Bridging to transplantation in acute liver failure in a 7-month-old infant.

BACKGROUND: Acute liver failure (ALF) in children is a rare but often fatal event. At present, liver transplantation is the only successful therapy in most cases. In the face of deteriorating hepatic encephalopathy in these children, some bridging therapy using artificial detoxification can be necessary to enable successful transplantation. In adults, albumin dialysis using the molecular absorbent recycling system (MARS) has been described as effective for bridging to liver transplantation. CASE REPORT: A previously healthy 7-month-old infant was admitted with ALF due to autoimmune hepatitis. King's College criteria for children with ALF indicated the need for transplantation (bilirubin 13.7 mg/dl, leukocytes 18,980/mm3, INR 5.83, age<2 years). Despite moderate hyperammonemia (75 microm/l) along with the development of pneumonia, the child deteriorated hemodynamically and neurologically, showing grade III encephalopathy proven by EEG. Albumin dialysis using MARS was used to bridge 36 hours to successful living-donor split-liver transplantation, and resulted in improvements in EEG, plasma levels of amino acids and hemodynamics. Twenty-four months after transplantation the child shows normal liver function and normal neuropsychological development. The explanted liver showed 80 % tissue destruction from autoimmune hepatitis. CONCLUSION: Albumin dialysis as described can be used successfully in infants < 1 year old for bridging to liver transplantation in cases of acute hepatic failure with deteriorating encephalopathy.

Surfactant application during extracorporeal membrane oxygenation improves lung volume and pulmonary mechanics in children with respiratory failure.

INTRODUCTION: This study was performed to determine whether surfactant application during extracorporeal membrane oxygenation (ECMO) improves lung volume, pulmonary mechanics, and chest radiographic findings in children with respiratory failure or after cardiac surgery. METHODS: This was a retrospective chart review study in a pediatric intensive care unit (PICU). Seven patients received surfactant before weaning from ECMO was started (group S). They were compared to six patients treated with ECMO who did not receive surfactant (group C). These control patients were matched based on age, weight, and underlying diagnosis. Demographic data, ventilator settings, tidal volume, compliance of respiratory system (calculated from tidal volume/(peak inspiratory pressure - positive end-expiratory pressure), and ECMO flow were extracted. Chest radiographs were scored by two blinded and independent radiologists. Changes over time were compared between groups by repeated-measures analysis of variance (time*group interaction). Values are given as percentages of baseline values. RESULTS: The groups did not differ with regard to demographic data, duration of ECMO, ventilator settings, PICU and hospital days. After application of surfactant, mean tidal volume almost doubled in group S (from 100% before to 186.2%; p = 0.0053). No change was found in group C (100% versus 98.7%). Mean compliance increased significantly (p = 0.0067) in group S (from 100% to 176.1%) compared to group C (100% versus 97.6%). Radiographic scores tended to decrease in group S within 48 h following surfactant application. ECMO flow tended to decrease in group S within 10 h following surfactant application but not in group C. Mortality was not affected by treatment. CONCLUSION: Surfactant application may be of benefit in children with respiratory failure treated with ECMO, but these findings need confirmation from prospective studies.

Impact of extracorporeal membrane oxygenation modality on cytokine release during rescue from infant hypoxia.

The treatment of acute respiratory failure in infants by means of extracorporeal membrane oxygenation (ECMO) is thought to be associated with a treatment-related inflammatory reaction, which may deteriorate the underlying disease process. The aim of this study was to compare the venoarterial (VA) and venovenous (VV) modality of ECMO with regard to their pulmonary and serological cytokine release during rescue from acute hypoxia. The inflammatory response was measured in piglets undergoing hypoxic ventilation with a gas mixture of 92% N2 and 8% O2, which were then rescued through VA- (n = 5) or VV-ECMO (n = 5). The effect of cannulation and anesthesia on the inflammatory response was deducted from regularly ventilated control animals (n = 5). The concentrations of the proinflammatory interleukins (IL)-1beta and IL-8 increased in the bronchoalveolar lavage fluid of all groups over a study period of 5 h but were significantly higher (P < 0.05) during VA-ECMO treatment, whereas the anti-inflammatory IL-10 concentrations were significantly higher in the bronchoalveolar lavage fluid of VV-treated animals (P < 0.001). No statistical difference between groups was found in the serum concentrations of cytokines. We conclude that in this animal model rescue from hypoxia by means of the VA modality of ECMO leads to a more pronounced inflammatory reaction of the lung than when applying the VV modality.

