Extracorporeal membrane oxygenation in myocardial failure after pediatric heart surgery

In spite of progressive improvement not only in myocardial protection but also in anesthetic and surgical techniques, the repair of complex congenital heart defects can still lead to cardiopulmonary compromise refractory to conventional treatment. We describe two patients in whom successful surgical repair of congenital heart defects was followed by severe heart failure refractory to medical treatment. Both patients were managed by extracorporeal membrane oxygenation (ECMO). We discuss the indications, contraindications and use of ECMO in the postoperative intensive care unit.     

Extracorporeal membrane oxygenation for acute respiratory failure induced by Legionella pneumoniae. (Case report)

We report a case of severe legionella pneumonia with acute respiratory failure, successfully managed with veno-venous extracorporeal membrane oxygenation (VV-ECMO). The patient presented with 4-day history of fever and cough. He was in critical condition, with exacerbated respiratory failure. Mechanical ventilation, volume replacement and antibiotic therapy were initiated. Despite increasing mechanical ventilatory support (FiO2 100%, TV 10 ml/kg, f 30/min, PEEP 5 cmH20), PaO2 fell below 40Torr and life sustaining measures were undertaken. VV-ECMO (flow 30 ml/kg/min) was commenced, and the patient responded well, with an elevation of PaO2. Erythromycin therapy was effective against the pneumonia. VV-ECMO was maintained for 92 hours, mechanical ventilation was successfully discontinued 11 days after and the patient was discharged 82 days after cessation of ventilator support. Serum antibody examination proved legionella infection. VV-ECMO may have a role in the management of patients with acute respiratory failure caused by bacterial pneumonia.     

The Blalock-Taussig operation: the procedure of choice in the hypoxic infant with tetralogy of Fallot

An experimental model is presented enabling an analysis of the healing process of completely cut and re-sutured free segments of rabbit flexor tendons, kept avascular in a synovial milieu and completely isolated from adhesion formation. Under these conditions the cut tendons heal within a few weeks. It can be shown that this healing process is a result of intrinsic tendon cell activity only.     

Sinus node dysfunction after complete correction of tetralogy of Fallot. Report of a case

Atrioventricular conduction defects after complete correction of tetralogy of Fallot are well known and their prevalence is decreasing with improved operative techniques. On the other hand, sinus node dysfunction has not been described after this type of surgery. The authors report the case of a 24 year old patient operated at the age of 2 for a favourable form of tetralogy of Fallot. In the long-term, this patient had a minimal anatomical sequel (mild pulmonary insufficiency) and first degree AVB with complete right bundle branch block with sinus bradycardia on the surface ECG. A recent aggravation of the patient's functional status led to rhythmological investigation which showed chronotropic atrial incompetence with nodal atrioventricular delay. The patient was implanted with a permanent DDD cardiac pacemaker programmed in the DDDR mode with a good outcome. Atrial chronotropic incompetence is one of the modes of expression of sinus node dysfunction. This has not been previously described in this context. This form of sinus node dysfunction should be systematically excluded after surgical cure of tetralogy of Fallot by exercise stress testing and 24 hour Holter ECG. Symptomatic patients are greatly improved by permanent cardiac pacing with hysteresis.     

The functional status of arrhythmia patients in the late period after the radical correction of tetralogy of Fallot

OBJECTIVE: To assess the cognitive performance of elderly patients referred to the memory clinic. DESIGN: The patients were interviewed using the computerised mental state programme, GMS-AGECAT, and assessed on the Cognitive Assessment Scale (CAS) which includes the Elderly Cognitive Assessment Questionnaire (ECAQ) and the Cambridge Memory Test (CMT), modified for Chinese elderly. SUBJECTS: There were 72 Chinese elderly subjects aged 65 years and above, referred to the NUH Memory Clinic in the first year. RESULTS: Only 45 (62.5%) of the 72 subjects were diagnosed to have dementia using DSM III R criteria. There were 25 cases of Alzheimer's Disease and 20 multi-infarct dementia. In the non-demented group, 15 (20.8%) had depression or anxiety disorders and 12 (16.7%), had no mental disorders but had physical illness which could affect memory. There was a highly significant difference in the ECAQ, CMT and CAS scores of demented and non-demented elderly. There was also a significant difference in the cognitive performance of elderly with mild dementia and those with no mental disorder. CONCLUSION: The memory clinic is a useful facility for the diagnosis and management of dementia. The Cognitive Assessment Scale provides a valid and reliable battery of tests for dementia.     

