Adult respiratory distress syndrome in children: associated disease, clinical course, and predictors of death

Is Serum Lactate a Good Predictor of Mortality in Children Aged 2 Months to 5 Years With Pneumonia in Central Vietnam

Pneumonia is a major cause of morbidity and mortality in children globally. Lactate, a product of anaerobic cellular metabolism, has been used as an indicator of poor tissue oxygenation and cellular hypoxia. Our objective was to determine whether serum lactate concentration at hospital admission predicted mortality in children aged 2 months to 5 years with pneumonia. Two hundred and eighty-one pediatric patients admitted to the Department of Pediatrics of a provincial hospital with WHO-defined pneumonia and severe pneumonia were included; of whom, 8 died during hospital stay. The median serum lactate concentration was 4.8 mmol/l (IQR 2.6-6.9) among children who died and 3.6 mmol/l (IQR 2.8-4.3) among children who survived (P > .05); 4.1 mmol/l (IQR 2.7-4.7) among children with severe pneumonia and 3.5 mmol/l (IQR 2.8-4.3) among children with pneumonia (P > .05). Serum lactate concentration had a low value in predicting pneumonia-related mortality (AUC 0.68, 95% CI 0.62-0.73); and the concentration cut-off of >4.06 mmol/l had the best sensitivity and specificity (75% and 68.9%, respectively) with a 2.4-fold risk of death (LR+ 2.4; 95% CI 1.6-3.7). Although hyperlactatemia was associated with severity and mortality in children 2 months to 5 years of age with pneumonia, its benefit was unclear.

Contribution of Bone Marrow-Derived Mesenchymal Stem Cells to Healing of Pulmonary Contusion-Created Rats

BACKGROUND

The most common thoracic injury in children, resulting in trauma, is pulmonary contusion (PC). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are used in wound healing and many other diseases. This study aims to examine the effects of BM-MSCs on PC healing in rats.

MATERIALS AND METHODS

A total of 45 male Wistar albino rats were used. Four groups were formed. BM-MSCs were labeled with the green fluorescent protein. PC was observed in the control group. In group II, PC occured and left to spontaneous healing. In group III, PC formed and BM-MSCs were given. In group IV, BM-MSCs were given without PC formation. Subjects were sacrificed 1 week later. Whether there was any difference in terms of BM-MSC involvement and lung injury score was investigated. Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS), version 17.0, software (SPSS Inc., Chicago, IL), and p value of <0.05 was considered statistically significant.

RESULTS

BM-MSCs were collected much more in the lungs in group III than in group IV. Group III had a lower lung injury score value than group II.

CONCLUSION

The greater involvement of the BM-MSCs in the injury site, and further reductions in lung injury score suggest that BM-MSCs are contributing to the healing of the injury. The use of BM-MSCs in risky patients with diffuse PC may be an alternative treatment to conventional methods.

Plasma Nucleosomes Are Associated With Mortality in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

Circulating nucleosomes and their component histones have been implicated as pathogenic in sepsis and acute respiratory distress syndrome in adults. However, their role in pediatric acute respiratory distress syndrome is unknown.

DESIGN

We performed a prospective cohort study in children with acute respiratory distress syndrome, with plasma collection within 24 hours of acute respiratory distress syndrome onset. We associated nucleosome levels with severity of acute respiratory distress syndrome and with nonpulmonary organ failures and tested for association of nucleosomes with PICU mortality and ventilator-free days at 28 days in univariate and multivariable analyses. We also performed proteomics of DNA-bound plasma proteins in a matched case-control study of septic children with and without acute respiratory distress syndrome in order to identify specific histone proteins elevated in acute respiratory distress syndrome.

SETTING

Large academic tertiary-care PICU.

PATIENTS

Intubated children meeting Berlin criteria for acute respiratory distress syndrome.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We enrolled 333 children with acute respiratory distress syndrome, with 69 nonsurvivors (21%). Plasma nucleosomes were correlated with acute respiratory distress syndrome severity and with the number of nonpulmonary organ failures at acute respiratory distress syndrome onset. Nucleosomes were higher (p < 0.001) in nonsurvivors (0.40 [interquartile range, 0.20-0.71] arbitrary units) relative to survivors (0.10 [interquartile range, 0.04-0.25] arbitrary units). Nucleosomes were associated with PICU mortality in multivariable analysis (adjusted odds ratio 1.84 per 1 sd increase; 95% CI, 1.38-2.45; p < 0.001). Nucleosomes were also associated with a lower probability of being extubated alive by day 28 after multivariable adjustment (adjusted subdistribution hazard ratio, 0.74; 95% CI, 0.63-0.88; p = 0.001). Proteomic analysis demonstrated higher levels of the core nucleosome histones H2A, H2B, H3, and H4 in septic children with acute respiratory distress syndrome, relative to septic children without acute respiratory distress syndrome.

CONCLUSIONS

Plasma nucleosomes are associated with acute respiratory distress syndrome severity, nonpulmonary organ failures, and worse outcomes in pediatric acute respiratory distress syndrome.

Pediatric trauma-associated acute respiratory distress syndrome: Incidence, risk factors, and outcomes

BACKGROUND/PURPOSE

Acute Respiratory Distress Syndrome (ARDS) results in significant morbidity and mortality in pediatric trauma victims. The objective of this study was to determine risk factors and outcomes specifically related to pediatric trauma-associated ARDS (PT-ARDS).

METHODS

A retrospective cohort (2007-2014) of children ≤18 years old from the American College of Surgeons National Trauma Data Bank (NTDB) was used to analyze incidence, risk factors, and outcomes related to PT-ARDS.

