Mark A. Scheurer

Rapid-Response Extracorporeal Membrane Oxygenation to Support Cardiopulmonary Resuscitation in Children With Cardiac Disease

Background— Survival of children with in-hospital cardiac arrest that does not respond to conventional cardiopulmonary resuscitation (CPR) is poor. We report on survival and early neurological outcomes of children with heart disease supported with rapid-response extracorporeal membrane oxygenation (ECMO) to aid cardiopulmonary resuscitation (ECPR). Methods and Results— Children with heart disease supported with ECPR were identified from our ECMO database. Demographic, CPR, and ECMO details associated with mortality were evaluated using multivariable logistic regression. Pediatric overall performance category and pediatric cerebral performance category scores were assigned to ECPR survivors to assess neurological outcomes. There were 180 ECPR runs in 172 patients. Eighty-eight patients (51%) survived to discharge. Survival in patients who underwent ECPR after cardiac surgery (54%) did not differ from nonsurgical patients (46%). Survival did not vary by cardiac diagnosis and CPR duration did not differ between survivors and nonsurvivors. Factors associated with mortality included noncardiac structural or chromosomal abnormalities (OR, 3.2; 95% CI, 1.3–7.9), use of blood-primed ECMO circuit (OR, 7.1; 95% CI, 1.4–36), and arterial pH <7.00 after ECMO deployment (OR, 6.0; 95% CI, 2.1–17.4). Development of end-organ injury on ECMO and longer ECMO duration were associated with increased mortality. Of pediatric overall performance category/pediatric cerebral performance category scores assigned to survivors, 75% had scores ≤2, indicating no to mild neurological injury. Conclusions— ECPR may promote survival in children with cardiac disease experiencing cardiac arrest unresponsive to conventional CPR with favorable early neurological outcomes. CPR duration was not associated with mortality, whereas patients with metabolic acidosis and noncardiac structural or chromosomal anomalies had higher mortality.

Blood Transfusion After Pediatric Cardiac Surgery Is Associated With Prolonged Hospital Stay

BACKGROUND Red blood cell transfusion is associated with morbidity and mortality among adults undergoing cardiac surgery. We aimed to evaluate the association of transfusion with morbidity among pediatric cardiac surgical patients. METHODS Patients discharged after cardiac surgery in 2003 were retrospectively reviewed. The red blood cell volume administered during the first 48 postoperative hours was used to classify patients into nonexposure, low exposure (≤15 mL/kg), or high exposure (>15 mL/kg) groups. Cox proportional hazards modeling was used to evaluate the association of red blood cell exposure to length of hospital stay (LOS). RESULTS Of 802 discharges, 371 patients (46.2%) required blood transfusion. Demographic differences between the transfusion exposure groups included age, weight, prematurity, and noncardiac structural abnormalities (all p<0.001). Distribution of Risk Adjusted Classification for Congenital Heart Surgery, version 1 (RACHS-1) categories, intraoperative support times, and postoperative Pediatric Risk of Mortality Score, Version III (PRISM-III) scores varied among the exposure groups (p<0.001). Median duration of mechanical ventilation (34 hours [0 to 493] versus 27 hours [0 to 621] versus 16 hours [0 to 375]), incidence of infection (21 [14%] versus 29 [13%] versus 17 [4%]), and acute kidney injury (25 [17%] versus 29 [13%] versus 34 [8%]) were highest in the high transfusion exposure group when compared with the low or nontransfusion groups (all p<0.001). In a multivariable Cox proportional hazards model, both the low transfusion group (adjusted hazard ratio [HR] 0.80, 95% confidence interval [CI]: 0.66 to 0.97, p=0.02) and high transfusion group (adjusted HR 0.66, 95% CI: 0.53 to 0.82, p<0.001) were associated with increased LOS. In subgroup analyses, both low transfusion (adjusted HR 0.81, 95% CI: 0.65 to 1.00, p=0.05) and high transfusion (adjusted HR 0.65, 95% CI: 0.49 to 0.87, p=0.004) in the biventricular group but not in the single ventricle group was associated with increased LOS. CONCLUSIONS Blood transfusion is associated with prolonged hospitalization of children after cardiac surgery, with biventricular patients at highest risk for increased LOS. Future studies are necessary to explore this association and refine transfusion practices.

