Madolin K. Witte

Experience With the Levitronix CentriMag in the Pediatric Population as a Bridge to Decision and Recovery

Short-term mechanical circulatory support in the pediatric population with acute cardiac failure has traditionally been limited to extracorporeal membrane oxygenation given the limited availability of pediatric-sized pumps. The Levitronix CentriMag system (Thoratec Corporation, Pleasanton, CA, USA) offers expanded options for short-term support for this population. We report our experience with the successful use of the CentriMag in the pediatric population as a bridge to decision after postcardiotomy ventricular failure and as a bridge to recovery after heart transplantation. The first patient was bridged to a long-term HeartMate II (Thoratec Corporation) as a bridge to potential recovery. The second patient was supported after severe graft failure post heart transplantation, with a full recovery. The Levitronix CentriMag has proven to be a versatile, safe, and effective short-term circulatory support system for our pediatric patients.

Management of Deep Wound Complications With Vacuum-Assisted Therapy After Berlin Heart EXCOR Ventricular Assist Device Placement in the Pediatric Population

Wound complications after ventricular assist device (VAD) placement remain a formidable challenge to surgeons. The Berlin Heart EXCOR VAD is a versatile pulsatile system that has been successful in pediatric patients of all ages and sizes. Prevention of device-related complications such as infection, particularly in pediatric patients, remains an essential issue in minimizing patient morbidity and mortality. The introduction of vacuum-assisted wound closure (VAC) therapy and its application in VAD-related wound complications provide an efficient and effective method for wound healing. We report our experience in the management of deep wound complications in two pediatric patients after placement of the Berlin Heart EXCOR VAD. The wound VAC system proved to achieve complete wound healing without any infectious complications.

Effect of red blood cell transfusion on oxygen consumption in the anemic pediatric patient.

Objective To compare oxygen consumption (Vo2) measured by indirect calorimetry before and after a packed red blood cell (PRBC) transfusion in patients with isovolemic anemia. Design Prospective, repeated-measures clinical study. Setting Outpatient pediatric hematology-oncology clinic. Patients A total of 17 pediatric hematology-oncology outpatients undergoing a PRBC transfusion for a hematocrit of <26%. Interventions Vo2 was measured by indirect calorimetry before and after a PRBC transfusion. Measurements and Main Results Baseline hematocrit averaged 23% (15.5–25.7%), hemoglobin averaged 8.24 g/dL (5.2 g/dL–9.3 g/dL). Patients received an average of 10.3 mL/kg (2.8–17.5 mL/kg) of PRBC. After PRBC transfusion, all patients had an increase in Vo2, with a mean increase of 35.09 mL·min−1·m−2 (5–75 mL·min−1·m−2) or 19% (3.1–52%; p < .001). No significant correlation was found between the pretransfusion hematocrit or the volume of red blood cells administered and the change in Vo2. No significant change was noted in systolic blood pressure or respiratory rate. There were 14 patients who had a decrease in heart rate after PRBC transfusion, and seven patients who demonstrated an increase in Vo2 of <10% were compared with patients with a ≥10% change. No significant difference was found in age, height, weight, initial hematocrit, or volume of red blood cells transfused between these two groups. Conclusions A significant increase in Vo2 was noted after a red blood cell transfusion in pediatric patients with isovolemic anemia. These findings suggest that Vo2 was dependent on the supply of oxygen in this subset of pediatric patients. Responding to increased oxygen delivery by increasing Vo2 implies that these patients were functioning in a state of relative oxygen deficit and had made physiologic adaptive changes to function in this state.

