title: Acoustic puncture assist device: A novel technique to identify the epidural space.
abstract: BACKGROUND
  Acoustic puncture assist device (APAD) is designed to detect and signal the loss of resistance during the epidural procedure. We aimed to evaluate this device in terms of successful identification of the epidural space and the incidence of accidental dural puncture.
  
  
  METHODS
  Following Institutional Review Board approval and written informed consent obtained from all patients, 200 adult patients (107 males) American Society of Anesthesiologists I-III who underwent lower limb orthopedic surgery under lumbar epidural anesthesia using APAD were enrolled in the study. APAD system was connected to the epidural needle using normal saline prefilled extension tube. Numbers of successful epidural attempts and accidental dural tap were documented.
  
  
  RESULTS
  The mean values of the depth of epidural space and the time to perform epidural puncture were 5.8 ± 1.0 cm and 3.3 ± 1.4 min, respectively. In 63% of patients, epidural puncture was successful from the first attempt and in 1% it was successful from the fourth attempt. Epidural anesthesia by APAD was successful in 198 cases (99 %). Dural tap occurred in 2 cases (1%).
  
  
  CONCLUSIONS
  Using APAD, the success of identifying the epidural space was high and reliable.
authors.affiliation: Consultant Anesthesiologist, Security Forces Hospital, King Saud bin Abdulaziz University for Health Science, Riyadh, Saudi Arabia.
authors.forename: M A
authors.initials: MA
authors.lastname: Al-Mokaddam
authors.affiliation: Consultant Anesthesiologist, King Saud bin Abdulaziz University for Health Science, Riyadh, Saudi Arabia.
authors.forename: M K
authors.initials: MK
authors.lastname: Al-Harbi
authors.affiliation: Consultant Anesthesiologist, Security Forces Hospital, King Saud bin Abdulaziz University for Health Science, Riyadh, Saudi Arabia.
authors.forename: S T
authors.initials: ST
authors.lastname: El-Jandali
authors.affiliation: Department of Anesthesia, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: T A
authors.initials: TA
authors.lastname: Al-Zahrani
keywords: Acoustic puncture assist device; anesthesia; epidural analgesia