Ann Thorac Surg 2014;97:1120–5
R. Scott Stephens, MD Division of Pulmonary and Critical Care Medicine Department of Medicine The Johns Hopkins University 1830 E Monument St 5th Flr Baltimore, MD 21205 e-mail: [email protected] Ashish S. Shah, MD Glenn J. R. Whitman, MD Division of Cardiac Surgery Department of Surgery
References 1. Mazzeffi M, Rock P. Should we prone cardiac surgery patients with acute respiratory distress syndrome (letter). Ann Thorac Surg 2014;97:1122. 2. Stephens RS, Shah AS, Whitman GJR. Lung injury and acute respiratory distress syndrome after cardiac surgery. Ann Thorac Surg 2013;95:1122–9. 3. Guerin C, Reignier J, Richard JC, et al. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med 2013;368:2159–68. 4. Gattinoni L, Tognoni G, Pesenti A, et al. Effect of prone positioning on the survival of patients with acute respiratory failure. N Engl J Med 2001;345:568–73. 5. Guerin C, Gaillard S, Lemasson S, et al. Effects of systematic prone positioning in hypoxemic acute respiratory failure: a randomized controlled trial. JAMA 2004;292: 2379–87. 6. The Acute Respiratory Distress Syndrome Network. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med 2000;342: 1301–8. 7. Maillet JM, Thierry S, Brodaty D. Prone positioning and acute respiratory distress syndrome after cardiac surgery: a feasibility study. J Cardiothorac Vasc Anesth 2008;22: 414–7. 8. Brussel T, Hachenberg T, Roos N, Lemzem H, Konertz W, Lawin P. Mechanical ventilation in the prone position for acute respiratory failure after cardiac surgery. J Cardiothorac Vasc Anesth 1993;7:541–6.
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
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9. Eremenko AA, Egorov VM, Levikov DI. Results of the treatment of cardiac surgery patients with postoperative acute respiratory distress syndrome by prone-position pulmonary ventilation [in Russian] Anesteziol Reanimatol 2000;(5):42–5.
Evidence of Normalized Cardiopulmonary Function After Pectus Excavatum Repair To the Editor: In their recent article, Maagaard and coworkers [1] demonstrated normalization of cardiopulmonary exercise function in adolescents with pectus excavatum (PEx) 3 years after Nuss repair and bar removal. We congratulate Maagaard and coworkers for their relevant article in which, however, they outlined a limitation of their study: “we only examined healthy adolescents and therefore our findings cannot be extrapolated to other age groups.” Thus, we take the opportunity to mention that Maagaard and coworkers failed to refer to our prospective study based on a large series of 70 adult patients undergoing a PEx Ravitch-type repair [2], and comparative pulmonary/cardiovascular function at rest and at maximal exercise before operation and 1 year afterward (ie, 6 months after support bar removal) [3]. We think this omission is critical because our study, conducted in a homogeneous group of adults with no postoperative changes in physical activity, clearly demonstrated that the PEx open repair significantly improved maximal oxygen uptake (VO2max) and O2 pulse. Increase of O2 pulse (a surrogate of heart stroke volume) after operation suggested that improvement in aerobic capacity (VO2max) was the result of a better cardiovascular adaptation at maximal workload. Furthermore, in a second series of 20 patients, we recently reported that inspiratory muscle strength was significantly impaired before operation and that normalization of thoracic geometry by PEx open repair could restore adequate capacity of the inspiratory muscle system to generate negative pulmonary pressure during ventilation (the so-called respiratory pump) that is necessary to enhance venous return, heart filling, cardiac output, and, consequently, aerobic capability [4]. Taken together, our previous studies and the article of Maagaard and coworkers indicate that PEx repair in any way and in all age groups significantly improves cardiovascular function, and contradicts arguments that correction is primarily cosmetic. Remi Neviere, MD, PhD Department of Pulmonary Function Tests Lille University Teaching Hospital CHULille
MISCELLANEOUS
cohorts. They did not include cardiac surgical patients in their analysis (indeed, sternotomy within the prior 15 days was an exclusion criterion). As Mazzeffi and Rock [1] note (and as we mentioned in our review), there are reports of successful use of the prone position with postoperative cardiac surgical patients [7–9]. However, that is not our practice, and we do not recommend it. As Mazzeffi and Rock point out, sternal destabilization and dislodgement of mediastinal drains and pacing wires are real concerns, as is the effect of prone positioning on cardiac output and hemodynamics. If ARDS and life-threatening hypoxemia develop in a postoperative patient despite standard ARDS care (low tidal volumes, negative fluid balance, consideration of neuromuscular blockade, inhaled nitric oxide), we utilize extracorporeal membrane oxygenation as a rescue therapy. We admit that there are few data to support this practice, but as Mazzeffi and Rock point out, there are limited data to support prone positioning in cardiac surgical patients, and many apparent reasons to avoid it.