Surfactant therapy in infants and children: three years experience in a pediatric intensive care unit.

Despite the established success of surfactant application in neonates, the use of surfactant in older children is still a matter of discussion. We hypothesized that surfactant application in children with acute respiratory distress syndrome (ARDS) secondary to a pulmonary or systemic disease or after cardiac surgery improves pulmonary function. We also asked whether repeated treatment could further improve pulmonary function. To answer these questions, we measured oxygenation index (OI) and hypoxemia score after the first and after a second application of surfactant (50-100 mg/kg body wt) at least 24 h later. We enrolled 19 children (older than 4 weeks) for a retrospective chart review study, and six of them underwent cardiac surgery. Demographic data were extracted. OI and hypoxemia score were estimated before and 2 and 24 h after surfactant application. Lung injury score was calculated before and 24 h after surfactant application. Outcome measures included survival, duration of mechanical ventilation, and pediatric ICU and hospital stay. The median patient age was 9.0 (quarter percentile 3.7/25) months. The median weight was 8.4 (4.1/11.5) kg. The median lung injury score before the first surfactant application was 2.3 (2.3/2.6). Hospital duration and pediatric ICU stay for all patients was 31.0 (20.0/49.5) days and 27.0 (15.5/32.5) days, respectively. The duration of mechanical ventilation was 24.0 (18.5/31.0) days. The overall mortality was 53%. Twenty-four hours after the first surfactant application, pulmonary function significantly improved. The median OI was 14 (5.5/26) before and 7 (4.5/14.5) 24 h after surfactant application (P= 0.027). The hypoxemia score was 91.7 (69.9/154.2) before and 148.4 (99.2/167.6) 24 h after surfactant application (P = 0.0026). Seven children received a second application, which did not further improve pulmonary function. The lung injury score was not influenced by either surfactant application. We conclude that a single surfactant application improves pulmonary function in children with ARDS. A second application of surfactant showed no further benefit. Outcome was not affected in our study population.

Methemoglobin formation in children with congenital heart disease treated with inhaled nitric oxide after cardiac surgery.

OBJECTIVE: Inhaled nitric oxide (NO) is used as a therapy of pulmonary hypertension in children after cardiac surgery. Hemoglobin binds to NO with great affinity and forms methemoglobin by oxidation in the erythrocyte. Once produced, methemoglobin is unable to transport and unload oxygen in the tissues. The amount of available hemoglobin in the body for oxygen transport is thereby reduced. Anemia, acidosis, respiratory compromise and cardiac disease may render patients more susceptible than expected for a given methemoglobin level. The goal of the present study was to review the cumulative effect of inhaled NO on methemoglobin formation in critically ill children. We therefore looked for methemoglobin levels in children with congenital heart disease after cardiac surgery who were treated with inhaled NO in a range of 5-40 ppm. METHODS: We retrospectively reviewed the medical charts of 38 children with congenital heart disease after cardiac surgery. We extracted demographic data and physiological measurements at the following time points: (1) T0 = before starting inhaled NO therapy, (2) T1 = 24 h after the beginning of inhaled NO therapy, (3) T2 = half-time therapy, (4) T3 = end of therapy, (5) T4 = 24 h after finishing inhaled NO therapy. RESULTS: The median duration of inhaled NO therapy was 5.5 days (interquartile range 6, range 2-29), NO concentrations at T1 and T2 were 16 ppm (10, 5-40) and 12.5 ppm (12.3, 2-40), respectively. The median cumulative dose of inhaled NO was 1699 ppm (2313, 193-7018). Methemoglobin levels increased moderately, but significantly, during therapy ( T0 vs T1 p<0.05 and T0 vs T2 p<0.001). The highest methemoglobin level measured was 3.9%. Methemoglobin levels correlated positively with the inhaled NO doses applied at T1 ( r(2)=0.8376; p<0.01) and at T2 ( r(2)=0.8945; p<0.01). At T1 the methemoglobin level correlated negatively with the T1 blood pH value. The overall mortality rate was 13.2% (5 of 38 study patients died). There was no significant difference in methemoglobin levels between survivors and non-survivors. CONCLUSION: We conclude from our data that the use of inhaled NO therapy for children with congenital heart disease after cardiac surgery in the described range of 5-40 ppm, resulting in a maximum of 4% methemoglobin blood level, is feasible and safe. However, we recommend the use of the minimal effective dose of inhaled NO and continuous monitoring of methemoglobin levels, especially in cases of anemia or sepsis in critically ill children.

