title: Hypoxic gas therapy using nitrogen in the preoperative management of neonates with hypoplastic left heart syndrome.
abstract: OBJECTIVE: To evaluate the efficacy of hypoxic gas therapy using nitrogen, where the fraction of inspired oxygen (Fio2) was reduced to <0.21 in patients with univentricular parallel circulation. DESIGN: Case report. SETTING: A pediatric intensive care unit at a university hospital. PATIENTS: Two neonatal patients with hypoplastic left heart syndrome admitted to the pediatric intensive care unit preoperatively. INTERVENTIONS: Nitrogen insufflation by using continuous-flow respiratory support. MEASUREMENTS AND MAIN RESULTS: We reduced the Fio2 in these patients by giving additional nitrogen to relieve pulmonary overcirculation and systemic hypoperfusion suspected by transcutaneous arterial oxygen saturation >90%, systemic arterial hypotension, and low urine output in the preoperative course. The improvement of systemic hemodynamics concomitant with decreases in transcutaneous arterial oxygen saturation <85% was accomplished by controlling Fio2 between 0.14 and 0.18. These infants were able to undergo Norwood's surgery after several days without complications relating to Fio2 reduction. CONCLUSION: Hypoxic gas therapy with nitrogen was effective clinically in preventing pulmonary overcirculation in neonatal patients with univentricular and parallel circulation.
authors.affiliation: Departments of Anesthesiology and Intensive Care (Drs. Shime, Hashimoto, Hiramatsu, Kageyama, and Tanaka), and Pediatric Cardiology (Dr. Oka), Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shime
authors.forename: S
authors.initials: S
authors.lastname: Hashimoto
authors.forename: N
authors.initials: N
authors.lastname: Hiramatsu
authors.forename: T
authors.initials: T
authors.lastname: Oka
authors.forename: K
authors.initials: K
authors.lastname: Kageyama
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka