Short-term renal support in postoperative repair of tetralogy of Fallot in the paediatric intensive care unit: can we predict those who need it?

INTRODUCTION: Fluid balance and renal function can be difficult to manage in the postoperative infant with tetralogy of Fallot. High fluid volumes are often needed to maintain cardiac output. Aims To stratify patients at risk for advanced renal support following tetralogy of Fallot repair. METHODS: Retrospective analysis of all consecutive tetralogy of Fallot cases operated at a single centre in a 3-year period. RESULTS: A total of 41 children were identified. All cases had loop diuretics administered. Of the cases, 17% required support with a peritoneal dialysis catheter, with only one complication of peritoneal dialysis catheter blockage. The mean length of paediatric intensive care unit stay in those receiving peritoneal dialysis catheter insertion was prolonged by an additional mean of 6 days (p<0.001). No statistical significance was found between those children requiring peritoneal dialysis and those who did not when considering patient age and weight at time of repair, cardiopulmonary bypass and aortic cross clamp times, the presence of a transannular patch, or junctional ectopic tachycardia. However, volume requirement of more than 35 ml/kg in the first 12 hours following repair did increase the likelihood to need peritoneal dialysis (p<0.0001). Furthermore, the higher the peak creatinine, the longer the stay on intensive care (p<0.01). CONCLUSIONS: Peritoneal dialysis is an effective method of dealing with fluid balance in children after tetralogy of Fallot repair, with minimal complications. Early consideration should be given to peritoneal dialysis when it is clear that high fluid volumes are required postoperatively.

Outcome following decompressive craniectomy for malignant middle cerebral artery infarction in children.

AIM: Mortality from malignant middle cerebral artery infarction (MMCAI) approaches 80% in adult series. Although decompressive craniectomy decreases mortality and leads to an acceptable outcome in selected adult patients, there are few data on MMCAI in children with stroke. This study evaluated the frequency of MMCAI and the use of decompressive craniectomy in children. METHOD: We retrospectively reviewed cases of MMCAI from five pediatric tertiary care centers. RESULTS: Ten children (two females, eight males; median age 9y 10mo, range 22mo-14y) had MMCAI, with a median Glasgow Coma Scale score of 6 (range 3-9). MMCAI represented fewer than 2% of cases of pediatric arterial ischemic stroke. Three patients who did not undergo decompression, all of whom had monitoring of intracranial pressure, developed intractable intracranial hypertension, and fulfilled criteria for brain death. In contrast, seven patients underwent decompressive craniectomy and survived, with rapid improvement in their level of consciousness postoperatively. All seven survivors now walk independently with mild to moderate residual hemiparesis and speak fluently, even though four had left-sided infarcts. INTERPRETATION: Decompressive craniectomy can lead to a moderately good outcome for children with MMCAI and should be considered, even with symptomatic stroke and deep coma. Monitoring of intracranial pressure may delay life-saving treatment.

The relationship among thromboelastography, hemostatic variables, and bleeding after cardiopulmonary bypass surgery in children.

BACKGROUND: Mediastinal bleeding is common after pediatric cardiopulmonary bypass (CPB) surgery. Thromboelastography (TEG) may predict bleeding and provide insight into likely mechanisms. We aimed to (a) compare perioperative temporal profiles of TEG and laboratory hemostatic variables between patients with significant hemorrhage (BLEED) and those without (CONTROL), (b) investigate the relationship between TEG variables and routine hemostatic variables, and (c) develop a model for prediction of bleeding. METHODS: TEG and laboratory hemostatic variables were measured prospectively at 8 predefined times for 50 children weighing <20 kg undergoing CPB. RESULTS: Patients who bled demonstrated different TEG profiles than those who did not. This was most apparent after protamine administration and was partly attributable to inadequate heparin reversal, but was also associated with a significantly lower nadir in mean (sd) fibrinogen for the BLEED group compared with CONTROL group: 0.44 (0.18) and 0.71 (0.40) g/L, respectively (P = 0.01). Significant nonlinear relationships were found between the majority of TEG and laboratory hemostatic variables. The strongest relationship was between the maximal amplitude and the platelet-fibrinogen product (logarithmic r(2) = 0.71). Clot strength decreased rapidly when (a) fibrinogen concentration was <1 g/L, (b) platelets were <120 x 10(9)/L, and (c) platelet-fibrinogen product was <100. A 2-variable model including the activated partial thromboplastin time at induction of anesthesia and TEG mean amplitude postprotamine discriminated well for subsequent bleeding (C statistic 0.859). CONCLUSIONS: Hypofibrinogenemia and inadequate heparin reversal are 2 important factors contributing to clot strength and perioperative hemorrhage after pediatric CPB. TEG may be a useful tool for predicting and guiding early treatment of mediastinal bleeding in this group.