RESULTS

PT-ARDS was identified in 0.5% (2660/488,381) of the analysis cohort, with an associated mortality of 18.6% (494/2660). Mortality in patients with PT-ARDS most commonly occurred in the first week after injury. Risk factors associated with the development of PTARDS included nonaccidental trauma, near drowning, severe injury (AIS ≥ 3) to the head or chest, pneumonia, sepsis, thoracotomy, laparotomy, transfusion, and total parenteral nutrition use. After adjustment for age, injury complexity, injury mechanism, and physiologic variables, PT-ARDS was found to be independently associated with higher mortality (adjusted OR 1.33, 95% CI 1.18-1.51, p < 0.001).

CONCLUSIONS

PT-ARDS is a rare complication in pediatric trauma patients, but is associated with substantial mortality within 7 days of injury. Recognition and initiation of lung-protective measures early in the postinjury course may represent the best opportunity to change outcomes.

LEVEL OF EVIDENCE

Level 3 - Epidemiologic.

Clinical Profile and Predictors of Outcome of Pediatric Acute Respiratory Distress Syndrome in a PICU: A Prospective Observational Study

OBJECTIVES

To study the clinical profile, predictors of mortality, and outcomes of pediatric acute respiratory distress syndrome.

DESIGN

A prospective observational study.

SETTING

PICU, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

PATIENTS

All children (age > 1 mo to < 14 yr) admitted in PICU with a diagnosis of pediatric acute respiratory distress syndrome (as per Pediatric Acute Lung Injury Consensus Conference definition) from August 1, 2015, to November 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Out of 1,215 children admitted to PICU, 124 (11.4%) had pediatric acute respiratory distress syndrome. Fifty-six children (45.2%) died. Median age was 2.75 years (1.0-6.0 yr) and 66.9% were male. Most common primary etiologies were pneumonia, severe sepsis, and scrub typhus. Ninety-seven children (78.2%) were invasively ventilated. On multiple logistic regressions, Lung Injury Score (p = 0.004), pneumothorax (p = 0.012), acute kidney injury at enrollment (p = 0.033), FIO2-D1 (p = 0.018), and PaO2/FIO2 ratio-D7 (p = 0.020) were independent predictors of mortality. Positive fluid balance (a cut-off value > 102.5 mL/kg; p = 0.016) was associated with higher mortality at 48 hours. Noninvasive oxygenation variables like oxygenation saturation index and saturation-FIO2 ratio were comparable to previously used invasive variables (oxygenation index and PaO2/FIO2 ratio) in monitoring the course of pediatric acute respiratory distress syndrome.

CONCLUSIONS

Pediatric acute respiratory distress syndrome contributes to a significant burden in the PICU of a developing country and is associated with significantly higher mortality. Infection remains the most common etiology. Higher severity of illness scores at admission, development of pneumothorax, and a positive fluid balance at 48 hours predicted poor outcome.

Acute Respiratory Failure

Acute respiratory distress syndrome (ARDS) is a condition affecting critically ill patients, characterized by pulmonary inflammation and defects in oxygenation due to either direct or indirect injury to the lungs. These guidelines will define the diagnosis and management of ARDS, particularly among combat casualties and patients in the deployed environment. The cornerstone of management of ARDS involves maintaining adequate oxygenation while avoiding further pulmonary injury through lung-protective ventilation. Additional strategies for advanced respiratory failure, such as prone positioning, neuromuscular blockade, and extracorporeal membrane oxygenation will be reviewed here as well. Particularly important to the care of the patient with ARDS in the deployed environment is a familiarity with the challenges and indications for transport/aeromedical evacuation.

Differences Between Pulmonary and Extrapulmonary Pediatric Acute Respiratory Distress Syndrome: A Multicenter Analysis

OBJECTIVES

Extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome are poorly described in the literature. We aimed to describe and compare the epidemiology, risk factors for mortality, and outcomes in extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome.

DESIGN

This is a secondary analysis of a multicenter, retrospective, cohort study. Data on epidemiology, ventilation, therapies, and outcomes were collected and analyzed. Patients were classified into two mutually exclusive groups (extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome) based on etiologies. Primary outcome was PICU mortality. Cox proportional hazard regression was used to identify risk factors for mortality.

SETTING

Ten multidisciplinary PICUs in Asia.

PATIENTS

Mechanically ventilated children meeting the Pediatric Acute Lung Injury Consensus Conference criteria for pediatric acute respiratory distress syndrome between 2009 and 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Forty-one of 307 patients (13.4%) and 266 of 307 patients (86.6%) were classified into extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome groups, respectively. The most common causes for extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome were sepsis (82.9%) and pneumonia (91.7%), respectively. Children with extrapulmonary pediatric acute respiratory distress syndrome were older, had higher admission severity scores, and had a greater proportion of organ dysfunction compared with pulmonary pediatric acute respiratory distress syndrome group. Patients in the extrapulmonary pediatric acute respiratory distress syndrome group had higher mortality (48.8% vs 24.8%; p = 0.002) and reduced ventilator-free days (median 2.0 d [interquartile range 0.0-18.0 d] vs 19.0 d [0.5-24.0 d]; p = 0.001) compared with the pulmonary pediatric acute respiratory distress syndrome group. After adjusting for site, severity of illness, comorbidities, multiple organ dysfunction, and severity of acute respiratory distress syndrome, extrapulmonary pediatric acute respiratory distress syndrome etiology was not associated with mortality (adjusted hazard ratio, 1.56 [95% CI, 0.90-2.71]).

CONCLUSIONS

Patients with extrapulmonary pediatric acute respiratory distress syndrome were sicker and had poorer clinical outcomes. However, after adjusting for confounders, it was not an independent risk factor for mortality.

