Prediction, Prevention, and Treatment

Whenswitchingfromtwo-lungtoone-lungventilation(OLV),shunt fraction increases, oxygenation is impaired, and hypox-emia may occur. Hypoxemia during OLV may be predicted frommeasurements of lung function, distribution of perfusion be-tween the lungs, whether the right or the left lung is ventilated,and whether the operation will be performed in the supine orinthelateraldecubitusposition.HypoxemiaduringOLVmaybeprevented by applying a ventilation strategy that avoids alveo-lar collapse while minimally impairing perfusion of the depen-dent lung. Choice of anesthesia does not influence oxygenationduring clinical OLV. Hypoxemia during OLV may be treatedsymptomatically by increasing inspired fraction of oxygen, byventilating, or by using continuous positive airway pressure inthe nonventilated lung. Hypoxemia during OLV may be treatedcausally by correcting the position of the double-lumen tube,clearing the main bronchi of the ventilated lung from secre-tions, and improving the ventilation strategy.