ABSTRACT
OBJECTIVE: To study diphenhydramine nebulization as a clinically applicable method for blunting laryngeal chemoreflex (LCR)-associated apnea. INTERVENTIONS: Fourteen piglets aged 15 to 18 days were studied. In 7 piglets, diphenhydramine hydrochloride (5.0 mg/kg) was nebulized onto the laryngeal mucosa after a baseline response was obtained. RESULTS: After a 10-minute waiting period, the mean +/- SD LCR-induced apnea duration decreased from 29 +/- 13 seconds in the control animals to 15 +/- 5 seconds in the treated group (P = .02, 1-factor analysis of variance). After 1 hour, no treatment effect was seen. CONCLUSIONS: Nebulization of diphenhydramine can effectively reduce LCR-induced apnea for a short time. Nebulization of longer-acting agents may provide an effective prophylaxis of LCR-induced apnea.