Pulmonary Functions in Children Ventilated for Acute Hypoxemic Respiratory Failure

OBJECTIVE

To assess pulmonary functions of children who received mechanical ventilation for acute hypoxemic respiratory failure.

DESIGN

Longitudinal study.

SETTING

PICU and Pediatric Pulmonology Clinic of a tertiary care teaching hospital in North India.

PATIENTS

All children, 5-12 years old, ventilated for acute hypoxemic respiratory failure in PICU from July 2012 to June 2013 and survived.

INTERVENTIONS

The baseline admission variables recorded were as follows: age, sex, duration of illness, primary diagnosis at admission, Pediatric Risk of Mortality III score, lung injury score, mechanical ventilation parameters, oxygenation indices, and duration of PICU stay. The children were followed up twice, at 3 and 9-12 months, after discharge from PICU and evaluated for any residual respiratory symptoms and signs, pulse oximetry, chest radiograph, 6-minute walk test, peak expiratory flow rate, and spirometry. Age, sex, duration of illness, primary diagnosis, Pediatric Risk of Mortality III score, lung injury score, mechanical ventilation parameters, oxygenation indices (PaO2/FIO2 ratio and oxygenation index), and duration of PICU stay were recorded from patient records.

MEASUREMENTS AND MAIN RESULTS

Twenty-nine children (25 boys and four girls; mean [SD] age, 8.4 [2.4] yr) were followed up at 3.5 (± 1.2) and 10.6 (± 2.7) months after discharge from PICU. Recurrent respiratory symptoms were noted in 37.9% patients (11/29) during first and in none during second follow-up. None had limitation of physical activity or need of supplemental oxygen. Chest examination was normal in all, except one during first follow-up, but 13.8% (4/29) had abnormal chest radiograph during first follow-up. Nearly all children could perform 6-minute walk test although mean distance walked increased significantly from first (352 ± 66.7 m) to second follow-up (401 ± 60.7 m; p = 0.002). Abnormal spirometry was seen in 82.7% (24/29) versus 18.5% (5/27) children during first and second follow-up visits, respectively (p = 0.0001). Most cases had restrictive abnormality (58.6% vs 11.1%; p = 0.002) during first and second follow-up, respectively. There was no correlation between pulmonary functions and lung injury scores, oxygenation indices (PaO2/FIO2 ratio and oxygenation index), and mechanical ventilation parameters.

CONCLUSIONS

Significant number of children ventilated for acute hypoxemic respiratory failure had subclinical pulmonary function abnormality, without limiting physical activity, which improved over time. Further research on this topic with a larger sample size and patient categorization according to recent pediatric acute respiratory distress syndrome definition is needed.

Treatment of Severe Non-Neonatal ARDS in Children with Surfactant and Nitric Oxide in a “PRE-ECMO”-Situation

The use of exogenous surfactant and nitric oxide in neonates has reduced the number of infants requiring ECMO. The purpose of this study was to demonstrate whether these two therapeutic options might reduce the number of over 28 days old children with severe ARDS requiring ECMO, without reducing changes of survival and morbidity. Over a 30 month period all non-neonatal ARDS patients transferred to our institution for ECMO evaluation were treated based on a study-algorithm. If they did not fulfill “fast entry criteria” (paO2< 40 for more than 3 hrs.) we first tried different ventilation, vasodilatation, and hemodynamic strategies for max. 4 hrs. (inv. I/E ratio, HFOV, epoprostenol, high doses norepinephrine. If the 01 did not decrease by< 10, 30-280 mg natural surfactant or 1-20 ppm nitric oxide were treatment options depending on the degree of pulmonary hypertension measured by echocardiography and by mixed venous saturation measurements. It was possible to use NO and surfactant sequentially. The patients had different etiologies of ARDS as near drowning, pneumonia, immunosuppression, and sepsis. If their 01 did not decrease by 10 in 8 hrs. ECMO was installed. Nineteen patients were evaluated, 6 improved with conventional therapy, their 01 decreased without a relapse (mean 01 at begin of the study: 38). Six patients improved with surfactant therapy alone (mean 01: 54), 4 patients improved after surfactant and sequential NO-treatment, 3 patients were initially treated with NO, 1 sequentially with surfactant. One patient did not show any benefit from NO or surfactant and was put on ECMO. Three patients died (withdrawal of life support because of severe brain damage caused by the underlying disease). We could not observe any respiratory related failure. No patient had to be discharged on oxygen. A sophisticated treatment algorithm integrating different modern ARDS treatment options can reduce the number of patients requiring ECMO. We speculate however that these options can only be used effectively in centers involved in ARDS treatment quite frequently and that these centers have to provide ECMO as one of their therapeutic tools.

Association of Response to Inhaled Nitric Oxide and Duration of Mechanical Ventilation in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

Literature regarding appropriate use of inhaled nitric oxide for pediatric acute respiratory distress syndrome is sparse. This study aims to determine if positive response to inhaled nitric oxide is associated with decreased mortality and duration of mechanical ventilation in pediatric acute respiratory distress syndrome.

DESIGN

Retrospective cohort study.

SETTING

Large pediatric academic medical center.

PATIENTS OR SUBJECTS

One hundred sixty-one children with pediatric acute respiratory distress syndrome and inhaled nitric oxide exposure for greater than or equal to 1 hour within 3 days of pediatric acute respiratory distress syndrome onset.

INTERVENTIONS

Patients with greater than or equal to 20% improvement in oxygenation index or oxygen saturation index by 6 hours after inhaled nitric oxide initiation were classified as "responders."

