Eudice E. Fontenot

Noninvasive Cerebral Oximeter as a Surrogate for Mixed Venous Saturation in Children

We evaluated the relationship between regional cerebral oxygen saturation (rSO2) measured by near-infrared spectroscopy (NIRS) cerebral oximeter with superior vena cava (SVC), inferior vena cava (IVC), right atrium (RA), and pulmonary artery (PA) saturation measured on room air and 100% inspired oxygen administered via a non-rebreather mask (NRB) in children. Twenty nine pediatric post-orthotopic heart transplant patients undergoing an annual myocardial biopsy were studied. We found a statistically significant correlation between rSO2 and SVC saturations at room air and 100% inspired oxygen concentration via NRB (r = 0.67, p = 0.0002 on room air; r = 0.44, p = 0.02 on NRB), RA saturation (r = 0.56, p = 0.002; r = 0.56, p = 0.002), and PA saturation (r = 0.67, p < 0.001; r = 0.4, p = 0.03). A significant correlation also existed between rSO2 and measured cardiac index (r = 0.45, p = 0.01) and hemoglobin levels (r = 0.41, p = 0.02). The concordance correlations were fair to moderate. Bias and precision of rSO2 compared to PA saturations on room air were −0.8 and 13.9%, and they were 2.1 and 15.6% on NRB. A stepwise linear regression analysis showed that rSO2 saturations were the best predictor of PA saturations on both room air (p = 0.0001) and NRB (p = 0.012). In children with biventricular anatomy, rSO2 readings do correlate with mixed venous saturation.

Single-institution experience with interhospital extracorporeal membrane oxygenation transport: A descriptive study.

Objective: Patients with refractory cardiopulmonary failure may benefit from extracorporeal membrane oxygenation, but extracorporeal membrane oxygenation is not available in all medical centers. We report our institutions nearly 20-yr experience with interhospital extracorporeal membrane oxygenation transport. Design: Retrospective review. Setting: Quaternary care childrens hospital. Patients: All patients undergoing interhospital extracorporeal membrane oxygenation transport by the Arkansas Childrens Hospital extracorporeal membrane oxygenation team. Interventions: Data (age, weight, diagnosis, extracorporeal membrane oxygenation course, hospital course, mode of transport, and outcome) were obtained and compared with the most recent Extracorporeal Life Support Organization Registry report. Results: Interhospital extracorporeal membrane oxygenation transport was provided to 112 patients from 1990 to 2008. Eight were transferred between outside facilities (TAXI group); 104 were transported to our hospital (RETURN group). Transport was by helicopter (75%), ground (12.5%), and fixed wing (12.5%). No patient died during transport. Indications for extracorporeal membrane oxygenation in RETURN patients were cardiac failure in 46% (48 of 104), neonatal respiratory failure in 34% (35 of 104), and other respiratory failure in 20% (21 of 104). Overall survival from extracorporeal membrane oxygenation for the RETURN group was 71% (74 of 104); overall survival to discharge was 58% (61 of 104). Patients with cardiac failure had a 46% (22 of 48) rate of survival to discharge. Neonates with respiratory failure had an 80% (28 of 35) rate of survival to discharge. Other patients with respiratory failure had a 62% (13 of 21) rate of survival to discharge. None of these survival rates were statistically different from survival rates for in-house extracorporeal membrane oxygenation patients or for survival rates reported in the international Extracorporeal Life Support Organization Registry (p > .1 for all comparisons). Conclusions: Outcomes of patients transported by an experienced extracorporeal membrane oxygenation team to a busy extracorporeal membrane oxygenation center are very comparable to outcomes of nontransported extracorporeal membrane oxygenation patients as reported in the Extracorporeal Life Support Organization registry. As has been previously reported, interhospital extracorporeal membrane oxygenation transport is feasible and can be accomplished safely. Other experienced extracorporeal membrane oxygenation centers may want to consider developing interhospital extracorporeal membrane oxygenation transport capabilities to better serve patients in different geographic regions.

