Abstract
One-lung ventilation (OLV) is an anaesthetic technique utilised for improved visualisation and access of the surgical field during thoracoscopy. Three intubation techniques can be used for OLV; selective intubation of a bronchus, use of a double lumen tube (DLT) or use of an endobronchial blocker. The authors present two cases that underwent OLV with use of a DLT. The first case was intubated with endoscopic guidance for bronchial port intubation of the right mainstem bronchus. This dog experienced prolonged periods of intraoperative hypoxaemia. Upon case review, it was suspected intubation of the mainstem bronchus resulted in occlusion of the right cranial lung lobe. In the second case, the DLT was placed bronchoscopically into the left mainstem bronchus with the aid of computed tomography (CT) was in addition to bronchoscopy. Excellent intraoperative oxygenation was achieved. CT guidance was fundamental for DLT placement in Case 2. When DLTs are used in dogs, their anatomical differences with humans make them susceptible to additional lung occlusion and pulmonary shunting, and consequently an increased risk of low arterial oxygenation. Careful preoperative planning, including DLT, tracheal and mainstem bronchus measurements, should be undertaken to minimise these risks. Computed tomography may be more a fundamental addition to bronchoscopy for correct tube placement.

Key words: Anaesthesia; one-lung ventilation; double lumen tube, thoracoscopy