MEASUREMENTS AND MAIN RESULTS

Oxygenation index, oxygen saturation index, and ventilator settings were evaluated prior to inhaled nitric oxide initiation and 1, 6, 12, and 24 hours following inhaled nitric oxide initiation. Primary outcomes were mortality and duration of mechanical ventilation. Baseline characteristics, including severity of illness, were similar between responders and nonresponders. Univariate analysis showed no difference in mortality between responders and nonresponders (21% vs 21%; p = 0.999). Ventilator days were significantly lower in responders (10 vs 16; p < 0.001). Competing risk regression (competing risk of death) confirmed association between inhaled nitric oxide response and successful extubation (subdistribution hazard ratio = 2.11; 95% CI, 1.41-3.17; p < 0.001). Response to inhaled nitric oxide was associated with decreased utilization of high-frequency oscillatory ventilation and extracorporeal membrane oxygenation and lower hospital charges (difference in medians of $424,000).

CONCLUSIONS

Positive response to inhaled nitric oxide was associated with fewer ventilator days, without change in mortality, potentially via reduced use of high-frequency oscillatory ventilation and extracorporeal membrane oxygenation. Future studies of inhaled nitric oxide for pediatric acute respiratory distress syndrome should stratify based on oxygenation response, given the association with favorable outcomes.

Mortality in Pediatric Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

Sparse and conflicting evidence exists regarding mortality risk from pediatric acute respiratory distress syndrome (ARDS). We aimed to determine the pooled mortality in pediatric ARDS and to describe its trend over time.

DATA SOURCES AND STUDY SELECTION

MEDLINE, EMBASE, and Web of Science were searched from 1960 to August 2015. Keywords or medical subject headings (MESH) terms used included "respiratory distress syndrome, adult," "acute lung injury," "acute respiratory insufficiency," "acute hypoxemic respiratory failure," "pediatrics," and "child." Study inclusion criteria were (1) pediatric patients aged 0 days to 18 years, (2) sufficient baseline data described in the pediatric ARDS group, and (3) mortality data. Randomized controlled trials (RCTs) and prospective observational studies were eligible.

DATA EXTRACTION AND SYNTHESIS

Data on study characteristics, patient demographics, measures of oxygenation, and mortality were extracted using a standard data extraction form. Independent authors conducted the search, applied the selection criteria, and extracted the data. Methodological quality of studies was assessed. Meta-analysis using a random-effects model was performed to obtain pooled estimates of mortality. Meta-regression was performed to analyze variables contributing to change in mortality over time. Eight RCTs and 21 observational studies (n = 2274 patients) were included. Pooled mortality rate was 24% (95% confidence interval [CI]: 19-31). There was a decrease in mortality rates over 3 epochs (≤2000, 2001-2009, and ≥2010: 40% [95% CI: 24-59], 35% [95% CI: 21-51], and 18% [95% CI: 12-26], respectively, P < .001). Observational studies reported a higher mortality rate than RCTs (27% [95% CI: 24-29] versus 16% [95% CI: 12-20], P < .001). Earlier year of publication was an independent factor associated with mortality.

CONCLUSION

Overall mortality rate in pediatric ARDS is approximately 24%. Studies conducted and published later were associated with better survival.

Pediatric Acute Hypoxemic Respiratory Failure: Management of Oxygenation

Acute hypoxemic respiratory failure (AHRF) is one of the hallmarks of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), which are caused by an inflammatory process initiated by any of a number of potential systemic and/or pulmonary insults that result in heterogeneous disruption of the capillary-pithelial interface. In these critically sick patients, optimizing the management of oxygenation is crucial. Physicians managing pediatric patients with ALI or ARDS are faced with a complex array of options influencing oxygenation. Certain treatment strategies can influence clinical outcomes, such as a lung protective ventilation strategy that specifies a low tidal volume (6 mL/kg) and a plateau pressure limit (30 cm H2O). Other strategies such as different levels of positive end expiratory pressure, altered inspiration to expiration time ratios, recruitment maneuvers, prone positioning, and extraneous gases or drugs may also affect clinical outcomes. This article reviews state-of-the-art strategies on the management of oxygenation in acute hypoxemic respiratory failure in children.

Comparison of Tidal Volumes at the Endotracheal Tube and at the Ventilator

OBJECTIVE

Lung protective ventilation for children with acute respiratory distress syndrome requires accurate assessment of tidal volume. Although modern ventilators compensate for ventilator tubing compliance, tidal volume measured at the ventilator may not be accurate, particularly in small children. Although ventilator-specific proximal flow sensors that measure tidal volume at the endotracheal tube have been developed, there is little information regarding their accuracy. We sought to test the accuracy of ventilator measured tidal volume with and without proximal flow sensors against a calibrated pneumotachometer in children.

DESIGN

Prospective, observational.

SETTING

Tertiary care PICU.

PATIENTS

Fifty-one endotracheally intubated and mechanically ventilated children younger than 18 years.

INTERVENTIONS

Tidal volumes were measured at the ventilator, using a ventilator-specific flow sensor, and a calibrated pneumotachometer connected to the SensorMedics 2600A Pediatric Pulmonary Function Cart.

MEASUREMENTS AND MAIN RESULTS

In a pressure control mode of ventilation: median tidal volume measured with the pneumotachometer (9.5 mL/kg [interquartile range, 8.2-11.7 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.2 mL/kg [7.1-9.6 mL/kg]) or at the proximal flow sensor (8.1 mL/kg [7.2-10.0 mL/kg]) (p < 0.001). In pressure regulated volume control mode of ventilation: median tidal volume measured with the pneumotachometer (10.2 mL/kg [8.8-12.4 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.0 mL/kg [7.1-9.7 mL/kg]) or at the proximal flow sensor (8.5 mL/kg [7.3-10.4 mL/kg]) (p < 0.001). These findings were consistent when subgrouped by ventilator type and circuit size.

