Evaluation of a constant rate intravenous infusion of dexmedetomidine on the duration of a femoral and sciatic nerve block using lidocaine in dogs

Abstract

ObjectivesThis study investigated the effects of 1 μg/kg/h intravenous constant rate infusion (CRI) of dexmedetomidine on the sensory and motor blockade for femoral and sciatic nerve blocks in dogs undergoing stifle surgery.Materials and methodsClient-owned dogs referred for stifle surgery were enrolled in this prospective, randomized, blinded study. Dogs were pre-medicated with acepromazine (0.005–0.01 mg/kg intramuscularly, IM); anesthesia was induced with propofol intravenously and maintained with isoflurane in a mixture of air and oxygen. Electrolocation-guided sciatic and femoral nerve blocks with lidocaine 2% (0.15 mL/kg) were performed using the parasacral and lateral pre-iliac approaches, respectively. After performing local block, a systemic infusion of saline solution (group C) or dexmedetomidine (group D) was started at a CRI at 1 ml/kg/h and continued until the end of surgery. Dexmedetomidine was infused at a dose of 1 μg/kg/h. Respiratory and hemodynamic variables were recorded during surgery. Sensory and motor blockade was evaluated by response to pinching the skin innervated by the sciatic/femoral nerves, with forceps and by observing the dogs' ability to walk and testing proprioception at 30, 60, 120, 180, and 240 min after extubation. Analgesia was monitored with SF-GCPS. Methadone IM was administered as rescue analgesia. Intraoperative data were analyzed by analysis of variance, while postoperative data were analyzed by the independent two-tailed t-test and a Kaplan–Meier test (p < 0.05).ResultsTwenty dogs were included in this study (10/group). A significant difference in the recovery of sensory nerve function was observed between the groups. The mean durations of the sensory blockade for femoral and sciatic nerves, respectively, was longer (p < 0.001) for group D [168 (146–191, 95% CI), 161 (143–179, 95% CI) min] than in group C [120 (96.1–144, 95% CI), 116 (90.9–142, 95% CI]. No differences in the recovery of patellar and tibial reflexes, proprioceptive function, and ability to walk were found among groups. The overall postoperative rescue analgesia requirement was significantly different (p = 0.019) between groups, with an incidence of 5/10 (50%) dogs in group D and 10/10 (100%) dogs in group C.ConclusionDexmedetomidine administered as a CRI (1 μg/kg/h) combined with local lidocaine increases the duration of the sensory component of the sciatic and femoral nerve blocks and reduces the requirement for additional analgesia during the immediate postoperative hours.

Effect of dexmedetomidine infusion on the analgesic duration of peripheral nerve blocks in dogs: a randomized clinical study

“…This nding suggested that dexmedetomidine selectively prolongs sensory blockade over motor blockade, a nding that has also been suggested previously in human medicine 21 . In veterinary medicine, a recent study revealed that an IV infusion of dexmedetomidine prolongs the duration of perineural lidocaine sensory blockade without impacting motor function 13 . Dexmedetomidine infusions have also been demonstrated to increase sensory blockade without signi cantly impairing motor function or causing bradycardia when given IV during bupivacaine-induced spinal anaesthesia 22 .…”

“…The ideal CRI dosage of dexmedetomidine required to provide analgesia is not well known and varies within the veterinary literature. The most frequently reported doses range from 0.5 to 1 mcg kg − 1 h − 1 and are administered alone or in combination with other drugs as a CRI 13,22,23 . However, it has been suggested that a CRI dosage of 3 mcg kg − 1 h − 1 is necessary in some cases to achieve an algesia effect in dogs and that 1 mcg kg − 1 h − 1 CRI doses provide only a sedative effect 34 .…”

“…However, intravenous administration of dexmedetomidine at 1 mcg kg − 1 h − 1 and local lidocaine increased the duration of sensory sciatic and femoral nerve blockade and reduced the need for additional analgesia during the immediate postoperative period in dogs undergoing orthopedic surgery for tibial tuberosity advancement (TTA) 13 . Although the exact underlying mechanisms are not fully understood, there is evidence suggesting that dexmedetomidine, when administered intravenously, can potentially prolong the duration of peripheral sensory blocks and reduce the need for additional analgesics during the postoperative period.…”

Gynecological Laparoscopic Surgeries under Spinal Anesthesia: Benefits and Challenges

“…Intraoperative nausea and vomiting can be minimized through effective implementation of perioperative strategies [ 5 , 18 ]. Based on our accumulated expertise, the intravenous administration of specific compounds, such as Dexmedetomidine from EVER Pharma in Unterach, Austria, known for its psychotropic effects, has demonstrated noteworthy results in reducing side effects associated with spinal anesthesia and laparoscopic surgery, including pain, nausea, and vomiting [ 28 , 29 , 30 ]. Our recent findings indicate a significant decrease in the occurrence of these side effects to 2.9% (19 out of 658 patients) under medical treatment with Dexmedetomidine in contrast to the observed rate of 10.3% (94 out of 915 patients) without the use of Dexmedetomidine.…”

Ultrasound-Guided Greater Ischiatic Notch Plane Block Combined with the Caudal Quadratus Lumborum Block (GIN-TONIC Block) in Dogs Undergoing Pelvic Limb Surgery: Preliminary Results

“…Dexmedetomidine is a systemic sedative and analgesic in dogs [ 22 ]. Multiple studies have confirmed that the systemic administration of dexmedetomidine, either through a single intramuscular injection or constant rate intravenous infusion, significantly prolongs the duration of regional anesthesia and improves postoperative pain relief following perineural lidocaine administration for stifle surgery in dogs [ 23 , 24 ]. However, when comparing the efficacy of perineural femoral and sciatic nerve blocks using 2% lidocaine in dogs undergoing stifle surgery, premedicated with acepromazine, to those receiving systemic dexmedetomidine, no discernible differences were observed between the groups regarding the incidence of nociceptive events requiring analgesic intervention [ 23 , 24 ].…”