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452
LETTERS TO THE EDITOR
10. Williams DC, Turi JL, Hornik CP, et al. Circuit oxygenator contributes to extracorporeal membrane oxygenation-induced hemolysis. ASAIO J 2015;61:190–5. 11. Bachus L, Custodio A. Know and Understand Centrifugal Pumps. Oxford: Elsevier, 2003. 12. Ganushchak YM, Severdija EE, Simons AP, van Garsse L, Weerwind PW. Can minimized cardiopulmonary bypass systems be safer? Perfusion 2012;27:176–82. 13. Lauten A, Liebing K, Franke U, Wahlers T. The Jena universal perfusion system: a universal cardiopulmonary bypass circuit for cardiac surgery. Interact Cardiovasc Thorac Surg 2007;6:1–4. 14. Simons AP, Ganushchak YM, Teerenstra S, Bergmans DC, Maessen JG, Weerwind PW. Hypovolemia in extracorporeal life support can lead to arterial gaseous microemboli. Artif Organs 2013;37:276–82. 15. Moazami N, Dembitsky WP, Adamson R, et al. Does pulsatility matter in the era of continuous-flow blood pumps? J Heart Lung Transplant 2014 Sep 28;pii:S10532498(14)01347-3. [Epub ahead of print].
Reply to Letter: Pulsatile Venoarterial Perfusion Using a Novel Synchronized Cardiac Assist Device Augments Coronary Artery Blood Flow During Ventricular Fibrillation We thank Drs. Ganushchak, Simons, and Weerwind for their very insightful comments on our article (1). The main observation of our small animal study is that the pulsatile electrocardiogramtriggered mode is not inferior to the nonpulsatile support, and the pulsatile approach has the potential to enhance coronary perfusion. The system itself is based on components that have been evaluated previously (2–6). Patel et al. have shown using the “Penn State Pseudo Patient” that the i-cor system can generate physiological quality pulsatile flow and that the membrane ventilator has low resistance and allows the transmission of hemodynamic energy to the patient (2). Wang et al. found that in adult pigs the energy equivalent pressure exceeded the mean arterial pressure by more than 10% at each measuring point during the 24-h extracorporeal life support time. The pressure drop of the membrane ventilator has been quantified (2–4). The pressure drop is significantly lower than in other gas exchange devices (please see Table 1 for details). Furthermore, system design from cannula tip to cannula tip is required to generate adequate reproducible pulsatility (2,4–6). The decrease of mean flow during the experiments applying pulse amplitude of 4500 rpm is not unexplained. The intention was to increase the energy in
doi:10.1111/aor.12524 Artif Organs, Vol. 39, No. 5, 2015
TABLE 1. Hemodynamic energy loss across the oxygenator in vivo (with permission) Time ECLS on 6h 12 h 24 h
Mode
Oxygenator SHE loss (%)
Oxygenator THE loss (%)
NP P NP P NP P NP P
— 7.3 ± 0.4 — 7.3 ± 0.6 — 7.3 ± 0.7 — 7.6 ± 0.5
6.1 ± 0.6 6.4 ± 0.5 6.0 ± 0.4 6.2 ± 0.3 6.0 ± 0.4 6.2 ± 0.4 6.2 ± 0.5 6.3 ± 0.4
Table was generated using the data from “In-Vivo Hemodynamic Performance Evaluation of Novel ECGSynchronized Pulsatile and Non-Pulsatile Cardiac Assist System in an Adult Swine Model,” by S. Wang, J. M. Izer, J. B. Clark, S. Patel, L. Pauliks, A. R. Kunselman, D. Leach, T. K. Cooper, R. P. Wilson, and A. Ündar, 2015, Artificial Organs, 39, in press, with permission. ECLS, extracorporeal life support; NP, nonpulsatile; P, pulsatile; SHE, surplus hemodynamic energy; THE, total hemodynamic energy.
