Evaluation of preoperative rectus sheath block with bupivacaine for analgesia in cats undergoing ovariohysterectomy: a cadaveric and randomized clinical study.
Adrienne L Haley, Martin J Kennedy, Colleen Hickey, Wanda J Gordon-Evans, Erin Wendt-Hornickle, Caitlin C Tearney, Brian Walters, Lauren Ienello, Alonso Gp Guedes
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引用次数: 0
Abstract
Objective: Phase 1: to determine the feasibility of desensitizing ventral branches of spinal nerves within the rectus sheath using an ultrasound-guided rectus sheath block (USRSB). Phase 2: to determine the effect of preoperative USRSB on intraoperative responses to surgical stimulation and postoperative pain.
Study design: Cadaveric study and prospective, randomized, blinded, parallel-arm clinical trial.
Animals: A group of five cat cadavers and 37 shelter-owned cats undergoing ovariohysterectomy.
Methods: Phase 1: anatomical dissection was performed on one uninjected cadaver. Abdominal walls were dissected in four cadavers (eight hemiabdomens) following bilateral USRSB using 1:1 new methylene blue and 0.5% bupivacaine (0.8 mL kg-1 total). Phase 2: preoperative bilateral USRSB was performed with 0.8 mL kg-1 of 0.25% bupivacaine (RSB) or equivalent volume of 0.9% saline (CONTROL). Intraoperative systolic arterial blood pressure (SAP), heart rate (HR), respiratory rate (fR) and vaporizer setting (vap%) were recorded before skin incision, during celiotomy and abdominal wall closure. In recovery, cats were administered robenacoxib (2 mg kg-1; CONTROL) or 0.9% saline (0.1 mL kg-1; RSB) subcutaneously. Postoperative pain was evaluated for 6 hours using the Glasgow Composite Measure Pain Scale.
Results: Phase 1: spinal nerves T9-L3 were identified within the rectus sheath, and stained in 0%, 40%, 63%, 75%, 100%, 88%, 50% and 13% of hemiabdomens, respectively. Phase 2: 37 cats were included (RSB, n = 17; CONTROL, n = 20). Intraoperatively, SAP, HR and fR were not significantly different between groups. Vap% was significantly lower in RSB during celiotomy (p = 0.036) and closure (p = 0.044). Postoperatively, RSB cats were 5.3 times (95% CI 1.8-8.3) more likely to require rescue analgesia than CONTROL cats.
Conclusions and clinical relevance: During surgery, USRSB with bupivacaine offered minor benefits and provided markedly less postoperative analgesia than robenacoxib, indicating that relying on USRSB provides insufficient postoperative analgesia for ovariohysterectomy in cats.
期刊介绍:
Veterinary Anaesthesia and Analgesia is the official journal of the Association of Veterinary Anaesthetists, the American College of Veterinary Anesthesia and Analgesia and the European College of Veterinary Anaesthesia and Analgesia. Its purpose is the publication of original, peer reviewed articles covering all branches of anaesthesia and the relief of pain in animals. Articles concerned with the following subjects related to anaesthesia and analgesia are also welcome:
the basic sciences;
pathophysiology of disease as it relates to anaesthetic management
equipment
intensive care
chemical restraint of animals including laboratory animals, wildlife and exotic animals
welfare issues associated with pain and distress
education in veterinary anaesthesia and analgesia.
Review articles, special articles, and historical notes will also be published, along with editorials, case reports in the form of letters to the editor, and book reviews. There is also an active correspondence section.