The impact of capnography monitoring among children and adolescents in the postanesthesia care unit: a randomized controlled trial.

Background: Pulse oximetry does not reliably recognize respiratory depression, particularly in the presence of supplemental oxygen. Capnography frequently detects hypoventilation and apnea among children recovering from anesthesia. Although children are routinely monitored with capnography during anesthesia, reducing the rate of adverse events, it is not routinely used in the postanesthesia care unit (PACU), where patients remain at risk for respiratory depression.

Aim: We hypothesized that children monitored with capnography would have more frequent staff interventions and fewer adverse events than children monitored with pulse oximetry alone.

Methods: Otherwise healthy children of age 1-20 years undergoing general anesthesia for elective surgery were eligible for enrollment upon entering the pediatric PACU. Subjects were randomized as to whether PACU staff could view the capnography monitor (intervention group) or not (control group). All children received standard monitoring with pulse oximetry. Vital signs and patient interventions were recorded every 30 s by a portable monitor or a research associate.

Results: Data from 201 children were analyzed. The rates of hypopneic hypoventilation [5% (95% CI: 2-8%) per minute vs 1% (95% CI: -1% to 3%) per minute, difference 4% (95% CI: 0.2-8%) per minute; P = 0.04] and apnea [11% (95% CI: 8-14%) per minute vs 1.5% (95% CI: -2% to 5%) per minute, difference 9% (5-14%) per minute; P < 0.001] decreased significantly faster in our intervention group as compared to the control group. The rates of bradypnea decreased faster in our control group [5% (95% CI: 2-8%) per minute vs 1% (95% CI: 0-4%) per minute, difference 4% per minute, 95% CI: 0-9%; P = 0.05]. Rates of respiratory events over time between groups were affected by the presence or absence of interventions. There were no differences in rates of hypoxemia between groups over time.

Conclusions: Children monitored with capnography have different rates of adverse respiratory events over time than children monitored solely with pulse oximetry. The addition of capnography improved the efficacy of staff interventions, however did not impact rates of oxygen desaturation.