Impairment in Preextubation Alveolar Gas Exchange Is Associated With Postextubation Respiratory Support Needs in Infants After Cardiac Surgery

OBJECTIVES: To determine if indices of alveolar gas exchange preextubation predict postextubation respiratory support needs as well as the need for escalation of therapies following infant cardiac surgery. DESIGN: Retrospective chart review. SETTING: Pediatric cardiac ICU in a quaternary-care teaching hospital. PATIENTS: Infants less than 1 year old who underwent biventricular repair from January 2015 to December 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Preextubation alveolar-arterial gradient, oxygenation index, oxygen saturation index, Pao(2)/Fio(2) ratio, and dead space ventilation (analyzed with both end-tidal carbon dioxide gradient and dead space fraction) were evaluated for each patient. All but dead space ventilation were associated with a higher level of noninvasive respiratory support immediately postextubation. Furthermore, impaired preextubation gas exchange was independently associated with escalation of respiratory support within the first 48-hour postextubation. CONCLUSIONS: Validated measures of alveolar gas exchange can be used as a tool to assess postextubation respiratory support needs including the risk of escalation of respiratory support in the first 48-hour postextubation. Prospective study with implementation of extubation guidelines, both for readiness and determination of early postextubation support, is needed to validate these findings.