Obstructive sleep apnea is the most common type of sleep disorder breathing.90%of them remain undiagnosed. These patients may be associated with an increased risk of perioperative complications. Our objective was to evaluate the proportion of surgical patients with risk of undiagnosed Obstructive sleep apnea. After research ethics board approval, patient attending preanesthetic clinic were asked to fill the STOP-Bang questionnaire. Prospective observational study is used with the sample size of 70 patients and the study duration is 4 months. In 70 patients, the proportion of surgical patients with the increased(intermediate-high) of developing Obstructive sleep apnea is 78%(55 patients) This study is conducted to find out the percentage of surgical patients having undiagnosed Obstructive sleep apnea can be identified and treated to prevent perioperative complications.

Keywords : Surgical population ,Obstructive sleep apnea ,STOP-Bang score.