[Axillary brachial plexus anesthesia. How many nerve stimulation responses do we look for?].
OBJECTIVE
To determine whether axillary block with nerve stimulation involving the location of four motor responses is more effective than other techniques using fewer locations, without increasing patient discomfort or the rate of complications.


METHODS
Prospective, randomized single blind study enrolling 100 patients undergoing orthopedic surgery under axillary block with nerve stimulation. Patients were randomly assigned to five groups of 20 patients: in group A, 4 motor responses were located; in group B three were located (musculocutaneous nerve and two more); in group C two responses, the musculocutaneous nerve and one more; in group D two non-musculocutaneous responses; and in group E only one non-musculocutaneous response was located (medial, cubital or radial). We used 40 ml of 1% mepivacaine. Data collected were location of responses, duration of blockade, adverse events occurring during the technique; level of motor and sensory block; tolerance to the tourniquet; level of patient discomfort; and presence of complications.


RESULTS
A full sensory block was achieved for 100% in group A, 90% in group B, 60% in group C, 75% in group D and 40% in group E. Patient discomfort was similar in all groups. One patient continued to suffer postoperative neurologic dysfunction three months after the block.


CONCLUSIONS
Locating 4 responses gives the greatest degree of assurance of obtaining full sensory block without increasing patient discomfort or rate of complications.
Serradell Catalán
A
A
Médico adjunto.Servicio de Anestesiología y Reanimación. Hospital de la Creu Roja. Barcelona. alecaster@terra.es
Moncho Rodríguez
J M
JM
Santos Carnés
J A
JA
Herrero Carbó
R
R
Villanueva Ferrer
J A
JA
Masdeu Castellví
J
J
D001365:Axilla; D001917:Brachial Plexus / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D016037:Single-Blind Method