CORRESPONDENCE
Alain Wurtz, MD Cardiac and Thoracic Surgery Division Lille University Teaching Hospital CHULille F59037 Lille Cedex, France e-mail: [email protected]
References 1. Maagaard M, Tang M, Ringgaard S, et al. Normalized cardiopulmonary exercise function in patients with pectus
0003-4975/$36.00
1124
CORRESPONDENCE
excavatum three years after operation. Ann Thorac Surg 2013;96:272–8. 2. Wurtz A, Rousse N, Benhamed L, et al. Simplified open repair for anterior chest wall deformities: analysis of results in 205 patients. Orthop Traumatol Surg Res 2012;98: 319–26. 3. Neviere R, Montaigne D, Benhamed L, et al. Cardiopulmonary response following surgical repair of pectus excavatum in adult patients. Eur J Cardiothorac Surg 2011;40: e77–82. 4. Neviere R, Montaigne D, Benhamed L, Catto M, Wurtz A. Pectus excavatum repair improves respiratory pump efficacy and cardiovascular function at exercise. J Thorac Cardiovasc Surg 2013;145:605–6.
Early Pediatric Renal Replacement Therapy: Is the Baby Wash Actually Killing the Baby? To the Editor:
MISCELLANEOUS
We read with great interest the article by Wolf and coauthors entitled “Early renal replacement therapy during pediatric cardiac extracorporeal support increases mortality” [1]. The article clearly remarks that extracorporeal membrane oxygenation (ECMO) with renal replacement (namely, continuous venovenous hemofiltration [CVVH]) is administered to patients with a particularly high risk of death. However, it is well known that patients receiving both CVVH and ECMO are significantly more severely ill with respect to those receiving only ECMO [2]. In severely overloaded patients, especially when renal failure occurs, hemofiltration is a firstline mandatory therapy [3], and the message that CVVH would worsen the outcome should be considered with great caution. Second, in our opinion, the timing of CVVH should be more adequately targeted on indications (ie, timely removal of inflammation mediators, treatment and prevention of fluid overload, cutoff of biomarkers, classification of acute kidney injury) rather than on time frames [4]. Finally, we would like to insist that a dedicated CVVH device, in series with the ECMO circuit, might be useful to exactly and accurately manage hemofiltration dose and net fluid balance [5]. and it would certainly perform better, in terms of accuracy and errors, than an adapted circuit allowing a lesser degree of fluid excess removal. In conclusion, children receiving ECMO with a need for renal replacement are a quite delicate population with a high risk of death, per se; currently, CVVH should be considered a lifesaving treatment that still needs optimization in the timing of therapy and the modality of delivery, but certainly not a direct cause of mortality. Zaccaria Ricci, MD Department of Pediatric Cardiosurgery Bambino Ges u Children’s Hospital Piazza S. Onofrio 4 00165 Rome, Italy e-mail: [email protected] Claudio Ronco, MD Department of Nephrology, Dialysis, and Transplantation S. Bortolo Hospital International Renal Research Institute Vicenza, Italy Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
Ann Thorac Surg 2014;97:1120–5
References 1. Wolf MJ, Chanani NK, Heard ML, Kanter KR, Mahle WT. Early renal replacement therapy during pediatric cardiac extracorporeal support increases mortality. Ann Thorac Surg 2013;96:917–22. 2. Paden ML, Warshaw BL, Heard ML, Fortenberry JD. Recovery of renal function and survival after continuous renal replacement therapy during extracorporeal membrane oxygenation. Pediatr Crit Care Med 2011;12:153–8. 3. Selewski DT, Cornell TT, Blatt NB, et al. Fluid overload and fluid removal in pediatric patients on extracorporeal membrane oxygenation requiring continuous renal replacement therapy. Crit Care Med 2012;40:2694–9. 4. Ricci Z, Morelli S, Favia I, Garisto C, Brancaccio G, Picardo S. Neutrophil gelatinase-associated lipocalin levels during extracorporeal membrane oxygenation in critically ill children with congenital heart disease: preliminary experience. Pediatr Crit Care Med 2012;13:e51–4. 5. Ronco C, Garzotto F, Ricci Z. CA.R.PE.DI.E.M. (CardioRenal Pediatric Dialysis Emergency Machine): evolution of continuous renal replacement therapies in infants. A personal journey. Pediatr Nephrol 2012;27:1203–11.