Utilizing a Collaborative Learning Model to Promote Early Extubation Following Infant Heart Surgery

Objective: To determine whether a collaborative learning strategy-derived clinical practice guideline can reduce the duration of endotracheal intubation following infant heart surgery. Design: Prospective and retrospective data collected from the Pediatric Heart Network in the 12 months pre- and post-clinical practice guideline implementation at the four sites participating in the collaborative (active sites) compared with data from five Pediatric Heart Network centers not participating in collaborative learning (control sites). Setting: Ten children’s hospitals. Patients: Data were collected for infants following two-index operations: 1) repair of isolated coarctation of the aorta (birth to 365 d) and 2) repair of tetralogy of Fallot (29–365 d). There were 240 subjects eligible for the clinical practice guideline at active sites and 259 subjects at control sites. Interventions: Development and application of early extubation clinical practice guideline. Measurements and Main Results: After clinical practice guideline implementation, the rate of early extubation at active sites increased significantly from 11.7% to 66.9% (p < 0.001) with no increase in reintubation rate. The median duration of postoperative intubation among active sites decreased from 21.2 to 4.5 hours (p < 0.001). No statistically significant change in early extubation rates was found in the control sites 11.7% to 13.7% (p = 0.63). At active sites, clinical practice guideline implementation had no statistically significant impact on median ICU length of stay (71.9 hr pre- vs 69.2 hr postimplementation; p = 0.29) for the entire cohort. There was a trend toward shorter ICU length of stay in the tetralogy of Fallot subgroup (71.6 hr pre- vs 54.2 hr postimplementation, p = 0.068). Conclusions: A collaborative learning strategy designed clinical practice guideline significantly increased the rate of early extubation with no change in the rate of reintubation. The early extubation clinical practice guideline did not significantly change postoperative ICU length of stay.

Simple versus complex truncus arteriosus: neutralization of risk but with increased resource utilization.

This study examined simple versus complex forms of truncus arteriosus (TA) results in the current era with regard to mortality, reintervention, and resource utilization. From 1999 to 2008, 42 infants underwent primary repair of TA, including 22 simple forms of TA without associated anomalies and 20 complex forms with risk factors such as interrupted aortic arch (n = 8), coarctation (n = 1), significant truncal valve regurgitation (n = 6), discontinuous pulmonary arteries (n = 3), and truncal valve stenosis (n = 2). There were 4 early deaths (4/42, 9.5%), with no difference between simple TA (2/22, 9.1%) and complex TA (2/20, 10%). Early mortality decreased to 1 patient (1/23, 4%) in the most recent era: 2003-2008. Late mortality occurred in 4 (4/38, 10.5%). Reintervention was required in 12 patients, a median of 2 years postoperatively: for conduit reasons in 8 and combined conduit and truncal valve insufficiency in 4. Actuarial survival was 82% ± 7% at 5 years and freedom from reintervention was 52% ± 17% at 5 years, which are not different between complex and simple forms. Complex TA, age, and weight were not predictors on multivariable analysis for early or late death or reintervention. Complex TA had significantly longer (P < .05) median length of stay (17 vs 13 days) and intensive care unit intubation times (8 vs 5 days) versus simple TA. Complex TA does not have a higher operative or late mortality risk or increased risk of reintervention compared with simple TA. However, complex patients can be expected to have increased resource utilization as compared with simple forms of TA.

Rationale and methodology of a collaborative learning project in congenital cardiac care

BACKGROUND Collaborative learning is a technique through which individuals or teams learn together by capitalizing on one anothers knowledge, skills, resources, experience, and ideas. Clinicians providing congenital cardiac care may benefit from collaborative learning given the complexity of the patient population and team approach to patient care. RATIONALE AND DEVELOPMENT Industrial system engineers first performed broad-based time-motion and process analyses of congenital cardiac care programs at 5 Pediatric Heart Network core centers. Rotating multidisciplinary team site visits to each center were completed to facilitate deep learning and information exchange. Through monthly conference calls and an in-person meeting, we determined that duration of mechanical ventilation following infant cardiac surgery was one key variation that could impact a number of clinical outcomes. This was underscored by one participating centers practice of early extubation in the majority of its patients. A consensus clinical practice guideline using collaborative learning was developed and implemented by multidisciplinary teams from the same 5 centers. The 1-year prospective initiative was completed in May 2015, and data analysis is under way. CONCLUSION Collaborative learning that uses multidisciplinary team site visits and information sharing allows for rapid structured fact-finding and dissemination of expertise among institutions. System modeling and machine learning approaches objectively identify and prioritize focused areas for guideline development. The collaborative learning framework can potentially be applied to other components of congenital cardiac care and provide a complement to randomized clinical trials as a method to rapidly inform and improve the care of children with congenital heart disease.