Primary thrombosis of pulmonary artery in a child with tetralogy of Fallot

A 34-month-old child with tetralogy of Fallot developed an acute, primary thrombosis of the pulmonary trunk. A greatly increased haematocrit was most probably a predisposing factor. An unusual postmortem finding was the large number of extremely dilated myocardial capillaries. In a review of a series of 394 consecutive necropsy cases with many kinds of cardiac anomalies, there was only one case (a 28-year-old man) with occluding thrombus formation in the pulmonary artery. This case also belonged to the Fallot group but a subacute glomerulonephritis seemed to be the major cause of death.     

Arterial oxygenation does not predict the outcome of patients with acute respiratory failure needing mechanical ventilation

One hundred and eighteen patients consecutively submitted to mechanical ventilation during a one year period, and admitted to the Respiratory Intensive Care Unit of the Hospital Clinic of Barcelona, were prospectively studied in order to define the importance of hypoxaemia as a predictor of mortality. Using a discriminant multivariate analysis, the following variables were selected as the best predictors of outcome: 1) the number of associated complications (NAC) on admission; 2) the simplified acute physiologic score (SAPS); 3) oxygenation index (PAO2-AaPO2)/PAO2 + 0.014 positive end-expiratory pressure (PEEP); and 4) the age of the patients. Using these predictors, 84% of the patients were accurately classified as survivors or as nonsurvivors. The partial contribution of each predictor to the model was also assessed using a logistic regression, by eliminating each single predictor and each possible pair of predictors. Using this means of analysis, the NAC and SAPS were the only predictors of mortality. The inclusion of short-term mechanically-ventilated patients did not bias the accuracy of prediction.     

Improved oxygenation utilizing a prone positioner in patients with acute respiratory distress syndrome

OBJECTIVES: (a) To determine whether placing patients with acute respiratory distress syndrome in the prone position by a light-weight portable support frame improves oxygenation, (b) whether one can determine which patients benefit from prone positioning, and (c) to determine an effective technique for prone positioning of patients. DESIGN: Prospective, controlled trial without blinding. SETTING: Medical intensive care units in two urban university-affiliated hospitals. PATIENTS: Fifteen patients meeting a standard definition for acute respiratory distress syndrome were studied prospectively. Each patient acted as his own control for purposes of comparison. INTERVENTION: Patients were assigned randomly to begin in either supine or prone positions. The positioning frame was used to turn patients from one position to the other, and oxygenation, ventilation, respiratory mechanics, and hemodynamics were measured. RESULTS: Significantly better oxygenation was seen in the prone positions than in the supine (P < 0.05). In the overall population there was a decrease in AaDO2 of 21 mmHg when the patients were placed prone. The groups were then divided into responders (n = 9) and nonresponders (n = 6). There were significant differences between the groups (but not between positions) regarding PaO2, baseline, PaCO2, pulmonary artery pressures, and peak inspiratory pressures on the ventilator and in ICU length of stay and time on mechanical ventilatory support. CONCLUSION: Prone positioning improves oxygenation in the majority of patients studied and can be achieved relatively easily.     

Treatment of acute renal failure with urodilatin after unrelated bone marrow transplantation in an 18-month-old boy

The effect of serum thymic factor (FTS) administration in bovine immunodeficiency-like virus (BIV)-infected calves and rabbits was examined. We previously found that some of the macrophage functions were depressed and humoral immune responses against foreign proteins were delayed in BIV-infected calves compared to uninfected calves. After FTS administration, however, no delay of antibody responses against foreign proteins was observed in BIV-infected calves. Though the chemiluminescence (CL) responses of macrophages in BIV-infected calves were significantly depressed (p < 0.05), FTS administration resulted in the recovery of the CL responses in the BIV-infected calves comparable to those in the control calves. Antibody responses against foreign proteins in BIV-infected rabbits were significantly depressed (p < 0.025) as compared with those in uninfected rabbits, though the depression became no significant after FTS administration.     

Neuromuscular blockade with acute respiratory failure in a patient receiving cibenzoline

Cibenzoline is a class Ic antiarrhythmic agent that can be used to treat supraventricular arrhythmias. A case is reported of cibenzoline overdose in a patient with impaired renal function, leading not only to the usual cardiac and metabolic symptoms (bradycardia and hypoglycaemia), but also to a myastheniform syndrome with acute respiratory failure. Neuromuscular blockade was demonstrated by repetitive supramaximal stimulation of the median nerve, and diaphragmatic involvement was evidenced by applying the same protocol to the phrenic nerve. Muscle strength recovered as serum cibenzoline levels decreased, allowing the patient to be weaned from the ventilator. This observation suggests that cibenzoline, like other antiarrhythmic agents, can be responsible for neuromuscular blockade, and should therefore be used with caution in patients with neuromuscular and respiratory diseases or with impaired renal function.     