Reply To the Editor: We appreciate the comments of Drs Ricci and Ronco [1] regarding our recent publication examining the impact of early renal replacement therapy during pediatric cardiac extracorporeal (ECMO) support [2]. We agree that continuous veno-venous hemofiltration (CVVH) plays a key role in treatment of acute renal failure, acute kidney injury, and severe fluid overload. Our paper addressed the initiation of CVVH within the first 48 hours of ECMO support, at which time the above issues may not yet be present or evident. We make the argument that reflexive CVVH during ECMO support should not be the standard of care; but rather careful consideration of clinical indications, acute kidney injury classification, and biomarkers is necessary prior to initiation of treatment. Pediatric cardiac patients requiring CVVH postoperatively carry a high mortality risk, even in the absence of ECMO support [3]. With regard to a dedicated CVVH device, we agree that such a device is needed for the pediatric population, whether or not they are on ECMO [4, 5]. There is variability in the accuracy of ultrafiltration volume when an in-line hemofilter is used to provide CVVH in ECMO patients [6]. In addition, the use of a commercially available CVVH device in combination with ECMO is a reasonable and more accurate way to achieve ultrafiltration [7]. Tighter control of fluid removal rates, especially early in the ECMO course could serve to prevent the intravascular depletion, which may contribute to increased mortality in these patients. In conclusion, we agree that CVVH is a potentially lifesaving treatment when used for the correct indications. We do, however. caution against its automatic use in pediatric cardiac ECMO patients, especially early in the ECMO course when the indications for its initiation may not be present. Michael J. Wolf, MD Department of Pediatrics Divisions of Cardiology and Critical Care Medicine Emory University School of Medicine Children’s Healthcare of Atlanta 1405 Clifton Rd NE Atlanta, GA 30329 e-mail: [email protected] 0003-4975/$36.00
R. Scott Stephens, MD Division of Pulmonary and Critical Care Medicine Department of Medicine The Johns Hopkins University 1830 E Monument St 5th Flr Baltimore, MD 21205 e-mail: [email protected] Ashish S. Shah, MD Glenn J. R. Whitman, MD Division of Cardiac Surgery Department of Surgery
References 1. Mazzeffi M, Rock P. Should we prone cardiac surgery patients with acute respiratory distress syndrome (letter). Ann Thorac Surg 2014;97:1122. 2. Stephens RS, Shah AS, Whitman GJR. Lung injury and acute respiratory distress syndrome after cardiac surgery. Ann Thorac Surg 2013;95:1122–9. 3. Guerin C, Reignier J, Richard JC, et al. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med 2013;368:2159–68. 4. Gattinoni L, Tognoni G, Pesenti A, et al. Effect of prone positioning on the survival of patients with acute respiratory failure. N Engl J Med 2001;345:568–73. 5. Guerin C, Gaillard S, Lemasson S, et al. Effects of systematic prone positioning in hypoxemic acute respiratory failure: a randomized controlled trial. JAMA 2004;292: 2379–87. 6. The Acute Respiratory Distress Syndrome Network. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med 2000;342: 1301–8. 7. Maillet JM, Thierry S, Brodaty D. Prone positioning and acute respiratory distress syndrome after cardiac surgery: a feasibility study. J Cardiothorac Vasc Anesth 2008;22: 414–7. 8. Brussel T, Hachenberg T, Roos N, Lemzem H, Konertz W, Lawin P. Mechanical ventilation in the prone position for acute respiratory failure after cardiac surgery. J Cardiothorac Vasc Anesth 1993;7:541–6.
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
1123
9. Eremenko AA, Egorov VM, Levikov DI. Results of the treatment of cardiac surgery patients with postoperative acute respiratory distress syndrome by prone-position pulmonary ventilation [in Russian] Anesteziol Reanimatol 2000;(5):42–5.