the vascular system to generate a higher energy equivalent pressure and thus enable an adequate coronary flow. Dhami et al. (7) have reported that the diagonal pump may produce a higher count of gaseous microemboli at the premembrane site in pulsatile mode compared with nonpulsatile mode, nonpulsatile roller pump, and pulsatile roller pump. However, this potentially negative effect was completely turned into an advantage for pulsatile mode when measured at the precannula site, which seems clinically more relevant to us because of delivery into the patient’s circulation. This draws attention to the entire circulation loop in different perfusion modes, especially to the gas retention of the gas exchanger device. At present, there are many clinical studies dealing with microemboli in extracorporeal circuits (Dr. Ganushchak has cited one of them), mostly single-center studies with different settings and very small numbers. We fully agree with the concerns and would like to stress that well-powered, multicenter trials should be performed to obtain clear clinical evidence (7). Thank you for your comment with regard to the “mean pulse pressure.” This value should differ between pulsatile and nonpulsatile mode. We apologize for a transcription error in our table that should read “mean pulmonary artery pressure” (pulmonary artery pressure mean) demonstrating persistent lung perfusion during pulsatile perfusion (Table 2). *Ivo Simundic, *Holger Gorhan, *Georg Matheis, and †Ulrich Laufs on behalf of the authors
— 78.3 ± 6.3 78.3 ± 6.3 78.3 ± 6.3 17.5 ± 1.3 20.3 ± 1.9 18.5 ± 1.3 5.3 ± 3.1
Nonpulsatile, 3.0 L/min
No pump — — — 21.5 ± 0.8 — — — 0.0 ± 0.0
68.6 ± 3.3 114.5 ± 6.3 98.0 ± 5.7 106.3 ± 7.0 15.6 ± 1.1 21.8 ± 1.8 14.4 ± 1.8 10.1 ± 2.5
69.7 ± 4.3 103.3 ± 4.8 74.1 ± 4.3 87.9 ± 4.9 15.0 ± 1.4 27.1 ± 2.9 15.3 ± 1.7 16.1 ± 4.6
All data are given as mean ± standard error of the mean.
Heart rate (bpm) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg) Mean arterial pressure (mm Hg) Central venous pressure (mm Hg) Mean pulmonary artery pressure (mm Hg) Pulmonary wedge pressure (mm Hg) Coronary artery flow (mL/min)
Heart rate (bpm) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg) Mean arterial pressure (mm Hg) Central venous pressure (mm Hg) Mean pulmonary artery pressure (mm Hg) Pulmonary wedge pressure (mm Hg) Coronary artery flow (mL/min)
Nonpulsatile, 65% CO
No pump
Nonpulsatile, 3.0 L/min — 83.7 ± 7.0 83.7 ± 7.0 83.6 ± 6.9 17.7 ± 0.7 21.5 ± 0.9 20.7 ± 0.4 4.8 ± 3.3
75.0 ± 0.0 86.2 ± 5.3 74.0 ± 5.9 75.6 ± 5.9 16.1 ± 1.5 19.8 ± 1.9 22.0 ± 0.1 8.4 ± 5.5
72.0 ± 3.5 113.4 ± 6.8 99.3 ± 5.8 106 ± 6.1 12.8 ± 1.2 21.1 ± 2.1 12.1 ± 1.2 6.7 ± 2.3
Nonpulsatile, 3.0 L/min
Pulsatile, 3.0 L/min, Δ 3500 rpm
Cardiac arrest
72.4 ± 3.8 111.1 ± 7.2 96.5 ± 6.0 104.3 ± 5.9 13.6 ± 0.9 21.6 ± 1.5 14.1 ± 1.3 8.4 ± 1.8
Pulsatile, 65% CO
Beating heart
TABLE 2. Cardiovascular parameters measured during the last minute of each setting
75.0 ± 0.0 82.5 ± 6.1 67.3 ± 6.5 71.0 ± 6.4 18.6 ± 0.4 23.2 ± 1.1 21.0 ± 0.5 15.2 ± 5.3
Pulsatile, 2.5 L/min, Δ 4500 rpm
LETTERS TO THE EDITOR 453
Artif Organs, Vol. 39, No. 5, 2015
454
LETTERS TO THE EDITOR
*Novalung GmbH, Heilbronn, and †Klinik für Innere Medizin III, Kardiologie, Angiologie und Internistische Intensivmedizin, Universitätsklinikum des Saarlandes, Homburg, Germany E-mail: [email protected]
4.
