Fig. 1. Perfusion of the nonventilated lung affects oxygenation during one-lung ventilation. ( A ) Oxygenation 30 min after initiating one-lung ventilation increases with decreasing preoperatively measured perfusion of the nonventilated lung. The lowest (< 100 mmHg) arterial oxygen tension (Pao2) occurs in patients with high perfusion levels in the nondependent lung. ( B ) Oxygenation 30 min after initiating one-lung ventilation for patients presenting for pneumonectomy, lobectomy, and metastasis resections. Mean preoperatively measured perfusion of the nonventilated lung was 55% in patients undergoing metastasectomy, 47% in patients undergoing lobectomy, and 32% in patients undergoing pneumonectomy. Modified with permission from Schwarzkopf et al. : Oxygenation during one-lung ventilation: The effects of inhaled nitric oxide and increasing levels of inspired fraction of oxygen. Anesth Analg 2001; 92:842–7. 1
