Arterial Oxygen Desaturation during One-lung Ventilation in a Patient with Segmental Pulmonary Infarction

Abstract

A left thoracotomy for decortication of an infected haemothorax was performed on a 52-year-old man with a partially infarcted left lower lobe that occurred as a rare complication of a pulmonary venous embolus. Before the completion of surgery, after an uncomplicated 40 minutes of one-lung ventilation, the left lung was temporarily re-expanded to assess air leak. On the resumption of one-lung ventilation the SpO 2 fell rapidly to 85%, despite apnoeic oxygenation of the non-ventilated lung. In the absence of evidence of double-lumen tube displacement, intra-pulmonary shunting as a consequence of impaired hypoxic pulmonary vasoconstriction in the newly expanded markedly pathological lung is considered the most likely mechanism.

Anesthesia for Tracheobronchial Surgery

“…With endobronchial intubation, 1 lung will not be ventilated, and the degree of shunt and desaturation is variable. [17][18][19] A full discussion of hypoxia and shunt physiology in 1-lung ventilation is beyond the scope of this article; however, standard management of hypoxia during 1-lung ventilation includes suctioning, confirming the position of the endotracheal tube by fiber-optic bronchoscopy, increasing FiO 2 , and varying the ventilatory patterns. Please see Appendix C for further discussion of singlelung ventilation.…”