Comparison of lidocaine, levobupivacaine or ropivacaine for distal paravertebral thoracolumbar anesthesia in ewes

摘要

Objective To compare the effects of lidocaine, levobupivacaine, or ropivacaine on the onset time and duration of anesthesia of the flank of ewes, using the distal paravertebral thoracolumbar approach.Study design Randomized experimental study.Animals Twenty-six healthy mixed-breed ewes (46 ± 3.1 kg).Methods Thoracolumbar paravertebral nerve blocks were performed using the distal approach in sheep for ruminal tistulation. The 13th thoracic (T13), first lumbar (LI) and second lumbar (L2) nerves were infiltrated with 2% lidocaine (group GLI, n = 9), 0.5% levobupivacaine (group GLE, n = 8) or 0.5% ropivacaine (group GRO, n = 9); 1.5 mL on the dorsal branch and 2.5 mL on the ventral branch, total volume of 12 mL per ewe. Anesthesia onset time and duration were assessed by application of superficial anddeep pin pricks, and skin clamping with a hemostat. Heart rate, respiratory rate, rectal temperature and systemic arterial pressures were recorded prior to nerve block (TO), after the anesthetic agent injection and onset time (Tl) and predetermined timepoints during the surgical procedure (T2-T6).