HEMODYNAMIC CHARACTERISTICS OF NEONATES FOLLOWING FIRST STAGE PALLIATION FOR HYPOPLASTIC LEFT-HEART SYNDROME

Background It is widely held that the postoperative course of patients with hypoplastic left heart syndrome (HLHS) after stage 1 palliation is characterized by hemodynamic instability, which in part may be due to excessive pulmonary blood flow. Hence, avoidance of alkalosis and t he use of minimally oxygen-enriched inspiratory gas are thought by man y to be important, although there is little pertinent published data. This study was undertaken to characterize the postoperative course and to determine whether the FIO2 and blood pH are related to indices of hemodynamic stability in these infants. Methods and Results The postop erative course of 25 consecutive infants undergoing first stage pallia tion for HLHS were retrospectively reviewed and the following data wer e obtained: arterial pressure, arterial blood gas measurements, the in otropic agents used, and multiple respiratory parameters. There was on e operative death, and 2 patients died within 2 days, but 22 were extu bated (mean, 5.2+/-4.1 days after surgery). Hospital mortality was 24% . Mean pH was greater than or equal to 7.51 for the first 9 hours afte r surgery and was greater than or equal to 7.45 for the entire period. The mean FIO2 was greater than or equal to 50% for the first 18 hours . The PaO2 was appropriate (37+/-6 mm Hg at 1 hour after surgery, incr easing to 45+/-5 mm Hg by hour 73). Only modest inotropic support was needed to maintain appropriate blood pressure. Conclusions These data suggest that neither alkalosis nor relatively high inspired oxygen nec essarily cause hemodynamic instability in these patients. To what exte nt these results are generalizabie is unclear, but they suggest that t here is nothing inherent with HLHS that mandates postoperative hemodyn amic instability or unacceptable mortality.