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

作者：Araos Joaquin D; Larenza M Paula^*; Boston Raymond C; De Monte Valentina; De Marzo Carmelinda; Grasso Salvatore; Haskins Steve C; Crovace Antonio; Staffieri Francesco

来源：American Journal of Veterinary Research, 2012, 73(12): 2013-2020.

DOI：10.2460/ajvr.73.12.2013

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 (Flo(2)s) in anesthetized sheep undergoing 1-lung or 2-lung ventilation. %26lt;br%26gt;Animals-6 healthy adult female sheep. %26lt;br%26gt;Procedures-Sheep were anesthetized and administered 5 different Flo2s (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 Fio(2) 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 ventilation. Blood samples were analyzed for arterial, pulmonary end-capillary, and mixed venous oxygen content anci partial pressure and for hemoglobin concentration. Oxygen hemoglobin saturation, Qs/Qt, Fshunt, and oxygen tension-based indices (OTIs; including Pao(2):Fio(2), alveolar-arterial difference in partial pressure of oxygen [PAo(2)-Pao(2);, [PAo(2)-Pao(2)]:Fto(2), [PAO(2) -Pao(2)]:Pao(2), and Pao(2):PAo(2)) were calculated at each Flo(2); associations were evaluated with linear rureyssion analysis, concordance, and correlation tests. Intermethod agreement between Qs/Qt and Fshunt was tested via Bland-Altman analysis. %26lt;br%26gt;Results-Strong and .significant associations and substantial agreement were detected between Fshunt and Qs/Qt. Relationships between OTIs and Qs/Qt varied, but overall correlations were weak. %26lt;br%26gt;Conclusions and Clinical Relevance-Whereas OTIs were generally poor indicators of Qs/Qt .Fshunt was a good indicator of Qs/Qt at various Flois, regardless of the magnitude of Qs/Qt, and could be potentially used as a surrogate for Ois/Ot measurements in healthy sheep. (Am J Vet Res 2012;73:2013-2020)

• 出版日期2012-12