title: The relationship between body mass index and post-dural puncture headache in obstetric patients.
abstract: BACKGROUND
  Difficult epidural insertion and accidental dural puncture are more likely in the obese pregnant population. Low-level evidence suggests that the risk of post-dural puncture headache declines as body mass index increases.
  
  
  METHODS
  We retrospectively reviewed prospective data on 18315 obstetric epidural and combined spinal-epidural insertions, identifying 125 (0.7%) accidental dural punctures or post-dural puncture headaches between 2007 and 2012. The audit record and patient medical record were examined to determine patient body mass index, headache characteristics and use of a therapeutic epidural blood patch. Women were classified into two groups: non-obese (body mass index <30 kg/m2, Group <30) or obese (body mass index ⩾30 kg/m2, Group ⩾30). Statistical analysis was by chi-square or Fisher exact tests, with P<0.05 considered significant.
  
  
  RESULTS
  Compared to Group <30 (n=65), women in Group ⩾30 (n=60) did not significantly differ in the incidence of post-dural puncture headache (82% vs. 80%, P=0.83); its intensity (severe 36% vs. 23%, P=0.34); or the need for epidural blood patch (57% vs. 54%, P=0.81). Groups also did not differ significantly when confining analysis to those who had a witnessed accidental dural puncture (n=93) or to women with a body mass index >40 kg/m2 (n=10) vs. Group <30.
  
  
  CONCLUSIONS
  This retrospective study found no evidence that women of higher body mass index are less likely to develop a post-dural puncture headache or that the characteristics of the headache and use of epidural blood patch were different.
authors.affiliation: Department of Anaesthesia and Pain Medicine, King Edward Memorial Hospital for Women, Perth, WA, Australia. Electronic address: michaelmiumiu@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Miu
authors.affiliation: Department of Anaesthesia and Pain Medicine, King Edward Memorial Hospital for Women, Perth, WA, Australia; Pharmacology, Pharmacy and Anaesthesiology Unit, School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Paech
authors.affiliation: Women and Infants Research Foundation, Perth, WA, Australia.
authors.forename: E
authors.initials: E
authors.lastname: Nathan
mesh_terms: D000328:Adult; D000367:Age Factors; D000767:Anesthesia, Epidural; D000773:Anesthesia, Obstetrical / Q000009:adverse effects*; D000775:Anesthesia, Spinal; D000784:Aortic Dissection; D017217:Blood Patch, Epidural; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D010147:Pain Measurement; D051299:Post-Dural Puncture Headache / Q000453:epidemiology* / Q000628:therapy; D011247:Pregnancy; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome; D014904:Western Australia / Q000453:epidemiology
keywords: Epidural blood patch; Headache; Obesity; Post-dural puncture