Simon Erickson

Acute lung injury in pediatric intensive care in Australia and New Zealand: a prospective, multicenter, observational study

Objective: Acute lung injury (ALI) is poorly defined in children. The objective of this prospective study was to clarify the incidence, demographics, management strategies, outcome, and mortality predictors of ALI in children in Australia and New Zealand. Design: Multicenter prospective study during a 12-month period. Setting: Intensive care unit. Patients: All children admitted to intensive care and requiring mechanical ventilation were screened daily for development of ALI based on American-European Consensus Conference guidelines. Identified patients were followed for 28 days or until death or discharge. Interventions: None. Measurements and Main Results: There were 117 cases of ALI during the study period, giving a population incidence of 2.95/100,000 <16 yrs. ALI accounted for 2.2% of pediatric intensive care unit admissions. Mortality was 35% for ALI, and this accounted for 30% of all pediatric intensive care unit deaths during the study period. Significant preadmission risk factors for mortality were chronic disease, older age, and immunosuppression. Predictors of mortality during admission were ventilatory requirements (peak inspiratory pressures, mean airway pressure, positive end-expiratory pressure) and indexes of respiratory severity on day 1 (Pao2/Fio2 ratio and oxygenation index). Higher maximum and median tidal volumes were associated with reduced mortality, even when corrected for severity of lung disease. Development of single and multiple organ failure was significantly associated with mortality. Conclusions: ALI in children is uncommon but has a high mortality rate. Risk factors for mortality are easily identified. Ventilatory variables and indexes of lung severity were significantly associated with mortality.

Pediatric acute respiratory distress syndrome: Definition, incidence, and epidemiology: Proceedings from the Pediatric Acute Lung Injury Consensus Conference

Objectives: Although there are similarities in the pathophysiology of acute respiratory distress syndrome in adults and children, pediatric-specific practice patterns, comorbidities, and differences in outcome necessitate a pediatric-specific definition. We sought to create such a definition. Design: A subgroup of pediatric acute respiratory distress syndrome investigators who drafted a pediatric-specific definition of acute respiratory distress syndrome based on consensus opinion and supported by detailed literature review tested elements of the definition with patient data from previously published investigations. Settings: International PICUs. Subjects: Children enrolled in published investigations of pediatric acute respiratory distress syndrome. Interventions: None. Measurements and Main Results: Several aspects of the proposed pediatric acute respiratory distress syndrome definition align with the Berlin Definition of acute respiratory distress syndrome in adults: timing of acute respiratory distress syndrome after a known risk factor, the potential for acute respiratory distress syndrome to coexist with left ventricular dysfunction, and the importance of identifying a group of patients at risk to develop acute respiratory distress syndrome. There are insufficient data to support any specific age for “adult” acute respiratory distress syndrome compared with “pediatric” acute respiratory distress syndrome. However, children with perinatal-related respiratory failure should be excluded from the definition of pediatric acute respiratory distress syndrome. Larger departures from the Berlin Definition surround 1) simplification of chest imaging criteria to eliminate bilateral infiltrates; 2) use of pulse oximetry–based criteria when PaO2 is unavailable; 3) inclusion of oxygenation index and oxygen saturation index instead of PaO2/FIO2 ratio with a minimum positive end-expiratory pressure level for invasively ventilated patients; 4) and specific inclusion of children with preexisting chronic lung disease or cyanotic congenital heart disease. Conclusions: This pediatric-specific definition for acute respiratory distress syndrome builds on the adult-based Berlin Definition, but has been modified to account for differences between adults and children with acute respiratory distress syndrome. We propose using this definition for future investigations and clinical care of children with pediatric acute respiratory distress syndrome and encourage external validation with the hope for continued iterative refinement of the definition.

