The Laryngoscope V C 2013 The American Laryngological, Rhinological and Otological Society, Inc. Polysomnographic Evaluation of Propofol-Induced Sleep in Patients with Respiratory Sleep Disorders and Controls F abio A. W. Rabelo, MD; Daniel S. Ku ¨pper, MD; Heidi H. Sander, MD, PhD; Regina M. F. Fernandes, MD, PhD; Fabiana C. P. Valera, MD, PhD Objectives/Hypothesis: The treatment for obstructive sleep apnea syndrome (OSAS) depends on correct localization of upper airway obstruction, exception made for continuous positive airway pressure (CPAP). Drug-induced sleep endoscopy (DISE) with propofol allows this evaluation, but the drug effects on sleep parameters are not yet well established. Our objec- tive was to study by polysomnography (PSG) whether propofol would change sleep parameters by means of a prospective cross-sectional clinical study in a tertiary hospital. Study Design: Thirty non-obese subjects (6 controls and 24 OSAS patients) underwent two daytime PSGs, one with DISE and the other without DISE. Methods: During DISE exam, propofol was administered intravenously in continuous infusion using a target-controlled infusion pump. The parameters evaluated were: presence of snoring, apnea-hypopnea index (AHI), oxyhemoglobin saturation (SaO 2 ), and sleep macroarchitecture. Results: Snoring was absent in all healthy subjects during DISE sleep with propofol, and present in all OSAS patients (100%). AHI and mean SaO 2 showed no statistical difference between the two tests, with and without propofol. However, minimum SaO 2 was significantly lower during propofol infusion (88.64 for without vs. 85.04 for with propofol; P < 0.01). Regarding sleep macroarchitecture, the tests with propofol significantly increased N3 sleep and totally extinguished REM sleep (P < 0.005). Conclusions: The results demonstrate that propofol significantly changes sleep macroarchitecture. However, the main respiratory parameters, AHI and mean SaO 2 , remained unaffected. Thus, in order to determine the sites of obstruction, propo- fol DISE used with target-controlled infusion proved to be an effective drug for endoscopic evaluation of patients with OSAS. Key Words: OSAS, obstructive sleep apnea syndrome, apnea, propofol, drug-induced sleep endoscopy, DISE, sleep endoscopy. Level of Evidence: 4. Laryngoscope, 123:2300–2305, 2013 INTRODUCTION The studies on obstructive sleep apnea syndrome (OSAS) have facilitated the diagnosis, demonstrated the need of treatment in order to control comorbidities, and also confirmed the efficacy of treatment with positive pressure devices. However, due to the difficulty in adhe- sion to these devices, 1 alternative treatments are widely proposed, especially surgical ones. The aim of surgical treatment is to correct either bone or soft tissue changes in upper airways that would induce collapse or vibration of specific regions in the nasal cavity, nasopharynx, oropharynx, or hypopharynx, either in isolated or multiple sites. However, it is diffi- cult to establish the efficacy of different surgeries in OSAS patients as many techniques have been described, and controlled and randomized studies are missing. The main reviews and meta-analyses in literature have shown inconsistent results in surgical outcomes for OSAS. The first review (Sher et al., 1996) 2 reported an approximate success rate of 40% for uvulopalatopharyng- oplasty (UPPP), the most frequently performed surgery for OSAS. The authors concluded that unsatisfactory results for UPPP might have occurred because of inad- equate preoperative evaluation of obstructive sites, and this would directly influence on treatment. Sundaram et al. (2005) 3 published a Cochrane Database review, in which they proposed that the deter- mination of the obstructive site should be the main focus of researches in OSAS as it would have direct relation with treatment’s success. The authors emphasized that higher efficacy of treatments will occur when patients with OSAS will be better stratified based on improved characterization of obstructive sites. From the Department of Ophthalmology, Otorhinolaryngology– Head and Neck Surgery ( F. A. W. R, D. S. K, F. C. P. V.); Division of Otorhinolaryngology of School of Medicine of Ribeira ˘o Preto; and the Department of Neuroscience and Sciences of Behavior (H.H.S., R.M.F .F .), Division of Neurology of School of Medicine of Ribeira ˘ o Preto, University of Sa ˘ o Paulo, Ribeira ˘ o Preto, Brazil. Editor’s Note: This Manuscript was accepted for publication July 19, 2012. Financial support: FAPESP (process number 2008/03771-0). The authors have no additional funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Fabiana C. P. Valera, MD, Departamento de Oftalmologia, Otorrinolaringologia e Cirurgia de Cabec ¸a e Pescoc ¸o, Avenida Bandeirantes, 3900 -12  andar, Ribeira ˘o Preto, Sa ˘o Paulo, Brasil, CEP 14049-900. E-mail: facpvalera@fmrp.usp.br DOI: 10.1002/lary.23664 Laryngoscope 123: September 2013 Rabelo et al.: PSG During Propofol-Induced Sleep 2300