Predictors of mortality at initiation of peritoneal dialysis in children after cardiac surgery.

BACKGROUND: The development of renal dysfunction in the postoperative course of cardiac surgery is still associated with high mortality in pediatric patients. In particular for small infants peritoneal dialysis offers a secure and useful treatment option. The aim of the present study was to investigate if routinely used laboratory and clinical variables could help predict mortality at initiation of peritoneal dialysis. METHODS: We performed a retrospective chart analysis of pediatric intensive care unit patients with renal dysfunction who were treated with peritoneal dialysis after cardiac surgery between 1993 and 2001 and analyzed variables obtained 3 hours or less before starting peritoneal dialysis. RESULTS: Results are documented as means and standard errors. A total of 1141 children underwent a cardiac operation on cardiopulmonary bypass. Sixty-two children (5.4%) were treated with peritoneal dialysis. Mortality was 40.3% (37 survivors, 25 nonsurvivors). The pH in survivors was 7.35 (0.01); in nonsurvivors it was 7.23 (0.03; p = 0.0037). Base excess in survivors was -1.37 mmol/L (0.61); in nonsurvivors it was -7.17 mmol/L (1.49; p = 0.0026). Lactate in survivors was 4.5 mmol/L (0.60); in nonsurvivors it was 10.5 mmol/L (1.78; p = 0.0089). Positive inspiratory pressure in survivors was 24.6 cm H(2)O (0.78); in nonsurvivors it was 28.9 cm H(2)O (1.08; p = 0.0274). Tidal volume per kilogram bodyweight in survivors was 11.0 mL/kg (0.48); in nonsurvivors it was 8.7 mL/kg (0.50; p = 0.0493). CONCLUSIONS: We conclude from our data that the consideration of pH, base excess, lactate, positive inspiratory pressure, and tidal volume per kilogram bodyweight help predict mortality at initiation of peritoneal dialysis. We were able to observe significant differences between survivors and nonsurvivors using these variables.

Early postoperative prediction of cerebral damage after pediatric cardiac surgery.

BACKGROUND: Cerebral damage is a serious complication of pediatric cardiac surgery. Early prediction of actual risk can be useful in counseling of parents, and in early diagnosis and rehabilitation therapy. Also, if all children at risk could be identified therapeutic strategies to limit perioperative cerebral damage might be developed. The aim of this study is to create a mathematical model to predict risk of neurologic sequelae within 24 hours after surgery using simple and readily available clinical measurements. METHODS: The hospital records of 534 children after cardiac surgery were reviewed. Variables examined were age at operation, diagnosis, use of cardiopulmonary bypass, arterial and central venous oxygen saturation, serum glucose, lactate and creatine kinase, mean arterial pressure, and body temperature. The endpoint for each study patient was the occurrence or lack of occurrence of seizures, movement or developmental disorders, cerebral hemorrhage, infarction, hydrocephalus, or marked cerebral atrophy. Univariate and multivariate regression analyses were used to evaluate the predictive power of the investigated factors as well as to create a predictive model. RESULTS: In 6.26% of children symptoms of cerebral damage were found. Significant risk factors were age at surgery, more complex malformations, metabolic acidosis, and increased lactate (odds ratio: age, 0.882/yr [0.772-1.008]; complex malformations, 10.32 [1.32-80.28]; arterial pH more than 7.35 to 0.4 [0.18-0.89]; lactate -1.018 per mg/dL [1.006-1.03]). CONCLUSIONS: It is possible to quantify the risk of appearance of symptoms of cerebral damage after cardiac surgery within 24 hours using simple and readily available clinical measurements.

Monitoring of cerebral oxygen saturation with a jugular bulb catheter after near-drowning and respiratory failure.