Hypothermia for traumatic brain injury in children - a Phase II randomized controlled trial

Objectives:To perform a pilot study to assess the feasibility of performing a phase III trial of therapeutic hypothermia started early and continued for at least 72 hours in children with severe traumatic brain injury. Design:Multicenter prospective randomized controlled phase II trial. Setting:All eight of the PICUs in Australia and New Zealand and one in Canada. Patients:Children 1–15 years old with severe traumatic brain injury and who could be randomized within 6 hours of injury. Interventions:The control group had strict normothermia to a temperature of 36–37°C for 72 hours. The intervention group had therapeutic hypothermia to a temperature of 32–33°C for 72 hours followed by slow rewarming at a rate compatible with maintaining intracranial pressure and cerebral perfusion pressure. Measurements and Main Results:Of 764 children admitted to PICU with traumatic brain injury, 92 (12%) were eligible and 55 (7.2%) were recruited. There were five major protocol violations (9%): three related to recruitment and consent processes and two to incorrect temperature management. Rewarming took a median of 21.5 hours (16–35 hr) and was performed without compromise in the cerebral perfusion pressure. There was no increase in any complications, including infections, bleeding, and arrhythmias. There was no difference in outcomes 12 months after injury; in the therapeutic hypothermia group, four (17%) had a bad outcome (pediatric cerebral performance category, 4–6) and three (13%) died, whereas in the normothermia group, three (12%) had a bad outcome and one (4%) died. Conclusions:Early therapeutic hypothermia in children with severe traumatic brain injury does not improve outcome and should not be used outside a clinical trial. Recruitment rates were lower and outcomes were better than expected. Conventional randomized controlled trials in children with severe traumatic brain injury are unlikely to be feasible. A large international trials group and alternative approaches to trial design will be required to further inform practice.

Pandemic H1N1 in children requiring intensive care in Australia and New Zealand during winter 2009

OBJECTIVE: To describe in detail the pediatric intensive care experience of influenza A, particularly pandemic H1N1-09, in Australia and New Zealand during the 2009 Southern Hemisphere winter and to compare the pediatric experience with that of adults. METHOD: This was an inception-cohort study of all children who were admitted to intensive care with confirmed influenza A during winter 2009 at all general ICUs and PICUs in Australia and New Zealand. RESULTS: From June 1 through August 31, 2009, 107 children (20.0 per million [95% confidence interval: 16.1–23.8]) with influenza A, including 83 (15.5 per million [95% confidence interval: 12.1–18.9]) with H1N1-09 were admitted to ICUs. Fifty-two percent (39 of 75) of children with H1N1-09 had 1 or more comorbidity, most commonly neurologic (20%). Most (48 of 83 [58%]) presented with pneumonia. Thirteen of 83 (16%) had neurologic presentations. Eighty percent of the children with H1N1-09 required ventilation. Mortality was lower than in adults: 6 of 83 (7%) vs 114 of 668 (17%) (P = .02). The median length of stay for children with H1N1-09 was 5 days. Children with H1N1-09 occupied 773 bed-days (147 per million children) and 5.8% of specialist PICU beds. Presentation with septic shock or after cardiac arrest and the presence of 1 or more comorbidities were risk factors for severe disease. CONCLUSIONS: H1N1-09 caused a substantial burden on pediatric intensive care services in Australia and New Zealand. Compared with adults, children more commonly had nonrespiratory presentations and required ventilation more often but had a lower mortality rate.

Five-Year Survival of Children With Chronic Critical Illness in Australia and New Zealand.

Objective:Outcomes for children with chronic critical illness are not defined. We examined the long-term survival of these children in Australia and New Zealand. Design:All cases of PICU chronic critical illness with length of stay more than 28 days and age 16 years old or younger in Australia and New Zealand from 2000 to 2011 were studied. Five-year survival was analyzed using Kaplan-Meir estimates, and risk factors for mortality evaluated using Cox regression. Setting:All PICUs in Australia and New Zealand. Patients:Nine hundred twenty-four children with chronic critical illness. Intervention:None. Measurements and Main Results:Nine hundred twenty-four children were admitted to PICU for longer than 28 days on 1,056 occasions, accounting for 1.3% of total admissions and 23.5% of bed days. Survival was known for 883 of 924 patients (95.5%), with a median follow-up of 3.4 years. The proportion with primary cardiac diagnosis increased from 27% in 2000–2001 to 41% in 2010–2011. Survival was 81.4% (95% CI, 78.6–83.9) to PICU discharge, 70% (95% CI, 66.7–72.8) at 1 year, and 65.5% (95% CI, 62.1–68.6) at 5 years. Five-year survival was 64% (95% CI, 58.7–68.6) for children admitted in 2000–2005 and 66% (95% CI, 61.7–70) if admitted in 2006–2011 (log-rank test, p = 0.37). After adjusting for admission severity of illness using the Paediatric Index of Mortality 2 score, predictors for 5-year mortality included bone marrow transplant (hazard ratio, 3.66; 95% CI, 2.26–5.92) and single-ventricle physiology (hazard ratio, 1.98; 95% CI, 1.37–2.87). Five-year survival for single-ventricle physiology was 47.2% (95% CI, 34.3–59.1) and for bone marrow transplantation 22.8% (95% CI, 8.7–40.8). Conclusions:Two thirds of children with chronic critical illness survive for at-least 5 years, but there was no improvement between 2000 and 2011. Cardiac disease constitutes an increasing proportion of pediatric chronic critical illness. Bone marrow transplant recipients and single-ventricle physiology have the poorest outcomes.

