title: The influence of timing on the effectiveness of epidural blood patches in parturients.
abstract: BACKGROUND
  Postdural puncture headache is common in parturients following lumbar puncture. If headache is severe and persistent, an epidural blood patch is recommended. In this paper we reviewed the efficacy of epidural blood patches over a 13-year period at two hospitals in Finland with a particular emphasis on its timing.
  
  
  METHODS
  The hospitals' databases were searched to identify parturients who underwent an epidural blood patch from March 1998 to June 2011. Parturients' records were reviewed to establish the characteristics and associated symptoms of headache and the effectiveness of the epidural blood patch.
  
  
  RESULTS
  A total of 129 parturients received 151 epidural blood patches. These followed spinal (n = 49), epidural (n = 47) or combined spinal-epidural blocks (n = 33). The success rate of the first procedure was 89%, with permanent relief in 76%. The first procedure provided permanent relief of postdural puncture headache for 86% of 78 patients having the procedure after 48 h, compared to 65% of 37 patients when it was performed between 24 and 48 h, and 50% of 14 patients with the procedure within the first 24 h after dural puncture (P = 0.003). A second procedure was performed for 22 parturients due to incomplete relief (n = 5) or recurrent symptoms (n = 17); all had complete resolution of symptoms.
  
  
  CONCLUSIONS
  Epidural blood patch performed later than 48 h following lumbar puncture or accidental dural puncture is effective in parturients with postdural puncture symptoms. The recurrence rate of symptoms after an initially successful epidural blood patch is high, and therefore patients should be provided with counselling and contact information.
authors.affiliation: Anaesthesia and Operative Services, Kuopio University Hospital, School of Medicine, University of Eastern Finland, Kuopio, Finland. Electronic address: merja.kokki@kuh.fi.
authors.forename: M
authors.initials: M
authors.lastname: Kokki
authors.forename: S
authors.initials: S
authors.lastname: Sjövall
authors.forename: M
authors.initials: M
authors.lastname: Keinänen
authors.forename: H
authors.initials: H
authors.lastname: Kokki
mesh_terms: D000293:Adolescent; D000328:Adult; D017217:Blood Patch, Epidural; D005260:Female; D006801:Humans; D008875:Middle Aged; D036801:Parturition; D051299:Post-Dural Puncture Headache / Q000628:therapy*; D011247:Pregnancy; D012189:Retrospective Studies; D013129:Spinal Puncture / Q000009:adverse effects; D013997:Time Factors
keywords: Complications; Epidural blood patch; Neuraxial analgesia; Parturients; Postdural puncture headache