title: Should we stop doing blind transversus abdominis plane blocks?
abstract: BACKGROUND
  Any landmark-based regional anaesthetic technique raises two important issues. The first is the accuracy of placement of the needle and thus the local anaesthetic in a 'blind' technique and the second is the potential for damage to adjacent structures. We designed a prospective, blinded study in an adult general surgical population to evaluate with ultrasound the placement of the needle tip and local anaesthetic during transversus abdominis plane (TAP) blocks using the landmark-based 'double-pop' technique.
  
  
  METHODS
  After induction of general anaesthesia, 36 adult patients had a TAP block performed bilaterally using the standard landmark-based technique. Ultrasonography was then used to record the actual needle position and local anaesthetic spread. The anaesthetist performing the block was blinded to the ultrasound images.
  
  
  RESULTS
  Thirty-six adult patients were included in the study, which was terminated early due to what was considered an unacceptably high level of peritoneal needle placements. The needle tip and local anaesthetic spread were in the correct plane in only 17 (23.6%) of the injections. In the remaining 55 (76.4%), the needle was in the subcutaneous tissue 1 (1.38%), external oblique muscle 1 (1.38%), plane between the external and internal oblique muscles 5 (6.94%), internal oblique muscle 26 (36.1%), transversus abdominis muscle 9 (12.5%), and peritoneum 13 (18%).
  
  
  CONCLUSIONS
  We conclude that the needle and local anaesthetic placement using the standard landmark-based approach to the TAP block is inaccurate, and the incidence of peritoneal placement is unacceptably high.
authors.affiliation: Department of Anaesthesia, St Vincent' s University Hospital, Dublin, Ireland. grainne_mcdermott@hotmail.com
authors.forename: G
authors.initials: G
authors.lastname: McDermott
authors.forename: E
authors.initials: E
authors.lastname: Korba
authors.forename: U
authors.initials: U
authors.lastname: Mata
authors.forename: M
authors.initials: M
authors.lastname: Jaigirdar
authors.forename: N
authors.initials: N
authors.lastname: Narayanan
authors.forename: J
authors.initials: J
authors.lastname: Boylan
authors.forename: N
authors.initials: N
authors.lastname: Conlon
mesh_terms: D034861:Abdominal Wall / Q000000981:diagnostic imaging / Q000294:innervation*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000768:Anesthesia, General / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000493:pharmacokinetics; D002983:Clinical Competence; D005260:Female; D005547:Foreign Bodies / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009339:Needles; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D010537:Peritoneum; D011446:Prospective Studies; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local