Burden of disease and change in practice in critically ill infants with bronchiolitis.

Bronchiolitis represents the most common cause of non-elective admission to paediatric intensive care units (ICUs). We assessed changes in admission rate, respiratory support, and outcomes of infants <24 months with bronchiolitis admitted to ICU between 2002 and 2014 in Australia and New Zealand. During the study period, bronchiolitis was responsible for 9628 (27.6%) of 34 829 non-elective ICU admissions. The estimated population-based ICU admission rate due to bronchiolitis increased by 11.76 per 100 000 each year (95% CI 8.11–15.41). The proportion of bronchiolitis patients requiring intubation decreased from 36.8% in 2002, to 10.8% in 2014 (adjusted OR 0.35, 95% CI 0.27–0.46), whilst a dramatic increase in high-flow nasal cannula therapy use to 72.6% was observed (p<0.001). We observed considerable variability in practice between units, with six-fold differences in risk-adjusted intubation rates that were not explained by ICU type, size, or major patient factors. Annual direct hospitalisation costs due to severe bronchiolitis increased to over USD30 million in 2014. We observed an increasing healthcare burden due to severe bronchiolitis, with a major change in practice in the management from invasive to non-invasive support that suggests thresholds to admittance of bronchiolitis patients to ICU have changed. Future studies should assess strategies for management of bronchiolitis outside ICUs. Changing thresholds to admit bronchiolitis patients to PICU have had a major impact on cost and resource utilisation http://ow.ly/AVA630a08rx

The burden of invasive infections in critically ill indigenous children in Australia

Objectives: To describe the incidence and mortality of invasive infections in Indigenous children admitted to paediatric and general intensive care units (ICUs) in Australia.

Pediatric Ventilator-associated Infections: The Ventilator-associated Infection Study

Objective: Suspected ventilator-associated infection is the most common reason for antibiotics in the PICU. We sought to characterize the clinical variables associated with continuing antibiotics after initial evaluation for suspected ventilator-associated infection and to determine whether clinical variables or antibiotic treatment influenced outcomes. Design: Prospective, observational cohort study conducted in 47 PICUs in the United States, Canada, and Australia. Two hundred twenty-nine pediatric patients ventilated more than 48 hours undergoing respiratory secretion cultures were enrolled as “suspected ventilator-associated infection” in a prospective cohort study, those receiving antibiotics of less than or equal to 3 days were categorized as “evaluation only,” and greater than 3 days as “treated.” Demographics, diagnoses, comorbidities, culture results, and clinical data were compared between evaluation only and treated subjects and between subjects with positive versus negative cultures. Setting: PICUs in 47 hospitals in the United States, Canada, and Australia. Subjects: All patients undergoing respiratory secretion cultures during the 6 study periods. Interventions: None. Measurements and Main Results: Treated subjects differed from evaluation-only subjects only in frequency of positive cultures (79% vs 36%; p < 0.0001). Subjects with positive cultures were more likely to have chronic lung disease, tracheostomy, and shorter PICU stay, but there were no differences in ventilator days or mortality. Outcomes were similar in subjects with positive or negative cultures irrespective of antibiotic treatment. Immunocompromise and higher Pediatric Logistic Organ Dysfunction scores were the only variables associated with mortality in the overall population, but treated subjects with endotracheal tubes had significantly lower mortality. Conclusions: Positive respiratory cultures were the primary determinant of continued antibiotic treatment in children with suspected ventilator-associated infection. Positive cultures were not associated with worse outcomes irrespective of antibiotic treatment although the lower mortality in treated subjects with endotracheal tubes is notable. The necessity of continuing antibiotics for a positive respiratory culture in suspected ventilator-associated infection requires further study.

