title: The Effect of patient warming during Caesarean delivery on maternal and neonatal outcomes: a meta-analysis.
abstract: BACKGROUND
  Perioperative warming is recommended for surgery under anaesthesia, however its role during Caesarean delivery remains unclear. This meta-analysis aimed to determine the efficacy of active warming on outcomes after elective Caesarean delivery.
  
  
  METHODS
  We searched databases for randomized controlled trials utilizing forced air warming or warmed fluid within 30 min of neuraxial anaesthesia placement. Primary outcome was maximum temperature change. Secondary outcomes included maternal (end of surgery temperature, shivering, thermal comfort, hypothermia) and neonatal (temperature, umbilical cord pH and Apgar scores) outcomes. Standardized mean difference/mean difference/risk ratio (SMD/MD/RR) and 95% confidence interval (CI) were calculated using random effects modelling (CMA, version 2, 2005).
  
  
  RESULTS
  13 studies met our criteria and 789 patients (416 warmed and 373 controls) were analysed for the primary outcome. Warming reduced temperature change (SMD -1.27°C [-1.86, -0.69]; P=0.00002); resulted in higher end of surgery temperatures (MD 0.43 °C [0.27, 0.59]; P<0.00001); was associated with less shivering (RR 0.58 [0.43, 0.79]; P=0.0004); improved thermal comfort (SMD 0.90 [0.36, 1.45]; P=0.001), and decreased hypothermia (RR 0.66 [0.50, 0.87]; P=0.003). Umbilical artery pH was higher in the warmed group (MD 0.02 [0, 0.05]; P=0.04). Egger's test (P=0.001) and contour-enhanced funnel plot suggest a risk of publication bias for the primary outcome of temperature change.
  
  
  CONCLUSIONS
  Active warming for elective Caesarean delivery decreases perioperative temperature reduction and the incidence of hypothermia and shivering. These findings suggest that forced air warming or warmed fluid should be used for elective Caesarean delivery.
authors.affiliation: Department of Anaesthesia, University College London Hospital, London, UK p.sultan@doctors.org.uk.
authors.forename: P
authors.initials: P
authors.lastname: Sultan
authors.affiliation: Department of Anesthesia, Duke University School of Medicine, Durham, NC, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Habib
authors.affiliation: Pacific Alliance Medical Center, Los Angeles, CA, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Department of Anesthesia, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: B
authors.initials: B
authors.lastname: Carvalho
mesh_terms: D001831:Body Temperature; D002585:Cesarean Section / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D007035:Hypothermia / Q000209:etiology / Q000517:prevention & control*; D019990:Perioperative Care / Q000379:methods*; D011247:Pregnancy; D017694:Rewarming / Q000379:methods*; D012768:Shivering
keywords: anaesthesia; body temperature, hypothermia; caesarean section; obstetric; temperature