Sciatic nerve block via posterior Labat approach is more efficient than lateral popliteal approach using a double-injection technique: a prospective, randomized comparison.
BACKGROUND
For peripheral nerve blockade, the double-injection technique proved to be superior to a single injection in previous investigations. The current study was designed to compare onset time and efficacy of two different double-injection approaches for sciatic nerve block with 0.75% ropivacaine.


METHODS
A total of 50 patients undergoing foot surgery were randomly assigned to receive sciatic nerve blockade by means of the classic (Labat) posterior approach (n = 25) or a lateral popliteal approach (n = 25). All blocks were performed with the use of a nerve stimulator, and both major components of the sciatic nerve (tibial and common peroneal nerves) received separately 10 ml ropivacaine, 0.75%. Success rate was defined as a complete sensory and motor block associated with pain-free surgery.


RESULTS
A greater success rate was observed in the classic group (96%) as compared with the popliteal group (68%; P < 0.05). A general anesthetic became necessary in six patients (24%) with the lateral popliteal approach and none with the classic approach (P < 0.05). The onset of complete sensory and motor blockade was significantly faster in the classic group (12 +/- 6 min) as compared with the popliteal group (26 +/- 10 min; P < 0.05).


CONCLUSIONS
A double injection with a relatively low volume of 0.75% ropivacaine generated a higher success rate and a shorter onset time of sensory and motor blockade after the classic Labat approach than after a lateral popliteal approach.
Taboada
Manuel
M
University of Santiago de Compostela, Department of Anesthesiology, Hospital Clínico Universitario de Santiago, Santiago de Compostela, Spain. manutabo@mixmail.com
Rodríguez
Jaime
J
ALvarez
Julián
J
Cortés
Joaquín
J
Gude
Francisco
F
Atanassoff
Peter G
PG
D000293:Adolescent; D000328:Adult; D000368:Aged; D000577:Amides; D000779:Anesthetics, Local; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000187:drug effects; D009407:Nerve Block / Q000379:methods*; D010543:Peroneal Nerve / Q000502:physiology; D011446:Prospective Studies; D000077212:Ropivacaine; D012584:Sciatic Nerve / Q000033:anatomy & histology; D016019:Survival Analysis; D013979:Tibial Nerve / Q000502:physiology
D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine