Michael L. Schmitz

Bridge to Cardiac Transplant in Children: Berlin Heart versus Extracorporeal Membrane Oxygenation

BACKGROUND For small children requiring mechanical circulatory support as a bridge to transplantation (BTT), extracorporeal membrane oxygenation (ECMO) has been the only option until the recent introduction of the Berlin Heart EXCOR ventricular assist device (Berlin Heart AG, Berlin, Germany). We reviewed our recent experience with these two technologies with particular focus on early outcomes. METHODS Data for 55 consecutive children undergoing BTT between 2001 and 2008 were abstracted from an institutional database. The analysis excluded 13 patients because EXCOR was not used for acute postcardiotomy BTT. Patients were divided into ECMO (n = 21) and EXCOR groups (n = 21). Specific end points included survival to transplant, overall survival, and bridge to recovery. Incidences of adverse events and the duration of support were determined. RESULTS Groups were similar in weight, age, and etiologies of heart failure. Likewise, the incidences of stroke and multisystem organ failure were similar. Survival to transplant, recovery, or continued support was 57% in ECMO and 86% in EXCOR (p = 0.040). EXCOR patients had overall significantly better survival (p = 0.049). Two ECMO patients and 1 EXOR patient were bridged to recovery. The mean duration of support was 15 +/- 12 days in the ECMO group and 42 +/- 43 days in the EXCOR group (p < 0.001). CONCLUSIONS In children requiring BTT, EXCOR provided substantially longer support times than ECMO, without significant increase in the rates of stroke or multisystem organ failure. Survival to transplant and long-term survival was higher with EXCOR.

An evaluation of the efficacy and tolerability of oral tramadol hydrochloride tablets for the treatment of postsurgical pain in children.

In this double-blinded, randomized, multicenter study, we examined analgesic efficacy and tolerability of tramadol in postoperative pediatric patients. Eighty-one postsurgical ASA physical status I and II patients ages 7–16 yr received oral tramadol (approximately 1 or 2 mg/kg) for postoperative analgesia when they were ready to transition from morphine patient-controlled analgesia to oral analgesics. Rescue analgesia consisted of morphine patient-controlled analgesia or an oral equivalent dose of oxycodone. Patients rated their pain just before the administration of tramadol and at regular intervals for 8 h afterwards using the Wong-Baker Faces Pain Rating Scale. The 2-mg/kg group required approximately half as much rescue analgesia as the 1-mg/kg group (P = 0.006). Parents rated the larger dose more favorably. Adverse events were generally mild to moderate in severity (vomiting [10%], nausea [9%], pruritus [7%], rash [4%]) and similar between the two treatment groups. There were no significant changes in hemodynamic variables, respiratory rate, or Spo2 percentages between the two treatment groups or in all patients compared with pretreatment values.

A comparison of sevoflurane to halothane in paediatric surgical patients: results of a multicentre international study

Induction, emergence and recovery characteristics were compared during sevoflurane or halothane anaesthetic in a large (428) multicentre, international study of children undergoing elective inpatient surgical procedures. Two hundred and fourteen children in each group underwent inhalation induction with nitrous oxide/oxygen and sevoflurane or halothane. Incremental doses of either study drug were added until loss of eyelash reflex was achieved. Steady state concentrations of anaesthesia were maintained until the end of surgery when anaesthetic agents were terminated simultaneously. Time variables were recorded for induction, emergence and the first need for analgesia in the recovery room. In addition, in 86 of the children in both groups, venous blood samples were drawn for plasma fluoride levels during and after surgery. There was a trend toward smoother induction (induction of anaesthesia without coughing, breath holding, excitement laryngospasm, bronchospasm, increased secretion, and vomiting) in the sevoflurane group with faster induction (2.1 min vs 2.9 min, P= 0.037) and rapid emergence times (10.3 min vs 13.9 min, P= 0.003). Among the children given sevoflurane, 2% developed bradycardia compared with 11% in the halothane group. Postoperatively, 46% of the children in the halothane group developed nausea and or vomiting versus 31% in the sevoflurane group (P= 0.002). Two children in the halothane group developed cardiac dysrhythmia and were dropped from the study. In addition, a child in the halothane group developed malignant hyperthermia, received dantrolene, and had an uneventful recovery. Mean maximum inorganic fluoride concentration was 18.3 μM˙l−1. The fluoride concentrations peaked within one h of termination of sevoflurane anaesthetic and returned rapidly to baseline within 48 h. This study suggests that sevoflurane may be the drug of choice for the anaesthetic management of children.

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.

Analgesia following surgery in children with and without cognitive impairment

Abstract Both children and adults with cognitive impairment (CI) have historically been excluded from research examining pain. This is unfortunate since patients with CI may be at higher risk for experiencing pain or having their pain undertreated due to the difficulty of pain assessment and communication. There are now several published reports about the general pain experience of both adult and pediatric patients with cognitive impairment. The purpose of this study was to compare the amount and type of pain medication administered in children with and without CI after surgery to ascertain if there were any differences in analgesic administration patterns between these two groups. One hundred and fifty‐two children with borderline to profound CI and 138 non impaired (NI) children were recruited to participate. Analgesic administration data include type and amount of opioid, type of non‐opioid medication, and prescribed discharge medications. Results of this study show that children with CI undergoing surgery received less opioid in the perioperative period than children without CI. However, children with CI received comparable amounts and types of analgesics in the postoperative period as children without CI.

