Persistent hypercapnia in children after treatment of obstructive sleep apnea syndrome by adenotonsillectomy

Obstructive sleep apnea syndrome (OSAS) in childhood is frequently in part a consequence of enlarged adenoids and/or tonsils and may lead to hypoxemia and hypercapnia during sleep. Whereas longterm blood gas alterations are w ell documented in adults, only few polygraphic data are available for child ren. It was the aim of this study to document blood gas alterations before and after treatment in this population. 9 children with OSAS (6 male, 3 fem ale, median age 5.9 years, range 1.1-13.5 years) were investigated by polys omnography before and after adenotonsillectomy. Prior to intervention most children presented with moderate hypercapnia (ETCO2 mean 44.3 +/- 3.8 mm Hg , ETCO2 maximum 53.2 +/- 5.2) and hypoxemic episodes (oxygen saturation mea n 93.2 +/- 3.2%, minimum 74.4 +/- 16.5%). Following adenotonsillectomy subs equent polygraphic investigations displayed normalisation of oxygen saturat ion (saturation mean 96.1 +/- 0.8%, minimum 90.1 +/- 3.1%). In contrast, mo derate hypercapnia in several patients persisted up to five months after tr eatment (ETCO2 mean 44.9 +/- 2.8 mm Hg, ETCO2 maximum 51.2 +/- 3.6). Persis tent hypercapnia most likely reflects an adaptation process of chemosensiti vity and respiratory control due to preceding long-term hypercapnia.