Interhospital transport of children requiring extracorporeal membrane oxygenation support for cardiac dysfunction.

OBJECTIVE Many centers are able to emergently deploy extracorporeal membrane oxygenation (ECMO) as support in children with refractory hemodynamic instability, but may be limited in their ability to provide prolonged circulatory support or cardiac transplantation. Such patients may require interhospital transport while on ECMO (cardiac mobile [CM]-ECMO) for additional hemodynamic support or therapy. There are only three centers in the United States that routinely perform CM-ECMO. Our center has a 20-year experience in carrying out such transports. The purpose of this study was twofold: (1) to review our experience with pediatric cardiac patients undergoing CM-ECMO and (2) identify risk factors for a composite outcome (defined as either cardiac transplantation or death) among children undergoing CM-ECMO. DESIGN Retrospective case series. SETTING Cardiovascular intensive care and pediatric transport system. PATIENTS Children (n = 37) from 0-18 years undergoing CM-ECMO transports (n = 38) between January 1990 and September 2005. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A total of 38 CM-ECMO transports were performed for congenital heart disease (n = 22), cardiomyopathy (n = 11), and sepsis with myocardial dysfunction (n = 4). There were 18 survivors to hospital discharge. Twenty-two patients were transported a distance of more than 300 miles from our institution. Ten patients were previously cannulated and on ECMO prior to transport. Thirty-five patients were transported by air and two by ground. Six patients underwent cardiac transplantation, all of whom survived to discharge. After adjusting for other covariates post-CM-ECMO renal support was the only variable associated with the composite outcome of death/need for cardiac transplant (odds ratio = 13.2; 95% confidence interval, 1.60--108.90; P = 0.003). There were two minor complications (equipment failure/dysfunction) and no major complications or deaths during transport. CONCLUSIONS Air and ground CM-ECMO transport of pediatric patients with refractory myocardial dysfunction is safe and effective. In our study cohort, the need for post-CM-ECMO renal support was associated with the composite outcome of death/need for cardiac transplant.

Surgical Management of Tetralogy of Fallot in the First Year of Life

BACKGROUND The surgical approach to tetralogy of Fallot (TOF) continues to evolve and now many centers favor early repair for TOF. METHODS Our experience includes 82 consecutive patients less than 1 year old with TOF (n = 74) and TOF with pulmonary atresia (n = 8) who were operated on between January 1992 and March 1998. Mean age at repair was 5.2 +/- 1.2 months and mean weight was 4.5 +/- 0.4 kg. Seven patients (anomalous left anterior descending artery [n = 1], pulmonary atresia with hypoplastic pulmonary arteries [n = 6]), underwent palliative procedures in the neonatal period followed by complete repair. Forty-nine patients (59%) were symptomatic (severe cyanosis or hypoxic spells), and 33 patients (41%) were asymptomatic. A combined transatrial-transpulmonary approach was employed in 28 patients (34%), and transannular patch or conduit for reconstruction of the right ventricular outflow tract (RVOT) was required in 54 patients (66%). The mean Nakata index was 160 +/- 25 mm2/m2. RESULTS There were no hospital deaths. Mean post-repair peak right ventricular/systemic pressure ratio was 0.48 +/- 0.1. There were no late deaths or reoperations during a mean follow-up of 23 +/- 5 months. All patients are currently asymptomatic and in New York Heart Association class 1. Postoperative evaluation by two-dimensional and Doppler echocardiography or cardiac catheterization showed minimal pulmonary artery stenosis with a mean pressure gradient of 15 +/- 6 mm Hg across the RVOT. CONCLUSIONS Our experience suggests that early repair of TOF can yield excellent results and initial palliation does not preclude early complete repair.