5.
REFERENCES 1. Cremers B., Link A., Werner C., et al. Pulsatile Venoarterial Perfusion Using a Novel Synchronized Cardiac Assist Device Augments Coronary Artery Blood Flow During Ventricular Fibrillation. Artif Organs 2015;39:77–82. 2. Patel S, Wang S, Pauliks L, et al. Evaluation of a novel pulsatile extracorporeal life support system synchronized to the cardiac cycle: effect of rhythm changes on hemodynamic performance. Artif Organs 2015;39:67–76. 3. Wang S, Izer JM, Clark JB, et al. In-vivo hemodynamic performance evaluation of novel ECG-synchronized pulsatile and
Artif Organs, Vol. 39, No. 5, 2015
6.
7.
non-pulsatile cardiac assist system in an adult swine model. Artif Organs 2015; doi: 10.1111/aor.12482. [Epub ahead of print]. Wang S, Kunselman AR, Clark JB, Ündar A. In vitro hemodynamic evaluation of a novel pulsatile extracorporeal life support system: impact of perfusion modes and circuit components on energy loss. Artif Organs 2015;39:59–66. Wolfe R, Strother A, Wang S, Kunselman AR, Ündar A. Impact of pulsatility and flow rates on hemodynamic energy transmission in an adult ECLS system. Artif Organs 2015; doi: 10.1111/aor.12484. [Epub ahead of print]. Wang S, Evenson A, Chin BJ, Kunselman AR, Ündar A. Evaluation of conventional nonpulsatile and novel pulsatile extracorporeal life support systems in a simulated pediatric extracorporeal life support model. Artif Organs 2015;39:E1–9. Dhami R, Wang S, Kunselman AR, Ündar A. In vitro comparison of the delivery of gaseous microemboli and hemodynamic energy for a diagonal and a roller pump during simulated infantile cardiopulmonary bypass procedures. Artif Organs 2014;38: 56–63.
Copyright of Artificial Organs is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
452
LETTERS TO THE EDITOR
10. Williams DC, Turi JL, Hornik CP, et al. Circuit oxygenator contributes to extracorporeal membrane oxygenation-induced hemolysis. ASAIO J 2015;61:190–5. 11. Bachus L, Custodio A. Know and Understand Centrifugal Pumps. Oxford: Elsevier, 2003. 12. Ganushchak YM, Severdija EE, Simons AP, van Garsse L, Weerwind PW. Can minimized cardiopulmonary bypass systems be safer? Perfusion 2012;27:176–82. 13. Lauten A, Liebing K, Franke U, Wahlers T. The Jena universal perfusion system: a universal cardiopulmonary bypass circuit for cardiac surgery. Interact Cardiovasc Thorac Surg 2007;6:1–4. 14. Simons AP, Ganushchak YM, Teerenstra S, Bergmans DC, Maessen JG, Weerwind PW. Hypovolemia in extracorporeal life support can lead to arterial gaseous microemboli. Artif Organs 2013;37:276–82. 15. Moazami N, Dembitsky WP, Adamson R, et al. Does pulsatility matter in the era of continuous-flow blood pumps? J Heart Lung Transplant 2014 Sep 28;pii:S10532498(14)01347-3. [Epub ahead of print].
