The effect of adenotonsillectomy on ventilatory control in children with obstructive sleep apnea.
The contribution of ventilatory control to the pathogenesis of obstructive sleep apnea (OSA) in children and the effect of adenotonsillectomy are unknown. We aimed to examine the difference in ventilatory control between children with OSA and those without OSA. We also examined the effect of adenotonsillectomy on parameters of ventilatory control. Healthy children with OSA and matched controls were recruited. Polysomnography was performed before adenotonsillectomy in the OSA group and 6 months postoperatively. Controls underwent the same assessment at the two time points. Loop gain (LG), controller gain (CG), and plant gain (PG), which reflect the stability of ventilatory control, chemoreceptor sensitivity and the pulmonary control of blood gas in response to a change in ventilation, respectively, were estimated from polysomnographic tracings which included spontaneous sighs and tracings with tidal breathing. A linear mixed model was used to examine the changes of the ventilatory control parameters from baseline to 6 months. Ninety-nine children aged 7-13 were recruited to the study. Fifty-three with OSA and 46 controls. At baseline, compared with controls, children with OSA had higher PG and lower CG. LG did not differ between groups. Six months following adenotonsillectomy, there was a significant decrease in PG in the OSA group, while no change observed in the control group. The study demonstrates that the pulmonary control of blood gas homeostasis is disturbed in children with OSA and it normalizes following adenotonsillectomy.