The beneficial hemodynamic effects of selective patent vertical vein following repair of obstructed total anomalous pulmonary venous drainage in infants

OBJECTIVES Postoperative low cardiac output may persist after repair of total anomalous pulmonary venous drainage (TAPVD) because of a relatively small and non-compliant left atrium and left ventricle. We examined the effects of selective vertical vein patency on postoperative hemodynamics. METHODS Thirty-four patients less than 3 months of age with TAPVD were operated from July 1993 to June 2000. The mean age at operation was 21+/-8 days (range, 3-62 days) and the mean weight was 3+/-0.2 kg (range, 2-4.1 kg). Supracardiac type drainage was found in 12 (35%), cardiac in three (9%), mixed in one (3%), and infracardiac in 18 (53%) patients. Twenty-two patients (65%) had obstructed venous drainage. All operations were performed with deep hypothermic circulatory arrest. Supracardiac, mixed and infracardiac types were repaired through a posterior approach, whereas, in the cardiac type, the coronary sinus was unroofed and the atrial septal defect was patched. The decision whether to keep the vertical vein open was made at the end of the operation and was based on the hemodynamic state of the patient. RESULTS There were no operative deaths. The suture on the vertical vein was released in 22 patients who had obstructed pulmonary venous drainage (infracardiac type, n=18; supracardiac type, n=3; and mixed type, n=1), resulting in a significant drop in the left atrial pressure from 19+/-2 to 12+/-2 mmHg (P<0.05), and in the mean pulmonary artery pressure from 42+/-6 to 35+/-3 mmHg (P<0.05), associated with an immediate increase in the mean arterial blood pressure from a mean of 46+/-3 to 60+/-4 mmHg (P<0.05). During a mean follow-up of 38+/-6 months (range, 8-71 months), there were no late deaths. Follow-up, two-dimensional echocardiography with Doppler studies demonstrated good left ventricular function and trivial or no left to right shunt through the vertical vein in those patients in whom the snare was released. CONCLUSIONS Maintaining the vertical vein patent in a selective group of patients with infracardiac total anomalous venous drainage contributes to a favorable outcome following surgery.

Long-term outcomes of intraoperative pulmonary artery stent placement for congenital heart disease

Objective:Our objective was to examine long‐term outcomes of intraoperative pulmonary artery stents and determine risk factors for reintervention Background:Short‐term outcomes of intraoperative pulmonary artery stents have been reported previously. However, long‐term results are unknown. Methods: We conducted a retrospective review of patients who underwent intraoperative pulmonary artery stent placement for branch pulmonary artery stenosis. Results: Ninety‐six stents were implanted intraoperatively in 67 patients. Twenty‐seven patients received two or more stents at initial intervention. Median patient age at initial stent placement was 1.8 years. Median post‐inflation diameter was 8 mm. At a mean follow‐up of 7.6 ± 4.5 years, 49% of stents required reintervention (balloon angioplasty at catheterization in 28 patients and surgical revision in 19 patients). Actuarial freedom from reintervention at 2, 5, and 10 years was 68%, 49%, and 40%, respectively. In univariate analysis of time to first reintervention, age at implantation < 2 yrs (P < 0.0009) and initial post‐inflation stent diameter < 10 mm (P < 0.0002) were associated with risk for reintervention. Multivariable Cox regression analysis showed age < 2 years (P < 0.005) and diagnosis of tetralogy of Fallot (p < 0.002) or truncus arteriosus (P < 0.007) to be significant risk factors for reintervention. Conclusion: Intraoperative placement of stents in the pulmonary arteries is an alternative to surgical angioplasty, but is associated with a high incidence of reintervention. Age < 2 years and the diagnosis of tetralogy of Fallot or truncus arteriosus are risk factors for reintervention.

Intrahospital transport of children on extracorporeal membrane oxygenation: Indications, process, interventions, and effectiveness

