Efficacy of concurrent epidural administration of neostigmine and lidocaine for perineal analgesia in geldings.

Abstract

OBJECTIVE:

To evaluate perineal analgesic effects of 3 doses of neostigmine coadministered epidurally with lidocaine to geldings.

ANIMALS:

6 healthy geldings.

PROCEDURES:

A few days before each treatment, a catheter was inserted between the first and second coccygeal vertebrae via the caudal approach in each gelding; the catheter tip was threaded approximately 10 cm cranial into the midsacral region. Each horse received 4 epidural treatments: 2% lidocaine (0.2 mg/kg) alone and 3 doses of neostigmine (0.5, 1, or 2 μg/kg) coadministered with that same dose of lidocaine. Horses were restrained in stocks in a standing position. Heart rate, blood pressure, respiratory rate, rectal temperature, intestinal motility, analgesia, behavior, and ataxia were determined before treatment (time 0; baseline); at 5, 10, 15, 30, 45, 60, 75, and 90 minutes; and every 30 minutes thereafter until the cessation of analgesia.

RESULTS:

All doses of neostigmine coadministered with lidocaine improved and extended the duration of analgesia in the perineal region of the geldings. Total duration of analgesia was not a dose-dependent effect (120, 150, and 150 minutes for 0.5, 1, and 2 μg/kg, respectively). All treatments induced mild or moderate ataxia. Cardiovascular changes were within acceptable limits.

CONCLUSIONS AND CLINICAL RELEVANCE:

Administration of neostigmine (1 μg/kg) combined with lidocaine (0.2 mg/kg) in the caudal epidural space induced analgesia for 2.5 hours with a low prevalence of adverse effects in standing conscious geldings. Epidural doses of neostigmine greater than these should be avoided because they may cause undesirable effects in geldings.

• Authors: Rafael DeRossi, Felipe B Maciel, Tiago J C Módolo, Ronaldo C Pagliosa
• Journal: American journal of veterinary research (Am J Vet Res) Vol. 73 Issue 9 Pg. 1356-62 (Sep 2012) ISSN: 1943-5681 [Electronic] United States
• PMID: 22924716 (Publication Type: Journal Article, Randomized Controlled Trial)

Chemical References

• Anesthetics, Local
• Cholinesterase Inhibitors
• Neostigmine
• Lidocaine

Topics

• Analgesia, Epidural (methods, veterinary)
• Anesthetics, Local (administration & dosage)
• Animals
• Ataxia (veterinary)
• Blood Pressure (drug effects, physiology)
• Body Temperature (drug effects, physiology)
• Cholinesterase Inhibitors (administration & dosage)
• Drug Therapy, Combination (veterinary)
• Gastrointestinal Motility (drug effects, physiology)
• Heart Rate (drug effects, physiology)
• Horses (physiology)
• Lidocaine (administration & dosage)
• Male
• Neostigmine (administration & dosage)
• Respiration
• Statistics, Nonparametric