ECMO. The chance of the occurrence of clot formation and/or DIC during ECMO is higher after iNO pretreatment. iNO pretreatment resulted also in a higher need for circulatory support with epinephrine.