Atrial arrhythmias in adults after repair of tetralogy of Fallot. Correlations with clinical, exercise, and echocardiographic findings

BACKGROUND: The long-term success of intracardiac repair of tetralogy of Fallot is hampered by the occurrence of arrhythmias. Numerous studies have stressed the potential role of ventricular arrhythmias. However, the importance of other arrhythmias in the morbidity of these patients appears to be underestimated. Furthermore, most follow-up studies have been limited to children or adolescents, whereas many patients have reached adulthood after earlier repair of tetralogy of Fallot. The aim of the present study was to determine the incidence of atrial fibrillation, atrial flutter, and other supraventricular arrhythmias in adult patients after intracardiac repair for tetralogy of Fallot and their correlation with surgical and clinical findings. METHODS AND RESULTS: The study group consisted of 53 consecutive patients referred to the Thoraxcenter adult congenital heart disease clinic. They underwent repair at a mean age of 9.1 years (range, 0.7 to 55 years). The median age at the time of study was 23.2 years (range, 15 to 57 years; mean age, 26.6 years), and the mean duration of follow-up of 17.5 years (range, 1.4 to 32 years) after surgery. Records were reviewed extensively for evidence of arrhythmias. The follow-up study included routine 12-lead ECG, 24-hour continuous ambulatory monitoring, and echocardiography, and 46 patients underwent exercise testing. Sinus node dysfunction was recorded in 19 patients (36%), of whom 4 required a permanent pacemaker. Atrial fibrillation or flutter was found in 12 patients, and other supraventricular tachycardias were found in 6. The former were more frequently of older age at follow-up. Antiarrhythmic therapy and cardioversion were typically directed at control of atrial (and not ventricular) tachyarrhythmias. Ten patients (19%) showed nonsustained ventricular tachycardia; they were older at initial surgery and older at follow-up and had more intracardiac repairs and longer cardiopulmonary bypass times. CONCLUSIONS: Despite an emphasis on ventricular ectopy in past series, the main sources of morbidity in adult patients after surgical correction of tetralogy of Fallot emanated from atrial arrhythmias, which were present in one third of the patients.     

Noninvasive mechanical ventilation in a patient with respiratory failure after hematopoietic progenitor transplantation

Respiratory failure requiring orotracheal intubation (OTI) and mechanical ventilation (MV) is almost always a fatal complication in patients who undergo hematopoietic progenitor transplantation (HPT). We present the case of a woman who suffered respiratory failure with bilateral infiltrates on a chest X-ray taken on day +14 following autologous bone marrow transplantation. We managed the patient satisfactorily with noninvasive ventilation, avoiding OTI. We believe that patients with non-progressive pulmonary lesions and without multiple system organ failure, may be correctly managed with noninvasive positive-pressure ventilation (NPPV).     

Inhaled nitric oxide in the premature infant with severe hypoxemic respiratory failure: a time for caution

Electrocautery can induce significant alterations in the connective tissues and epithelium of specimens removed for diagnostic or therapeutic purposes. When electrocautery is used during parotid surgery, it can cause an oncocytoid artifact. The alterations described in this article are enlarged, tightly packed serous acinar cells with coarse to granular eosinophilic cytoplasm, distinct cell borders, and round basal nuclei that on cursory microscopic examination resemble oncocytes with respect to morphology. These changes are seen in conjunction with other, more recognized changes secondary to electrocautery and are believed to occur as a consequence of the electrothermal discharge. On the basis of our findings, this artifact is common is parotid surgical specimens and was misdiagnosed as benign oncocytic lesions in 5 cases.     

Communication breakdown: a preventable cause of acute renal failure in a newborn infant

A three-week-old boy had life-threatening renal failure which was successfully treated by salbutamol and sodium bicarbonate infusion, rectal resonium and a left percutaneous nephrostomy. Ultrasonography of this child at 19 weeks' gestation had shown a treatable renal tract abnormality (bilateral hydronephrosis). No arrangements had been made for follow-up.     

Cost of extracorporeal life support in pediatric patients with acute respiratory failure

