Amelia Sánchez

The use of continuous renal replacement therapy in series with extracorporeal membrane oxygenation

A large percentage of patients on extracorporeal membrane oxygenation (ECMO) require continuous renal replacement therapy (CRRT) usually performed through a different venous access or by introducing a filter into the ECMO circuit. Here, we evaluated the efficacy and safety of including a CRRT machine in the circuit by connecting its inlet line after the centrifugal pump and its outlet line before the oxygenator. We tested the function of the combined system initially in a closed circuit, followed by an experimental animal study, and, finally, in a clinical trial with six children. Both machines functioned adequately and there were no significant changes in the pressures of the ECMO circuit after the introduction of the CRRT device, thus achieving the preset negative balances and normalization of the serum urea and creatinine concentrations. The mean life of the filters was about 138 h, and only one filter needed changing due to clotting. Our study shows that the introduction of a CRRT device into the ECMO circuit is a safe and effective technique that improves fluid balance, increases filter life, and does not cause complications. For these reasons, this may be a good method for performing CRRT in patients on ECMO.

Life-threatening effects of discontinuing inhaled nitric oxide in children

We treated 40 children, aged between 15 d and 17 y, diagnosed with acute respiratory distress syndrome and/ or pulmonary hypertension, with inhaled nitric oxide. The most frequent underlying diagnosis associated with ARDS were bronchopneumonia (eight), cardiac surgery (five), and sepsis (three). Pulmonary hypertension was secondary to cardiomyopathy in 2 patients and occurred in the postoperative period of cardiac surgery in 17 patients–the most frequent were ventricular septal defect (5), transposition of great arteries (4), and atrioventricular septal defect (3). In 11 patients, sudden discontinuation of nitric oxide induced a decrease in oxygenation associated in some of the patients with an increase in pulmonary artery pressure. In two patients discontinuation of nitric oxide induced severe pulmonary hypertension, extreme bradycardia and hypoxaemia, which required cardiopulmonary resuscitation. When exogenous nitric oxide is abruptly interrupted, hypoxaemia and pulmonary hypertension are found in some patients, due to a decrease in the nitric oxide concentration in the pulmonary circulation. This may be caused by the exogenous nitric oxide administration that may have inhibited endogenous production. We recommend making a progressive withdrawal of inhaled nitric oxide to avoid the side effects observed in the sudden discontinuation.

Transpyloric enteral feeding in critically ill children.

BACKGROUND Nutrition is important in childhood because the child has a lower energy reserve than the adult and a higher demand for calories because of ongoing growth. In this study, the utility of transpyloric enteral feeding (TEF) in critically ill children was evaluated. METHODS A prospective, descriptive study was made in a pediatric intensive care unit of a tertiary pediatric center of 41 critically ill children, 30 after surgical procedures and 11 with nonsurgical illness, aged 8 days to 12 years, who received transpyloric enteral feeding with 8- or 10-Fr weighted feeding tubes. Analysis was made of tolerance and complications (vomiting, abdominal distension, excessive gastric residual, diarrhea, and pulmonary aspiration) of TEF. RESULTS The mean duration of TEF was 19.5 +/- 26.8 days (range, 1-120 days). The administration of sedative agents or inotropic drugs did not alter toleration of TEF. Eight of 12 patients treated with continuous infusion of vecuronium tolerated TEF without complications. Eleven gastrointestinal complications occurred in 10 patients, abdominal distension and excessive gastric residual in 7 (17%), and diarrhea in 4 (9.7%). In 7 patients gastrointestinal complications improved, with decreasing use or transitory interruption of TEF, but in 4 patients (9.7%), TEF had to be withdrawn. Gastrointestinal complications were more frequent in postsurgical than in nonsurgical patients (p < 0.001). No patients suffered from pulmonary aspiration, and the incidence of pulmonary infection and hepatic dysfunction diminished during TEF. CONCLUSIONS Transpyloric enteral feeding is a good method of nutritional support in critically ill children and can be used in patients treated with neuromuscular blocking agents. The frequency and severity of complications and the risks of pulmonary infection and hepatic dysfunction related to TEF are low.

Hypotonic versus isotonic maintenance fluids in critically ill children: a multicenter prospective randomized study

Aim:  Study the influence of hypotonic (HT) and isotonic (IT) maintenance fluids in the incidence of dysnatraemias in critically ill children.

