Mechanical ventilation in pediatric intensive care units during the season for acute lower respiratory infection: a multicenter study.

OBJECTIVE: To describe the characteristics and outcomes of mechanical ventilation in pediatric intensive care units during the season of acute lower respiratory infections. DESIGN: Prospective cohort of infants and children receiving mechanical ventilation for at least 12 hrs. SETTING: Sixty medical-surgical pediatric intensive care units. PATIENTS: All consecutive patients admitted to participating pediatric intensive care units during a 28-day period. MEASUREMENTS AND MAIN RESULTS: Of 2,156 patients admitted to pediatric intensive care units, 1185 (55%) received mechanical ventilation for a median of 5 days (interquartile range 2-8). Median age was 7 months (interquartile range 2-25). Main indications for mechanical ventilation were acute respiratory failure in 78% of the patients, altered mental status in 15%, and acute on chronic pulmonary disease in 6%. Median length of stay in the pediatric intensive care units was 10 days (interquartile range 6-18). Overall mortality rate in pediatric intensive care units was 13% (95% confidence interval: 11-15) for the entire population, and 39% (95% confidence interval: 23 - 58) in patients with acute respiratory distress syndrome. Of 1150 attempts at liberation from mechanical ventilation, 62% (95% confidence interval: 60-65) used the spontaneous breathing trial, and 37% (95% confidence interval: 35-40) used gradual reduction of ventilatory support. Noninvasive mechanical ventilation was used initially in 173 patients (15%, 95% confidence interval: 13-17). CONCLUSION: In the season of acute lower respiratory infections, one of every two children admitted to pediatric intensive care units requires mechanical ventilation. Acute respiratory failure was the most common reason for mechanical ventilation. The spontaneous breathing trial was the most commonly used method for liberation from mechanical ventilation.

The impact of daily evaluation and spontaneous breathing test on the duration of pediatric mechanical ventilation: a randomized controlled trial.

OBJECTIVES: To assess whether the combination of daily evaluation and use of a spontaneous breathing test could shorten the duration of mechanical ventilation as compared with weaning based on our standard of care. Secondary outcome measures included extubation failure rate and the need for noninvasive ventilation. DESIGN: A prospective, randomized controlled trial. SETTING: Two pediatric intensive care units at university hospitals in Brazil. PATIENTS: The trial involved children between 28 days and 15 yrs of age who were receiving mechanical ventilation for at least 24 hrs. INTERVENTIONS: Patients were randomly assigned to one of two weaning protocols. In the test group, the children underwent a daily evaluation to check readiness for weaning with a spontaneous breathing test with 10 cm H2O pressure support and a positive end-expiratory pressure of 5 cm H2O for 2 hrs. The spontaneous breathing test was repeated the next day for children who failed it. In the control group, weaning was performed according to standard care procedures. MEASUREMENTS AND MAIN RESULTS: A total of 294 eligible children were randomized, with 155 to the test group and 139 to the control group. The time to extubation was shorter in the test group, where the median mechanical ventilation duration was 3.5 days (95% confidence interval, 3.0 to 4.0) as compared to 4.7 days (95% confidence interval, 4.1 to 5.3) in the control group (p = .0127). This significant reduction in the mechanical ventilation duration for the intervention group was not associated with increased rates of extubation failure or noninvasive ventilation. It represents a 30% reduction in the risk of remaining on mechanical ventilation (hazard ratio: 0.70). CONCLUSIONS: A daily evaluation to check readiness for weaning combined with a spontaneous breathing test reduced the mechanical ventilation duration for children on mechanical ventilation for >24 hrs, without increasing the extubation failure rate or the need for noninvasive ventilation.

Characterization of pediatric patients receiving prolonged mechanical ventilation.

