Transient respiratory arrest after quadratus lumborum block in a dog

• Published in: Veterinary record case reports Vol. 10; no. 4
• Main Authors: Herrera‐Linares, Manuel E., Martínez, Miguel
• Format: Journal Article
• Language: English
• Published: 01.12.2022
• Subjects: complication; dog; erector spinae block; loco‐regional anaesthesia; quadratus lumborum block; respiratory arrest
• ISSN: 2052-6121; 2052-6121
• DOI: 10.1002/vrc2.448

A 13.9 kg, 4‐year‐old, male cocker spaniel dog was scheduled for cystotomy. Premedication consisted of intravenous medetomidine (5 µg/kg), induction with propofol (1 mg/kg, intravenous) and anaesthesia maintenance with isoflurane in O2 100%. A medetomidine constant‐rate infusion (1 µg/kg/h) was administered throughout. A bilateral quadratus lumborum block with 3 ml of 0.5% bupivacaine (each side) was performed, and intermittent positive‐pressure ventilation was initiated. At the end of the surgery, medetomidine constant‐rate infusion and intermittent positive‐pressure ventilation ceased. The patient remained in apnoea and developed severe hypercapnia (end‐tidal carbon dioxide: 12 kPa). Thirty minutes after isoflurane discontinuation, respiratory muscles movement started. Three days before, the dog underwent a mini‐hemilaminectomy (similar anaesthetic protocol) without complications. Epidural/spinal migration from the right quadratus lumborum block was suspected, although the definitive cause of transient respiratory arrest after bilateral quadratus lumborum block could not be ascertained. We advise caution when performing quadratus lumborum if previous neighbouring spinal surgery was performed.