Continuous renal replacement therapy in children after cardiac surgery

OBJECTIVE The objective was to study the clinical course of children requiring continuous renal replacement therapy (CRRT) after cardiac surgery and to analyze the factors associated with mortality. METHODS A prospective observational study was performed that included all children requiring CRRT after cardiac surgery, comparing these patients with other critically ill children requiring CRRT. Univariate and multivariate analyses were performed to determine the influence of each factor on mortality. RESULTS Eighty-one (4.9%) of 1650 children undergoing cardiac surgery required CRRT; 65 of them (80.2%) presented multiorgan failure. Children starting CRRT after cardiac surgery had lower mean arterial pressure and lower urea and creatinine levels, and were more likely to require mechanical ventilation than other children on CRRT. The incidence of complications was similar. Cardiac surgery increased the probability of requiring CRRT for more than 14 days. Mortality was 43% in children receiving CRRT after cardiac surgery and 29% in other children (P = .05). Factors associated with mortality in the univariate analysis were age less than 12 months, weight less than 10 kg, higher Pediatric Risk of Mortality Score, hypotension, lower urea and creatinine on starting CRRT, and use of hemofiltration. In the multivariate analysis, the only factor associated with mortality was hypotension on starting CRRT (hazard ratio, 4.01; 95% confidence interval, 1.2-13.4; P = .024). CONCLUSIONS Although only a small percentage of children undergoing cardiac surgery required CRRT, mortality in these patients was high. Hypotension at the time of starting the technique was the only factor associated with a higher mortality.

Evaluación de los cursos de simulación médica avanzada para la formación de los médicos residentes de pediatría en situaciones de emergencia

OBJECTIVE To analyse the usefulness of simulation courses in paediatric emergencies in a new training program for paediatrics residents. METHODS An advanced simulation course with practical cases of paediatric emergencies was designed. Assessment of each clinical case was rated from 1 to 5 in the following sections: organization and coordination of team work, physician orders, monitoring, clinical examination, treatments, interpretation of laboratory tests, parent information, and global evaluation. The results were compared by year of residency of the participants. Student satisfaction with the course was assessed through a survey. RESULTS There were six courses of simulation with 55 residents, of whom 29% were second-year residents (R2), 47% third year (R3), and 23% fourth year (R4). The median global score was 3.4 (IR: 3.2 to 3.7). The highest score was the initial monitoring (median: 4; IR: 4 to 4.3) and the initial medical examination (median: 4; IR: 3.4 to 4.2). The worst aspect was the information to the parents (median: 3; IR: 2.3 to 3.4). There were no significant differences in the global score according to the year of residency. The residents felt very positive about simulation courses, emphasizing the realism and practicality. CONCLUSIONS The inclusion of advanced simulation courses in paediatric emergencies in the training program of paediatric residents is a useful educational method, and is appreciated by residents.

Ultrafiltración combinada perioperatoria en cirugía cardíaca pediátrica. Resultados preliminares

Introduccion y objetivos Las tecnicas de ultrafiltracion se emplean cada vez mas para el control exacto de fluidos y de la respuesta inflamatoria que provoca la circulacion extracorporea. El objetivo de este estudio es describir una nueva tecnica que combina la ultrafiltracion convencional con la modificada y analizar los resultados obtenidos. Pacientes y metodos Fueron incluidos 22 pacien- tes con un peso medio de 13,1 ± 8,4 kg operados con circulacion extracorporea, a los que se les realizaron ultrafiltracion convencional durante la circulacion extracorporea y ultrafiltracion modificada poscirculacion extracorporea. Se analizaron variables de bomba, valores hemodinamicos durante las primeras 24 h, gasometrias, coagulacion, recuentos corpusculares, moleculas inflamatorias IL-6, ICAM-1 y VCAM-1. Resultados El volumen ultrafiltrado combinado medio fue de 1.399 ± 680 ml/m2 (657 ± 386 ml/m2 du- rante la circulacion extracorporea y 845 ± 358 ml/m2 poscirculacion extracorporea). Tras el periodo de ultrafiltracion modificada, el hematocrito medio au- mento desde 23 ± 2,3 hasta 32 ± 4,1, la presion arterial sistolica aumento desde 74 ± 13 a 98 ± 20 mmHg, la frecuencia disminuyo de 133 ± 22 a 126 ± 23 lat/min, y la presion venosa central se mantuvo estable. Se demostro una relacion significativa por analisis multivariante entre el tiempo de ultrafiltracion modificada y el nivel de VCAM-1 tras la tecnica. El numero de plaquetas disminuyo en relacion con el volumen ultrafiltrado en bomba y la diuresis aumento. Conclusiones La ultrafiltracion combinada perioperatoria es una tecnica realizable sin morbilidad, y los resultados hemodinamicos y de hemoconcentracion son excelentes. Se necesitan mayores muestras y grupos de control para definir mejor su influencia terapeutica en la respuesta inflamatoria motivada por la circulacion extracorporea.

