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Superior vena cava drainage improves upper body oxygenation during veno-arterial extracorporeal membrane oxygenation in sheep.

Hou X, Yang X, Du Z, Xing J, Li H, Jiang C, Wang J, Xing Z, Li S, Li X, Yang F, Wang H, Zeng H - Crit Care (2015)

Bottom Line: SVC-FA achieved oxygen-rich blood return from the IVC to the RA without shifting the arterial cannulation.Subsequently, SO₂ of the SVC and the pulmonary artery increased (70.4 ± 1.0% and 73.4 ± 1.1%, respectively).With knowledge of this mechanism, we can apply better cannula configurations in clinical practice.

View Article: PubMed Central - PubMed

Affiliation: Center for Cardiac Intensive Care, Beijing Anzhen Hospital, Capital Medical University, 2 Anzhen Road, Beijing, 100029, P.R. China. xt.hou@ccmu.edu.cn.

ABSTRACT

Introduction: Differential hypoxia is a pivotal problem in patients with femoral veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) support. Despite recognition of differential hypoxia and attempts to deliver more oxygenated blood to the upper body, the mechanism of differential hypoxia as well as prevention strategies have not been well investigated.

Methods: We used a sheep model of acute respiratory failure that was supported with femoral VA ECMO from the inferior vena cava to the femoral artery (IVC-FA), ECMO from the superior vena cava to the FA (SVC-FA), ECMO from the IVC to the carotid artery (IVC-CA) and ECMO with an additional return cannula to the internal jugular vein based on the femoral VA ECMO (FA-IJV). Angiography and blood gas analyses were performed.

Results: With IVC-FA, blood oxygen saturation (SO₂) of the IVC (83.6 ± 0.8%) was higher than that of the SVC (40.3 ± 1.0%). Oxygen-rich blood was drained back to the ECMO circuit and poorly oxygenated blood in the SVC entered the right atrium (RA). SVC-FA achieved oxygen-rich blood return from the IVC to the RA without shifting the arterial cannulation. Subsequently, SO₂ of the SVC and the pulmonary artery increased (70.4 ± 1.0% and 73.4 ± 1.1%, respectively). Compared with IVC-FA, a lesser difference in venous oxygen return and attenuated differential hypoxia were observed with IVC-CA and FA-IJV.

Conclusions: Differential venous oxygen return is a key factor in the etiology of differential hypoxia in VA ECMO. With knowledge of this mechanism, we can apply better cannula configurations in clinical practice.

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Related in: MedlinePlus

Paradigm depicting the mechanism of differential oxygen return. (A) Differential venous oxygen return between the IVC and the SVC exists in IVC-FA. Oxygen-rich blood is drained back to the ECMO circuit by the drainage cannula at the IVC, and the oxygen-poor blood from the SVC enters the heart and perfuses the upper body, which leads to differential hypoxia. (B) In SVC-FA, oxygen-poor blood in the SVC is drained to the ECMO circuit, whereas the oxygen-rich blood from the IVC enters the RA. (C) In IVC-CA, the oxygenated blood from the ECMO circuit is directly supplied to the whole body. (D) In FA-IJV, a certain amount of oxygenated blood is shunted into the SVC to improve upper body oxygenation. Differential venous oxygen return is attenuated in B, C, D. ECMO: extracorporeal membrane oxygenation; FA-IJV: an additional return cannula was added into the internal jugular vein on the basis of femoral veno-arterial extracorporeal membrane oxygenation; IVC-CA: a drainage cannula was inserted into the inferior vena cava and a return cannula was inserted into the carotid artery; IVC-FA: a drainage cannula was placed into the inferior vena cava through the femoral vein and a return cannula was inserted into the femoral artery; RA: right atrium; SO2: oxygen saturation; SVC-FA: a drainage cannula was placed into the superior vena cava through the femoral vein and a return cannula was placed into the femoral artery.
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Fig5: Paradigm depicting the mechanism of differential oxygen return. (A) Differential venous oxygen return between the IVC and the SVC exists in IVC-FA. Oxygen-rich blood is drained back to the ECMO circuit by the drainage cannula at the IVC, and the oxygen-poor blood from the SVC enters the heart and perfuses the upper body, which leads to differential hypoxia. (B) In SVC-FA, oxygen-poor blood in the SVC is drained to the ECMO circuit, whereas the oxygen-rich blood from the IVC enters the RA. (C) In IVC-CA, the oxygenated blood from the ECMO circuit is directly supplied to the whole body. (D) In FA-IJV, a certain amount of oxygenated blood is shunted into the SVC to improve upper body oxygenation. Differential venous oxygen return is attenuated in B, C, D. ECMO: extracorporeal membrane oxygenation; FA-IJV: an additional return cannula was added into the internal jugular vein on the basis of femoral veno-arterial extracorporeal membrane oxygenation; IVC-CA: a drainage cannula was inserted into the inferior vena cava and a return cannula was inserted into the carotid artery; IVC-FA: a drainage cannula was placed into the inferior vena cava through the femoral vein and a return cannula was inserted into the femoral artery; RA: right atrium; SO2: oxygen saturation; SVC-FA: a drainage cannula was placed into the superior vena cava through the femoral vein and a return cannula was placed into the femoral artery.