Experience with an anesthesiologist interventional model for endoscopy in a pediatric hospital.

Background Endoscopy is now a routine part of the work-up for many patients with gastrointestinal symptoms. Adults tolerate these procedures well, with either no sedation or a relatively light level. In contrast, children often require deep sedation or a general anesthetic to successfully perform these procedures. Therefore, pediatric endoscopies may require more time, personnel, and monitoring equipment to provide optimal conditions for the patient. The goals of this retrospective case series were to describe the anesthesia times and recovery duration of the different procedures, the types and amounts of medications commonly used, and the types and rates of complications experienced. Methods Patients (2,306) who underwent endoscopy in the Arkansas Children’s Hospital endoscopy suite during a 4-year period were identified. A random sample of 720 charts was reviewed retrospectively. Results Patients ranged in age from younger than 1 year to 29 years. Patients most often had abdominal pain or multiple gastrointestinal symptoms. Sixty-eight percent of patients underwent esophagogastroduodenoscopies; 30% colonoscopy or a combination of the two. Ninety-five percent of patients received a propofol-based anesthetic. Midazolam, fentanyl, and alfentanil were frequently used as supplemental agents. Complications occurred infrequently and were airway related. All complications were easily treated, with no adverse sequelae. Conclusions This model of anesthesiologist-provided sedation/anesthesia for gastrointestinal endoscopy procedures has been extremely successful in the Arkansas Children’s Hospital and has served to heighten awareness of many issues surrounding sedation and anesthesia outside of the operating room, while ensuring a high level of care is provided.

Efficacy of Parental Application of Eutectic Mixture of Local Anesthetics for Intravenous Insertion

Objective. To demonstrate that parent application of eutectic mixture of local anesthetics (EMLA) results in equal reduction of the pain of intravenous (IV) placement compared with clinician application of EMLA, and to assess potential difficulties with parental application. Study Design. A 2 × 2 randomized block design was used, with 41 children divided into two age groups (5–12 years vs 13–18 years) and randomized to one of two experimental groups (parent-applied EMLA vs clinician-applied EMLA). Methods. All children were scheduled to have outpatient gastrointestinal endoscopies with IV sedation. EMLA was placed at least 60 minutes before IV insertion either by the parent or a clinician, depending on the experimental group assignment. Outcome measures were child pain ratings and observed behavioral distress ratings. Parents and children were interviewed to determine parent and child anxiety levels in anticipation of the IV insertion, previous needle stick experience, and previous difficulty coping. Feasibility outcomes included technical difficulty with application of EMLA and appearance of the EMLA cream and occlusive covering. Results. Pain ratings and behavioral distress ratings were generally in the low to moderate range for all groups and were consistent with previous empiric reports of EMLA outcome. There were no significant differences in pain or distress ratings for either the age or the experimental groups. Parent ratings of their childs previous difficulty coping was related to the level of behavioral distress exhibited before (r = .50), during (r = .32) and after (r = .44) the IV insertion. In addition, childrens anxiety ratings about IV insertion seemed to differ among groups (although not statistically significant for post hoc comparisons), with the most anxiety reported by the younger children when clinicians applied the EMLA and by older children when parents applied the EMLA. Conclusion. Parent application of EMLA appears to be as effective as clinician application in reducing childrens pain and distress associated with IV insertion. Permitting parents to apply the EMLA at home can allow children who are having procedures on an outpatient basis to benefit from topical anesthesia without having to arrive early to the clinic or hospital. Additionally, application by parents may result in less anticipatory anxiety for younger children.

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.

The slipping rib syndrome in children

The slipping rib syndrome is an infrequent cause of thoracic and upper abdominal pain and is thought to arise from the inadequacy or rupture of the interchondral fibrous attachments of the anterior ribs. This disruption allows the costal cartilage tips to sublux, impinging on the intercostal nerves. Children with this entity are seldom described in the literature. We present a retrospective review of 12 children and young adults with slipping rib syndrome and a systematic approach for evaluation and treatment.

Incremental reduction in the incidence of stroke in children supported with the Berlin EXCOR ventricular assist device.

BACKGROUND Cerebrovascular events (CVEs) are common among children supported with the Berlin EXCOR (Berlin Heart GmbH, Berlin, Germany) ventricular assist device (VAD). Given the high incidence of CVEs associated with this device, we sought to describe our institutional experience in incrementally reducing CVEs in children supported with the Berlin EXCOR VAD. METHODS We collected pertinent data on 39 consecutive patients who underwent Berlin EXCOR VAD implantation at a single center. Frequency of CVEs was described in risk per implantation, per day, and in reference to the time of therapeutic anticoagulation. Risk factors were analyzed for association with CVEs. RESULTS Of the initial 39 Berlin EXCOR VAD implantations, 16 CVEs occurred in 12 patients. The incidence of CVEs decreased with institutional experience per patient (R(2) = 0.6909, p = 0.007) and per patient-day (R(2) = 0.8051, p = 0.002). CVEs occurred more frequently before therapeutic anticoagulation targets were achieved (4.1%/day) compared with after therapeutic anticoagulation targets were achieved (0.9%/day; p = 0.044). CONCLUSIONS Incidence of CVEs decreased with institutional experience. The risk of CVE is highest in the immediate postoperative period before therapeutic anticoagulation is achieved. Further studies are warranted in pediatric patients supported with the Berlin EXCOR VAD to confirm our findings in a larger cohort.