Abstract 1722
Poster Session I, Saturday, 5/1 (poster 109)
Introduction: Over the past decade ECMO has been responsible for the survival of newborns with severe pulmonary hypertension with an overall survival rate of 80%. Over 13,000 patients nationwide have required the procedure, with over 550 from our institution alone. However, virtually nothing is known about the long-term cardiopulmonary outcome of these patients. Our objective was to compare the aerobic capacity of ECMO children ages 10-13 years to same age non-ECMO controls, and to determine the number of ECMO children with residual pulmonary hypertension by ECHO.Methods: Ten ECMO and 5 control children were enrolled in the study. ECMO patients had a GA of 39.4±2.2, an average PaO2 of 44 ± 23 and were on PIP of 52 ± 8 prior to ECMO. Diagnosis for the ECMO group included:5 MAS, 2 CDH, 3 RDS/PPHN. The average duration of ECMO was 128.2 ± 78.9 hrs, and 1 ECMO patient required supplemental oxygen (>1 month). We obtained medical history and information on physical activity from both groups. Height and weight measurements were recorded. All patients had a standard pediatric transthoracic ECHO and an ECG. Each child exercised on a treadmill using the Bruce protocol until they requested to stop or reached 85% of their target heart rate. During testing, oxygen consumption (VO2) was measured at rest, 3 minute intervals, and at maximal exercise VO2max with a face mask connected to a mass spectrometer. Heart rate and blood pressure measurements were continuously recorded during testing. The aerobic capacity was determined from the VO2max.Results: There was a statistically significant difference between the ECMO patients and the controls in VO2max (ml/kg/min) (35.2 ± 11.2 vs 58.1 ± 5.5), p= 0.0004. We also observed a statistically significant difference amongst male ECMO subjects and controls (38.8 ± 10.5 vs 58.8 ± 6.5), p=0.008. All echocardiograms were normal in both groups. There were no significant differences between ECMO and control children in right ventricular end-diastolic dimension (1.1 ± 0.52 vs 1.0 ± 0.28 cm), shortening fraction (0.39 ± 0.05 vs 0.37 ± 0.05) or right ventricular ejection fraction (0.61 ± 0.11 vs 0.57 ± 0.06). Ninety percent of ECMO and 80% of control children had mild TR and 70% of ECMO and all control patients had mild PI. Pulmonary artery pressures estimated from these regurgitant velocities (32 ± /13 ± 4 vs 23 ± 8/14 ± 2 mmHg) were normal and not significantly different between the two groups.Estimated PAP from RV outflow doppler was also normal in all patients.All patients had a normal ECG except 1 ECMO patient who had RVH.There were no differences between HR and BP measurements between the two groups.Conclusion: Current data suggests that ECMO survivors have decreased aerobic capacity compared to their non-ECMO counterparts. This observed difference could be due to the effects of residual lung disease in this population as echocardiographic long-term follow-up shows no evidence of residual pulmonary hypertension.
