Polysomnography parameters assessing gas exchange best predict postoperative respiratory complications following adenotonsillectomy in children with severe OSA

Study Objectives: Adenotonsillectomy (AT) is the treatment of choice for obstructive sleep apnea (OSA) in children with adenotonsillar hypertrophy. Severe OSA, identified by the apnea-hypopnea index (AHI), is a risk factor for surgical complications and AHI thresholds are used by surgeons to decide elective postoperative hospital admissions. The objective of this study was to identify the prevalence of surgical complications of AT in children with severe OSA and determine their association with specific parameters of polysomnography (PSG). Methods: Retrospective evaluation of respiratory and nonrespiratory complications in children undergoing AT for severe OSA was performed. Events were then compared to several individual PSG indices. PSG indices included classic parameters such as AHI, and obstructive apnea indexes (OAI) as well as gas exchange parameters including the oxygen desaturation index (ODI), lowest oxyhemoglobin saturation (lowest SpO₂), peak end-tidal CO₂ (peak ETCO₂), the percentage of the total sleep time (%TST) with ETCO₂ > 50 mmHg (%TST ETCO₂ > 50 mmHg) and oxygen saturation < 90% (%TST O₂ < 90%). Results: A total of 158 children were identified with severe OSA. Major respiratory complications occurred in 21.5% and were only associated with the ODI (P =.014), lowest SpO₂ (P =.001) and %TST O₂ < 90% (P <.001). Minor respiratory complications occurred in 19.6% and these were not associated with any PSG parameters. Major nonrespiratory complications occurred in 4.4% and also were not associated with any PSG parameters; however, minor nonrespiratory complications occurring in 37.3%, and were associated with %TST O₂ < 90% (P < 0.001). Conclusions: PSG measures of gas exchange are strongly associated with postoperative complications of AT and are better suited for postoperative planning than classic indices such as AHI.