title: Effective local anaesthetic volumes for sciatic nerve blockade: a clinical evaluation of the ED99.
abstract: Previous results in volunteers have indicated the effective dose in 99% of subjects (ED99 ) of local anaesthetic volume to be 0.10 ml.mm(-2) of cross-sectional nerve area for sciatic nerve blockade. The objective of this prospective, randomised, double-blind study was to investigate the ED99 of local anaesthetic for ultrasound-guided sciatic nerve blockade in patients undergoing foot surgery, according to Dixon's up-and-down method and probit analysis. A starting volume of 0.20 ml local anaesthetic per mm(2) cross-sectional nerve area was used. If surgical anaesthesia was judged to be adequate, the volume of local anaesthetic for the next case was reduced by 0.02 ml.mm(-2), until the first block failed. Thereafter, the volume of local anaesthetic was increased by 0.02 ml.mm(-2). The ED99 volume of local anaesthetic for ultrasound-guided sciatic nerve blockade was calculated to be 0.15 ml.mm(-2) cross-sectional nerve area, which is higher than the previously evaluated ED99 volume in volunteers.
authors: Department of Anaesthesiology and General Intensive Care Medicine, Medical University of Vienna, Vienna, Austria.
authors: M
authors: M
authors: Keplinger
authors: P
authors: P
authors: Marhofer
authors: D
authors: D
authors: Marhofer
authors: K
authors: K
authors: Schroegendorfer
authors: W
authors: W
authors: Haslik
authors: M
authors: M
authors: Zeitlinger
authors: C V
authors: CV
authors: Mayer
authors: S C
authors: SC
authors: Kettner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000577:Amides / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005528:Foot / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009407:Nerve Block / Q000379:methods*; D010147:Pain Measurement / Q000187:drug effects; D011446:Prospective Studies; D000077212:Ropivacaine; D012584:Sciatic Nerve / Q000000981:diagnostic imaging; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine