[Factors associated with the prognosis of mechanically ventilated infants and children. An international study]. / Factores asociados al pronóstico de los pacientes pediátricos ventilados mecánicamente. Un estudio internacional.

OBJECTIVE: Identify factors associated with the survival of pediatric patients who are submitted to mechanical ventilation (MV) for more than 12 hours. DESIGN: International prospective cohort study. It was performed between April 1 and May 31 1999. All patients were followed-up during 28 days or discharge to pediatric intensive care unit (PICU). SETTING: 36 PICUs from 7 countries. PATIENTS: A total of 659 ventilated patients were enrolled but 15 patients were excluded because their vital status was unknown on discharge. RESULTS: Overall in-UCIP mortality rate was 15,6%. Recursive partitioning and logistic regression were used and an outcome model was constructed. The variables significantly associated with mortality were: peak inspiratory pressure (PIP), acute renal failure (ARF), PRISM score and severe hypoxemia (PaO2/FiO2 < 100). The subgroup with best outcome (mortality 7%) included patients who were ventilated with a PIP < 35 cmH2O, without ARF, or PaO2/FiO2 > 100 and PRISM < 27. In patients with a mean PaO2/FiO2 < 100 during MV mortality increased to 26% (OR: 4.4; 95% CI 2.0 to 9.4). Patients with a PRISM score > 27 on admission to PICU had a mortality of 43% (OR: 9.6; 95% CI 4,2 to 25,8). Development of acute renal failure was associated with a mortality of 50% (OR: 12.7; 95% CI 6.3 to 25.7). Finally, the worst outcome (mortality 58%) was for patients with a mean PIP >/= 35 cmH2O (OR 17.3; 95% CI 8.5 to 36.3). CONCLUSION: In a large cohort of mechanically ventilated pediatric patients we found that severity of illness at admission, high mean PIP, development of acute renal failure and severe hypoxemia over the course of MV were the factors associated with lower survival rate.

What is the daily practice of mechanical ventilation in pediatric intensive care units? A multicenter study.

OBJECTIVE: To describe the daily practice of mechanical ventilation (MV), and secondarily, its outcome in pediatric intensive care units (PICUs). DESIGN: Prospective cohort of infants and children who received MV for at least 12 h. SETTING: Thirty-six medical surgical PICUs. PATIENTS: All consecutive patients admitted to the PICUs during 2-month period. MEASUREMENTS AND MAIN RESULTS: Of the 1893 patients admitted, 659 (35%) received MV for a median time of 4 days (25th percentile, 75%: 2, 6). Median of age was 13 months (25th percentile, 75%: 5, 48). Common indications for MV were acute respiratory failure (ARF) in 72% of the patients, altered mental status in 14% of the patients, and ARF on chronic pulmonary disease in 10% of the patients. Median length of stay in the PICUs was 8 days (25th percentile, 75%: 5, 13). Overall mortality rate in the PICUs was 15% (confidence interval 95%: 13-18) for the entire population, 50% (95% CI: 25-74) in patients who received MV because of acute respiratory distress syndrome, 24% (95% CI: 16-35) in patients who received MV for altered mental status and 16% (95% CI: 9-29) in patients who received MV for ARF on chronic pulmonary disease. CONCLUSION: One in every 3 patients admitted to the PICUs requires ventilatory support. The ARF was the most common reason for MV, and survival of unselected infants and children receiving MV for more than 12 h was 85%.

An evaluation of extubation failure predictors in mechanically ventilated infants and children.

OBJECTIVE: To assess the accuracy of traditional weaning indices in predicting extubation failure, and to compare their accuracy when indices are measured at the onset of a breathing trial (SBT) and at the end of the SBT before extubation. DESIGN: Prospective study. SETTING: Medical-surgical intensive care unit at a tertiary care hospital. PATIENTS: Four hundred eighteen consecutive infants and children who received mechanical ventilation for at least 48 h and were deemed ready to undergo a SBT by their primary physician. INTERVENTIONS: Respiratory frequency (RR), tidal volume (V(T)), maximal inspiratory pressure (P(imax)) and frequency-to-tidal volume ratio (f/V(T)) were obtained within the first 5 min of breathing through a T-piece. The primary physicians were unaware of those measurements and the decision to extubate a patient was made by them. RR, V(T), f/V(T) were remeasured before extubation by the respiratory therapists. Extubation failure was defined as needing re intubation within 48 h after extubation. The area under the receiver operating characteristic (ROC) curve was calculated for each index as a measure of the accuracy in predicting extubation outcome. MEASUREMENTS AND MAIN RESULTS: Three hundred twenty-three patients successfully underwent the SBT and were extubated, but 48 of them (14%) required re-intubation. The ROC curve for V(T), RR, P(imax) and f/V(T) measured within the first 5 min of breathing were 0.54, 0.56, 0.57 and 0.57, respectively. The ROC curve did not increase significantly when the above indices were remeasured before extubation. CONCLUSIONS: In a population which had passed SBT, the ability of the traditional weaning indices to discriminate between children successfully extubated and children re-intubated is very poor.