Trombólisis con dosis bajas de factor activador de plasminógeno en niños

OBJECTIVE To analyse the efficacy and side effects of low doses of tissue plasminogen activator for the treatment of acute arterial and/or venous thrombosis in children. PATIENTS AND METHODS Prospective observational clinical study. 18 children between 1 months and 11 years treated with low doses (0.01-0.06 mg/kg/h) of continuous intravenous thrombolytic therapy with t-PA were studied. RESULTS A total of 94% of patients improved with low doses t-PA (72% complete resolution of the thrombosis and 22% partial resolution). One patient suffered a severe haemorrhage secondary to t-Pa and had to stop the treatment. The incidence of severe side effects was low (5%) CONCLUSIONS Thrombolytic therapy with low doses of t-PA (0.01-0.05 mg/kg/h) is effective in a high percentage of children with acute arterial and/or venous thrombosis and produces a relatively low frequency of side effects.

Multichannel intraluminal impedance to study gastroesophageal reflux in mechanically ventilated children in the first 48 h after PICU admission

OBJECTIVE The aim of this study was to determine the incidence, characteristics, related factors, and clinical implications of gastroesophageal reflux (GER) in critically ill children using esophageal pH monitoring and multichannel intraluminal impedance. METHODS A prospective observational clinical study was performed including 36 non-enterally fed critically ill children with mechanical ventilation, aged 1 mo to 7 y, in the first 48 h after admission in the pediatric intensive care unit (PICU). Esophageal pH monitoring and multichannel intraluminal impedance were used. RESULTS Multichannel intraluminal impedance detected 352 episodes of GER (20.1% acid, 53.8% weak acid, 26% alkaline), whereas pH monitoring detected 171 episodes (100% acid). There were no differences in the type of reflux according to age and no differences in the number or type of reflux according to the administration of inotropic or sedatives drugs or the duration of mechanical ventilation. Patients treated with vecuronium had fewer episodes of GER than those without muscle relaxant drugs. CONCLUSIONS The incidence of GER in non-enterally fed critically ill children with mechanical ventilation is high in the first 48 h after admission to the PICU. Multichannel intraluminal impedance is more sensitive than pH monitoring for establishing the diagnosis of GER because the refluxate is alkaline or weak acid in the majority of episodes. Patients who received muscle relaxants had a lower frequency of GER.

Infection in critically ill pediatric patients on continuous renal replacement therapy.

Introduction Continuous renal replacement therapies (CRRT) are frequently used in critically ill children and may increase the risk of infection. However, the incidence, characteristics and prognosis of infection in critically ill children on CRRT have not been studied. Methods Data from a prospective, single-center register of critically ill children treated with CRRT was analyzed. Results 55 children (40% under 1 year of age) were treated with CRRT between June 2008 and January 2012; 43 patients (78.2%) presented 1 or more infections. The most common condition of patients requiring CRRT was heart disease (69%). Infection occurred a median of 11 days after the initiation of CRRT (IQ range: 4 to 21 days). A total of 21 patients (48.8 %) developed 1 infection, 7 (16.2%) developed 2 infections and 15 (34.9%) developed 3 or more infections. The most frequent infection was catheter-related bacteremia, with no differences in catheter location. CRRT duration longer than 4.5 days was the only risk factor for infection. Patients with infection had a longer length of stay (LOS) in the Pediatric Intensive Care Unit (PICU) than patients without it (37.8 vs. 17.6, p = 0.019), but there were no differences in mortality (30.2% vs. 33.3%; p = 0.84). Conclusions Infection rate is high in critically ill children treated with CRRT. More than 4 days of CRRT increases the risk of infection. Infection in these patients entails a longer stay in the PICU but did not increase mortality.