Original Article
Does Single Ventricle Physiology Affect Survival of Children Requiring Extracorporeal Membrane Oxygenation Support Following Cardiac Surgery?
World Journal for Pediatric and Congenital Heart Surgery 2014, Vol 5(1) 7-15 ª The Author(s) 2014 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/2150135113507292 pch.sagepub.com
Bahaaldin Alsoufi, MD1,2, Abid Awan, MD1, Cedric Manlhiot, BSc3, Zohair Al-Halees, MD1, Mamdouh Al-Ahmadi, MD1, Brian W. McCrindle, MD, MPH3, and Abdullah Alwadai, MD1
Abstract Background: Improved survival with postoperative extracorporeal membrane oxygenation (ECMO) has expanded its application to children with single ventricle (SV) anomalies. We examine current-era outcomes of postoperative ECMO with special focus on patients with SV. Methods: Demographic, anatomic, surgical, and support details of 100 consecutive children requiring postoperative ECMO (2007-2012) were included into multivariable regression models to identify factors affecting survival. Results: Median age was 73 days (4 days-16.2 years), 31 patients had SV physiology. The ECMO indication was failure to wean cardiopulmonary bypass (34%) and postoperative low cardiac output (66%) including 37% having extracorporeal cardiopulmonary resuscitation (ECPR). Median ECMO duration was four days (1-21). The ECMO decannulation and survival to hospital discharge were 62% and 37%. In SV group, decannulation and survival rates were 55% and 32%. The SV-ECMO outcomes were best in ECPR subgroup (54%), following shunt (57%) or Norwood (46%) and worst following Glenn, Fontan, or total anomalous pulmonary venous connection repair (0% survival). On multivariable analysis, factors affecting odds of survival were performing angiogram (odds ratio [OR]: 15.28, confidence interval [CI]: 2.34-99.89, P ¼ .004), prolonged ECMO duration (OR: 0.64, CI: 0.47-0.88 per day, P ¼ .005), leaving cannulation snares (OR: 28.41, CI: 2.65-304.70, P ¼ .006), higher HCO3 (OR: 1.19, CI: 1.04-1.36, P ¼ .01), renal failure requiring hemodialysis (OR: 0.21, CI: 0.06-0.76, P ¼ .02), bleeding requiring re-exploration (OR: 0.21, CI: 0.06-0.75, P ¼ .02), ECPR in patients with SV (OR: 11.84, CI: 1.11-126.07, P ¼ .04), delayed lactate normalization (OR: 0.95, CI: 0.90-0.99 per hour, P ¼ .02), and elevated liver enzymes (OR: 0.97, CI: 0.95-1.00 per 10 unit/L, P ¼ .05). Conclusions: The ECMO is valuable in patients with SV however results depend on anatomy, procedure, and support indication. Persistent markers of poor perfusion, end-organ injury, and prolonged ECMO duration are associated with mortality. Those factors could be modified by early ECMO application before organ damage, meticulous homeostasis to ensure adequate perfusion, early diagnosis, and reoperation on residual lesions to expedite weaning. Keywords CHD, univentricular heart, circulatory assistance, congenital heart surgery, extracorporeal membrane oxygenation Submitted June 20, 2013; Accepted September 06, 2013.
Introduction The use of extracorporeal membrane oxygenation (ECMO) following surgical repair of congenital heart disease has steadily increased over the past two decades and has become an invaluable tool in the support of children failing to successfully wean off cardiopulmonary bypass (CPB) or having persistent postoperative low cardiac output (LCO).1-8 Similarly, the use of extracorporeal cardiopulmonary resuscitation (ECPR) with rapid ECMO deployment to provide immediate cardiovascular support to patients having cardiac arrest (CA) unresponsive to conventional cardiopulmonary
1 Heart Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia 2 Division of Cardiothoracic Surgery, Children’s Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA 3 Labatt Family Heart Center, Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
Corresponding Author: Bahaaldin Alsoufi, Division of Cardiothoracic Surgery, Emory University School of Medicine, Children’s Healthcare of Atlanta, 1405 Clifton Road, NE, Atlanta, GA 30322, USA. Email: [email protected]
Downloaded from pch.sagepub.com at FLORIDA INTL UNIV on June 7, 2015
8
World Journal for Pediatric and Congenital Heart Surgery 5(1)
Abbreviations and Acronyms AVV BV CA CI ICU CPR CPB CNS ECMO ECPR IQR LCO LVOTO OR PA RACHS-1 SV TAPVC VSD
atrioventricular valve two ventricle cardiac arrest confidence interval intensive care unit cardiopulmonary resuscitation cardiopulmonary bypass central nervous system extracorporeal membrane oxygenation extracorporeal cardiopulmonary resuscitation interquartile range low cardiac output left ventricular outflow tract obstruction odds ratio pulmonary artery Risk Adjustment in Congenital Heart Surgery single ventricle total anomalous pulmonary venous connection ventricular septal defect
resuscitation (CPR) measures has been increasingly utilized and has proven its value salvaging children who would have otherwise succumbed to refractory CA.9-14 Successful experiences with ECMO and ECPR have led to expansion of their utility to support patients with single ventricle (SV) physiology with variable results.8,15-20 Despite increased understanding of postoperative ECMO application, risk factors affecting outcome have varied, and ideal candidates have not been identified, especially for SV population.6,8,15-20 In the current study, we describe our institutional ECMO protocol, report current-era outcomes, and assess factors associated with hospital survival, with special focus on patients with SV.
