Comparison between Bilateral Ultrasound-Guided Quadratus Lumborum Block and Sacrococcygeal Epidural in Cats Undergoing Ovariectomy

Abstract

Background: Ultrasound-guided quadratus lumborum block (QLB) and sacrococcygeal epidural anaesthesia (ScE) have been used for neutering cats, providing effective pain relief. Objectives: To compare the effects of the QLB with those of ScE in cats undergoing ovariectomies. Methods: Feral cats undergoing ovariectomy were premedicated with dexmedetomidine (20 μg kg−1) and methadone (0.2 mg kg−1) intramuscularly. Anaesthesia was induced with 2–4 mg kg−1 of propofol intravenously and maintained with isoflurane in oxygen. The cats were randomly allocated to the groups QLB (bilateral QLB with 0.4 mL kg−1 of 0.25% bupivacaine) and ScE (0.3 mL kg−1 of 0.25% bupivacaine). Hemodynamic data and analgesia rescue were collected at four intraoperative periods. The pain scale and motor block were assessed in both groups during the postoperative period. Results: The ScE results in increased hypotension, prolonged extubation time, and higher postoperative motor block than the QLB (p < 0.05). The QLB and ScE groups required a similar number of intraoperative rescues and presented the same postoperative pain scale classification. Conclusions: The QLB with 0.25% bupivacaine is a potential alternative to ScE with 0.25% bupivacaine in perioperative pain management in elective cat ovariectomy. The QLB promoted less hypotension and postoperative motor block when compared with the ScE group.

Can a Sacrococcygeal Epidural of 0.25% Bupivacaine Prevent the Activation of the Sympathetic Nervous System during Feline Ovariectomy?

“…The notable disparities observed in the monitored hemodynamic parameters, including HR, SAP, and f R , along with the subsequent variations in the need for rescue analgesia, signify a significant opioid-sparing effect associated with ScE administration of bupivacaine in response to surgical stimuli. As studies in cats have suggested, the increased efficacy of ScE injection is attributed to the ability of the administered drugs within the epidural space to inhibit the activation and transmission of afferent neuronal impulses to the central nervous system in response to nociceptive stimuli [ 1 , 3 ].…”

“…During ovariectomy (OVE), celiotomy, traction, and ligation of the ovarian pedicles and uterine horns can trigger somatosensory and visceral peritoneal nociception [ 1 ]. To maintain hemodynamic stability during general anesthesia and undesirable autonomic responses, adequate analgesia should be provided during the intraoperative period [ 2 , 3 ].…”

“…Sacrococcygeal epidural (ScE) anesthesia is a locoregional technique that prevents perioperative nociception [ 1 , 3 ] and can complement or replace systemic analgesia in cats [ 1 , 2 ]. This technique in cats is safer than lumbosacral epidural since it reduces the risk of piercing of the meninges and adverse effects related to the volume of the administered solution in inadvertent intrathecal injections, given that in cats the spinal cord ends more caudally and the dural sac terminates at the level of the third sacral vertebra [ 1 , 2 , 7 , 8 , 9 , 10 ].…”

“…This technique in cats is safer than lumbosacral epidural since it reduces the risk of piercing of the meninges and adverse effects related to the volume of the administered solution in inadvertent intrathecal injections, given that in cats the spinal cord ends more caudally and the dural sac terminates at the level of the third sacral vertebra [ 1 , 2 , 7 , 8 , 9 , 10 ]. The epidural application with 0.3 mL kg −1 of volume at this level has already been shown to have analgesic advantages in spaying female cats [ 1 , 3 ].…”

Description and Evaluation of Dye and Contrast Media Distribution of Ultrasound-Guided Rectus Sheath Block in Cat Cadavers

“…The inclusion of these techniques into balanced anaesthetic protocols improves patient comfort, reduces perioperative opioid consumption and enhances recovery after surgery [ 4 ]. Recently, new ultrasound-guided anaesthetic techniques such as the transversus abdominis plane (TAP) [ 5 , 6 ] and the quadratus lumborum (QL) [ 7 , 8 , 9 ] blocks have been described in cats in both cadaveric and clinical studies [ 10 , 11 ]. The objective of these techniques is to provide analgesia to the abdomen.…”