Dependent Lung Pulmonary Artery Hypoplasia as a Cause of Hypoxia during One-lung Ventilation

Hypoxemia remains a well-described occurrence during one-lung ventilation.1 We recently observed unexpected refractory hypoxemia ventilation in previously healthy nonsmoking 30-yr-old female undergoing left thoracotomy the right lateral decubitus position to facilitate complex descending aorta subclavian/carotid artery bypass grafting treat upper limb and cerebral ischemia resulting from Takayasu’s arteritis. Despite endotracheal suctioning, reconfirmation of optimal bronchial blocker positioning, optimizing fraction inspired oxygen, using both dependent lung positive end-expiratory pressure nondependent continuous airway pressure,2 Pao2 remained ~50 mmHg. No intracardiac shunt was seen on transesophageal echocardiography. Only intermittent two-lung temporarily corrected hypoxemia. A postoperative computed tomography angiogram three-dimensional reconstruction (panel A) performed evaluate vascular showed hypoplastic pulmonary (10 mm diameter; panel B) compared normal (19 C). speculate that this hypoplasia resulted enhanced shunting nondependent, nonventilated lung; is unreported potential cause for Although estimated occur only 1:200,000 population, consideration should be given reviewing routinely acquired preoperative scan assess size differential as rare risk factor ventilation. If present, anticipation an increased prompt rapid escalation adjunct therapies (i.e., pressure; ventilation, with conversion thoracoscopic technique open thoracotomy). Extracorporeal membrane oxygenation also option.The authors declare no competing interests.