Arterial Oxygenation During One-Lung Ventilation: Combined Versus General Anesthesia

A noninvasive partial carbon dioxide rebreathing technique for measurement of pulmonary capillary blood flow is also a useful oxygenation monitor during one-lung ventilation

“…In previous studies, pulmonary shunt fraction (Qs/Qt) was about 10% to 20% during two-lung ventilation and increased to approximately 30% to 50% during one-lung ventilation; effective pulmonary capillary blood flow decreased by approximately 20% to 30% during one-lung ventilation. [7][8][9][10][11] The increase in shunt fraction and the reduction of effective pulmonary capillary blood flow observed in the present study were similar to those values reported in previous studies. In the present study, pulmonary shunt fraction increased to 46.3%, and effective pulmonary capillary blood flow index and effective pulmonary blood stroke flow index decreased by 31.6% during one-lung ventilation.…”

Compressing the non-dependent lung during one-lung ventilation improves arterial oxygenation, but impairs systemic oxygen delivery by decreasing cardiac output

“…However, it should be noted that arterial oxygenation may be impaired after the release of the retractor, since our previous study showed that there was a mild drop in Pao 2 (approximately 43 mmHg on average) in 2 min after decompression of the non-dependent lung by using continuous intra-arterial blood gas monitoring [11]. Since oxygenation is affected by several factors during OLV, such as the time course of hypoxic pulmonary vasoconstriction [14], CO [15][16][17], and epidural anesthesia [18], it is very difficult to analyze the effects of the non-dependent lung compression on the gradual improvement in arterial oxygenation. We previously found that improvement in arterial oxygenation during OLV was partly related to a marked increase in Pao 2 during the second compression of the non-dependent lung [11].…”

The Effects of Intravenous Hyperoxygenated Solution Infusion on Systemic Oxygenation and Intrapulmonary Shunt During One-Lung Ventilation in Pigs

“…When one-lung ventilation is initiated in the lateral decubitus position, pulmonary blood flow continues to the upper lung, creating a true shunt in a lung where there is blood flow to the alveoli but no ventilation, and intrapulmonary shunt (Qs/Qt) increases from a value of approximately 10% to 15% during two-lung ventilation to 30% to 40% during OLV [10]. This shunt is the major cause of hypoxemia during OLV.…”