Hypoxaemia and bradyarrhythmia in a foal undergoing surgical bladder repair

Abstract

A five‐day‐old female Thoroughbred foal was diagnosed with uroperitoneum and ruptured bladder. Prior to general anaesthesia mild hyperkalaemia (5.2 mmol L−1) and respiratory distress were noticed. Under general anaesthesia urine was drained rapidly by free flow through an abdominal incision. During abdominal drainage heart rate declined from 80 to 40 beats per minute and atrial standstill was suspected on the electrocardiogram. Arterial blood gas analysis revealed worsening hyperkalaemia (6 mmol L−1) and severe hypoxaemia (PaO2 31 mmHg). Calcium gluconate, 23% 4 mg kg−1 diluted 1:4 with sodium chloride 0.9%, was administer over 20 minutes to restoring the resting membrane potential. To treat hypoxaemia, mechanical ventilation was started and salbutamol 100 μg was administered through the endotracheal tube. Atrial standstill resolved and heart rate increased. General anaesthesia ended without further complications. Careful pre‐operative preparation is required in foals with uroperitoneum to avoid the exacerbation of relatively mild alterations in electrolyte balance.