title: Variability in determination of point of needle insertion in peripheral nerve blocks: a comparison of experienced and inexperienced anaesthetists.
abstract: Accurate identification of surface landmarks is essential for the successful performance of peripheral nerve blocks. The variability between experienced and inexperienced practitioners in identifying anatomical landmarks has not been studied previously. Anaesthetists were asked to identify the point of needle insertion for posterior lumbar plexus and sciatic nerve blocks on a volunteer using a standard textbook description. The chosen point for needle insertion was described in terms of X and Y co-ordinates, measured in millimetres, from a zero reference point marked on a volunteer's back. Fifteen experienced and 22 inexperienced anaesthetists took part in the study. The lumbar plexus block mean [range] values for the X, Y co-ordinates were 80 [62-108], 66 [46-86] and 92 [49-150], 62 [0-131] in the experienced and inexperienced groups, respectively. The sciatic nerve block X, Y co-ordinates were 77 [62-99], 70 [49-89] and 68 [29-116], 62 [26-93] in the experienced and inexperienced groups, respectively. The variance for the point of needle insertion was significantly greater in the inexperienced group (p <0.01) for both the lumbar plexus and sciatic nerve blocks. We conclude that with increasing experience, there is decreased variability in determining the point of needle insertion using anatomical landmarks.
authors.affiliation: Department of Anaesthesiology, Duke University Medical Centre, North Hospital, Durham, NC 27710, USA. grant021@mc.duke.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Grant
authors.forename: D S
authors.initials: DS
authors.lastname: Breslin
authors.forename: D B
authors.initials: DB
authors.lastname: MacLeod
authors.forename: D
authors.initials: D
authors.lastname: Demeyts
authors.forename: G
authors.initials: G
authors.lastname: Martin
authors.forename: F
authors.initials: F
authors.lastname: D'Ercole
authors.forename: D
authors.initials: D
authors.lastname: Hardman
mesh_terms: D000776:Anesthesiology / Q000193:education / Q000592:standards*; D002983:Clinical Competence; D004503:Education, Medical, Graduate; D006801:Humans; D008160:Lumbosacral Plexus; D008297:Male; D009339:Needles; D009407:Nerve Block / Q000592:standards*; D015203:Reproducibility of Results; D012584:Sciatic Nerve