title: Multilevel surgery in patients with rapid eye movement-related obstructive sleep apnea.
abstract: OBJECTIVE
  To compare the anatomic features and the results of a multilevel surgery in patients with rapid eye movement-related obstructive sleep apnea (REM OSA) and non-REM OSA.
  
  
  METHODS
  Cohort study of 90 consecutive mild or moderate OSA patients.
  
  
  METHODS
  The apnea-hypopnea index (AHI) was also calculated during REM sleep (AHI(REM)) and during non-REM sleep (AHI(NREM)), and patients were classified as having REM OSA if their AHI(REM)/AHI(NREM) ratio was >2, otherwise they were classified as non-REM OSA patients. All patients underwent concurrent uvulopalatopharyngoplasty and a radiofrequency tongue base reduction procedure.
  
  
  RESULTS
  A total of 31.1 percent patients were classified as REM OSA and 68.9 percent patients as non-REM OSA. There were no differences in the anatomical features between two groups. However, the AHI, HI, and arousal index were significantly higher in the non-REM OSA group than in the REM OSA group. When a successful outcome was defined as a postoperative AHI <20 with at least a 50 percent reduction from the preoperative level, 50 percent of the patients with REM OSA and 35.5 percent of the patients with non-REM OSA met the criteria for a successful outcome.
  
  
  CONCLUSIONS
  REM OSA patients had milder obstructive sleep apnea, and multilevel surgery might be more effective in REM OSA patients.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, School of Medicine, Kyunghee University, Dongdaemun-Gu, Seoul, Korea.
authors.forename: Young Gyu
authors.initials: YG
authors.lastname: Eun
authors.forename: Kee Hwan
authors.initials: KH
authors.lastname: Kwon
authors.forename: Seung Youp
authors.initials: SY
authors.lastname: Shin
authors.forename: Kun Hee
authors.initials: KH
authors.lastname: Lee
authors.forename: Jae Yong
authors.initials: JY
authors.lastname: Byun
authors.forename: Sung Wan
authors.initials: SW
authors.lastname: Kim