Association Between Intraoperative and Early Postoperative Glucose Levels and Adverse Outcomes After Complex Congenital Heart Surgery

Background— This study sought to determine whether associations exist between perioperative glucose exposure, prolonged hospitalization, and morbid events after complex congenital heart surgery. Methods and Results— Metrics of glucose control, including average, peak, minimum, and SD of glucose levels, and duration of hyperglycemia were determined intraoperatively and for 72 hours after surgery for 378 consecutive high-risk cardiac surgical patients. Multivariable regression analyses were used to determine relationships between these metrics of glucose control, hospital length of stay, and a composite morbidity-mortality outcome after controlling for multiple variables known to influence early outcomes after congenital heart surgery. Intraoperatively, a minimum glucose ≤75 mg/dL was associated with greater adjusted odds of reaching the composite morbidity-mortality end point (odds ratio [OR], 3.10; 95% confidence interval [CI], 1.49 to 6.48), but other metrics of glucose control were not associated with the composite end point or length of stay. Greater duration of hyperglycemia (glucose >126 mg/dL) during the 72 postoperative hours was associated with longer duration of hospitalization (P<0.001). In the 72 hours after surgery, average glucose <110 mg/dL (OR, 7.30; 95% CI, 1.95 to 27.25) or >143 mg/dL (OR, 5.21; 95% CI, 1.37 to 19.89), minimum glucose ≤75 mg/dL (OR, 2.85; 95% CI, 1.38 to 5.88), and peak glucose level ≥250 mg/dL (OR, 2.55; 95% CI, 1.20 to 5.43) were all associated with greater adjusted odds of reaching the composite morbidity-mortality end point. Conclusions— In children undergoing complex congenital heart surgery, the optimal postoperative glucose range may be 110 to 126 mg/dL. Randomized trials of strict glycemic control achieved with insulin infusions in this patient population are warranted.

Extracorporeal membrane oxygenation after stage 1 palliation for hypoplastic left heart syndrome

OBJECTIVE To report the outcomes from a large multicenter cohort of neonates requiring extracorporeal membrane oxygenation (ECMO) after stage 1 palliation for hypoplastic left heart syndrome. METHODS Using data from the Extracorporeal Life Support Organization (2000-2009), we computed the survival to hospital discharge for neonates (age ≤30 days) supported with ECMO after stage 1 palliation for hypoplastic left heart syndrome. The factors associated with mortality were evaluated using multivariate logistic regression analysis. RESULTS Among 738 neonates, the survival rate was 31%. The median age at cannulation was 7 days (interquartile range, 4-11). Black race (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.2-3.6), mechanical ventilation before ECMO (>15-131 hours: OR, 1.6; 95% CI, 1.1-2.4; >131 hours: OR, 1.9; 95% CI, 1.3-2.9), use of positive end expiratory pressure (>6-8 cm H(2)O: OR, 1.7; 95% CI, 1.1-2.7; >8 cm H(2)O: OR, 1.9; 95% CI, 1.2-3.1), and longer ECMO duration (per day, OR, 1.2; 95% CI, 1.1-1.3) increased mortality. ECMO support for failure to wean from cardiopulmonary bypass (OR, 1.6; 95% CI, 1.02-2.4) also decreased survival. ECMO complications, including renal failure (OR, 1.9; 95% CI, 1.2-3.1), inotrope requirement (OR, 1.5; 95% CI, 1.1-2.1), myocardial stun (OR, 3.2; 95% CI, 1.3-7.7), metabolic acidosis (OR, 2.9; 95% CI, 1.3-6.7), and neurologic injury (OR, 1.7; 95% CI, 1.1-2.6), during support also increased mortality. CONCLUSIONS Mortality for neonates with hypoplastic left heart syndrome supported with ECMO after stage 1 palliation is high. Longer ventilation before cannulation, longer support duration, and ECMO complications increased mortality.