Evidence of Normalized Cardiopulmonary Function After Pectus Excavatum Repair To the Editor: In their recent article, Maagaard and coworkers [1] demonstrated normalization of cardiopulmonary exercise function in adolescents with pectus excavatum (PEx) 3 years after Nuss repair and bar removal. We congratulate Maagaard and coworkers for their relevant article in which, however, they outlined a limitation of their study: “we only examined healthy adolescents and therefore our findings cannot be extrapolated to other age groups.” Thus, we take the opportunity to mention that Maagaard and coworkers failed to refer to our prospective study based on a large series of 70 adult patients undergoing a PEx Ravitch-type repair [2], and comparative pulmonary/cardiovascular function at rest and at maximal exercise before operation and 1 year afterward (ie, 6 months after support bar removal) [3]. We think this omission is critical because our study, conducted in a homogeneous group of adults with no postoperative changes in physical activity, clearly demonstrated that the PEx open repair significantly improved maximal oxygen uptake (VO2max) and O2 pulse. Increase of O2 pulse (a surrogate of heart stroke volume) after operation suggested that improvement in aerobic capacity (VO2max) was the result of a better cardiovascular adaptation at maximal workload. Furthermore, in a second series of 20 patients, we recently reported that inspiratory muscle strength was significantly impaired before operation and that normalization of thoracic geometry by PEx open repair could restore adequate capacity of the inspiratory muscle system to generate negative pulmonary pressure during ventilation (the so-called respiratory pump) that is necessary to enhance venous return, heart filling, cardiac output, and, consequently, aerobic capability [4]. Taken together, our previous studies and the article of Maagaard and coworkers indicate that PEx repair in any way and in all age groups significantly improves cardiovascular function, and contradicts arguments that correction is primarily cosmetic. Remi Neviere, MD, PhD Department of Pulmonary Function Tests Lille University Teaching Hospital CHULille
MISCELLANEOUS
cohorts. They did not include cardiac surgical patients in their analysis (indeed, sternotomy within the prior 15 days was an exclusion criterion). As Mazzeffi and Rock [1] note (and as we mentioned in our review), there are reports of successful use of the prone position with postoperative cardiac surgical patients [7–9]. However, that is not our practice, and we do not recommend it. As Mazzeffi and Rock point out, sternal destabilization and dislodgement of mediastinal drains and pacing wires are real concerns, as is the effect of prone positioning on cardiac output and hemodynamics. If ARDS and life-threatening hypoxemia develop in a postoperative patient despite standard ARDS care (low tidal volumes, negative fluid balance, consideration of neuromuscular blockade, inhaled nitric oxide), we utilize extracorporeal membrane oxygenation as a rescue therapy. We admit that there are few data to support this practice, but as Mazzeffi and Rock point out, there are limited data to support prone positioning in cardiac surgical patients, and many apparent reasons to avoid it.
CORRESPONDENCE
Alain Wurtz, MD Cardiac and Thoracic Surgery Division Lille University Teaching Hospital CHULille F59037 Lille Cedex, France e-mail: [email protected]
References 1. Maagaard M, Tang M, Ringgaard S, et al. Normalized cardiopulmonary exercise function in patients with pectus
0003-4975/$36.00
1124
CORRESPONDENCE
excavatum three years after operation. Ann Thorac Surg 2013;96:272–8. 2. Wurtz A, Rousse N, Benhamed L, et al. Simplified open repair for anterior chest wall deformities: analysis of results in 205 patients. Orthop Traumatol Surg Res 2012;98: 319–26. 3. Neviere R, Montaigne D, Benhamed L, et al. Cardiopulmonary response following surgical repair of pectus excavatum in adult patients. Eur J Cardiothorac Surg 2011;40: e77–82. 4. Neviere R, Montaigne D, Benhamed L, Catto M, Wurtz A. Pectus excavatum repair improves respiratory pump efficacy and cardiovascular function at exercise. J Thorac Cardiovasc Surg 2013;145:605–6.