Screening for left ventricular systolic dysfunction in high-risk patients in primary-care: a cost-benefit analysis.

BACKGROUND: Appropriate screening strategies are needed to cost effectively identify patients with undiagnosed and untreated left ventricular systolic dysfunction (LVSD). AIM: To investigate the cost-benefit of screening high-risk patients in primary-care for LVSD (EF<40%) using various screening strategies. METHODS: Patients considered at high-risk of developing LVSD were recruited from three primary-care practices. Patients with known LVSD were excluded. Echocardiography, electrocardiography and blood tests were performed blinded to an NT-proBNP result. Logistic regression (LR) and receiver-operating characteristic analysis were used to assess the univariate and multivariable utility of NT-proBNP, QRS duration, symptoms and evidence of myocardial infarction (MI) to detect LVSD. RESULTS: 427 patients were assessed. 7.5% had undiagnosed LVSD. NT-proBNP, QRS, symptoms and MI were independent predictors of LVSD (p<0.014) and the resultant LR-model had an area-under-the-curve of 0.89 (0.84-0.94) and specificity of 54% (51-79%) at a sensitivity of 100%. The LR-model avoided 24.1% (18.1- 48.3%) of the cost and 50.1% (44.1-74.3%) of the echocardiograms compared to screening using echocardiography alone. CONCLUSIONS: Screening high-risk groups in primary-care increases the pick-up rate for undiagnosed LVSD and using an LR-model combining NT-proBNP, QRS, symptoms and evidence of MI has significant cost benefits.

Severe Enterovirus Infections in Hospitalized Children in the South of England: Clinical Phenotypes and Causative Genotypes.

BACKGROUND: Most enterovirus surveillance studies lack detailed clinical data, which limits their clinical usefulness. This study aimed to describe the clinical spectrum and outcome of severe enterovirus infections in children, and to determine whether there are associations between causative enterovirus genotypes and clinical phenotypes. METHODS: Retrospective analysis of microbiological and clinical data from a tertiary children's hospital in the South of England over a 17-month period (2012-2013). RESULTS: In total, 30 patients were identified, comprising sepsis (n = 9), myocarditis (n = 8), meningitis (n = 8) and encephalitis (n = 5). Cases with sepsis or myocarditis were significantly younger than those with central nervous system disease (median age 21 and 15 days vs. 79 days; P = 0.0244 and P = 0.0310, respectively). There was considerable diversity in the causative genotypes in each of the clinical phenotypes, with some predominance of echoviruses in the meningitis group, and coxsackie B viruses in the myocarditis group. Thirteen cases required mechanical ventilation, 11 cases inotropic support, 3 cases dialysis and 3 cases extracorporal membrane oxygenation. The overall mortality was 10% (sepsis group, n = 1; myocarditis group, n = 2). Of the survivors, 5 (19%) had long-term sequelae (myocardial dysfunction, n = 2; neurological sequelae, n = 3). Patients with encephalitis had the longest hospital stay (median: 16 days), compared with 9, 6 and 3 days in patients with myocarditis, sepsis and meningitis, respectively (P = 0.005). CONCLUSIONS: Enterovirus infections, particularly enteroviral myocarditis and encephalitis, can cause significant morbidity and mortality. The results show that there are currently no strong associations between clinical phenotypes and particular causative enterovirus genotypes in the South of England.