Affiliations: [a] Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA | [b] Department of Pediatrics, University at Buffalo, John R. Oishei Children’s Hospital, Buffalo, NY, USA | [c] Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA | [d] University Hospitals Rainbow Babies & Children’s Hospital, Case Western Reserve University, Cleveland, OH, USA | [e] Department of Pediatrics, University of California at Davis, Sacramento, CA, USA
Address for correspondence: Rita Dadiz, DO, Department of Pediatrics, Division of Neonatology, University of
Rochester Medical Center, 601 Elmwood Avenue, Box 651, Rochester, NY 14642, USA. Tel.: 585 275 2972; Fax: 585 461
3614; E-mail: [email protected].
Abstract: BACKGROUND:We aimed to investigate whether the change in methemoglobin levels (ΔMHb) predicts oxygenation response to inhaled nitric oxide (iNO) in persistent pulmonary hypertension of the newborn (PPHN) with lung disease, with or without pulmonary hypoplasia. METHODS:In this prospective observational study, infants were categorized based on ΔMHb and oxygenation response (ΔPaO2/FiO2) following iNO: ΔMHb ≤0 or ΔMHb>0, and ΔPaO2/FiO2 < 20 mmHg (Non-responder) or≥20 mmHg (Responder). ΔMHb levels were compared among infants with or without pulmonary hypoplasia. RESULTS:Among infants with pulmonary hypoplasia (n = 28), ΔMHb was not associated with an oxygenation response to iNO or survival without ECMO. Among infants without hypoplasia (n = 29), subjects with ΔMHb>0 following iNO (n = 21) had a greater ΔPaO2/FiO2 (median, 64 mmHg; IQR, 127; p < 0.01) and 100% survival without extracorporeal membrane oxygenation (ECMO) when compared to infants with ΔMHb ≤0 (n = 8; median 10 mmHg; IQR, 33). CONCLUSIONS:PPHN secondary to lung disease without hypoplasia with increased ΔMHb following iNO was associated with better oxygenation response and survival without ECMO compared to subjects without an increase in MHb.