Anesthetic management of an off-pump open-heart surgery in a dog

Abstract

ObservationsA 9 year-old, 40 kg, female spayed Bouvier des Flandres was anesthetized for surgical removal of an intra-cardiac mass. Pre-anesthetic work-up included thoracic radiographs, which revealed moderate pleural effusion, and cardiac ultrasound, which identified a mass attached to the wall of the right ventricular outflow tract (RVOT). The mass caused dynamic obstruction of the RVOT during systole. The dog was pre-medicated with intravenous (IV) hydromorphone (0.05 mg kg−1). Following pre-oxygenation, anesthesia was induced with ketamine (3.75 mg kg−1, IV) and diazepam (0.18 mg kg−1, IV). Anesthesia was maintained with isoflurane in oxygen, an intravenous constant rate infusion (CRI) of fentanyl (10–30 μg kg−1 hour−1) and a CRI of lidocaine (50–200 μg kg−1 minute−1). A right lateral thoracotomy was performed. The heart was stopped transiently with a cold cardioplegic solution for 7.83 minutes to allow the removal of the mass through an open-heart procedure. No cardiopulmonary bypass was used. The heart was successfully restarted after cardiopulmonary resuscitation with internal cardiac massage and internal defibrillation. The dog recovered uneventfully from anesthesia without any apparent neurological sequelae. Post-operative analgesia consisted of intercostal nerve blocks with bupivacaine, CRIs of fentanyl (2–5 μg kg−1 hour−1) and lidocaine (40 μg kg−1 minute−1) and with oral meloxicam (0.1 mg kg−1). Five days following surgery, the dog was discharged from the hospital. Histopathology and immunohistochemistry of the mass identified an ectopic thyroid carcinoma. ConclusionsThis case showed the feasibility of whole body hypothermia and using a cold cardioplegic solution to induce cardiac arrest for a short open-heart procedure.