Respiratory depression detected by capnography among children in the postanesthesia care unit: a cross-sectional study

Abstract

Background: Children are at risk for respiratory depression while recovering from anesthesia. Currently, monitoring children in the postanesthesia care unit (PACU) with pulse oximetry is recommended. However, pulse oximetry does not reliably recognize hypoventilation or apnea, particularly in the presence of supplemental oxygen. Capnography is a sensitive monitor of ventilation that is not often used in the PACU. Aim: To determine the frequency of hypoventilation and apnea as detected by capnography among children in the PACU. Methods: In a cross-sectional study, capnography monitoring was applied to healthy children of age 1–17 years in the PACU of a tertiary care hospital. Staff was blinded to the capnography monitor; alarms were disabled. Staff provided routine care and monitoring with pulse oximetry to all patients. Vital signs, patient interventions, and medication administration were recorded by a research assistant every 30 s until all monitoring was discontinued by staff. Outcome measures included frequency of hypoventilation and apnea as measured by capnography and oxygen desaturations as measured by pulse oximetry, as well as staff interventions for these events. Results: Data from 194 children were analyzed. Capnography detected hypoventilation or apnea in 45.5% (95% CI 38.5%, 52.5%) of patients. Oxygen desaturations occurred in 19% (95% CI 13%, 24%) of patients. Interventions occurred in 9% (95% CI 5%, 13%) of patients. Patients who received narcotic medications were more likely to experience hypoventilation (OR 2.3, 95% CI 1.02, 5.3) and apnea (OR 2.7, 95% CI 1.1, 7). Hypoventilation was seen more often among children who received supplemental oxygen (OR 3.1, 95% CI 1.1, 12). Conclusions: Hypoventilation and apnea are common among children in the PACU; however, few interventions occur to address these events. Routine monitoring with capnography may improve recognition of respiratory depression and enhance patient safety in the PACU.