We report on monitoring oxygen saturation with a jugular bulb fiber-optical catheter in an 18-month-old girl after fresh water near-drowning followed by acute respiratory failure. The first measured cerebral oxygen saturation was 22% despite normal values for arterial and central venous oxygen saturation. After conventional therapy had failed to improve cerebral oxygen saturation, we started veno-venous extracorporeal membrane oxygenation. Normal levels of cerebral oxygen saturation were achieved after six hours. The girl was extubated after seven days and discharged after twenty-five days in good general condition and without obvious evidence of neurological damage. We believe that in this case of near-drowning, monitoring cerebral oxygen saturation with a jugular bulb catheter was important for surveillance of cerebral hypoxia.

Peritoneal dialysis for continuing renal support after cardiac ECMO and hemofiltration.

Postoperative acute renal insufficiency after cardiac surgery in neonates is associated with increased mortality and is usually treated (while using ECMO, extracorporeal membrane oxygenation) with hemofiltration. Renal support has to be continued after weaning from ECMO when oliguria persists. When using hemofiltration, prolonged anticoagulation and a vascular access is needed, which, however, carries the risk of hemorrhagic as well as thromboembolic complications. Alternatively, peritoneal dialysis (PD) can be performed. We report data from 5 infants treated with ECMO after corrective cardiac surgery, who experienced oliguria after ECMO weaning and were consequently treated with PD. Arterial and central venous pressures, inotropic demand, urinary output, blood urea nitrogen, creatinine and survival were investigated. All patients survived. Installation of PD resulted in stable hemodynamics in all patients, despite continued oliguria. Normal renal function was established in four patients. One patient, suffering from persistent renal insufficiency, remained on PD. PD effectively supports insufficient renal functioning after ECMO weaning without the need for anticoagulation or a vascular access. Acute renal insufficiency may be reversible even after weeks and, if necessary, PD also enables prolonged treatment until renal transplantation.

Acute hemorrhagic respiratory failure caused by Wegener's granulomatosis successfully treated by bronchoalveolar lavage with diluted surfactant.

Wegener's granulomatosis (WG) is an idiopathic inflammatory systemic disease that can occasionally cause an acute respiratory distress syndrome. We report on a 17-year-old girl with Wegener's granulomatosis and acute hemorrhagic respiratory failure successfully treated using bronchoalveolar lavage with diluted porcine surfactant (Curosurf; 4.8 mg/mL) followed by a low-dose bolus of surfactant. The cumulative dose of surfactant was 40 mg/kg BW. The lavage with diluted surfactant and the administration of the bolus were performed with a flexible bronchoscope. The patient was ventilated during the whole procedure, stayed hemodynamically stable and showed only a very short phase of desaturation. The PaO2/FiO2 ratio increased from 54.8 to 62.4 after one hour, to 106 after 17 hours and finally to 280 after four days. The patient was extubated five days after lavage treatment, and almost normal lung function was restored after eight weeks. Bronchoalveolar lavage with diluted surfactant by flexible bronchoscopy allows selective and direct drug administration and removes airway and alveolar debris. The technique reduces the amount of surfactant needed to overcome inhibition and thereby reduces therapy costs. We conclude that this early therapeutic intervention with surfactant might help to avoid an invasive rescue therapy such as extra corporeal membrane oxygenation, thus improving outcome in terms of faster recovery of lung function.

Prehospital pediatric emergencies in Austrian helicopter emergency medical service - a nationwide, population-based cohort study.

INTRODUCTION: Arguably, the most challenging emergencies encountered by emergency medical service crews involve children. Because only scant data exist about the epidemiology of pediatric emergencies in helicopter emergency medical service (HEMS) on a population level, we sought to determine the epidemiological characteristics stratified by responding area in a large nationwide sample. METHODS: This was a retrospective cohort study including all pediatric patients (0-14 years of age) who were treated by HEMS in Austria from January 2006 to June 2007 (18 months). RESULTS: Pediatric emergencies accounted for 2207 (8.2%) of a total of 26.850 helicopter rescue missions. Of those, 69.9% (n = 1543) were not involved in life-threatening emergencies. The rate of critical pediatric emergencies was higher in urban than in rural or alpine environment (45.2%, 38.2% and 20.3%, respectively). The most common chief complaint was trauma; the frequency of injuries ranged from 54.2% (582/1074) in rural area and 60.3% (44/73) in urban area to 91.4% (969/1060) in alpine environment. Fracture and head trauma (34.9%; 557/1595 and 26.3%; 419/1595, respectively) were the most common injuries. Advanced life support measures like tracheal intubation, cardiopulmonary resuscitation and intraosseous access were rarely performed (3.7%; n = 82, 1.9%; n = 42 and 0.9%; n = 19, respectively). CONCLUSIONS: Pediatric emergencies in Austrian HEMS show different epidemiological characteristics in alpine, urban and rural operational environments. Because of challenges and infrequency of prehospital pediatric emergencies, HEMS crews need to maintain their skills in pediatric advanced life support and trauma care.