Reply to Letter: Pulsatile Venoarterial Perfusion Using a Novel Synchronized Cardiac Assist Device Augments Coronary Artery Blood Flow During Ventricular Fibrillation We thank Drs. Ganushchak, Simons, and Weerwind for their very insightful comments on our article (1). The main observation of our small animal study is that the pulsatile electrocardiogramtriggered mode is not inferior to the nonpulsatile support, and the pulsatile approach has the potential to enhance coronary perfusion. The system itself is based on components that have been evaluated previously (2–6). Patel et al. have shown using the “Penn State Pseudo Patient” that the i-cor system can generate physiological quality pulsatile flow and that the membrane ventilator has low resistance and allows the transmission of hemodynamic energy to the patient (2). Wang et al. found that in adult pigs the energy equivalent pressure exceeded the mean arterial pressure by more than 10% at each measuring point during the 24-h extracorporeal life support time. The pressure drop of the membrane ventilator has been quantified (2–4). The pressure drop is significantly lower than in other gas exchange devices (please see Table 1 for details). Furthermore, system design from cannula tip to cannula tip is required to generate adequate reproducible pulsatility (2,4–6). The decrease of mean flow during the experiments applying pulse amplitude of 4500 rpm is not unexplained. The intention was to increase the energy in
doi:10.1111/aor.12524 Artif Organs, Vol. 39, No. 5, 2015
TABLE 1. Hemodynamic energy loss across the oxygenator in vivo (with permission) Time ECLS on 6h 12 h 24 h
Mode
Oxygenator SHE loss (%)
Oxygenator THE loss (%)
NP P NP P NP P NP P
— 7.3 ± 0.4 — 7.3 ± 0.6 — 7.3 ± 0.7 — 7.6 ± 0.5
6.1 ± 0.6 6.4 ± 0.5 6.0 ± 0.4 6.2 ± 0.3 6.0 ± 0.4 6.2 ± 0.4 6.2 ± 0.5 6.3 ± 0.4
Table was generated using the data from “In-Vivo Hemodynamic Performance Evaluation of Novel ECGSynchronized Pulsatile and Non-Pulsatile Cardiac Assist System in an Adult Swine Model,” by S. Wang, J. M. Izer, J. B. Clark, S. Patel, L. Pauliks, A. R. Kunselman, D. Leach, T. K. Cooper, R. P. Wilson, and A. Ündar, 2015, Artificial Organs, 39, in press, with permission. ECLS, extracorporeal life support; NP, nonpulsatile; P, pulsatile; SHE, surplus hemodynamic energy; THE, total hemodynamic energy.
the vascular system to generate a higher energy equivalent pressure and thus enable an adequate coronary flow. Dhami et al. (7) have reported that the diagonal pump may produce a higher count of gaseous microemboli at the premembrane site in pulsatile mode compared with nonpulsatile mode, nonpulsatile roller pump, and pulsatile roller pump. However, this potentially negative effect was completely turned into an advantage for pulsatile mode when measured at the precannula site, which seems clinically more relevant to us because of delivery into the patient’s circulation. This draws attention to the entire circulation loop in different perfusion modes, especially to the gas retention of the gas exchanger device. At present, there are many clinical studies dealing with microemboli in extracorporeal circuits (Dr. Ganushchak has cited one of them), mostly single-center studies with different settings and very small numbers. We fully agree with the concerns and would like to stress that well-powered, multicenter trials should be performed to obtain clear clinical evidence (7). Thank you for your comment with regard to the “mean pulse pressure.” This value should differ between pulsatile and nonpulsatile mode. We apologize for a transcription error in our table that should read “mean pulmonary artery pressure” (pulmonary artery pressure mean) demonstrating persistent lung perfusion during pulsatile perfusion (Table 2). *Ivo Simundic, *Holger Gorhan, *Georg Matheis, and †Ulrich Laufs on behalf of the authors
— 78.3 ± 6.3 78.3 ± 6.3 78.3 ± 6.3 17.5 ± 1.3 20.3 ± 1.9 18.5 ± 1.3 5.3 ± 3.1
Nonpulsatile, 3.0 L/min
No pump — — — 21.5 ± 0.8 — — — 0.0 ± 0.0
68.6 ± 3.3 114.5 ± 6.3 98.0 ± 5.7 106.3 ± 7.0 15.6 ± 1.1 21.8 ± 1.8 14.4 ± 1.8 10.1 ± 2.5
69.7 ± 4.3 103.3 ± 4.8 74.1 ± 4.3 87.9 ± 4.9 15.0 ± 1.4 27.1 ± 2.9 15.3 ± 1.7 16.1 ± 4.6
All data are given as mean ± standard error of the mean.