Early Pediatric Renal Replacement Therapy: Is the Baby Wash Actually Killing the Baby? To the Editor:
MISCELLANEOUS
We read with great interest the article by Wolf and coauthors entitled “Early renal replacement therapy during pediatric cardiac extracorporeal support increases mortality” [1]. The article clearly remarks that extracorporeal membrane oxygenation (ECMO) with renal replacement (namely, continuous venovenous hemofiltration [CVVH]) is administered to patients with a particularly high risk of death. However, it is well known that patients receiving both CVVH and ECMO are significantly more severely ill with respect to those receiving only ECMO [2]. In severely overloaded patients, especially when renal failure occurs, hemofiltration is a firstline mandatory therapy [3], and the message that CVVH would worsen the outcome should be considered with great caution. Second, in our opinion, the timing of CVVH should be more adequately targeted on indications (ie, timely removal of inflammation mediators, treatment and prevention of fluid overload, cutoff of biomarkers, classification of acute kidney injury) rather than on time frames [4]. Finally, we would like to insist that a dedicated CVVH device, in series with the ECMO circuit, might be useful to exactly and accurately manage hemofiltration dose and net fluid balance [5]. and it would certainly perform better, in terms of accuracy and errors, than an adapted circuit allowing a lesser degree of fluid excess removal. In conclusion, children receiving ECMO with a need for renal replacement are a quite delicate population with a high risk of death, per se; currently, CVVH should be considered a lifesaving treatment that still needs optimization in the timing of therapy and the modality of delivery, but certainly not a direct cause of mortality. Zaccaria Ricci, MD Department of Pediatric Cardiosurgery Bambino Ges u Children’s Hospital Piazza S. Onofrio 4 00165 Rome, Italy e-mail: [email protected] Claudio Ronco, MD Department of Nephrology, Dialysis, and Transplantation S. Bortolo Hospital International Renal Research Institute Vicenza, Italy Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
Ann Thorac Surg 2014;97:1120–5
References 1. Wolf MJ, Chanani NK, Heard ML, Kanter KR, Mahle WT. Early renal replacement therapy during pediatric cardiac extracorporeal support increases mortality. Ann Thorac Surg 2013;96:917–22. 2. Paden ML, Warshaw BL, Heard ML, Fortenberry JD. Recovery of renal function and survival after continuous renal replacement therapy during extracorporeal membrane oxygenation. Pediatr Crit Care Med 2011;12:153–8. 3. Selewski DT, Cornell TT, Blatt NB, et al. Fluid overload and fluid removal in pediatric patients on extracorporeal membrane oxygenation requiring continuous renal replacement therapy. Crit Care Med 2012;40:2694–9. 4. Ricci Z, Morelli S, Favia I, Garisto C, Brancaccio G, Picardo S. Neutrophil gelatinase-associated lipocalin levels during extracorporeal membrane oxygenation in critically ill children with congenital heart disease: preliminary experience. Pediatr Crit Care Med 2012;13:e51–4. 5. Ronco C, Garzotto F, Ricci Z. CA.R.PE.DI.E.M. (CardioRenal Pediatric Dialysis Emergency Machine): evolution of continuous renal replacement therapies in infants. A personal journey. Pediatr Nephrol 2012;27:1203–11.
Reply To the Editor: We appreciate the comments of Drs Ricci and Ronco [1] regarding our recent publication examining the impact of early renal replacement therapy during pediatric cardiac extracorporeal (ECMO) support [2]. We agree that continuous veno-venous hemofiltration (CVVH) plays a key role in treatment of acute renal failure, acute kidney injury, and severe fluid overload. Our paper addressed the initiation of CVVH within the first 48 hours of ECMO support, at which time the above issues may not yet be present or evident. We make the argument that reflexive CVVH during ECMO support should not be the standard of care; but rather careful consideration of clinical indications, acute kidney injury classification, and biomarkers is necessary prior to initiation of treatment. Pediatric cardiac patients requiring CVVH postoperatively carry a high mortality risk, even in the absence of ECMO support [3]. With regard to a dedicated CVVH device, we agree that such a device is needed for the pediatric population, whether or not they are on ECMO [4, 5]. There is variability in the accuracy of ultrafiltration volume when an in-line hemofilter is used to provide CVVH in ECMO patients [6]. In addition, the use of a commercially available CVVH device in combination with ECMO is a reasonable and more accurate way to achieve ultrafiltration [7]. Tighter control of fluid removal rates, especially early in the ECMO course could serve to prevent the intravascular depletion, which may contribute to increased mortality in these patients. In conclusion, we agree that CVVH is a potentially lifesaving treatment when used for the correct indications. We do, however. caution against its automatic use in pediatric cardiac ECMO patients, especially early in the ECMO course when the indications for its initiation may not be present. Michael J. Wolf, MD Department of Pediatrics Divisions of Cardiology and Critical Care Medicine Emory University School of Medicine Children’s Healthcare of Atlanta 1405 Clifton Rd NE Atlanta, GA 30329 e-mail: [email protected] 0003-4975/$36.00
