Intraoperative Effect of a Bilateral Ultrasound-Guided Quadratus Lumborum Block in Cats Undergoing Ovariectomy

Objective: Investigate the effect of bilateral ultrasound-guided quadratus lumborum block (QLB) in the need for additional opioid administration in response to intraoperative nociception during ovariectomy in cats. Methods: Thirty-six feral cats were randomly allocated to group control (C) or group QLB with 0.4 mL kg(-1) of 0.25% bupivacaine per hemiabdomen. Hemodynamic data were collected at five intraoperative time points. A 20% increase in pulse rate or respiratory rate was treated with fentanyl. Results: Pulse rate and respiratory rate were higher in the C group compared to the QLB group during ovarian manipulation. No differences in systolic and mean arterial pressure and hypotension were comparable in both groups. The QLB group required less administration of intraoperative fentanyl than the C group at 4/16 and 10/16, respectively (p < 0.05). Conclusions: The bilateral QLB with bupivacaine led to a reduction in opioid consumption in feral cats undergoing elective ovariectomy.