Objective: To evaluate indications, process, interventions, and effectiveness of patients undergoing intrahospital transport. Critically ill patients supported with extracorporeal membrane oxygenation are transported within the hospital to the radiology suite, cardiac catheterization suite, operating room, and from one intensive care unit to another. No studies to date have systematically evaluated intrahospital transport for patients on extracorporeal membrane oxygenation. Design: Retrospective cohort analysis. Setting: Cardiac intensive care unit in a tertiary care childrens hospital. Patients: All patients on extracorporeal membrane oxygenation who required intrahospital transport between January 1996 and March 2007 were included and analyzed. Measurements and Main Results: A total of 57 intrahospital transports for cardiac catheterization and head computed tomography scans were analyzed. In 14 (70%) of 20 of patients with cardiac catheterization, a management change occurred as a result of the diagnostic cardiac catheterization. In ten (59%) of 17 patients, bedside echocardiography was of limited value in defining the critical problem. In the interventional group, the majority of transports were for atrial septostomy. In the head computed tomography group, significant pathology was identified, which led to management change. No major complications occurred during these intrahospital transports. Conclusions: Although transporting patients on extracorporeal membrane oxygenation is labor intensive and requires extensive logistic support, it can be carried out safely in experienced hands and it can result in important therapeutic and diagnostic yields. To our knowledge, this is the first study designed to evaluate safety and efficacy of intrahospital transport for patients receiving extracorporeal membrane oxygenation support.

Extracorporeal membrane oxygenation support for intractable primary arrhythmias and complete congenital heart block in newborns and infants: Short-term and medium-term outcomes

Objectives: To describe the experience with extracorporeal membrane oxygenation support for intractable primary arrhythmias in newborns and infants. Design: Retrospective study. Setting: A tertiary care pediatric hospital. Patients: Patients younger than 1 yr supported with extracorporeal membrane oxygenation for primary cardiac arrhythmias were identified from the institutional extracorporeal membrane oxygenation registry. Interventions: Extracorporeal membrane oxygenation support. Measurements and Main Results: Clinical characteristics and outcomes were investigated for patients with primary cardiac arrhythmia supported with extracorporeal membrane oxygenation. Outcomes investigated were time from initiation of extracorporeal membrane oxygenation support to arrhythmia control, duration of extracorporeal membrane oxygenation support, and results of interventions performed while supported with extracorporeal membrane oxygenation. We summarized the independent categorical and continuous variables using frequencies, percentages, and medians and ranges, respectively. Extracorporeal membrane oxygenation support was used in nine patients for rescue therapy for primary tachyarrhythmia and bradycardia. The primary arrhythmias were: focal atrial tachycardia (n = 2); reentrant supraventricular tachycardia (n = 3); junctional ectopic tachycardia (n = 2); and congenital complete atrioventricular block (n = 2) patients. Seven patients presented with severe hemodynamic compromise, with six patients requiring extracorporeal cardiopulmonary resuscitation. All patients required extracorporeal membrane oxygenation within 24 hrs of initial presentation. Balloon atrial septostomy was performed in three patients and ablation was performed in two patients. Sinus rhythm was achieved in all reentrant supraventricular tachycardia and rate control was established in both patients with focal atrial tachycardia and in one patient with junctional ectopic tachycardia while using extracorporeal membrane oxygenation support. All patients survived to hospital discharge, and median follow-up for the cohort was 5 yrs. There was one late death; all survivors had good overall and neurologic outcomes. Conclusions: The requirement of extracorporeal membrane oxygenation support in newborns and infants with intractable arrhythmia is rare. Extracorporeal membrane oxygenation support does potentially carry morbidity; however, to prevent arrhythmia-related mortality, extracorporeal membrane oxygenation support and/or extracorporeal cardiopulmonary resuscitation should be considered in the management of hemodynamically unstable primary arrhythmias as an emergent lifesaving procedure.

Stenting for superior vena cava obstruction in pediatric heart transplant recipients

Superior vena cava (SVC) obstruction can be a complication in heart transplant recipients. We reviewed our experience with relief of SVC obstruction using endovascular stents in pediatric heart transplant recipients.

“Tele-Mentoring”: An Interventional Procedure Using a Wearable Computer: First-in-Man

![Figure][1] [![Graphic][3] ][3][![Graphic][4] ][4] We report remote “tele-mentoring” of an interventional procedure using a wearable computer. Four months post-pneumonectomy, a patient developed dyspnea from right-to-left shunting (arterial saturation 77%) from a patent