Mentions: From angiography, we proved dual circulation by directly illustrating that blood flow to the lower body and the upper body was from the ECMO circuit and left ventricle, respectively. On one side, our results indicate that the femoral arterial reinfusion created a high level of lower body oxygenation when heart function is normal. This could lead to a high level of oxygen saturation in the returning venous blood from the lower body, as we saw from the high SO2 values in the IVC. This oxygen-rich blood was drained back into the ECMO circuit by the drainage cannula. On the other side, the oxygen-poor blood from the SVC entered the heart and perfused the upper body (Figure 5A). Thus, differential venous oxygen return between the IVC and the SVC was an important factor contributing to differential hypoxia. Draining the blood from the SVC where the returning blood is not as well saturated might be a key strategy for attenuating differential hypoxia (Figure 5B).Figure 5


Superior vena cava drainage improves upper body oxygenation during veno-arterial extracorporeal membrane oxygenation in sheep.

Hou X, Yang X, Du Z, Xing J, Li H, Jiang C, Wang J, Xing Z, Li S, Li X, Yang F, Wang H, Zeng H - Crit Care (2015)

Paradigm depicting the mechanism of differential oxygen return. (A) Differential venous oxygen return between the IVC and the SVC exists in IVC-FA. Oxygen-rich blood is drained back to the ECMO circuit by the drainage cannula at the IVC, and the oxygen-poor blood from the SVC enters the heart and perfuses the upper body, which leads to differential hypoxia. (B) In SVC-FA, oxygen-poor blood in the SVC is drained to the ECMO circuit, whereas the oxygen-rich blood from the IVC enters the RA. (C) In IVC-CA, the oxygenated blood from the ECMO circuit is directly supplied to the whole body. (D) In FA-IJV, a certain amount of oxygenated blood is shunted into the SVC to improve upper body oxygenation. Differential venous oxygen return is attenuated in B, C, D. ECMO: extracorporeal membrane oxygenation; FA-IJV: an additional return cannula was added into the internal jugular vein on the basis of femoral veno-arterial extracorporeal membrane oxygenation; IVC-CA: a drainage cannula was inserted into the inferior vena cava and a return cannula was inserted into the carotid artery; IVC-FA: a drainage cannula was placed into the inferior vena cava through the femoral vein and a return cannula was inserted into the femoral artery; RA: right atrium; SO2: oxygen saturation; SVC-FA: a drainage cannula was placed into the superior vena cava through the femoral vein and a return cannula was placed into the femoral artery.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
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Fig5: Paradigm depicting the mechanism of differential oxygen return. (A) Differential venous oxygen return between the IVC and the SVC exists in IVC-FA. Oxygen-rich blood is drained back to the ECMO circuit by the drainage cannula at the IVC, and the oxygen-poor blood from the SVC enters the heart and perfuses the upper body, which leads to differential hypoxia. (B) In SVC-FA, oxygen-poor blood in the SVC is drained to the ECMO circuit, whereas the oxygen-rich blood from the IVC enters the RA. (C) In IVC-CA, the oxygenated blood from the ECMO circuit is directly supplied to the whole body. (D) In FA-IJV, a certain amount of oxygenated blood is shunted into the SVC to improve upper body oxygenation. Differential venous oxygen return is attenuated in B, C, D. ECMO: extracorporeal membrane oxygenation; FA-IJV: an additional return cannula was added into the internal jugular vein on the basis of femoral veno-arterial extracorporeal membrane oxygenation; IVC-CA: a drainage cannula was inserted into the inferior vena cava and a return cannula was inserted into the carotid artery; IVC-FA: a drainage cannula was placed into the inferior vena cava through the femoral vein and a return cannula was inserted into the femoral artery; RA: right atrium; SO2: oxygen saturation; SVC-FA: a drainage cannula was placed into the superior vena cava through the femoral vein and a return cannula was placed into the femoral artery.
