Is there an OAHI or O₂ nadir that predicts the need for preoperative echocardiogram prior to adenotonsillectomy for children with severe obstructive sleep apnea?

Purpose: To investigate threshold values for obstructive apnea–hypopnea index (OAHI) and nadir oxygen saturation (NspO₂) in children with severe obstructive sleep apnea (OSA) to identify children most appropriate for preoperative echocardiography. Methods: A multi-institutional retrospective chart review was performed on children who underwent echocardiography and polysomnogram within a year. Children with severe OSA as defined by OAHI > 10 or NspO₂ < 80% were included. Receiver operator curves and Youden’s J index were used to assess the discriminatory ability and threshold values of OAHI and NspO₂ for right heart strain (RHS) on echocardiography. Results: A total of 173 prepubertal (< 10 years) children and 71 postpubertal (≥ 10 years) children of age were included. RHS was seen in 9 (5%) prepubertal children and 4 (6%) postpubertal children. In prepubertal children, OAHI and NspO₂ were poor predictors of RHS (area under the curve [AUC] 0.53 [95%CI 0.45–0.61], p = 0.748; AUC 0.56 [95%CI 0.48–0.64], p = 0.609). In postpubertal children, threshold values of 55 events/hour and 69% were strong predictors for RHS (AUC 0.88 [95%CI 0.78–0.95], p < 0.001; AUC 0.92 [95%CI 0.83–0.97], p < 0.001). Conclusion: In children with severe OSA, evidence of RHS is low. Postpubertal children with OAHI > 55 and NspO₂ < 69% appear most appropriate for echocardiography. Clinicians should weigh the risks and benefits of preoperative echocardiography for each child with these threshold values in mind.