Department of Companion Animal Clinical Studies, University of Pretoria, Pretoria, South Africa
Routine immobilisation of buffalo occurs daily in South Africa, but prolonged immobilisation has been associated with significant mortality. A 2-month-old female buffalo immobilised with thiafentanil, ketamine and azaperone presented to the veterinary academic hospital for a left tibia fracture. The animal was suffering from hyperthermia, tachycardia, tachypnoea and reduced capillary refill time. Induction and intubation were performed, shortly after which blood-stained fluid filled the lumen of the tracheal tube. Arterial blood gas indicated severe hypoxemia with respiratory acidosis. Intraoperative monitoring revealed severe systemic hypertension, hypercapnia and hypoxemia. Based on these findings, pulmonary hypertension with pulmonary oedema and haemorrhage was also suspected. The animal was placed on a circle breathing circuit supplemented with 100% oxygen and isoflurane. A protective lung ventilation strategy was also initiated to reverse the hypoxemia and hypercapnia. The strategy involved setting peak inspiratory pressure to 30 cm H2O, positive end-expiratory pressure to 5 cm H2O, and frequency to 12 breaths per minute. The animal responded well to the intermittent positive pressure ventilation and within 90 minutes of its commencement, the respiratory acidosis and hypercapnia had been resolved. The animal breathed spontaneously for the remainder of the procedure and recovered uneventfully.
This case illustrates the potential cardiopulmonary effects of prolonged immobilisation in buffalo. But with timeous intervention of a protective lung ventilation strategy, they can be reversed.
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