title: Increased risk of unintentional dural puncture in night-time obstetric epidural anesthesia.
abstract: OBJECTIVE
  To evaluate the experience of the operator and the time of epidural anesthesia as factors contributing to unintentional dural puncture (UDP).
  
  
  METHODS
  In a prospective analysis of recorded cases of UDP the following variables were recorded: maternal height, weight, and weight gain, type of personnel providing epidural analgesia, number of attempts, and hour of the epidural procedure. Work time was divided into day-time (8 AM to 7 PM) and night-time (7 PM to 8 AM), according to the change of coverage of the delivery suite. Night-time was divided into first (7 PM to midnight) and second parts (midnight to 8 AM). Relative risk was used to compare the incidence of UDP among different work-times.
  
  
  RESULTS
  A total of 1489 consecutive epidural procedures were considered. The incidence of dural puncture was 0.8% (12 cases). The relative risk was higher for night-time than day-time (risk ratio 6.33; 95% confidence interval, 1.39 to 28.80; P = 0.006). Seven cases were caused by three operators with poor expertise, and five by two skilled obstetric anesthesiologists.
  
  
  CONCLUSIONS
  Operator experience and hour of procedure appear to be two important risk factors of UDP The increased risk of UDP in night-work could result from human factors such as fatigue, sleep deprivation or interruption.
authors.affiliation: Département d'Anesthésie-Réanimation, CHU Gaston Doumergue, Nîmes, France.
authors.forename: A G
authors.initials: AG
authors.lastname: Aya
authors.forename: R
authors.initials: R
authors.lastname: Mangin
authors.forename: C
authors.initials: C
authors.lastname: Robert
authors.forename: J M
authors.initials: JM
authors.lastname: Ferrer
authors.forename: J J
authors.initials: JJ
authors.lastname: Eledjam
mesh_terms: D000328:Adult; D000767:Anesthesia, Epidural / Q000009:adverse effects*; D000773:Anesthesia, Obstetrical / Q000009:adverse effects*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D012306:Risk; D013129:Spinal Puncture; D013997:Time Factors