Reducing blood testing in pediatric patients after heart surgery: a quality improvement project.

Objectives: To safely optimize blood testing and costs for pediatric cardiac surgical patients without adversely impacting patient outcomes. Design: This is a quality improvement cohort project with pre- and postintervention groups. Setting: University-affiliated pediatric cardiac ICU in a tertiary care children’s hospital. Patients: All patients were surgical patients for whom Risk Adjustment for Congenital Heart Surgery categories allowed for stratification by complexity. The preintervention group was treated in 2010 and the postintervention group in 2011. Interventions: Laboratory ordering processes were analyzed, and practice changed to limit standing blood test orders and requires individualized ordering. Measurements and Main Results: Three hundred nineteen patients were studied in 2010 and 345 in 2011. Groups were similar in median age, weight, length of stay (ICU length of stay), and Risk Adjustment for Congenital Heart Surgery category. There was a reduction in the total blood tests per patient (24 vs 38; p < 0.0001) and length of stay adjusted tests per patient-day (10.4 vs 14.4; p = 0.0001) in the postintervention group. The largest test reductions were blood gases and single electrolytes. Adverse outcomes, such as extubation failure (6.4% vs 5.6%), central catheter-associated bloodstream infection (2.2 vs 1.5), and hospital mortality (0.6% vs 0.6%), were not significantly different between the groups. Cost analysis demonstrated an overall laboratory cost savings of 32%. In addition, the volume of packed RBC transfusions was also significantly decreased in the postintervention group among the most complex patients (Risk Adjustment for Congenital Heart Surgery, 6). Conclusions: Blood testing rates were safely decreased in postoperative pediatric cardiac patients by changing laboratory ordering practices. In addition, packed RBC transfusion was decreased among the most complex patients.

Transthoracic echocardiographic predictors of left atrial hypertension in patients on venoarterial extracorporeal membrane oxygenation.

Decompression of the left heart in patients supported with extracorporeal membrane oxygenation (ECMO) is often warranted to protect the myocardium and facilitate recovery. We studied the ability of standard echocardiographic parameters to predict left atrial hypertension by reviewing 3 cardiac patients supported with ECMO who subsequently underwent left atrial decompression. We found that standard echocardiographic parameters poorly predict the need for left atrial decompression on ECMO. Following a more specific diagnostic algorithm to estimate left-sided filling pressure in patients with depressed ejection fraction may significantly improve the ability of echocardiography to accurately predict left atrial hypertension and the need for decompression.

A Controlled Study of the 1-hour and 24-hour Effects of Inhaled Nitric Oxide on Oxygenation in Children With Acute Hypoxemic Respiratory Failure † 176

A prospective, randomized, controlled study of children (age: 1 month - 17 years) with acute hypoxemic respiratory failure was performed to determine whether 24 hrs of inhaled nitric oxide (INO) improves oxygenation index (OI) more than conventional therapy alone. Twelve patients were treated with 10 ppm INO from the onset of randomization and 12 control patients were initially managed by conventional therapy alone. After 24 hours, control patients were also treated with 10 ppm INO. Blood gases were measured at baseline, at 1 hour after randomization, and at 24-hour intervals for 2 days. INO improved OI during the initial hour of therapy. However, 24 hours after randomization, the OI of surviving treated patients were not improved in comparison to baseline or the OI of 10 surviving controls. A similar number of patients in each group developed >20% decrease, or >20% increase, in OI during the initial 24 hours after randomization. OI acutely improved in control patients when INO was started after 24 hours of conventional therapy. The OI of these patients remained improved on INO 48 hours after randomization. In conclusion, OI is initially improved by 10 ppm INO in children with acute hypoxemic respiratory failure. However, a sustained improvement in oxygenation may not occur during prolonged therapy in some patients.