Variation in Perioperative Care across Centers for Infants Undergoing the Norwood Procedure

OBJECTIVES In the Single Ventricle Reconstruction trial, infants undergoing the Norwood procedure were randomly allocated to undergo a right ventricle-to-pulmonary artery shunt or a modified Blalock-Taussig shunt. Apart from shunt type, subjects received the local standard of care. We evaluated variation in perioperative care during the Norwood hospitalization across 14 trial sites. METHODS Data on preoperative, operative, and postoperative variables for 546 enrolled subjects who underwent the Norwood procedure were collected prospectively on standardized case report forms, and variation across the centers was described. RESULTS Gestational age, birth weight, and proportion with hypoplastic left heart syndrome were similar across sites. In contrast, all recorded variables related to preoperative care varied across centers, including fetal diagnosis (range, 55%-85%), preoperative intubation (range, 29%-91%), and enteral feeding. Perioperative and operative factors were also variable across sites, including median total support time (range, 74-189 minutes) and other perfusion variables, arch reconstruction technique, intraoperative medication use, and use of modified ultrafiltration (range, 48%-100%). Additional variation across centers was seen in variables related to postoperative care, including proportion with an open sternum (range, 35%-100%), median intensive care unit stay (range, 9-44 days), type of feeding at discharge, and enrollment in a home monitoring program (range, 1%-100%; 5 sites did not have a program). Overall, in-hospital death or transplant occurred in 18% (range across sites, 7%-39%). CONCLUSIONS Perioperative care during the Norwood hospitalization varies across centers. Further analysis evaluating the underlying causes and relationship of this variation to outcome is needed to inform future studies and quality improvement efforts.

Factors Associated With Prolonged Recovery After the Fontan Operation

Background— Mortality and major morbidity after the Fontan operation is low in the current era. However, factors contributing to prolonged postoperative recovery are not clearly understood. Methods and Results— Data on all patients admitted to the cardiac intensive care unit (CICU) after a Fontan operation between June 2001 and December 2005 were retrospectively analyzed. We excluded all patients who died, required Fontan takedown, or required ECMO. The study cohort was further divided into a prolonged recovery group that included patients with >75%ile for duration of mechanical ventilation or pleural drainage, and a standard recovery group which included all other patients. A multivariable logistic regression model was used to compare demographic, anatomic, and physiological variables between the prolonged and standard recovery groups. There were 226 Fontan operations performed. Of the study population (n=218), the median age was 2.61 years (1.0 to 31.9 years) and weight was 12.45 kg (8.4 to 77.5 kg). The most common diagnosis was hypoplastic left heart syndrome (n=80, 36.7%). A systemic right atrioventricular valve was present in 139 (63.7%). The lateral tunnel fenestrated Fontan was the most common surgery (n=195, 89.4%). Within the study population, 81 (38%) patients meet criteria for prolonged recovery. Univariate risk factors for prolonged recovery included higher preoperative PVR (P=0.033), longer bypass times (P=0.009), higher postbypass lactate level (P=0.017), higher postoperative central venous (P<0.001) common atrial pressure (P=0.042), inotropic score (P<0.001), and need for greater volume resuscitation during the 24 postoperative hours (>75% for the entire group; P<0.001). In a multivariable model, need for greater volume resuscitation (OR 2.81, 95% CI 1.30, 6.05) was the only independent risk factor for prolonged outcome after the Fontan operation. Conclusions— High volume expansion in the early postoperative period is an independent risk factor for prolonged recovery. The need for high volume expansion may represent the compound effects of multiple risk factors including preoperative hemodynamics and a marked systemic inflammatory response to surgery and cardiopulmonary bypass, which in turn may mediate prolonged recovery.

Does a ventriculotomy have deleterious effects following palliation in the Norwood procedure using a shunt placed from the right ventricle to the pulmonary arteries

INTRODUCTION A recent modification to the Norwood procedure involving a shunt placed directly from the right ventricle to the pulmonary arteries may improve postoperative haemodynamics. Concerns remain, however, about the potential problems produced by the required ventriculotomy. METHODS We compared 76 patients with hypoplastic left heart syndrome who underwent the Norwood procedure, 35 receiving a modified Blalock-Taussig shunt and the remaining 41 a shunt placed directly from the right ventricle to the pulmonary arteries. We reviewed their subsequent progress through the second stage of palliation. A single observer graded right ventricular function, and the severity of tricuspid regurgitation, based on blinded review of the most recent echocardiograms prior to the second stage of palliation. RESULTS At the time of catheterization prior to the second stage, patients with a shunt placed from the right ventricle to the pulmonary arteries, rather than a modified Blalock-Taussig shunt, had higher arterial diastolic blood pressure, at 44 versus 40 millimetres of mercury, p equal to 0.02, lower ventricular end diastolic pressures, at 8 versus 11 millimetres of mercury, p equal to 0.0002, and larger pulmonary arteries as judged using the Nakata index, at 270 versus 188 millimetres squared per metres squared, p equal to 0.009. There was no difference in qualitative ventricular systolic function or tricuspid regurgitation between groups. No differences were found between groups during the hospitalization following the second stage of palliation. A trend towards improved survival to the second stage was seen following the construction of a shunt from the right ventricle to the pulmonary arteries. CONCLUSIONS Construction of a shunt from the right ventricle to the pulmonary arteries is associated with lower right ventricular end diastolic pressures, larger pulmonary arterial size, and higher systemic arterial diastolic pressures. No apparent deleterious effects of the right ventriculotomy were observed in terms of qualitative ventricular systolic function or tricuspid regurgitation.

