title: Deliberate hypotension with propofol under anaesthesia for functional endoscopic sinus surgery (FESS).
abstract: BACKGROUND
  Functional endoscopic sinus surgery (FESS) is a minimally invasive technique that is used to treat chronic sinusitis. Small bleeding areas can reduce operative visibility and result in destruction of surrounding structures. Deliberate hypotension (lowering the mean arterial blood pressure to between 50 and 65 mm Hg in normotensive patients) using a range of pharmacological agents during general anaesthesia reduces blood loss in many operations.
  
  
  OBJECTIVE
  We aimed to compare the use of the intravenous anaesthetic agent propofol versus other techniques for deliberate hypotension during FESS with regard to blood loss and operative conditions.
  
  
  METHODS
  We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE (1950 to April 2012), EMBASE (1980 to April 2012), LILACS (1982 to April 2012) and ISI Web of Science (1946 to April 2012). We also searched the reference lists of relevant articles and conference proceedings and contacted the authors of included trials.
  
  
  METHODS
  We sought all randomized controlled trials (RCTs) conducted to compare propofol with other techniques. Our primary outcome was total blood loss (TBL). Other outcomes included surgical field quality, operation time, mortality within 24 hour, complications and failure to reach target blood pressure.
  
  
  METHODS
  Two review authors independently extracted details of trial methodology and outcome data from reports of all trials considered eligible for inclusion. All analyses were made on an intention-to-treat basis where possible. When I(2) was < 40% and the P value from the Chi(2) test was > 0.10, we pooled data by using the fixed-effect model. Otherwise we pooled data by using the random-effects model.
  
  
  RESULTS
  We included four studies with 278 participants in the review. Deliberate hypotension with propofol did not decrease TBL (millilitres) when compared with inhalation anaesthetics in either children or adults. Propofol improved the quality of the surgical field by less than one category on a scale from 0 (no bleeding) to 5 (severe bleeding) (mean difference (MD) 0.64 better with propofol, 95% confidence interval (CI) 0.37 to 0.91 better), but no difference in operation time was reported. Failure to lower blood pressure to target was less common in the propofol group (relative risk of failure with propofol (RR) 0.24, 95% CI 0.09 to 0.66).
  
  
  CONCLUSIONS
  Using propofol to achieve deliberate hypotension may improve the surgical field, but the effect is small. Deliberate hypotension with propofol did not decrease TBL and operation time. RCTs with good quality methodology and large sample size are required to investigate the effectiveness of deliberate hypotension with propofol for FESS.
authors.affiliation: Department of Anaesthesiology, Faculty ofMedicine, Khon Kaen University, Khon Kaen, Thailand. suhattayab@hotmail.com
authors.forename: Suhattaya
authors.initials: S
authors.lastname: Boonmak
authors.forename: Polpun
authors.initials: P
authors.lastname: Boonmak
authors.forename: Malinee
authors.initials: M
authors.lastname: Laopaiboon
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D002648:Child; D004724:Endoscopy / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D007023:Hypotension, Controlled / Q000379:methods*; D061646:Operative Time; D010256:Paranasal Sinuses / Q000601:surgery*; D015742:Propofol; D016032:Randomized Controlled Trials as Topic
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol