Effects of ropivacaine combined with morphine at 0.15 and 0.2 mg kg-1 in bitches undergoing epidural anesthesia

Abstract

Conception, design, intellectual and scientific content of the study, critical revision. ABSTRACT PURPOSE:To investigate cardiorespiratory effects and serum concentration of ropivacaine combined with morphine at different doses. METHODS:Sixteen healthy adult female dogs weighting 9.8±4.1 kg were included in the study. Twenty minutes after being premedicated with acepromazine and midazolam, the animals were randomly assigned to receive an epidural injection according to each group: RM0.15 = ropivacaine + morphine (0.15 mg kg -1 ) and RM0.2 = ropivacaine + morphine (0.2 mg kg -1 ). Variables recorded consisted of: heart rate and cardiac rhythm, respiratory rate, oxyhemoglobin saturation, inspired oxygen fraction, end-tidal carbon dioxide tension, systolic, mean and diastolic arterial pressures, serum cortisol, plasma ropivacaine and morphine.RESULTS: SAP, MAP and DAP were significantly increased at TPR in RM0.15 but returned to normal values at the end of the procedure. Arterial pH was decreased in T30 and TESu in both groups and also returned to acceptable ranges at TR. Both PaO 2 and PaCO 2 were increased along the duration period of the epidural blockade (T30 and TESu) and returned to acceptable values at TR.Serum cortisol was lower at TB, T30 and TR when compared to TESu. CONCLUSION:The procedures were performed safely and minimal changes in cardiovascular and respiratory variables.

An Update on Drugs Used for Lumbosacral Epidural Anesthesia and Analgesia in Dogs

“…Of interest, both drugs have similar pharmacokinetic profiles (61–64). It is believed that ropivacaine causes less motor blockade than bupivacaine in humans (65) and dogs (29, 66), but this has not been confirmed in clinical trials using dogs.…”

“…Other combinations using local anesthetics and different opioids have been reported (e.g., methadone–lidocaine, morphine–ropivacaine, tramadol–lidocaine, oxymorphone–bupivacaine) but it seems that none of these protocols provided clear benefits over the administration of morphine–bupivacaine (64, 88, 127, 131, 132). However, they may be useful when the latter two drugs are not available.…”

Analgesic effect of intra-articular ropivacaine injection after arthroscopic surgery on the shoulder joint in dogs

“…In veterinary surgery, relief of postoperative pain has recently become an essential procedure to reduce the physical effects of postoperative pain and to address ethical issues in veterinary practice (Crane 1987;Mathews et al 1996). Various studies have been conducted to investigate the relief of postoperative pain using parenteral opioids, local anaesthetics and epidural anaesthetics (Hoelzler et al 2005;Aarnes et al 2014;Abimussi et al 2014;Lewis et al 2014;Albuquerque et al 2015). Opioids such as tramadol, butorphanol and morphine, are well-known and effective analgesics, but they can cause sedation, dysphoria and respiratory and cardiovascular depression (Soto et al 2014).…”