Heart rate (bpm) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg) Mean arterial pressure (mm Hg) Central venous pressure (mm Hg) Mean pulmonary artery pressure (mm Hg) Pulmonary wedge pressure (mm Hg) Coronary artery flow (mL/min)
Heart rate (bpm) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg) Mean arterial pressure (mm Hg) Central venous pressure (mm Hg) Mean pulmonary artery pressure (mm Hg) Pulmonary wedge pressure (mm Hg) Coronary artery flow (mL/min)
Nonpulsatile, 65% CO
No pump
Nonpulsatile, 3.0 L/min — 83.7 ± 7.0 83.7 ± 7.0 83.6 ± 6.9 17.7 ± 0.7 21.5 ± 0.9 20.7 ± 0.4 4.8 ± 3.3
75.0 ± 0.0 86.2 ± 5.3 74.0 ± 5.9 75.6 ± 5.9 16.1 ± 1.5 19.8 ± 1.9 22.0 ± 0.1 8.4 ± 5.5
72.0 ± 3.5 113.4 ± 6.8 99.3 ± 5.8 106 ± 6.1 12.8 ± 1.2 21.1 ± 2.1 12.1 ± 1.2 6.7 ± 2.3
Nonpulsatile, 3.0 L/min
Pulsatile, 3.0 L/min, Δ 3500 rpm
Cardiac arrest
72.4 ± 3.8 111.1 ± 7.2 96.5 ± 6.0 104.3 ± 5.9 13.6 ± 0.9 21.6 ± 1.5 14.1 ± 1.3 8.4 ± 1.8
Pulsatile, 65% CO
Beating heart
TABLE 2. Cardiovascular parameters measured during the last minute of each setting
75.0 ± 0.0 82.5 ± 6.1 67.3 ± 6.5 71.0 ± 6.4 18.6 ± 0.4 23.2 ± 1.1 21.0 ± 0.5 15.2 ± 5.3
Pulsatile, 2.5 L/min, Δ 4500 rpm
LETTERS TO THE EDITOR 453
Artif Organs, Vol. 39, No. 5, 2015
454
LETTERS TO THE EDITOR
*Novalung GmbH, Heilbronn, and †Klinik für Innere Medizin III, Kardiologie, Angiologie und Internistische Intensivmedizin, Universitätsklinikum des Saarlandes, Homburg, Germany E-mail: [email protected]
4.
5.
REFERENCES 1. Cremers B., Link A., Werner C., et al. Pulsatile Venoarterial Perfusion Using a Novel Synchronized Cardiac Assist Device Augments Coronary Artery Blood Flow During Ventricular Fibrillation. Artif Organs 2015;39:77–82. 2. Patel S, Wang S, Pauliks L, et al. Evaluation of a novel pulsatile extracorporeal life support system synchronized to the cardiac cycle: effect of rhythm changes on hemodynamic performance. Artif Organs 2015;39:67–76. 3. Wang S, Izer JM, Clark JB, et al. In-vivo hemodynamic performance evaluation of novel ECG-synchronized pulsatile and
Artif Organs, Vol. 39, No. 5, 2015
6.
7.
non-pulsatile cardiac assist system in an adult swine model. Artif Organs 2015; doi: 10.1111/aor.12482. [Epub ahead of print]. Wang S, Kunselman AR, Clark JB, Ündar A. In vitro hemodynamic evaluation of a novel pulsatile extracorporeal life support system: impact of perfusion modes and circuit components on energy loss. Artif Organs 2015;39:59–66. Wolfe R, Strother A, Wang S, Kunselman AR, Ündar A. Impact of pulsatility and flow rates on hemodynamic energy transmission in an adult ECLS system. Artif Organs 2015; doi: 10.1111/aor.12484. [Epub ahead of print]. Wang S, Evenson A, Chin BJ, Kunselman AR, Ündar A. Evaluation of conventional nonpulsatile and novel pulsatile extracorporeal life support systems in a simulated pediatric extracorporeal life support model. Artif Organs 2015;39:E1–9. Dhami R, Wang S, Kunselman AR, Ündar A. In vitro comparison of the delivery of gaseous microemboli and hemodynamic energy for a diagonal and a roller pump during simulated infantile cardiopulmonary bypass procedures. Artif Organs 2014;38: 56–63.
Copyright of Artificial Organs is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
