Comparison of Analgesic Effects of Caudal Epidural 0.25% Bupivacaine with Bupivacaine Plus Morphine or Bupivacaine Plus Ketamine for Analgesia in Conscious Horses

Dexmedetomidine and Bupivacaine Association in Caudal Epidural Injection in Mares

The objective of the study was to compare the effects of caudal epidural bupivacaine and dexmedetomidine (DEX) combination, with bupivacaine or DEX plain for perineal analgesia in mares. Six healthy saddle mares weighing 330-370 kg and aged 10-15 years were used in this study. Each mare was assigned to receive three treatments: 0.04 mg/kg 0.25% bupivacaine (BP), 2 μg/kg DEX (DX), or 0.02 mg/kg bupivacaine and 1 μg/kg DEX (BPDX). The order of treatments was randomized. All drugs were injected into the caudal epidural space (Co1-Co2) through a 16-G Tuohy epidural needle. After the epidural injections, heart rate, respiratory rate, arterial blood pressures (systolic, diastolic, and mean), and rectal temperature were measured at 5, 10, 15, 30, 60, 90, and 120 minutes, and after this time, every 60 minutes until the end of the experiments. A subjective score system was used to assess analgesia, behavioral and motor blockade at the same time points. The BPDX treatment produced analgesic action with twice the duration (200 minutes) of the BP treatment (97 minutes), but with an analgesic duration shorter than the DX treatment (240 minutes) in the regions of the tail, perineum, and upper hind limbs in mares. All treatments showed mild motor blockade. No behavioral changes were observed in any of the animals. There was hemodynamic stability without significant changes in respiratory rate for all treatments. Epidural analgesia using DEX alone or the combination of DEX and bupivacaine may be an option for painful obstetric and gynecological procedures in mares.

Cervical relaxation for non-surgical uterus access in Santa Inês ewes

ABSTRACT The present study was composed by two experiments aiming to develop a cervical dilation technique for non-surgical access to Santa Inês ewe’s uterus. In Experiment 1, thirty ewes underwent four epidural treatments. The three experimental treatments used 2.0mg/kg ketamine. The group receiving this drug alone was denominated KG, whereas other group had ketamine associated with 0.1mg/kg morphine (KM) and KX a third group had ketamine associated with 0.05mg/kg xylazine (KX). Control treatment was 1mL/7.5kg saline solution epidurally (CON). Cervical dilation was evaluated in both experiments by attempting to pass a metal rod through the cervix. In Experiment 2, three different hormonal protocols for cervical dilation were tested in thirty ewes. Epidural anesthesia with 2.0mg/kg ketamine was the control treatment (KG) and was combined with hormonal treatments: Misoprostol (MI); Oxytocin + Estradiol (OE); Misoprostol + Oxytocin + Estradiol (MOE). In Experiment 1 transposition rate was not different among groups. In Experiment 2, OE presented the highest rate (90%) while MOE presented 86.2%, MI 68.9% and CON 62.1%. The study developed a pharmacological protocol that increased cervical transposition making the non-surgical access to the uterus feasible in Santa Inês ewes.

Comparison of analgesic and systemic effects of bupivacaine, methadone, or bupivacaine/methadone administered epidurally in conscious sheep

OBJECTIVE

The aim of this study was to evaluate the combination of bupivacaine and methadone administered epidurally in sheep.

METHODS

Six healthy female mixed-breed sheep weighing 35-46 kg and aged 12-18 months were included. Each sheep was assigned to receive three treatments: 0.5 mg/kg 0.25% bupivacaine (BP), 0.3 mg/kg 1% methadone (MT) or 0.25 mg/kg bupivacaine and 0.15 mg/kg methadone (BPMT). All drugs were injected into the lumbosacral space through an epidural catheter. Each animal received each treatment at random. Heart rate, arterial blood pressure (systolic, diastolic and mean), respiratory rate, rectal temperature, analgesia, sedation and motor block were determined before treatment and at predetermined intervals.

RESULTS

The duration of analgesia was 240, 220, and 180 min for BP, MT and BPMT, respectively (P < 0.05). Motor block for all agents was mild to moderate. None or the treatments significantly altered the heart rate, blood pressure or respiratory rate.

CONCLUSION

Our findings suggest that lumbosacral epidural administration of bupivacaine, methadone or a combination of the two drugs can provide perioperative analgesia in sheep as part of their management for surgical procedures in the flank and hindlimbs.