Hemofilter BC 20 Plus (Maquet, Hirrlingen, Germany). Total prime is approximately 360 mL. This system can provide maximum flow of 2.8 L/min and can support patients 2.8 L/min, a similar circuit utilizing 3/8-inch internal diameter tubing and Quadrox PLS polymethylpentane diffusion membrane (surface area 1.8 m2; Maquet, Hirrlingen, Germany) is utilized. Total prime is approximately 460 mL. This system can provide maximum flow of 7 L/min and can support patients >28 kg. Our institutional protocols for patient management while on ECMO support have been described previously.21
Statistical Analysis Descriptive statistics were reported as median, range, and interquartile range (IQR) for continuous variables and as frequencies and percentages for categorical variables. Inotrope score was calculated by obtaining the amount of inotrope support the patients received prior to arrest and then entering the data into the following equation: Inotrope score: dopamine þ dobutamine þ ([epinephrine þ norepinephrine] 100) þ (Milrinone 20). Units of inotrope dosage used in this equation were in micrograms per kilogram per minute. Unrelated two-group comparisons were done with unpaired, two-tailed t tests for continuous variables and Fisher exact test for categorical data. Potential demographic, anatomic, clinical, operative, and ECMO risk factors were analyzed with both univariable and multivariable logistic regression models. The response variable was survival to hospital discharge (binary). In all multivariable models, the normality and linearity of continuous variables were assessed and appropriate transformations were utilized where necessary. A P value of .05 was considered significant. All analyses were done using the SAS statistical software v9.3 (SAS Institute, Cary, North Carolina).
Results Patients’ Characteristics
Inclusion Criteria From 2007 to 2012, 100 children
Does Single Ventricle Physiology Affect Survival of Children Requiring Extracorporeal Membrane Oxygenation Support Following Cardiac Surgery?
World Journal for Pediatric and Congenital Heart Surgery 2014, Vol 5(1) 7-15 ª The Author(s) 2014 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/2150135113507292 pch.sagepub.com
Bahaaldin Alsoufi, MD1,2, Abid Awan, MD1, Cedric Manlhiot, BSc3, Zohair Al-Halees, MD1, Mamdouh Al-Ahmadi, MD1, Brian W. McCrindle, MD, MPH3, and Abdullah Alwadai, MD1
Abstract Background: Improved survival with postoperative extracorporeal membrane oxygenation (ECMO) has expanded its application to children with single ventricle (SV) anomalies. We examine current-era outcomes of postoperative ECMO with special focus on patients with SV. Methods: Demographic, anatomic, surgical, and support details of 100 consecutive children requiring postoperative ECMO (2007-2012) were included into multivariable regression models to identify factors affecting survival. Results: Median age was 73 days (4 days-16.2 years), 31 patients had SV physiology. The ECMO indication was failure to wean cardiopulmonary bypass (34%) and postoperative low cardiac output (66%) including 37% having extracorporeal cardiopulmonary resuscitation (ECPR). Median ECMO duration was four days (1-21). The ECMO decannulation and survival to hospital discharge were 62% and 37%. In SV group, decannulation and survival rates were 55% and 32%. The SV-ECMO outcomes were best in ECPR subgroup (54%), following shunt (57%) or Norwood (46%) and worst following Glenn, Fontan, or total anomalous pulmonary venous connection repair (0% survival). On multivariable analysis, factors affecting odds of survival were performing angiogram (odds ratio [OR]: 15.28, confidence interval [CI]: 2.34-99.89, P ¼ .004), prolonged ECMO duration (OR: 0.64, CI: 0.47-0.88 per day, P ¼ .005), leaving cannulation snares (OR: 28.41, CI: 2.65-304.70, P ¼ .006), higher HCO3 (OR: 1.19, CI: 1.04-1.36, P ¼ .01), renal failure requiring hemodialysis (OR: 0.21, CI: 0.06-0.76, P ¼ .02), bleeding requiring re-exploration (OR: 0.21, CI: 0.06-0.75, P ¼ .02), ECPR in patients with SV (OR: 11.84, CI: 1.11-126.07, P ¼ .04), delayed lactate normalization (OR: 0.95, CI: 0.90-0.99 per hour, P ¼ .02), and elevated liver enzymes (OR: 0.97, CI: 0.95-1.00 per 10 unit/L, P ¼ .05). Conclusions: The ECMO is valuable in patients with SV however results depend on anatomy, procedure, and support indication. Persistent markers of poor perfusion, end-organ injury, and prolonged ECMO duration are associated with mortality. Those factors could be modified by early ECMO application before organ damage, meticulous homeostasis to ensure adequate perfusion, early diagnosis, and reoperation on residual lesions to expedite weaning. Keywords CHD, univentricular heart, circulatory assistance, congenital heart surgery, extracorporeal membrane oxygenation Submitted June 20, 2013; Accepted September 06, 2013.
