Ventilatory response to CO2 in children with obstructive sleep apnea from adenotonsillar hypertrophy

We measured the ventilatory response to CO, as an indicator of respiratory control dysfunction in children with obstructive sleep apnea (OSA) schedule d for adenotonsillectomy. Measurements were performed in unpremedicated chi ldren via an endotracheal tube under 0.4%-0.5% end-tidal halothane anesthes ia. Mean ventilatory CO, response slopes for 11 children with OSA requiring adenotonsillectomy (Group I) were compared with those for 14 children with out OSA requiring adenotonsillectomy (Group II) and 15 children without OSA requiring nonairway surgery (Group III). The mean ventilatory slope correc ted for body surface area for Groups I, II, and III were 539 +/- 338, 828 /- 234, and 850 +/- 380 mL . min(-1) mm Hg ETCO2-1. m(-2), respectively (P < 0.05, Group I versus Groups IT and III). Historical data-including snorin g, apneic episodes >10 s, daytime hypersomnolence, and nocturnal enuresis-d efined those with OSA. Obesity occurred more frequently in patients with OS A and with depressed ventilatory responses (P < 0.001). Children with OSA f rom adenotonsillar hypertrophy have a diminished ventilatory response to CO 2 stimulation, compared with those without OSA symptoms. The depressed resp onse may account, in part, for the reported increased risk of perioperative respiratory complications in this population. Implications: Children with obstructive sleep apnea undergoing adenotonsillar surgery are at risk of po stoperative respiratory compromise. We found that patients with a clinical history suggesting obstructive sleep apnea have a diminished ventilatory re sponse to CO2 rebreathing, compared with controls.