Quantitative electroencephalography values of neonates during and after venoarterial extracorporeal membrane oxygenation and permanent ligation of right common carotid artery.

Venoarterial extracorporeal membrane oxygenation (ECMO) in neonates commonly needs neck vessel cannulation leading to ligation of right common carotid artery (RCCA) in some cases. Quantitative electroencephalography (EEG) measurements provide reproducible data of cerebral function. The aim of this case-control study was to test whether ligation of the RCCA results in EEG changes after ECMO weaning. Ten mechanically ventilated neonates not treated with ECMO were eligible as control patients. Seven ECMO patients receiving similar sedoanalgesia were investigated during and after ECMO and RCCA ligation. Dominant frequency, absolute alpha, theta, delta, and total powers of right and left frontocentral and temporooccipital derivations were calculated. Dominant frequency did not differ among groups. Power was found to be significantly decreased in all frequency bands during ECMO. After weaning from ECMO, EEG differences between the ECMO and control groups disappeared in spite of permanent RCCA ligation. It is concluded that ligation of the RCCA per se does not result in quantitative EEG changes.

Testing of extracorporeal membrane oxygenation circuit related hemolysis using long-term stored packed red cells and fresh frozen plasma.

BACKGROUND: The resistance of blood used in these studies to hemolysis differs markedly from that used in neonatal extracorporeal circulation under clinical circumstances. In this study, the possibility of using expired packed red cells to determine hemolysis caused by mechanical and/or environmental factors was investigated. METHODS: Packed red blood cells stored for 42 days were mixed with fresh frozen plasma and the resultant mixture was divided into three groups, two study groups and a control. For the study groups, two different centrifugal pump heads (Medtronic BP 50 and Jostra RF 32) were used in an extracorporeal membrane oxygenation (ECMO) circuit. Free hemoglobin, lactate dehydrogenase, lactic acid, pH, potassium, and glucose were investigated at various time intervals. RESULTS: Hemolysis did not differ between the groups. Free hemoglobin increased in all groups after 12 h. Lactic acid increased linearly in all groups up to 12 h. Glucose and pH decreased steadily in all groups. Hemolysis created during mock ECMO did not differ between the circuits using the two different pump heads noted. CONCLUSION: Human donor blood stored up to its expiration date is a feasible medium for mock circulation tests of up to 12 h duration under the circumstances described.

Low-volume peritoneal dialysis in 116 neonatal and paediatric critical care patients.

UNLABELLED: Acute renal insufficiency accounts for high mortality in paediatric intensive care patients, particularly in infants. Peritoneal dialysis, usually carried out with dialysate volumes of >20 ml/kg body weight, increases pulmonary artery pressure, which may compromise myocardial function in critical illness. In this paper we report our experiences with the use of lower dialysate volumes in the treatment of critically ill children with renal impairments. We suggest that low-volume peritoneal dialysis is able to achieve adequate ultrafiltration, which relieves overhydration in ventilated and haemodynamically compromised children. A total of 116 paediatric intensive care patients treated between 1992 and 2000 was the subject of this investigation. Diagnosis, indication for dialysis, arterial and central venous pressure, blood gases, creatinine, blood urea nitrogen, urinary output at installation, ultrafiltration, fluid balance, duration and complications during dialysis as well as survival were investigated. The overall mortality was 53%. The respective diagnoses and mortality rates were as follows: 65% of the patients suffered from cardiac diseases (54% mortality), 7% from renal diseases (13%) and 28% from multi-organ system failure (62%). Low-volume peritoneal dialysis was started at evidence of total body fluid overload with inadequate urinary output and resulted in a mean ultrafiltration of 2.8 ml/kg body weight per h. A negative fluid balance was achieved in 53% of patients, mainly in those suffering from hypervolaemia and minor oliguria. None of the complications resulted in death. CONCLUSION: early installation of low-volume peritoneal dialysis offers a safe and adequate ultrafiltration procedure for paediatric critical care patients suffering from minor oliguria and fluid overload.