Comparison of two volumes for sciatic perineural injection using 1% methylene blue in rabbit cadavers

D.R. Jané,B.S. Gusmão,B.B. Oliveira,B.P. Floriano,N.P. Reis Filho,T.A. Trein,L.P. Custódio

doi:10.1590/1678-4162-12302

Abstract

ABSTRACT The purpose of this study was to assess the efficacy of a blind technique for sciatic and femoral nerve block in rabbit cadavers by evaluating the spread of 1% methylene blue at two different volumes. Nine recently euthanized rabbits weighing 2.5(0.3kg were used. The sciatic (SN) and femoral (FN) nerves of each limb were randomly assigned for injection with 1% methylene blue at 0.2mL/kg (G0.2) or 0.3mL/kg (G0.3). Nerves were dissected and measured for depth and extension of staining (cm). Mean comparisons were performed using paired t test. The relation between volume and nerve staining ( 2cm was assessed using chi-square test. The mean depth of SN was 1.9±0.2 and 1.6±0.3cm and staining 1.9±1.4 and 2.0±1.2cm, respectively in G0.2 and G0.3. No relation was found between depth and dye spread and there was no association between nerve staining ( 2.0cm and volume of solution. The FN failed to be stained in all subjects. In conclusion, SN injection can be successfully performed without guidance in rabbits. The lower volume (0.2mL/kg) is recommended to avoid systemic toxicity.

Highlights

O objetivo deste estudo foi avaliar a eficácia de uma técnica para bloqueio às cegas dos nervos isquiático e femoral em cadáveres de coelhos, por meio da avaliação da dispersão de azul de metileno 1% em dois volumes distintos
Lagomorph anesthesia is gaining companion animals has increased due to the attention as these species become more present in interest for smaller and quieter pets, which require less maintenance and space compared to the small animal clinical care practice
No correlation was found between sciatic nerve depth and dye spread in any group and there was no statistically significant association between the 2-cm extension of the dye and the volume of solution in each group (P>0.05)

Summary

Introduction

O objetivo deste estudo foi avaliar a eficácia de uma técnica para bloqueio às cegas dos nervos isquiático e femoral em cadáveres de coelhos, por meio da avaliação da dispersão de azul de metileno 1% em dois volumes distintos. One study described the use of a peripheral nerve stimulator for sciatic nerve staining in rabbit cadavers with low volumes of solution (Sung, 2004). The common fibular nerves supply the abductor cruralis caudalis muscle before giving rise to the superficial and deep fibular nerves. These nerves extend distally to the tarsal flexors and digit extensors at the dorsal aspect of the foot. Few studies report the use of peripheral nerve location and ultrasound guidance for sciatic nerve block in dogs (Shilo et al, 2010; Costa-Farré et al, 2011; Echeverry et al, 2012)

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