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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

Study protocol. Heparin was infused to maintain an active clotting time of 180 to 220 sec after ECMO cannulation during the whole experiment. Of the 20 sheep, two were used for angiography. The other 18 sheep were randomly assigned to undertake one of three cannulation procedures. After 15 min of ECMO, ARF was initiated by removing the ventilator and discontinuing mechanical ventilation. The ARF animals were supported with IVC-FA for another 15 min and then were shifted to SVC-FA, IVC-CA or FA-IJV depending on the group assignment. The black arrow indicates the drainage cannula and the white arrow indicates the return cannula. Comparisons between IVC-FA and SVC-FA, IVC-FA and IVC-CA and IVC-FA and FA-IJV were made with paired t test. ARF: acute respiratory failure; 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; 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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Fig1: Study protocol. Heparin was infused to maintain an active clotting time of 180 to 220 sec after ECMO cannulation during the whole experiment. Of the 20 sheep, two were used for angiography. The other 18 sheep were randomly assigned to undertake one of three cannulation procedures. After 15 min of ECMO, ARF was initiated by removing the ventilator and discontinuing mechanical ventilation. The ARF animals were supported with IVC-FA for another 15 min and then were shifted to SVC-FA, IVC-CA or FA-IJV depending on the group assignment. The black arrow indicates the drainage cannula and the white arrow indicates the return cannula. Comparisons between IVC-FA and SVC-FA, IVC-FA and IVC-CA and IVC-FA and FA-IJV were made with paired t test. ARF: acute respiratory failure; 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; 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: The ECMO model was established as described previously with minor modifications [22-24]. Briefly, before anesthesia, all sheep were premedicated with dexmedetomidine (Dexdomitor; Orion Pharma, Madrid, Spain; 4 μg/kg) and morphine (Morfina 2%; B. Braun, Melsungen, Germany; 0.2 mg/kg) intravenously. Anesthesia was then induced with propofol (1% Propofol Lipuro; Fresenius Kabi AB, Beijing, China; 4 mg/kg) and maintained with sufentanil (5%; Yichang Humanwell Pharmaceutical Co., Ltd., Yichang, China; 5 μg/kg/h) and atracurium (0.2% Cisatracurium Besilate; Shanghai Hengrui Pharmaceutical Co. Ltd., Shanghai, China; 0.2 mg/kg/h) intravenously. After sheep were anesthetized, they were intubated with an endotracheal tube and connected to a mechanical ventilator (Servos-S, Maquet, Solna, Sweden) at a respiratory rate of 16 to 18 beats/min and a tidal volume of 6 to 8 ml/kg. An FA line was established to measure the arterial blood pressure (BP). A bolus of heparin (125 U/kg) was administered, and IVC-FA was established with 19-Fr and 15-Fr Carmeda heparin-coated cannulas (Medtronic) using the open Seldinger method. The venous cannula was placed within the IVC through the femoral vein. Placement of the cannulas was confirmed via ultrasonography. To stabilize the contribution of cardiac output (CO) and the pump flow to the body, we utilized dopamine, anesthesia and fluid to maintain heart rate (HR) and BP at a normal range. The pump flow was maintained at 50 ml/kg/min and 100% oxygen was administered at a flow rate equal to the blood flow rate. The sheep model of ARF was established as described previously through discontinuing ventilation (Figure 1) [25].Figure 1


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)

Study protocol. Heparin was infused to maintain an active clotting time of 180 to 220 sec after ECMO cannulation during the whole experiment. Of the 20 sheep, two were used for angiography. The other 18 sheep were randomly assigned to undertake one of three cannulation procedures. After 15 min of ECMO, ARF was initiated by removing the ventilator and discontinuing mechanical ventilation. The ARF animals were supported with IVC-FA for another 15 min and then were shifted to SVC-FA, IVC-CA or FA-IJV depending on the group assignment. The black arrow indicates the drainage cannula and the white arrow indicates the return cannula. Comparisons between IVC-FA and SVC-FA, IVC-FA and IVC-CA and IVC-FA and FA-IJV were made with paired t test. ARF: acute respiratory failure; 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; 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
Show All Figures
getmorefigures.php?uid=PMC4352275&req=5

Fig1: Study protocol. Heparin was infused to maintain an active clotting time of 180 to 220 sec after ECMO cannulation during the whole experiment. Of the 20 sheep, two were used for angiography. The other 18 sheep were randomly assigned to undertake one of three cannulation procedures. After 15 min of ECMO, ARF was initiated by removing the ventilator and discontinuing mechanical ventilation. The ARF animals were supported with IVC-FA for another 15 min and then were shifted to SVC-FA, IVC-CA or FA-IJV depending on the group assignment. The black arrow indicates the drainage cannula and the white arrow indicates the return cannula. Comparisons between IVC-FA and SVC-FA, IVC-FA and IVC-CA and IVC-FA and FA-IJV were made with paired t test. ARF: acute respiratory failure; 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; 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: The ECMO model was established as described previously with minor modifications [22-24]. Briefly, before anesthesia, all sheep were premedicated with dexmedetomidine (Dexdomitor; Orion Pharma, Madrid, Spain; 4 μg/kg) and morphine (Morfina 2%; B. Braun, Melsungen, Germany; 0.2 mg/kg) intravenously. Anesthesia was then induced with propofol (1% Propofol Lipuro; Fresenius Kabi AB, Beijing, China; 4 mg/kg) and maintained with sufentanil (5%; Yichang Humanwell Pharmaceutical Co., Ltd., Yichang, China; 5 μg/kg/h) and atracurium (0.2% Cisatracurium Besilate; Shanghai Hengrui Pharmaceutical Co. Ltd., Shanghai, China; 0.2 mg/kg/h) intravenously. After sheep were anesthetized, they were intubated with an endotracheal tube and connected to a mechanical ventilator (Servos-S, Maquet, Solna, Sweden) at a respiratory rate of 16 to 18 beats/min and a tidal volume of 6 to 8 ml/kg. An FA line was established to measure the arterial blood pressure (BP). A bolus of heparin (125 U/kg) was administered, and IVC-FA was established with 19-Fr and 15-Fr Carmeda heparin-coated cannulas (Medtronic) using the open Seldinger method. The venous cannula was placed within the IVC through the femoral vein. Placement of the cannulas was confirmed via ultrasonography. To stabilize the contribution of cardiac output (CO) and the pump flow to the body, we utilized dopamine, anesthesia and fluid to maintain heart rate (HR) and BP at a normal range. The pump flow was maintained at 50 ml/kg/min and 100% oxygen was administered at a flow rate equal to the blood flow rate. The sheep model of ARF was established as described previously through discontinuing ventilation (Figure 1) [25].Figure 1

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