Surgical patients with Obstructive Sleep Apnea (OSA) are more likely than non-OSA surgical patients to suffer post-operative complications. (See: Gupta et al. "Postoperative Complications in Patients With Obstructive Sleep Apnea Syndrome Undergoing Hip or Knee Replacement: A Case-Control Study" Mayo Clin Proc. 2001;76:897-905, and Liao et al. "Postoperative complications in patients with obstructive sleep apnea: a retrospective matched cohort study" Can J Anesth/J Can Anesth (2009) 56:819