A comparison of two methods to perform a breathing trial before extubation in pediatric intensive care patients.

OBJECTIVE: To compare the percentage of infants and children successfully extubated after a trial of breathing performed with either pressure support or T-piece. DESIGN: Prospective and randomized study. SETTING: Three medical-surgical pediatric intensive care units (PICUs). PATIENTS: Two hundred fifty-seven consecutive infants and children who received mechanical ventilation for at least 48 h and were deemed ready to undergo a breathing trial by their primary physician. INTERVENTIONS: Patients were randomly assigned to undergo a trial of breathing in one of two ways: pressure support of 10 cmH2O or T-piece. Bedside measurements of respiratory function were obtained immediately before discontinuation of mechanical ventilation and within the first 5 min of breathing through a T-piece. The primary physicians were unaware of those measurements, and the decision to extubate a patient at the end of the breathing trial was made by them. MEASUREMENTS AND MAIN RESULTS: Of the 125 patients in the pressure support group, 99 (79.2%) completed the breathing trial and were extubated, but 15 of them (15.1%) required reintubation within 48 h. Of the 132 patients in the T-piece group, 102 (77.5%) completed the breathing trial and were extubated, but 13 of them (12.7%) required reintubation within 48 h. The percentage of patients who remained extubated for 48 h after the breathing trial did not differ in the pressure support and T-piece groups (67.2% versus 67.4%, p=0.97). CONCLUSIONS: In infants and children mechanically ventilated, successful extubation was achieved equally effectively after a first breathing trial performed with pressure support of 10 cmH2O or a T-piece.

Modos ventilatorios y retirada de la ventilación mecánica en pediatría: corte de prevalencia, estudio multicéntrico / Modes of ventilation and weaning of the mechanical ventilation in pediatrics: prevalence cut-multicentric study

Objetivo: Conocer la proporción de los pacientes que requieren ventilación mecánica (AVM) entre los ingresados en la unidad de cuidados intensivos pediátricos (UCIP) y los modos de ventilación utilizados. Material y métodos: Se realizó un estudio observacional y prospectivo de la ventilación mecánica en 12 UCIP distribuidas por Argentina durante 1997, en dos fechas climatológicas diferenciadas, 13 de mayo (M97) y 13 de agosto (A97). Se utilizó un cuestionario cumplmentado para cada paciente. Resultados: 92 pacientes ingresaron a la UCIP en M97 y 107 en A97. El 54,3 por ciento (IC 97 por ciento 47,6-61) y 51,4 por ciento (IC 95 por ciento 44,7-58,1) estaban en AVM respectivamente. La causa más frecuente de ingreso al respirador fue la insuficiencia respiratoria aguda 62 por ciento (IC 95 por ciento 48,5-75,4) en M97 y 61,8 por ciento (IC 95 por ciento 48,9-74,6) en A97. El modo de ventilación más utilizado en ambos cortes fue la IMV/SIMV 48 por ciento (IC 95 por ciento 35-61) y 52,7 (IC 95 por ciento 39,5-65,7). El porcentaje de pacientes en proceso de retirada de la ventilación fue del 40 por ciento (IC 95 por ciento 26,5-53) en M97 y 38 por ciento (IC 95 por ciento 25,2-50,8) en A97. Conclusiones: Nuestro estudio, que es el primero realizado en pediatría con carácter multicéntrico y con éstos objetivos, muestra un porcentaje de pacientes ventilados en torno al 50 por ciento. Igual porcentaje de pacientes estaban en ventilación con IMV/SIMV y los modos más recientes de ventilación fueron escasamente utilizados. Parece aconsejable adecuar las adquisiciones de los respiradores a las patologías que haya que tratar. La utilización racional de los recursos será sin duda uno de los objetivos en los próximos años (AU)

Modos ventilatorios y retirada de la ventilación mecánica en pediatría: corte de prevalencia, estudio multicéntrico / Modes of ventilation and weaning of the mechanical ventilation in pediatrics: prevalence cut-multicentric study

