Cold Saline Is More Effective Than Room Temperature Saline in Inducing Paresthesia During Axillary Block

Abstract

Confirmation of the perivascular position of the needle by the injection of cold saline may be helpful to the perivascular technique, since the elicitation of a paresthesia indicates the correct positioning of the needle. In this prospective, randomized study of 48 patients, we found a 100% incidence of successful block with saline at 8-11 degrees C compared to 75% in a control group with saline at room temperature. The paresthesia induced by cold saline appears to be due to thermic stimulation and not to mechanical nerve compression by the saline entering the axillary space. A more frequent rate of correct positioning of the needle was found in the group with cold saline.

A new brachial plexus block technique in dogs

“…(1994), advocated a maximum of 0.5 mA to induce a motor response because they found that when they needed 0.6 mA they had greater failure rates. The efficacy of regional anesthetic techniques is directly proportional to the ability to administer the local anesthetic solution as near as possible to the nerve to be blocked (Rodriguez et al 1995).…”

Bloqueio do plexo braquial por via axilar com neuroestimulador: verificação da latência e da eficácia

“…O bloqueio do plexo braquial pode ser realizado por diversas vias -interescalênica, supraclavicular -Winnie 7 , Winnie modificada por Vieira 8 e axilar 1 , assim como por diversas técni-cas -parestesia 9 , estimulador de nervo 5 , transarterial 6 ou combinadas e, mais recentemente, parestesia induzida por solução fisiológica fria 10 . A via interescalênica, embora muito usada para cirurgias acima do cotovelo, além de, com freqüência, promover anestesia incompleta do nervo ulnar, não é recomendada para pacientes que não tolerem 25% de redução na função pulmonar, já que a paralisia do frênico ocorre em todos os casos 11 .…”

“…Brachial plexus block can be performed by several routes -interscalenic, supraclavicular -Winnie 7 and Winnie modified by Vieira 8 and axillary 1 , as well as by different techniquesparestesia 9 , nerve stimulator 5 , transarterial 6 , or combined and, more recently, cold saline-induced parestesia 10 . The interscalenic route, although widely used for surgeries above the elbow very often promotes incomplete anesthesia of the ulnar nerve and is not recommended for patients sensitive to 25% reduction in pulmonary function, since phrenic nerve paralysis is present in all cases 11 .…”