CONCLUSIONS

Tidal volume measured either at the endotracheal tube with a proximal flow sensor or at the ventilator with compensation for tubing compliance are both significantly lower than tidal volume measured with a calibrated pneumotachometer. This underestimation of delivered tidal volume may be particularly important when managing children with acute respiratory distress syndrome.

Pediatric Blunt Thoracic Trauma

Thoracic injury in children deserves special attention because, although it accounts for less than 10% of traumatic injuries in children, there is a significant associated morbidity and mortality. This review discusses the anatomic and physiologic factors resulting in such injury severity with blunt thoracic trauma in children. Specific organ injuries, including most common chest wall injuries, hemo- and pneumothoraces, and pulmonary parenchymal injuries, are discussed, encompassing epidemiology, presentation, diagnosis, and management. Rare injuries including tracheobronchial tree injuries, cardiovascular injuries, esophageal injuries, and diaphragmatic injuries are also briefly discussed.

Characterizing degree of lung injury in pediatric acute respiratory distress syndrome

OBJECTIVE

Although all definitions of acute respiratory distress syndrome use some measure of hypoxemia, neither the Berlin definition nor recently proposed pediatric-specific definitions proposed by the Pediatric Acute Lung Injury Consensus Conference utilizing oxygenation index specify which PaO2/FIO2 or oxygenation index best categorizes lung injury. We aimed to identify variables associated with mortality and ventilator-free days at 28 days in a large cohort of children with acute respiratory distress syndrome.

DESIGN

Prospective, observational, single-center study.

SETTING

Tertiary care, university-affiliated PICU.

PATIENTS

Two-hundred eighty-three invasively ventilated children with the Berlin-defined acute respiratory distress syndrome.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between July 1, 2011, and June 30, 2014, 283 children had acute respiratory distress syndrome with 37 deaths (13%) at the Children's Hospital of Philadelphia. Neither initial PaO2/FO2 nor oxygenation index at time of meeting acute respiratory distress syndrome criteria discriminated mortality. However, 24 hours after, both PaO2/FIO2 and oxygenation index discriminated mortality (area under receiver operating characteristic curve, 0.68 [0.59-0.77] and 0.66 [0.57-0.75]; p < 0.001). PaO2/FIO2 at 24 hours categorized severity of lung injury, with increasing mortality rates of 5% (PaO2/FIO2, > 300), 8% (PaO2/FIO2, 201-300), 18% (PaO2/FIO2, 101-200), and 37% (PaO2/FIO2, ≤ 100) across worsening Berlin categories. This trend with 24-hour PaO2/FIO2 was seen for ventilator-free days (22, 19, 14, and 0 ventilator-free days across worsening Berlin categories; p < 0.001) and duration of ventilation in survivors (6, 9, 13, and 24 d across categories; p < 0.001). Similar results were obtained with 24-hour oxygenation index.

CONCLUSIONS

PaO2/FIO2 and oxygenation index 24 hours after meeting acute respiratory distress syndrome criteria accurately stratified outcomes in children. Initial values were not helpful for prognostication. Definitions of acute respiratory distress syndrome may benefit from addressing timing of oxygenation metrics to stratify disease severity.

Comorbidities and assessment of severity of pediatric acute respiratory distress syndrome: proceedings from the Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

To determine the impact of patient-specific and disease-related characteristics on the severity of illness and on outcome in pediatric patients with acute respiratory distress syndrome with the intent of guiding current medical practice and identifying important areas for future research.

DESIGN

Electronic searches of PubMed, EMBASE, Web of Science, Cochrane, and Scopus were conducted. References were reviewed for relevance and features included in the following section.

SETTINGS

Not applicable.

SUBJECTS

PICU patients with evidence of acute lung injury, acute hypoxemic respiratory failure, and acute respiratory distress syndrome.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

The comorbidities associated with outcome in pediatric acute respiratory distress syndrome can be divided into 1) patient-specific factors and 2) factors inherent to the disease process. The primary comorbidity associated with poor outcome is preexisting congenital or acquired immunodeficiency. Severity of disease is often described by factors identifiable at admission to the ICU. Many measures that are predictive are influenced by the underlying disease process itself, but may also be influenced by nutritional status, chronic comorbidities, or underlying genetic predisposition. Of the measures available at the bedside, both PaO2/FIO2 ratio and oxygenation index are fairly consistent and robust predictors of disease severity and outcomes. Multiple organ system dysfunction is the single most important independent clinical risk factor for mortality in children at the onset of acute respiratory distress syndrome.

CONCLUSIONS

The assessment of oxygenation and ventilation indices simultaneously with genetic and biomarker measurements holds the most promise for improved risk stratification for pediatric acute respiratory distress syndrome patients in the very near future. The next phases of pediatric acute respiratory distress syndrome pathophysiology and outcomes research will be enhanced if 1) age group differences are examined, 2) standardized datasets with adequately explicit definitions are used, 3) data are obtained at standardized times after pediatric acute respiratory distress syndrome onset, and 4) nonpulmonary organ failure scores are created and implemented.

The outcomes of children with pediatric acute respiratory distress syndrome: proceedings from the Pediatric Acute Lung Injury Consensus Conference

OBJECTIVE

To provide additional details and evidence behind the recommendations for outcomes assessment of patients with pediatric acute respiratory distress syndrome from the Pediatric Acute Lung Injury Consensus Conference.

DESIGN

Consensus conference of experts in pediatric acute lung injury.

METHODS

A panel of 27 experts met over the course of 2 years to develop a taxonomy to define pediatric acute respiratory distress syndrome and to make recommendations regarding treatment and research priorities. The outcomes subgroup comprised four experts. When published data were lacking, a modified Delphi approach emphasizing strong professional agreement was used.