Objetivo: Conocer la proporción de los pacientes que requieren ventilación mecánica (AVM) entre los ingresados en la unidad de cuidados intensivos pediátricos (UCIP) y los modos de ventilación utilizados. Material y métodos: Se realizó un estudio observacional y prospectivo de la ventilación mecánica en 12 UCIP distribuidas por Argentina durante 1997, en dos fechas climatológicas diferenciadas, 13 de mayo (M97) y 13 de agosto (A97). Se utilizó un cuestionario cumplmentado para cada paciente. Resultados: 92 pacientes ingresaron a la UCIP en M97 y 107 en A97. El 54,3 por ciento (IC 97 por ciento 47,6-61) y 51,4 por ciento (IC 95 por ciento 44,7-58,1) estaban en AVM respectivamente. La causa más frecuente de ingreso al respirador fue la insuficiencia respiratoria aguda 62 por ciento (IC 95 por ciento 48,5-75,4) en M97 y 61,8 por ciento (IC 95 por ciento 48,9-74,6) en A97. El modo de ventilación más utilizado en ambos cortes fue la IMV/SIMV 48 por ciento (IC 95 por ciento 35-61) y 52,7 (IC 95 por ciento 39,5-65,7). El porcentaje de pacientes en proceso de retirada de la ventilación fue del 40 por ciento (IC 95 por ciento 26,5-53) en M97 y 38 por ciento (IC 95 por ciento 25,2-50,8) en A97. Conclusiones: Nuestro estudio, que es el primero realizado en pediatría con carácter multicéntrico y con éstos objetivos, muestra un porcentaje de pacientes ventilados en torno al 50 por ciento. Igual porcentaje de pacientes estaban en ventilación con IMV/SIMV y los modos más recientes de ventilación fueron escasamente utilizados. Parece aconsejable adecuar las adquisiciones de los respiradores a las patologías que haya que tratar. La utilización racional de los recursos será sin duda uno de los objetivos en los próximos años

Weaning from mechanical ventilation in pediatric intensive care patients.

OBJECTIVE: The development of weaning predictors in mechanically ventilated children has not been sufficiently investigated. The purpose of this study was to evaluate the accuracy of some weaning indices in predicting weaning failure. DESIGN: Prospective, interventional study. SETTING: University-affiliated children's hospital with a 19-bed intensive care unit. PATIENTS: 84 consecutive infants and children requiring mechanical ventilation for at least 48 h and judged ready to wean by their primary physicians. INTERVENTIONS: Patients who met the criteria to start weaning underwent a trial of spontaneous breathing lasting up to 2 h. Bedside measurements of respiratory function were obtained immediately before discontinuation of mechanical ventilation and within the first 5 min of spontaneous breathing. The primary physicians were blinded to those measurements, and the decision to extubate a patient at the end of the spontaneous breathing trial or reinstitute mechanical ventilation was made by them. Failure to wean was defined as the requirement for mechanical ventilation at any time during the trial of spontaneous breathing (trial failure) or needing reintubation within 48 h of extubation (extubation failure). MEASUREMENTS AND MAIN RESULTS: Seventy-five patients had neither signs of respiratory distress nor deterioration in gas exchange during the trial and were extubated. Twelve patients required reintubation within 48 h. In 9 patients, mechanical ventilation was reinstituted after a median duration of the spontaneous breathing trial of 35 min. The only independent predictor of trial failure was tidal volume indexed to body weight [odds ratio 2.60, 95 % confidence interval (CI) 1.40 to 24.9]. The only independent predictor of extubation failure was frequency-to-tidal volume ratio indexed to body weight (odds ratio 1.23, 95 % CI 1.11 to 1.36). The sensitivity, specificity, and positive and negative predictive values to predict weaning failure were calculated for each of the above variables. These values were 0.48, 0.86, 0.53, and 0.83, respectively, for a frequency-to-tidal volume ratio higher than 11 breaths/min per ml per kg and 0.43, 0.94, 0.69, and 0.83, respectively, for a tidal volume lower than 4 ml/kg. CONCLUSIONS: Three-quarters of ventilated children can be successfully weaned after a trial of spontaneous breathing lasting 2 h. Both tidal volume and frequency-to-tidal volume ratio indexed to body weight were poor predictors of weaning failure in the study population.

Cuando la retirada de la ventilación mecánica es dificultosa en la UCIP: caso clínico / When the weaning from mechanical ventilation is difficult in the UCIP: report of a case

Paciente de 22 meses que presenta como complicación postquirúrgica, de cirugía torácica, sección del nervio frénico derecho con la consiguiente parálisis hemidiafragmática. Se comentan algunos aspectos fisiopatológicos de tal afección y se discuten las estrategias ante un weaning dificultoso (AU)

Cuando la retirada de la ventilación mecánica es dificultosa en la UCIP: caso clínico / When the weaning from mechanical ventilation is difficult in the UCIP: report of a case

Paciente de 22 meses que presenta como complicación postquirúrgica, de cirugía torácica, sección del nervio frénico derecho con la consiguiente parálisis hemidiafragmática. Se comentan algunos aspectos fisiopatológicos de tal afección y se discuten las estrategias ante un weaning dificultoso