OBJECTIVES: To determine the impact of extracorporeal life support (ECLS) on mortality in pediatric patients with acute hypoxemic respiratory failure (AHRF) at our institution; and to calculate the hospital charges associated with the use of ECLS. DESIGN: Retrospective review of medical records and hospital charges. SETTING: Pediatric intensive care unit (ICU) of a university-affiliated children's hospital. PATIENTS: Twenty patients admitted to the pediatric ICU between 1991 and 1995 for AHRF who received ECLS as a part of their hospital course. INTERVENTIONS: Predicted mortality was calculated using the Pediatric Respiratory Failure score and was compared with survival at the time of hospital discharge. Hospital charges were used as a proxy for resource utilization. Cost-per-life-year-saved calculations were performed based on a normal life expectancy for survivors. MEASUREMENTS AND MAIN RESULTS: Twenty patients were identified. The median age was 4.83 yrs. The median duration of ECLS was 9 days, with 19.5 days in the pediatric ICU and 23.5 days for the entire hospital length of stay. The observed mortality rate for these patients was 20%. Median predicted mortality rate based on the Pediatric Respiratory Failure score calculation was 83%. The hospital charges incurred by these patients was a median of $199,096. Based on a normal life expectancy for survivors, this results in a cost of $4,190/life-year. CONCLUSIONS: ECLS for the pediatric patient with AHRF is done at a considerable cost. However, ECLS affects survival favorably, and compares favorably when considering cost/life-year calculations. The data presented in this study may serve as a benchmark for comparison with newer therapies (i.e., liquid ventilation, nitric oxide). These data also provide a framework for cost-based analyses at other ECLS institutions.     

Radiofrequency catheter ablation of multiple haemodynamically unstable ventricular tachycardias in a patient with surgically repaired tetralogy of Fallot

A 55-year-old man was admitted following an overdose of sustained-release verapamil (calcium channel blocker) and ordinary-release atenolol (beta-1 blocker). At admission, there was extreme bradycardia (20-25 beats min-1) and hypotension (systolic arterial pressure 40-50 mm Hg). To counteract the cardiovascular depression, prenalterol, dopamine, dobutamine, isoprenaline, adrenaline and noradrenaline were used. A satisfactory state was obtained with adrenaline, noradrenaline and dopamine infused at high rates. Cardiac output was then more than 101 min-1, with a very low total peripheral resistance. The infusion of the adrenergic agonists could be interrupted on day 3. Prolonged ventilator treatment was necessary but the patient recovered without sequelae. Treatment options for similar cases are outlined.     

Sudden death in a 4-month-old infant associated with anomalous origin of the left coronary artery

We describe the autopsy findings of a 4 months-old boy, who died suddenly after an episode of high airway infection of 3 days time. Autopsy examination showed cardiomegaly (80 g) with widening of the left cavities and thick and white endocardial surface, besides a severe thinning of the cardiac apex at the level of the left ventricle. Left coronary origin was in the pulmonary artery trunk. Histologically, the myocardium shows endomyocardial fibroelastosis and also multiple and extensive areas of old and recent infarcts in the left ventricle. The collateral coronary arteries, were increased in number, and branches showed a marked intimal oedema and a reduction of the luminal diameter.     

Effect of noninvasive positive pressure ventilation on mortality in patients admitted with acute respiratory failure: a meta-analysis

Changes in angiogenesis and expression of extracellular matrix-degrading enzymes have been substantiated during progression of solid tumours, whereas information on haematological tumours remains circumstantial. In this study, 57 biopsies of mycosis fungoides (MF), a haematological tumour of T-cell lineage, were investigated immunohistochemically for the extent of angiogenesis, and by in situ hybridisation for the expression of matrix metalloproteinases 2 (MMP-2, collagenase A) and 9 (MMP-9, collagenase B). The biopsies we grouped according to the stage of progression: patch-->plaque-->nodular (most advanced). The extent of angiogenesis, as microvessel area, of MF lesions as a whole was significantly higher than that of normal uninjured skin, used as a control. When the stages of MF progression were compared, the values of MF patch stage overlapped that of control skin, while values were significantly higher in the plaque stage and even higher in the nodular stage. In these stages, microvessels were widely scattered in the tumour tissue, in close association with tumour cells, and they frequently displayed arborisation and microaneurysmatic dilation. In contrast, in the patch stage microvessels were irregularly distributed around the tumour aggregates, and arborisation or dilated structures were only rarely seen. The expression of MMP-2 and MMP-9 mRNAs underwent significant upregulation in relation to advancing stage. Indeed, the upstaging was significantly associated with higher proportions of lesions positive for each mRNA or for both, and with lesions with the greatest intensity of expression for each mRNA. Besides tumour cells, the MMP-2 mRNA was expressed by microvascular endothelial cells of intratumour and peri-tumour vessels, and by fibroblasts which were especially abundant in the stroma adjacent to the tumour nodules. The MMP-9 mRNA was found to be present in a subset of tissue macrophages which were more frequently located in close vicinity to the tumour nodules. In contrast, in control skin, a weak positivity for the MMP-2 mRNA in very few microvascular endothelial cells and no signal for the MMP-9 mRNA were observed. These in situ data suggest that angiogenesis and degradation of the extracellular matrix occur simultaneously during MF progression. They imply that interaction between tumour cells and their microvasculature are all the more likely to occur during progression, occasionally with the contribution of tumour-associated stromal cells.