OBJECTIVE: To describe the characteristics and risk factors of pediatric patients who receive prolonged mechanical ventilation, defined as ventilatory support for >21 days. DESIGN: Prospective cohort. SETTING: Four medical-surgical pediatric intensive care units in four university-affiliated hospitals in Argentina. PATIENTS: All consecutive patients from 1 month to 15 yrs old admitted to participating pediatric intensive care units from June 1, 2007, to August 31, 2007, who received mechanical ventilation (invasive or noninvasive) for >12 hrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographic and physiologic data on admission to the pediatric intensive care units, drugs and events during the study period, and outcomes were prospectively recorded. A total of 256 patients were included. Of these, 23 (9%) required mechanical ventilation for >21 days and were assigned to the prolonged mechanical ventilation group. Patients requiring prolonged mechanical ventilation had higher mortality (43% vs. 21%, p < .05) and longer pediatric intensive care unit stay: 35 days [28-64 days] vs. 10 days [6-14]). There was no difference between the groups in age and gender distribution, reasons for admission, incidence of immunodeficiencies, or Paediatric Index of Mortality 2 score. The only difference at admission was a higher rate of genetic diseases in prolonged mechanical ventilation patients (26% vs. 9%, p < .05). There was a higher incidence of septic shock (87% vs. 34%, p < .01), acute respiratory distress syndrome (43% vs. 20%, p < .01), and ventilator-associated pneumonia (35% vs. 8%, p < .01) and higher utilization of dopamine (78% vs. 42%, p < .01), norepinephrine (61% vs. 15%, p < .01), multiple antibiotics (83% vs. 20%, p < .01), and blood transfusions (52% vs. 14%, p < .01). The proportion of extubation failure was higher in the prolonged mechanical ventilation group with similar rates of unplanned extubations in both groups. Variables remaining significantly associated with prolonged mechanical ventilation after multivariate analysis were treatment with multiple antibiotics, septic shock, ventilator-associated pneumonia, and use of norepinephrine. CONCLUSIONS: Patients with prolonged mechanical ventilation have more complications and require more pediatric intensive care unit resources. Mortality in these patients duplicates that from those requiring shorter support.

Emergence of intratreatment resistance to oseltamivir in pandemic influenza A H1N1 2009 virus.

BACKGROUND: Pandemic influenza A H1N1 2009 virus presents a new challenge to health authorities and communities worldwide. In Argentina, the outbreak was at its peak by the end of June 2009, during the southern winter. A systematic analysis of samples from patients with pandemic H1N1 2009 studied in our laboratory (Virology Laboratory, Hospital de Niños R Gutiérrez, Buenos Aires, Argentina) detected two patients presenting intratreatment emergence of the H275Y neuraminidase mutation, which confers resistance to oseltamivir. METHODS: Complementary DNAs, including the 275 codon, were obtained by reverse transcriptase PCR using viral RNAs extracted from nasopharyngeal or tracheal aspirates. Conventional sequencing and pyrosequencing were performed on each sample. In order to measure the virus susceptibility to oseltamivir, 50% inhibitory concentration determinations were performed by chemiluminescence. RESULTS: Sequential samples of two paediatric patients under oseltamivir treatment were analysed. Pretreatment samples were composed of 100% oseltamivir-sensitive variants. In case 1, the oseltamivir-resistant variant was found 8 days after the beginning of treatment. In case 2, the viral population became resistant on the second day of treatment, with 83% of the viral population bearing the mutation and this reached 100% on the seventh day. CONCLUSIONS: We describe the intratreatment emergence of oseltamivir resistance in two paediatric patients. Pyrosequencing allowed us to detect variant mixtures, showing the transition of the viral population from sensitive to resistant.

Critically ill infants and children with influenza A (H1N1) in pediatric intensive care units in Argentina.

OBJECTIVE: To determine the epidemiological features, course, and outcomes of critically ill pediatric patients with Influenza A (H1N1) virus. DESIGN: Prospective cohort of children in pediatric intensive care units (PICUs) due to Influenza A (H1N1) virus infection. SETTING: Seventeen medical-surgical PICUs in tertiary care hospital in Argentina. PATIENTS: All consecutive patients admitted to the PICUs with influenza A (H1N1) viral infection from 15 June to 31 July 2009. MEASUREMENTS AND MAIN RESULTS: Of 437 patients with acute lower respiratory infection in PICUs, 147 (34%) were diagnosed with influenza A (H1N1) related to critical illness. The median age of these patients was 10 months (IQR 3-59). Invasive mechanical ventilation was used in 117 (84%) on admission. The rate of acute respiratory distress syndrome (ARDS) was 80% (118 of 147 patients). Initial non-invasive ventilation failed in 19 of 22 attempts (86%). Mortality at 28 days was 39% (n = 57). Chronic complex conditions (CCCs), acute renal dysfunction (ARD) and ratio PaO(2)/FiO(2) at day 3 on MV were independently associated with a higher risk of mortality. The odds ratio (OR) for CCCs was 3.06, (CI 95% 1.36-6.84); OR for ARD, 3.38, (CI 95% 1.45-10.33); OR for PaO(2)/FiO(2), 4 (CI 95% 1.57-9.59). The administration of oseltamivir within 24 h after admission had a protective effect: OR 0.2 (CI 95% 0.07-0.54). CONCLUSIONS: In children with ARDS, H1N1 as an etiologic agent confers high mortality, and the presence of CCCs in such patients increases the risk of death.