Mentions: From angiography, we proved dual circulation by directly illustrating that blood flow to the lower body and the upper body was from the ECMO circuit and left ventricle, respectively. On one side, our results indicate that the femoral arterial reinfusion created a high level of lower body oxygenation when heart function is normal. This could lead to a high level of oxygen saturation in the returning venous blood from the lower body, as we saw from the high SO2 values in the IVC. This oxygen-rich blood was drained back into the ECMO circuit by the drainage cannula. On the other side, the oxygen-poor blood from the SVC entered the heart and perfused the upper body (Figure 5A). Thus, differential venous oxygen return between the IVC and the SVC was an important factor contributing to differential hypoxia. Draining the blood from the SVC where the returning blood is not as well saturated might be a key strategy for attenuating differential hypoxia (Figure 5B).Figure 5

Bottom Line: SVC-FA achieved oxygen-rich blood return from the IVC to the RA without shifting the arterial cannulation.Subsequently, SO₂ of the SVC and the pulmonary artery increased (70.4 ± 1.0% and 73.4 ± 1.1%, respectively).With knowledge of this mechanism, we can apply better cannula configurations in clinical practice.

View Article: PubMed Central - PubMed

Affiliation: Center for Cardiac Intensive Care, Beijing Anzhen Hospital, Capital Medical University, 2 Anzhen Road, Beijing, 100029, P.R. China. xt.hou@ccmu.edu.cn.

ABSTRACT

Introduction: Differential hypoxia is a pivotal problem in patients with femoral veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) support. Despite recognition of differential hypoxia and attempts to deliver more oxygenated blood to the upper body, the mechanism of differential hypoxia as well as prevention strategies have not been well investigated.

Methods: We used a sheep model of acute respiratory failure that was supported with femoral VA ECMO from the inferior vena cava to the femoral artery (IVC-FA), ECMO from the superior vena cava to the FA (SVC-FA), ECMO from the IVC to the carotid artery (IVC-CA) and ECMO with an additional return cannula to the internal jugular vein based on the femoral VA ECMO (FA-IJV). Angiography and blood gas analyses were performed.

Results: With IVC-FA, blood oxygen saturation (SO₂) of the IVC (83.6 ± 0.8%) was higher than that of the SVC (40.3 ± 1.0%). Oxygen-rich blood was drained back to the ECMO circuit and poorly oxygenated blood in the SVC entered the right atrium (RA). SVC-FA achieved oxygen-rich blood return from the IVC to the RA without shifting the arterial cannulation. Subsequently, SO₂ of the SVC and the pulmonary artery increased (70.4 ± 1.0% and 73.4 ± 1.1%, respectively). Compared with IVC-FA, a lesser difference in venous oxygen return and attenuated differential hypoxia were observed with IVC-CA and FA-IJV.

Conclusions: Differential venous oxygen return is a key factor in the etiology of differential hypoxia in VA ECMO. With knowledge of this mechanism, we can apply better cannula configurations in clinical practice.

Show MeSH
Related in: MedlinePlus