RESULTS

The Pediatric Acute Lung Injury Consensus Conference experts developed and voted on a total of 151 recommendations addressing the topics related to pediatric acute respiratory distress syndrome, seven of which related to outcomes after pediatric acute respiratory distress syndrome. All seven recommendations had strong agreement. Children with acute respiratory distress syndrome continue to have a high mortality, specifically, in relation to certain comorbidities and etiologies related to pediatric acute respiratory distress syndrome. Comorbid conditions, such as an immunocompromised state, increase the risk of mortality even further. Likewise, certain etiologies, such as non-pulmonary sepsis, also place children at a higher risk of mortality. Significant long-term effects were reported in adult survivors of acute respiratory distress syndrome: diminished lung function and exercise tolerance, reduced quality of life, and diminished neurocognitive function. Little knowledge of long-term outcomes exists in children who survive pediatric acute respiratory distress syndrome. Characterization of the longer term consequences of pediatric acute respiratory distress syndrome in children is vital to help identify opportunities for improved therapeutic and rehabilitative strategies that will lessen the long-term burden of pediatric acute respiratory distress syndrome and improve the quality of life in children.

CONCLUSIONS

The Consensus Conference developed pediatric-specific recommendations for pediatric acute respiratory distress syndrome regarding outcome measures and future research priorities. These recommendations are intended to promote optimization and consistency of care for children with pediatric acute respiratory distress syndrome and identify areas of uncertainty requiring further investigation.

Effect of body position on ventilation distribution during PEEP titration in a porcine model of acute lung injury using advanced respiratory monitoring and electrical impedance tomography

Background

Lung failure after acute lung injury remains a challenge in different clinical settings. Various interventions for restoration of gas exchange have been investigated. Recruitment of collapsed alveoli by positive end expiratory pressure (PEEP) titration and optimization of ventilation-perfusion ratio by prone positioning have been extensively described in animal and clinical trials. This animal study was conducted to investigate the effects of PEEP and positioning by means of advanced respiratory monitoring including gas exchange, respiratory mechanics, volumetric capnography and electrical impedance tomography.

Methods

After induction of acute lung injury by oleic acid and lung lavage, 12 domestic pigs were studied in randomly assigned supine or prone position during a PEEP titration trial with maximal PEEP of 30 mbar.

Results

Induction of lung injury resulted in significant deterioration of oxygenation [partial pressure of arterial oxygen/inspiratory fraction of oxygen (PaO₂/FiO₂): p = 0.002] and ventilation [partial pressure of arterial carbon dioxide (PaCO₂): p = 0.002] and elevated alveolar dead-space ratios (Valv/Vte: p = 0.003) in both groups. Differences in the prone and the supine group were significant for PaCO₂ at incremental PEEP 10 and 20 and at decremental PEEP 20 (20d) and 10 (10d), for PaO₂/FiO₂ at PEEP 10 and 10d and for alveolar dead space at PEEP 10d. Electrical impedance tomography revealed homogenous ventilation distribution in prone position during PEEP 20, 30 and 20d.

Conclusions

Prone position leads to improved oxygenation and ventilation parameters in a lung injury model. Respiratory monitoring with measurement of alveolar dead space and electrical impedance tomography may visualize optimized ventilation in a PEEP titration trial.

Partial liquid ventilation for the prevention of mortality and morbidity in paediatric acute lung injury and acute respiratory distress syndrome

BACKGROUND

Acute lung injury and acute respiratory distress syndrome are syndromes of severe respiratory failure. Children with acute lung injury or acute respiratory distress syndrome have high mortality and the survivors have significant morbidity. Partial liquid ventilation is proposed as a less injurious form of respiratory support for these children. Uncontrolled studies in adults have shown improvements in gas exchange and lung compliance with partial liquid ventilation. A single uncontrolled study in six children with acute respiratory syndrome showed some improvement in gas exchange during three hours of partial liquid ventilation. This review was originally published in 2004, updated in 2009 and again in 2012.

OBJECTIVES

To assess whether partial liquid ventilation reduces mortality or morbidity, or both, in children with acute lung injury or acute respiratory distress syndrome.

SEARCH METHODS

In this updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 11); CINAHL (Cumulative Index to Nursing & Allied Health Literature) via Ovid (1982 to November 2011); Ovid MEDLINE (1950 to November 2011); and Ovid EMBASE (1982 to November 2011). The search was last performed in August 2008.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) which compared partial liquid ventilation with other forms of ventilation in children (aged 28 days to 18 years) with acute lung injury or acute respiratory distress syndrome. Trials had to report one or more of the following: mortality; duration of mechanical ventilation, respiratory support, oxygen therapy, stay in the intensive care unit, or stay in hospital; infection; long-term cognitive impairment, neurodevelopmental progress, or other long-term morbidities.

DATA COLLECTION AND ANALYSIS

We independently evaluated the quality of the relevant studies and extracted the data from the included studies.

MAIN RESULTS

Only one study enrolling 182 patients (reported as an abstract in conference proceedings) was identified and found eligible for inclusion; the authors reported only limited results. The trial was stopped prematurely and was, therefore, under-powered to detect any significant differences and at high risk of bias. The only available outcome of clinical significance was 28-day mortality. There was no statistically significant difference between groups, with a relative risk for 28-day mortality in the partial liquid ventilation group of 1.54 (95% confidence interval 0.82 to 2.9).

AUTHORS' CONCLUSIONS

There is no evidence from RCTs to support or refute the use of partial liquid ventilation in children with acute lung injury or acute respiratory distress syndrome. Adequately powered, high quality RCTs are still needed to assess its efficacy. Clinically relevant outcome measures should be assessed (mortality at discharge and later, duration of both respiratory support and hospital stay, and long-term neurodevelopmental outcomes). The studies should be published in full.

