Comparative study of different concentrations of prilocaine and ropivacaine for intraoperative axillary brachial plexus block.
OBJECTIVE
To compare the anaesthetic characteristics in terms of onset and offset times of the sensory and motor blocks of prilocaine 1% and ropivacaine 0.75% alone and in different combinations when used for brachial plexus anaesthesia in axillary perivascular blocks.


METHODS
After informed consent 96 ASA I-III patients undergoing forearm or hand surgery participated in this prospective, randomized, double-blind study. Patients received either prilocaine 1% 40 mL (G1), prilocaine 1% 30 mL and ropivacaine 0.75% 10 mL (G2), prilocaine 1% 20 mL and ropivacaine 0.75% 20 mL (G3) or ropivacaine 0.75% 40 mL (G4) for axillary perivascular brachial plexus anaesthesia. Onset and duration of sensory and motor blocks in the distribution of the musculocutaneous, radial, median and ulnar nerves were assessed.


RESULTS
The onset time of the sensory and motor blocks of the whole brachial plexus differed only between patients in G4 with ropivacaine 0.75% 40 mL demonstrating a later motor onset in comparison to all other groups and a later sensory onset in comparison to G1 and G2 (P < 0.01). The addition of ropivacaine resulted in longer offset times of the sensory and motor blocks. The median offset time of the motor block was 179.5 min in G1, 262 min in G2, 389.5 min in G3 and 745 min in G4 (P < 0.01). The median offset time of the sensory block was 163.5 min in G1, 277 min in G2, 383.5 min in G3 and 784 min in G4 (P < 0.01). There was no difference in onset and offset times between sensory and motor blocks within the groups.


CONCLUSIONS
For axillary perivascular brachial plexus block prilocaine 1% alone and in combination with ropivacaine 0.75% was similar in terms of onset of sensory and motor blocks but different in duration of sensory and motor blocks without a differential sensory and motor offset.
Freitag
M
M
Department of Anaesthesiology, University Medical Centre Hamburg, Hamburg, Germany. freitag@uke.uni-hamburg.de
Zbieranek
K
K
Gottschalk
A
A
Bubenheim
M
M
Winter
R
R
Tuszynski
S
S
Standl
T G
TG
D000293:Adolescent; D000328:Adult; D000368:Aged; D000577:Amides / Q000627:therapeutic use*; D019162:Anesthetics, Combined / Q000627:therapeutic use; D000779:Anesthetics, Local / Q000627:therapeutic use*; D001917:Brachial Plexus / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005542:Forearm / Q000601:surgery; D006225:Hand / Q000601:surgery; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D011318:Prilocaine / Q000627:therapeutic use*; D011446:Prospective Studies; D000077212:Ropivacaine; D018709:Statistics, Nonparametric; D013997:Time Factors
D000577:Amides; D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D011318:Prilocaine; D000077212:Ropivacaine