Cardiorespiratory effects of naloxone in children.

Background: Data on the cardiorespiratory changes and complications following administration of naloxone in children are limited.

Objective: To evaluate the cardiorespiratory changes and complications following naloxone treatment in children.

Methods: The maximal changes in respiratory rate (RR), heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, and any complications within 1 and 2 hours following naloxone were tabulated.

Results: One hundred ninety-five children received naloxone over 3 years. The mean +/- SD age was 9.7 +/- 6 years. The total doses of naloxone ranged from 0.01 to 7 mg (0.001-0.5 mg/kg body weight), with a median dose of 0.1 mg. Group 1 patients consisted of 116 (60%) children who were postoperative and had been given naloxone by an anesthesiologist; group 2 patients consisted of 79 (40%) children who received naloxone in the emergency department or pediatric intensive care unit. Patients in group 1 were older: 10.6 +/- 5.3 versus 8.2 +/- 6.7 years (p < 0.006), but received significantly lower doses of naloxone (0.09 +/- 0.2 vs. 1.1 +/- 0.76 mg; p < 0.001). When the entire cohort was evaluated, a significant increase in RR (15 +/- 7 vs. 21 +/- 8 breaths/min; p < 0.001), HR (102 +/- 29 vs.107 +/- 29 beats/min; p < 0.001), SBP (109 +/- 17 vs. 115 +/- 15 mm Hg; p < 0.001), and DBP (56 +/- 10 vs. 60 +/- 13 mm Hg; p < 0.001) within 1 hour following naloxone was noted. When the 2 groups were compared, only the changes in RR were greater in group 2 patients (6.8 +/- 7.9 vs. 4.7 +/- 5 breaths/min; p < 0.001) following naloxone. Systolic hypertension occurred in 33 of 195 (16.9%) of all patients, while diastolic hypertension occurred in 13 (6.6%) of all patients after naloxone. Only the incidence of diastolic hypertension was higher in group 2 compared with group 1 patients following naloxone (16% vs. 2%; p < 0.001). Hypertension resolved spontaneously. One child developed pulmonary edema and required positive pressure ventilation for 22 hours.

Conclusions: Moderate increases in RR, HR, and BP occur after naloxone administration to children, but development of more serious complications is rare.