The Implications of Local Anesthetic Volume in Adductor Canal Blockade: An Integrative Review

Abstract

<p><strong>Introduction:</strong> Maintaining patient safety is of utmost concern for anesthesia providers. The adductor canal block, a peripheral nerve block identified as a motor-sparing sensory block, may decrease fall risk and associated adverse outcomes seen in total knee arthroplasty patients following femoral nerve block. A large volume of local anesthetic administered in the adductor canal has been questioned due to concern about impaired quadriceps strength if volume extends beyond the adductor canal, causing an unintended femoral nerve block due to spread of local anesthetic into the femoral triangle. </p> <p><strong>Methods:</strong> A review of literature was performed on the following databases: PubMed, CINAHL Complete, and Cochrane Collection. </p> <p><strong>Results:</strong> A 20 ml volume provides approximately 95% of patients with pain control due to complete distal spread within the adductor canal while ensuring statistically insignificant motor blockade compared to femoral nerve block. Doses of 15 ml no longer provided statistically significant strength preservation 24-hours post-block suggesting volumes less than 20 ml should be avoided. Studies indicate that, although 30 ml volumes may cause proximal spread, the effect on quadriceps strength appears significantly less than that of the femoral nerve block. </p> <p><strong>Conclusions:</strong>: Volumes of 20 to 30 ml are appropriate for adductor canal blockade.</p>