Pediatric acute respiratory distress syndrome

Objectives: Although there are similarities in the pathophysiology of acute respiratory distress syndrome in adults and children, pediatric-specific practice patterns, comorbidities, and differences in outcome necessitate a pediatric-specific definition. We sought to create such a definition. Design: A subgroup of pediatric acute respiratory distress syndrome investigators who drafted a pediatric-specific definition of acute respiratory distress syndrome based on consensus opinion and supported by detailed literature review tested elements of the definition with patient data from previously published investigations. Settings: International PICUs. Subjects: Children enrolled in published investigations of pediatric acute respiratory distress syndrome. Interventions: None. Measurements and Main Results: Several aspects of the proposed pediatric acute respiratory distress syndrome definition align with the Berlin Definition of acute respiratory distress syndrome in adults: timing of acute respiratory distress syndrome after a known risk factor, the potential for acute respiratory distress syndrome to coexist with left ventricular dysfunction, and the importance of identifying a group of patients at risk to develop acute respiratory distress syndrome. There are insufficient data to support any specific age for “adult” acute respiratory distress syndrome compared with “pediatric” acute respiratory distress syndrome. However, children with perinatal-related respiratory failure should be excluded from the definition of pediatric acute respiratory distress syndrome. Larger departures from the Berlin Definition surround 1) simplification of chest imaging criteria to eliminate bilateral infiltrates; 2) use of pulse oximetry–based criteria when PaO2 is unavailable; 3) inclusion of oxygenation index and oxygen saturation index instead of PaO2/FIO2 ratio with a minimum positive end-expiratory pressure level for invasively ventilated patients; 4) and specific inclusion of children with preexisting chronic lung disease or cyanotic congenital heart disease. Conclusions: This pediatric-specific definition for acute respiratory distress syndrome builds on the adult-based Berlin Definition, but has been modified to account for differences between adults and children with acute respiratory distress syndrome. We propose using this definition for future investigations and clinical care of children with pediatric acute respiratory distress syndrome and encourage external validation with the hope for continued iterative refinement of the definition.

Pediatric Acute Respiratory Distress Syndrome: Definition, Incidence, and Epidemiology

Objectives: Although there are similarities in the pathophysiology of acute respiratory distress syndrome in adults and children, pediatric-specific practice patterns, comorbidities, and differences in outcome necessitate a pediatric-specific definition. We sought to create such a definition. Design: A subgroup of pediatric acute respiratory distress syndrome investigators who drafted a pediatric-specific definition of acute respiratory distress syndrome based on consensus opinion and supported by detailed literature review tested elements of the definition with patient data from previously published investigations. Settings: International PICUs. Subjects: Children enrolled in published investigations of pediatric acute respiratory distress syndrome. Interventions: None. Measurements and Main Results: Several aspects of the proposed pediatric acute respiratory distress syndrome definition align with the Berlin Definition of acute respiratory distress syndrome in adults: timing of acute respiratory distress syndrome after a known risk factor, the potential for acute respiratory distress syndrome to coexist with left ventricular dysfunction, and the importance of identifying a group of patients at risk to develop acute respiratory distress syndrome. There are insufficient data to support any specific age for “adult” acute respiratory distress syndrome compared with “pediatric” acute respiratory distress syndrome. However, children with perinatal-related respiratory failure should be excluded from the definition of pediatric acute respiratory distress syndrome. Larger departures from the Berlin Definition surround 1) simplification of chest imaging criteria to eliminate bilateral infiltrates; 2) use of pulse oximetry–based criteria when PaO2 is unavailable; 3) inclusion of oxygenation index and oxygen saturation index instead of PaO2/FIO2 ratio with a minimum positive end-expiratory pressure level for invasively ventilated patients; 4) and specific inclusion of children with preexisting chronic lung disease or cyanotic congenital heart disease. Conclusions: This pediatric-specific definition for acute respiratory distress syndrome builds on the adult-based Berlin Definition, but has been modified to account for differences between adults and children with acute respiratory distress syndrome. We propose using this definition for future investigations and clinical care of children with pediatric acute respiratory distress syndrome and encourage external validation with the hope for continued iterative refinement of the definition.