title: Effects of tonsillectomy on sleep study parameters in adult patients with obstructive sleep apnea--a prospective study.
abstract: OBJECTIVE
  The objective of this study is to evaluate the efficacy of tonsillectomy in reduction of respiratory disturbance index (RDI) and other sleep study parameters in patients with obstructive sleep apnea (OSA).
  
  
  METHODS
  This study involves 34 adults with OSA and Friedman grade 3 or 4 tonsils. All 34 patients were treated with tonsillectomy, as the only surgical treatment for OSA from 2007 to 2011. Pre- and postoperative polysomnography were performed in all these patients.
  
  
  RESULTS
  Prior to tonsillectomy, 21 patients had severe, 9 had moderate, and 4 had mild OSA. Surgical response rate (defined as 50% or more reduction in apnea-hypopnea index (AHI) and a postoperative AHI of less than 20) was 71.4% among patients with severe OSA, 77.7% among patients with moderate, and 75% among patients with mild. Among all the 34 patients, there was a reduction of 24.6 (p = 0.000) in the RDI postoperatively. In our sub-analysis, we arbitrarily divided the patients into three groups: patients with RDI less than 30, patients with RDI between 30 and 60, and patients with RDI above 60. It showed that, in the group with RDI >60, an average reduction of RDI by 57.6 (p = 0.000) was achieved and was the greatest reduction in RDI.
  
  
  CONCLUSIONS
  Tonsillectomy alone may be considered as an effective first line surgical procedure in the treatment of OSA in selected patients. Patients with Friedman grade 3 or 4 tonsils may be considered for tonsillectomy as the initial surgical procedure, reserving other upper airway procedures at a later stage if necessary.
authors.affiliation: Department of Otolaryngology, Changi General Hospital, 2 Simei Street 3, Singapore, 529889, Singapore, leonard.tan@mohh.com.sg.
authors.forename: Leonard Toh Hui
authors.initials: LT
authors.lastname: Tan
authors.forename: Alvin Kah Leong
authors.initials: AK
authors.lastname: Tan
authors.forename: Pon Poh
authors.initials: PP
authors.lastname: Hsu
authors.forename: Ian Chi Yuan
authors.initials: IC
authors.lastname: Loh
authors.forename: Heng Wai
authors.initials: HW
authors.lastname: Yuen
authors.forename: Yiong Huak
authors.initials: YH
authors.lastname: Chan
authors.forename: Peter Kuo Sun
authors.initials: PK
authors.lastname: Lu
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography; D011446:Prospective Studies; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000601:surgery*; D014068:Tonsillectomy; D016896:Treatment Outcome