title: Carbon dioxide versus normal saline as distension medium for diagnostic hysteroscopy: a systematic review and meta-analysis of randomized controlled trials.
abstract: OBJECTIVE
  To appraise critically the published randomized controlled trials (RCTs) comparing carbon dioxide (CO2) with normal saline (NS) as distension medium for diagnostic hysteroscopy.
  
  
  METHODS
  Systematic review and meta-analysis of RCTs.
  
  
  METHODS
  Outpatient and inpatient hysteroscopy clinics.
  
  
  METHODS
  Women undergoing diagnostic hysteroscopy.
  CO2 or NS as distension medium for diagnostic hysteroscopy.
  
  
  METHODS
  Procedural and shoulder pain, side effects, satisfaction, quality of view, duration of procedure.
  
  
  RESULTS
  Ten RCTs involving 1,839 women (905 in the CO2 group, 934 in the NS group) were systematically analyzed. There was significant heterogeneity among the included trials. Compared with NS, CO2 was associated with greater procedural pain, more occurrences of shoulder pain and side effects, less satisfaction, less quality of view, and greater duration of procedure.
  
  
  CONCLUSIONS
  A meta-analysis from the available moderate quality trials suggests that NS might be superior to CO2 for use in diagnostic hysteroscopy. Owing to problems of clinical diversity, statistical heterogeneity, and risk of bias, it is clear that additional pragmatic multicenter RCTs are needed to corroborate these findings before firm evidence-based guidelines can be given.
authors.affiliation: Department of Obstetrics and Gynaecology, St. Mary's Hospital, Manchester, United Kingdom. Electronic address: lcraciunas@doctors.org.uk.
authors.forename: Laurentiu
authors.initials: L
authors.lastname: Craciunas
authors.forename: Muhammad Shafique
authors.initials: MS
authors.lastname: Sajid
authors.forename: Rosemary
authors.initials: R
authors.lastname: Howell
mesh_terms: D002245:Carbon Dioxide; D015897:Comorbidity; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D015907:Hysteroscopy / Q000379:methods / Q000706:statistics & numerical data*; D015994:Incidence; D010146:Pain / Q000453:epidemiology*; D017060:Patient Satisfaction; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012965:Sodium Chloride; D014591:Uterine Diseases / Q000453:epidemiology* / Q000473:pathology*
chemical_list: D002245:Carbon Dioxide; D012965:Sodium Chloride
keywords: Diagnostic hysteroscopy; carbon dioxide; distension medium; normal saline