Permissive hypercapnia practices among neonatologists in the United States: Results of a national survey

Abstract. Objective: There is no consensus among practicing neonatologists regarding the definition of permissive hypercapnia and yet its practice is commonly employed to prevent lung injury from excessive ventilation. The goal of this study was to determine clinical practice among neonatologists regarding a definition of permissive hypercapnia in a preterm infant based upon gestational age at birth, degree of respiratory support, and acute vs. chronic management. Methods: Surveys were e-mailed to neonatologists who are members of the AAP Section on Perinatal Pediatrics containing a link to an on-line survey company ( Responses were compared using Pearson X2 analyses. Results: Of 2689 individuals surveyed, 747 (28%) completed the survey. 97% of those respondents reported practicing permissive hypercapnia. Regardless of stated permissive hypercapnia practice preferences, the majority of neonatologists accept 45–55mm Hg as their target PaCO2 levels on the first day of life and 55–65mm Hg thereafter. Conclusions: Our data suggest most neonatologists surveyed employ a permissive hypercapnia respiratory management strategy, as they accept higher than normal PaCO2 levels for preterm infants . Our findings highlight the need for continuing studies to document whether the values of targeted PaCO2 reported here provide lung protection without compromising overall safety and long-term complications.


*Corresponding Author: 

Thornton Mu, MD, Tripler Army Medical Center, Department of Pediatrics, 1 Jarrett White Rd, Honolulu, HI 96859, USA.

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