Pediatric Acute Lung Injury Epidemiology and Natural History study: Incidence and outcome of the acute respiratory distress syndrome in children

OBJECTIVES

The incidence and outcome of the acute respiratory distress syndrome in children are not well-known, especially under current ventilatory practices. The goal of this study was to determine the incidence, etiology, and outcome of acute respiratory distress syndrome in the pediatric population in the setting of lung protective ventilation.

DESIGN

A 1-yr, prospective, multicenter, observational study in 12 geographical areas of Spain (serving a population of 3.77 million ≤ 15 yrs of age) covered by 21 pediatric intensive care units.

SUBJECTS

All consecutive pediatric patients receiving invasive mechanical ventilation and meeting American-European Consensus Criteria for acute respiratory distress syndrome.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data on ventilatory management, gas exchange, hemodynamics, and organ dysfunction were collected. A total of 146 mechanically ventilated patients fulfilled the acute respiratory distress syndrome definition, representing a incidence of 3.9/100,000 population ≤ 15 yrs of age/yr. Pneumonia and sepsis were the most common causes of acute respiratory distress syndrome. At the time of meeting acute respiratory distress syndrome criteria, mean PaO2/FIO2 was 99 mm Hg ± 41 mm Hg, mean tidal volume was 7.6 mL/kg ± 1.8 mL/kg predicted body weight, mean plateau pressure was 27 cm H2O ± 6 cm H2O, and mean positive end-expiratory pressure was 8.9 cm ± 2.9 cm H2O. Overall pediatric intensive care unit and hospital mortality were 26% (95% confidence interval 19.6-33.7) and 27.4% (95% confidence interval 20.8-35.1), respectively. At 24 hrs, after the assessment of oxygenation under standard ventilatory settings, 118 (80.8%) patients continued to meet acute respiratory distress syndrome criteria (PaO2/FIO2 104 mm Hg ± 36 mm Hg; pediatric intensive care units mortality 30.5%), whereas 28 patients (19.2%) had a PaO2/FIO2 >200 mm Hg (pediatric intensive care units mortality 7.1%) (p = .014).

CONCLUSIONS

This is the largest study to estimate prospectively the pediatric population-based acute respiratory distress syndrome incidence and the first incidence study performed during the routine application of lung protective ventilation in children. Our findings support a lower acute respiratory distress syndrome incidence and mortality than those reported for adults. PaO2/FIO2 ratios at acute respiratory distress syndrome onset and at 24 hrs after onset were helpful in defining groups at greater risk of dying (clinical trials registered with http://www.clinicaltrials.gov; NCT 01142544).

Radiological findings in 210 paediatric patients with viral pneumonia: a retrospective case study

OBJECTIVE

The objective of this study was to assess the radiological presentations of different types of viral pneumonia in children.

METHODS

Nasopharyngeal swab specimens and bronchial aspirate samples from children with acute respiratory infections were obtained and tested for influenza B, adenovirus, respiratory syncytial virus and parainfluenza (Types 1, 2 and 3) by direct immunofluorescence assay, or for influenza A (Subtype H1N1) by quantitative real-time polymerase chain reaction. The chest radiographs of the 210 confirmed cases of viral pneumonia were analysed retrospectively by two independent radiologists for the identification, characterisation and description of the distribution of imaging abnormalities. The cases were divided into six groups on the basis of confirmed causative viral agent, and radiographic findings were compared, analysed and presented.

RESULTS

The abnormal chest radiograph findings consisted of bilateral patchy areas of consolidation (n=133), interstitial lung disease (n=33), diffuse areas of air space consolidation (n=29) and lobar consolidation (n=15). The abnormalities were distributed bilaterally in 195 cases and observed more frequently in the lower zones than in other regions. The radiological findings varied significantly among the six groups (p=0.0050). Pairwise comparison showed significant difference between influenza A (H1N1) and adenovirus (p=0.0031) only.

CONCLUSION

The predominant radiological finding in paediatric viral pneumonia was bilateral patchy areas of consolidation. The radiological findings differed significantly only between adenovirus and influenza A pneumonia. The diagnosis of the specific causative organism requires laboratory confirmation.

Epidemiological features and risk factor analysis of children with acute lung injury

BACKGROUND

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) represents a devastating complication observed in critical care medicine. The purpose of this study is to investigate the epidemiological aspects of ALI/ARDS in pediatric intensive care unit (PICU) and risk factors of mortality.

METHODS

Patients with ALI/ARDS in PICU of Beijing Children's Hospital, a tertiary medical center from November 1, 2005 to October 31, 2006 were included in this prospective study. We identified the risk factors for underlying diseases and mortality during a 3-month followup using multivariate logistic regression analysis.

RESULTS

In 562 critically ill patients admitted to PICU of Beijing Children's Hospital, there were 15 ALI-non ARDS patients and 29 ARDS patients, resulting in an incidence of 7.8% (44/562). The mortality rate of ARDS was 24.1% (7/29) and that of ALI/ARDS was 18.2% (8/44). At a 3-month follow-up, 12 patients died after being discharged from PICU and the total mortality rate was 45.5% (20/44). ALI/ARDS patients with pulmonary disease had better outcomes than those with extra-pulmonary involvements (P<0.05). Discharge against medical advice, low PaO(2)/FiO(2) during hospital stay and high PaCO2 on PICU admission were risk factors of mortality.

CONCLUSIONS

ARDS has a high mortality rate in PICU, especially in those with extra-pulmonary diseases. In addition to aggressive medical management of comorbidity, lung protection and avoidance of discharge against medical advice will decrease the mortality.

Daily practice of mechanical ventilation in Italian pediatric intensive care units: a prospective survey

OBJECTIVES

To assess how children requiring endotracheal intubation are mechanically ventilated in Italian pediatric intensive care units (PICUs).

