Anaesthetic management of a dog with severe subaortic stenosis and mitral valve disease complicated with atrial fibrillation undergoing ovariohysterectomy

Abstract

The anaesthetic management in patients with subaortic stenosis and mitral valve disease should involve intensive monitoring and the anaesthesiologist’s main concern are to ensure oxygen delivery and tissue perfusion. Since anaesthetic procedures in such patients are rare, there is no previous report about the anaesthetic management. A 5.5 year old, 32 kg Boxer, suffering a severe heart disease due to a final stage subaortic stenosis and mitral insufficiency, was anaesthetized for an ovariohysterectomy to remove an ovarian tumour that was producing high volume ascites. Methadone (0.3 mg kg-1) was administered intramuscularly (IM) for pre-anaesthetic medication, etomidate (1.3 mg kg-1) and midazolam (0.2 mg kg-1) were used for induction of anaesthesia and after endotracheal intubation, anaesthesia was maintained with sevoflurane vaporized in oxygen and air. Fentanyl (5-10 μg kg-1 h-1) and paracetamol (15 mg kg-1) were administered to improve analgesia. Previous persistent atrial fibrillation was refractory to medication (digoxin, diltiazem and pimobendan) and continued during the anaesthetic procedure. Dobutamine (1.5-5 µg kg-1 min-1) helped to maintain mean arterial blood pressure above 60 mmHg. Epidural morphine (0.1 mg kg-1) and incisional bupivacaine (2 mg kg-1) were administered at the end of surgery to provide postoperative analgesia. Anaesthesia was otherwise uneventful, and recovery was considered excellent.

Keywords

• Anaesthesia
• Atrial fibrillation
• Dog
• Mitral
• Subaortic stenosis