A comparison of transdermal fentanyl versus epidural morphine for analgesia in dogs undergoing major orthopedic surgery

Abstract

Postoperative analgesia provided by transdermal fentanyl was compared with that provided by epidural morphine in dogs undergoing major orthopedic surgery. Dogs randomly were assigned to receive either a 100 microg per hour transdermal fentanyl patch 24 hours prior to surgery (n=8) or epidural morphine (0.1 mg/kg body weight) administered following induction of anesthesia (n=10). Temperature, heart rate, respiratory rate, and pain score were recorded prior to surgery and zero, six, 18, 30, and 42 hours after surgery. Blood samples were collected from the dogs in the transdermal fentanyl group beginning 24 hours preoperatively to 42 hours postoperatively. Fentanyl concentrations were determined by radioimmunoassay. When all time periods after surgery were combined, dogs in the transdermal fentanyl group were experiencing significantly less pain after surgery than dogs given epidural morphine. The transdermal fentanyl provided analgesia after major orthopedic surgery greater than or equivalent to that of epidural morphine.

Comparison of analgesia provided by lidocaine, lidocaine-morphine or lidocaine-tramadol delivered epidurally in dogs following orchiectomy

“…Epidural morphine can cause various effects that were not observed in this study, such as pruritus, urinary retention, hypoventilation, and hypotension (Herperger 1998;Robinson et al 1999;Jones 2001). Such adverse reactions have been seen when morphine was administered intramuscularly or intravenously (Valadão et al 2002).…”

“…Morphine was chosen as the standard analgesic for comparison, since various studies have shown that, when administered by the epidural route, it has a potent and prolonged analgesic effect (Popilskis et al 1993;Robinson et al 1999;Valadão et al 2002). This study and some others support the analgesic effect of epidural tramadol, compared to morphine by the same route (Mastrocinque & Fantoni 2001;Turker et al 2005;Castro et al 2009).…”

Postoperative analgesic effects of epidural administration of neostigmine alone or in combination with morphine in dogs undergoing orthopedic surgery of the pelvic limbs

“…Robinson et al 14 reported that fentanyl plasma concentrations of 0.95 ng/mL were associated with analgesia in dogs. In another study 15 on the pharmacokinetics of fentanyl, analgesic plasma concentrations (approx 1 ng/mL) were detected for 45 minutes after administration of a bolus (10 µg/kg, IV) of fentanyl.…”

Effects of Intravenous Fentanyl Administration on End-Tidal Sevoflurane Concentrations in Thoroughbred Racehorses undergoing Orthopedic Surgery

“…Therefore, plasma fentanyl concentrations of 6.12  0.88 to 7.78  1.12 ng/ml appeared to produce a certain degree of analgesic for serve pain in horses, and this effect might have lead to reduction of the sevoflurane requirement. The minimum effective analgesic concentrations of fentanyl have been reported to be 0.63  0.25 ng/ml or between 1 and 1.5 ng/ml for humans [2,7] and 0.95 ng/ml for dogs [15]. However, the response to opioids varies among species which may be related to different opioid receptor types and distributions.…”