How is mechanical ventilation employed in a pediatric intensive care unit in Brazil?

OBJECTIVE: To investigate the relationship between mechanical ventilation and mortality and the practice of mechanical ventilation applied in children admitted to a high-complexity pediatric intensive care unit in the city of São Paulo, Brazil. DESIGN: Prospective cohort study of all consecutive patients admitted to a Brazilian high-complexity PICU who were placed on mechanical ventilation for 24 hours or more, between October 1(st), 2005 and March 31(st), 2006. RESULTS: Of the 241 patients admitted, 86 (35.7%) received mechanical ventilation for 24 hours or more. Of these, 49 met inclusion criteria and were thus eligible to participate in the study. Of the 49 patients studied, 45 had chronic functional status. The median age of participants was 32 months and the median length of mechanical ventilation use was 6.5 days. The major indication for mechanical ventilation was acute respiratory failure, usually associated with severe sepsis / septic shock. Pressure ventilation modes were the standard ones. An overall 10.37% incidence of Acute Respiratory Distress Syndrome was found, in addition to tidal volumes > 8 ml/kg, as well as normo- or hypocapnia. A total of 17 children died. Risk factors for mortality within 28 days of admission were initial inspiratory pressure, pH, PaO2/FiO2 ratio, oxygenation index and also oxygenation index at 48 hours of mechanical ventilation. Initial inspiratory pressure was also a predictor of mechanical ventilation for periods longer than 7 days. CONCLUSION: Of the admitted children, 35.7% received mechanical ventilation for 24 h or more. Pressure ventilation modes were standard. Of the children studied, 91% had chronic functional status. There was a high incidence of Acute Respiratory Distress Syndrome, but a lung-protective strategy was not fully implemented. Inspiratory pressure at the beginning of mechanical ventilation was a predictor of mortality within 28 days and of a longer course of mechanical ventilation.

How is mechanical ventilation employed in a pediatric intensive care unit in Brazil?

OBJECTIVE: to investigate the relationship between mechanical ventilation and mortality and the practice of mechanical ventilation applied in children admitted to a high-complexity pediatric intensive care unit in the city of São Paulo, Brazil. DESIGN: Prospective cohort study of all consecutive patients admitted to a Brazilian high-complexity PICU who were placed on mechanical ventilation for 24 hours or more, between October 1st, 2005 and March 31st, 2006. RESULTS: Of the 241 patients admitted, 86 (35.7 percent) received mechanical ventilation for 24 hours or more. Of these, 49 met inclusion criteria and were thus eligible to participate in the study. Of the 49 patients studied, 45 had chronic functional status. The median age of participants was 32 months and the median length of mechanical ventilation use was 6.5 days. The major indication for mechanical ventilation was acute respiratory failure, usually associated with severe sepsis / septic shock. Pressure ventilation modes were the standard ones. An overall 10.37 percent incidence of Acute Respiratory Distress Syndrome was found, in addition to tidal volumes > 8 ml/kg, as well as normo- or hypocapnia. A total of 17 children died. Risk factors for mortality within 28 days of admission were initial inspiratory pressure, pH, PaO2/FiO2 ratio, oxygenation index and also oxygenation index at 48 hours of mechanical ventilation. Initial inspiratory pressure was also a predictor of mechanical ventilation for periods longer than 7 days. CONCLUSION: Of the admitted children, 35.7 percent received mechanical ventilation for 24 h or more. Pressure ventilation modes were standard. Of the children studied, 91 percent had chronic functional status. There was a high incidence of Acute Respiratory Distress Syndrome, but a lung-protective strategy was not fully implemented. Inspiratory pressure at the beginning of mechanical ventilation was a predictor of mortality within 28 days and of a longer...