1984/10/01 by R. T. Skarda, W. W. Muir, William W. Muir +2
Medicine · Neuroscience · Veterinary · #Anesthesia and Pain Management #Neuropeptides and Animal Physiology #Veterinary Equine Medical Research
paper · doi:10.2460/ajvr.1984.45.10.1967
openalex publication_date 1984/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
SUMMARY The venous plasma concentrations of mepivacaine were determined in 7 adult mares (420 ± 17.1 kg) given an injection of a 2% solution of the hydrochloride at either the sacral (S2-3 to S5-C1) epidural space or the midsacral (S2-3) subarachnoid space. An average dose of 91.4 ± 15.7 mg (4.6 ± 0.8 ml) was needed to produce caudal epidural analgesia ( cea ) and 26.7 ± 5.4 mg (1.3 ± 0.3 ml) to produce caudal subarachnoid analgesia ( csa ). Maximal caudal analgesia extended from spinal cord segments S-l to coccyx during cea and csa . The onset of analgesia as measured by response to superficial and deep muscular pinprick stimulations was significantly ( P < 0.05) faster in mares with csa than with cea (8.3 ± 2,4 minutes vs 21.4 ± 3.8 minutes). The period of analgesia was significantly ( P < 0.05) longer in mares with cea than with csa (80.0 ± 11.5 minutes vs 67.4 ± 26.3 minutes). The rate of vascular absorption of mepivacaine from the epidural space was significantly ( P < 0.05) faster than from the subarachnoid space. Maximum venous plasma concentrations of mepivacaine were similar ( P > 0.05) after epidural and subarachnoid injections (0.05 ± 0.03 μg/ml and 0.05 ± 0.03 μg/ml) at the same times after mepivacaine administration (51.4 ± 33.4 minutes and 53.6 ± 24.3 minutes). Mean venous plasma concentrations of mepivacaine at 60 and 75 minutes were significantly higher after epidural than subarachnoid injection (0.04 ± 0.03 μg/ml vs 0.02 ± 0.03 μg/ml and 0,03 ± 0.02 μg/ml vs 0.02 ± 0.02 μg/ml). Mean plasma concentrations of mepivacaine at the cessation of analgesia were not significantly different ( P > 0.05) after epidural and subarachnoid injections (0.03 ± 0.02 μg/ml vs 0.02 ± 0.02 μg/ml). The venous plasma concentrations of mepivacaine determined during cea and csa did not produce measurable direct systemic effects on the cardiovascular system of conscious mares.