Perioperative Effects and Safety of Nesiritide Following Cardiac Surgery in Children

Nesiritide (Natrecor, Scios Inc), human B-type natriuretic peptide, has hemodynamic effects that may be beneficial in pediatric patients after cardiac surgery. Experience with nesiritide and pediatrics is limited. The purpose of this study was to evaluate perioperative effects and safety of nesiritide in pediatric cardiothoracic surgery. Seventeen patients with congenital heart disease undergoing cardiac surgery were given a loading dose (1 µg/kg) while on cardiopulmonary bypass (constant flow) followed by continuous infusion for 24 hours (0.01 µg/kg/min × 6 hours, then 0.02 µg/kg/min × 18 hours). A 7% decrease in mean blood pressure was seen following nesiritide loading dose on cardiopulmonary bypass. No patient required intervention for hypotension while receiving nesiritide load or infusion. Nesiritide load during surgery and continuous infusion after cardiac surgery in pediatric patients resulted in no significant hemodynamic compromise.

Collaborative quality improvement in the cardiac intensive care unit: development of the Paediatric Cardiac Critical Care Consortium (PC4)

Despite many advances in recent years for patients with critical paediatric and congenital cardiac disease, significant variation in outcomes remains across hospitals. Collaborative quality improvement has enhanced the quality and value of health care across specialties, partly by determining the reasons for variation and targeting strategies to reduce it. Developing an infrastructure for collaborative quality improvement in paediatric cardiac critical care holds promise for developing benchmarks of quality, to reduce preventable mortality and morbidity, optimise the long-term health of patients with critical congenital cardiovascular disease, and reduce unnecessary resource utilisation in the cardiac intensive care unit environment. The Pediatric Cardiac Critical Care Consortium (PC4) has been modelled after successful collaborative quality improvement initiatives, and is positioned to provide the data platform necessary to realise these objectives. We describe the development of PC4 including the philosophical, organisational, and infrastructural components that will facilitate collaborative quality improvement in paediatric cardiac critical care.

Risk factors for failed staged palliation after bidirectional Glenn in infants who have undergone stage one palliation

OBJECTIVE The bidirectional Glenn procedure (BDG) is a routine intermediary step in single-ventricle palliation. In this study, we examined risk factors for death or transplant and failure to reach Fontan completion after BDG in patients, who had previously undergone stage one palliation (S1P). METHODS All patients at our institution, who underwent BDG following S1P between 2002 and 2009 (n=194), were included in the analysis. RESULTS Transplant-free survival through 18 months post BDG was 91%. Univariable competing risk analyses showed atrioventricular valve regurgitation (AVVR) >mild, age ≤ 3 months at BDG, ventricular dysfunction >mild, and prolonged hospital stay after S1P to be associated with increased risk of death or orthotopic heart transplant. Multivariable competing risk analysis through 5 years of follow-up showed >mild AVVR (hazard ratio (HR) 7.5, 95% confidence interval (CI) 3.0-18.8), prolonged hospitalization after S1P (HR 4.5, 95% CI 1.8-11.5), and age ≤ 3 months at BDG (HR 6.8, 95% CI 2.3-20.0) to be independent risk factors for death or transplant. Concomitantly, > mild AVVR and age ≤ 3 months were independently associated with an overall decreased rate of Fontan completion. CONCLUSIONS Pre-BDG AVVR, age ≤ 3 months at time of BDG, and prolonged hospitalization after S1P are independently associated with decreased successful progression of staged palliation in midterm follow-up after BDG.