Use of the oxygen content-based index, fshunt, as an indicator of pulmonary venous admixture at various inspired oxygen fractions in anesthetized sheep

Abstract

Objective-To evaluate the use of the oxygen content-based index, Fshunt, as an indicator of venous admixture (Qs/Qt) at various fractions of inspired oxygen (FIO2s) in anesthetized sheep undergoing 1-lung or 2-lung ventilation. Animals-6 healthy adult female sheep. Procedures-Sheep were anesthetized and administered 5 different FIO2s (0.21, 0.40, 0.60, 0.80, and 1.00) in random order during 2-lung mechanical ventilation. Arterial and mixed venous blood samples were obtained at each FIO2 after a 15-minute stabilization period. Vital capacity alveolar recruitment maneuvers were performed after blood collection. The previously used FIO2 sequence was reversed for sample collection during 1-lung ..