Introduction The use of extracorporeal membrane oxygenation (ECMO) following surgical repair of congenital heart disease has steadily increased over the past two decades and has become an invaluable tool in the support of children failing to successfully wean off cardiopulmonary bypass (CPB) or having persistent postoperative low cardiac output (LCO).1-8 Similarly, the use of extracorporeal cardiopulmonary resuscitation (ECPR) with rapid ECMO deployment to provide immediate cardiovascular support to patients having cardiac arrest (CA) unresponsive to conventional cardiopulmonary
1 Heart Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia 2 Division of Cardiothoracic Surgery, Children’s Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA 3 Labatt Family Heart Center, Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
Corresponding Author: Bahaaldin Alsoufi, Division of Cardiothoracic Surgery, Emory University School of Medicine, Children’s Healthcare of Atlanta, 1405 Clifton Road, NE, Atlanta, GA 30322, USA. Email: [email protected]
Downloaded from pch.sagepub.com at FLORIDA INTL UNIV on June 7, 2015
8
World Journal for Pediatric and Congenital Heart Surgery 5(1)
Abbreviations and Acronyms AVV BV CA CI ICU CPR CPB CNS ECMO ECPR IQR LCO LVOTO OR PA RACHS-1 SV TAPVC VSD
atrioventricular valve two ventricle cardiac arrest confidence interval intensive care unit cardiopulmonary resuscitation cardiopulmonary bypass central nervous system extracorporeal membrane oxygenation extracorporeal cardiopulmonary resuscitation interquartile range low cardiac output left ventricular outflow tract obstruction odds ratio pulmonary artery Risk Adjustment in Congenital Heart Surgery single ventricle total anomalous pulmonary venous connection ventricular septal defect
resuscitation (CPR) measures has been increasingly utilized and has proven its value salvaging children who would have otherwise succumbed to refractory CA.9-14 Successful experiences with ECMO and ECPR have led to expansion of their utility to support patients with single ventricle (SV) physiology with variable results.8,15-20 Despite increased understanding of postoperative ECMO application, risk factors affecting outcome have varied, and ideal candidates have not been identified, especially for SV population.6,8,15-20 In the current study, we describe our institutional ECMO protocol, report current-era outcomes, and assess factors associated with hospital survival, with special focus on patients with SV.
Hemofilter BC 20 Plus (Maquet, Hirrlingen, Germany). Total prime is approximately 360 mL. This system can provide maximum flow of 2.8 L/min and can support patients 2.8 L/min, a similar circuit utilizing 3/8-inch internal diameter tubing and Quadrox PLS polymethylpentane diffusion membrane (surface area 1.8 m2; Maquet, Hirrlingen, Germany) is utilized. Total prime is approximately 460 mL. This system can provide maximum flow of 7 L/min and can support patients >28 kg. Our institutional protocols for patient management while on ECMO support have been described previously.21
Statistical Analysis Descriptive statistics were reported as median, range, and interquartile range (IQR) for continuous variables and as frequencies and percentages for categorical variables. Inotrope score was calculated by obtaining the amount of inotrope support the patients received prior to arrest and then entering the data into the following equation: Inotrope score: dopamine þ dobutamine þ ([epinephrine þ norepinephrine] 100) þ (Milrinone 20). Units of inotrope dosage used in this equation were in micrograms per kilogram per minute. Unrelated two-group comparisons were done with unpaired, two-tailed t tests for continuous variables and Fisher exact test for categorical data. Potential demographic, anatomic, clinical, operative, and ECMO risk factors were analyzed with both univariable and multivariable logistic regression models. The response variable was survival to hospital discharge (binary). In all multivariable models, the normality and linearity of continuous variables were assessed and appropriate transformations were utilized where necessary. A P value of .05 was considered significant. All analyses were done using the SAS statistical software v9.3 (SAS Institute, Cary, North Carolina).
Results Patients’ Characteristics
Inclusion Criteria From 2007 to 2012, 100 children
