Distribution of bupivacaine hydrochloride after sciatic and femoral nerve blocks in cats: A magnetic resonance imaging study

Author(s)

Evangelista, Marina C. ^[1] ; de lassalle, Julie ^[2] ; Chevrier, Christine ^[2] ; Carmel, Eric N. ^[2] ; Fantoni, Denise T. ^[1] ; Steagall, Paulo V. M. ^[2]

Affiliation

^[1] Univ Sao Paulo, Fac Vet Med & Anim Sci, Dept Surg, Sao Paulo, SP - Brazil

^[2] Univ Montreal, Fac Med Vet, Dept Sci Clin, 3200 Rue Sicotte, St Hyacinthe, PQ J2S 2M2 - Canada

• Document type: Journal article
• Source: Research in Veterinary Science; v. 115, p. 61-65, DEC 2017.
• Web of Science Citations: 3

Abstract

The objective of this study was to evaluate the distribution of bupivacaine hydrochloride using magnetic resonance imaging (MRI) after electrical nerve stimulator (ENS)-guided sciatic (ScN) and femoral (FN) nerve blocks in cats. Six adult cats (body weight 4.8 +/- 0.6 kg) were anesthetized with acepromazine-buprenorphine-propofol-isoflurane. Transverse and sagittal plan sequences of pelvic limbs were obtained using a high-field magnet (1.5 T). Afterwards, the ScN and FN blocks (one block per limb) were performed using 0.1 mL/kg of bupivacaine 0.5% per site and the MRI sequence was repeated after each block. The injection was considered successful when bupivacaine was in contact with the nerve. Injectate location and complications were recorded. The length (mm) of contact (spread) between bupivacaine and nerves was measured and classified as fair (<15 mm) or adequate (>= 15 mm). Five out of six ScN injections were successful; of these, four had adequate spread over the nerve {[}26 (13-39) mm]. All FN injections were successful, but in one case bupivacaine was administered over the motor branch of FN, distally to the bifurcation between the femoral and saphenous nerve. It was not possible to measure neither the length of contact between bupivacaine and FN nor to identify iatrogenic trauma caused by the injections. MRI can be used for the evaluation of bupivacaine distribution, but not complications, following ENS-guided ScN and FN blocks in cats. Despite most of the injections were considered successful, individual variability regarding the injectate location may explain differences in efficacy in the clinical setting. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 15/01712-0 - Assessment of bupivacaine alone or in combination with dexmedetomidine or buprenorphine for sciatic and femoral nerve blocks in cats
• Grantee: Marina Cayetano Evangelista
• Support Opportunities: Scholarships in Brazil - Master