ABSTRACT
OBJECTIVES: The aim of this study was to evaluate the effects of hyaluronidase added to levobupivacaine in lumbosacral epidural blockade in dogs. METHODS: Six adult mixed breed dogs (two males and four females) weighing 7 to 14 kg (10.5 ±1.5 kg) and aged two to five years were used. Each dog received both treatments in random order: levobupivacaine alone (LBA; n=6) or levobupivacaine plus hyaluronidase (LBH; n=6) administered in the lumbosacral epidural space. Systemic effects, spread and duration of anaesthesia and motor block were determined before treatment and at predetermined intervals. RESULTS: The duration of local anaesthesia was 90 ±10 minutes (P=0.001) for LBH treatment and 150 ±15 minutes for LBA treatment. In the LBH treatment, anaesthesia reached the T12 to T13 dermatome and in the LBA treatment it reached the T11 to T12 dermatome in all animals in 5 and 15 minutes, respectively. Complete motor blockade was 75 ±12 minutes (P=0.01) and 120 ±15 minutes for LBH and LBA treatments, respectively. CLINICAL SIGNIFICANCE: Hyaluronidase added to levobupivacaine significantly shortens the duration of epidural anaesthesia with the same dermatome spread into the epidural space in dogs.
Subject(s)
Anesthesia, Epidural/veterinary , Dogs/physiology , Hyaluronoglucosaminidase/pharmacology , Anesthesia, Epidural/methods , Anesthetics, Local/administration & dosage , Anesthetics, Local/pharmacology , Animals , Bupivacaine/administration & dosage , Bupivacaine/analogs & derivatives , Bupivacaine/antagonists & inhibitors , Bupivacaine/pharmacology , Drug Interactions , Female , Hyaluronoglucosaminidase/administration & dosage , Levobupivacaine , Male , Random Allocation , Time FactorsABSTRACT
OBJECTIVE: To determine the anaesthetic and systemic effects of dorsolumbar epidural anaesthesia using non-stylet multiport catheters via the caudal approach to administer hypertonic 5% lignocaine (HL) or hypertonic 0.5% bupivacaine (HB) to the flank in standing cattle. MATERIALS AND METHODS: Six healthy adult cattle weighing 310-455 kg received 0.2 mg/kg HL or 0.025 mg/kg of HB; control animals received 0.9% saline solution. All drugs were injected into the dorsolumbar epidural space via a caudal approach through a non-stylet multiport catheter. Each animal received each treatment at random. Evaluations of anaesthesia, ataxia, heart rate, arterial pressures, respiratory rate and rectal temperature were obtained at 0 (basal), 5, 10, 15, 30, 45, 60, 75, and 90 min after epidural injection and then at 30-min intervals until loss of anaesthesia. All animals received a standard noxious stimulus and a 4-point scale was used to score the response. A second scale was used to score ataxia. RESULTS: The duration of anaesthesia in the upper and lower flanks in cattle was 68 +/- 12 and 110 +/- 15 min (mean +/- SD) after dorsolumbar epidural HL or HB, respectively. Both hypertonic local anaesthetics produced a mild ataxia. The systemic changes were within acceptable limits in these clinically healthy cattle. CONCLUSION: In standing cattle the dorsolumbar epidural injection of hypertonic lignocaine provided faster onset of anaesthesia and fewer cardiovascular effects, but had a shorter duration of anaesthesia than hypertonic bupivacaine.