DESIGN

A prospective, national, observational, multicenter, 6-month study.

SETTING

Eighteen medical-surgical PICUs.

PATIENTS

A total of 1943 consecutive children, aged 0-16 yrs, admitted between November 1, 2006 and April 30, 2007.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data on cause of respiratory failure, length of mechanical ventilation (MV), mode of ventilation, use of specific interventions were recorded for all children requiring endotracheal intubation for >24 hrs. Children were stratified for age, type of patient, and cause of respiratory failure. A total of 956 (49.2%) patients required MV via an endotracheal tube; 673 (34.6%) were ventilated for >24 hrs. The median length of MV was 4.5 days for all patients. If postoperative patients were excluded, the median time was 5 days. Bronchiolitis (6.7%), pneumonia (6.7%), and upper airway obstruction (5.3%) were the most frequent causes of acute respiratory failure, and altered mental status (9.2%) was the most frequent reason for MV. The overall mortality was 6.7% with highest rates for heart disease (nonoperative), sepsis, and acute respiratory distress syndrome (26.1%, 22.2%, and 16.7% respectively). Length of stay, associated chronic disease, severity score on admission, and PICU mortality were significantly higher in children who received MV (p < .05) than in children who did not. Controlled MV and pressure support ventilation + synchronized intermittent mandatory ventilation were the most frequently used modes of ventilatory assistance during PICU stay.

CONCLUSIONS

Mechanical ventilation is frequently used in Italian PICUs with almost one child of two requiring endotracheal intubation. Children treated with MV represent a more severe category of patients than children who are breathing spontaneously. Describing the standard care and how MV is performed in children can be useful for future clinical studies.

Acute respiratory distress syndrome in pediatric intensive care unit

OBJECTIVE

To report causes, clinical feature and outcome of children with Acute Respiratory Distress Syndrome (ARDS).

METHODS

The case records of children admitted with ARDS from June 2003 to June 2006 were retrospectively reviewed and the data collected was analyzed.

RESULTS

A total of 17 children were diagnosed as ARDS during study period giving an incidence of 22.7/1,000 admissions. The mean (SD) age was 74.5 (56.32) mo [range 6-144 mo]. Primary lung pathology contributed to a (53%) cases of ARDS while the rest (47%) had non pulmonary causes. There was not any significant different in mortality between these two groups. Similarly when infections and non infections conditions were considered separately there was no difference in survival. All children were ventilated using Pressure Controlled Ventilation. The mean (SD) duration of ventilation was 5.0 days [range 1-10 days]. The maximum PEEP (SD) used during the course of ventilation was 10 (3.37) cm H2O [range 7-18], while the maximum PIP (SD) used was 31 (3.75) cm H2O (range 25-36). The overall mortality was 70%; highest in children less than 2 years of age. Majority of the children had shock as the most common comorbid factor and had a high mortality (73.3%).

CONCLUSION

The high incidence and mortality of ARDS and the presence of a large proportion of potentially preventable accidents and poisoning cases in the study group underline the need for health education measures addressing preventive strategies among the rural population.

Incidence and outcomes of pediatric acute lung injury

OBJECTIVE

This population-based, prospective, cohort study was designed to determine the population incidence and outcomes of pediatric acute lung injury.

METHODS

Between 1999 and 2000, 1 year of screening was performed at all hospitals admitting critically ill children in King County, Washington. County residents 0.5 to 15 years of age who required invasive (through endotracheal tube or tracheostomy) or noninvasive (through full face mask) mechanical ventilation, regardless of the duration of mechanical ventilation, were screened. From this population, children meeting North American-European Consensus Conference acute lung injury criteria were eligible for enrollment. Postoperative patients who received mechanical ventilation for <24 hours were excluded. Data collected included the presence of predefined cardiac conditions, demographic and physiological data, duration of mechanical ventilation, and deaths. US Census population figures were used to estimate incidence. Associations between outcomes and subgroups identified a priori were assessed.

RESULTS

Thirty-nine children met the criteria for acute lung injury, resulting in a calculated incidence of 12.8 cases per 100000 person-years. Severe sepsis (with pneumonia as the infection focus) was the most common risk factor. The median 24-hour Pediatric Risk of Mortality III score was 9.0, and the mean +/- SD was 11.7 +/- 7.5. The hospital mortality rate was 18%, lower than that reported previously for pediatric acute lung injury. There were no statistically significant associations between age, gender, or risk factors and outcomes.

CONCLUSIONS

We present the first population-based estimate of pediatric acute lung injury incidence in the United States. Population incidence and mortality rates are lower than those for adult acute lung injury. Low mortality rates in pediatric acute lung injury may necessitate clinical trial outcome measures other than death.

Blood product transfusions and clinical outcomes in pediatric patients with acute lung injury

OBJECTIVE

There are data suggesting that blood product transfusions increase the risk of developing acute lung injury (ALI) in adults, and may be associated with increased mortality in adults with ALI. A possible association between transfusions and adverse outcomes of pediatric patients with ALI has not been studied previously. We tested the hypothesis that blood product transfusions to pediatric patients with ALI within the first 72 hours of the diagnosis would be associated with increased mortality and prolonged mechanical ventilation.

DESIGN

An epidemiologic database of pediatric ALI prospectively gathered from July 1996 to May 2000 was analyzed.

SETTING

Children were enrolled from both a tertiary referral hospital and a major community children's hospital.

PATIENTS

Three hundred fifteen patients who met the 1994 American European Consensus Committee definition of ALI between the ages of 36 weeks corrected gestational age and 18 years.

MAIN OUTCOME MEASURE

Mortality in the pediatric intensive care unit.

RESULTS

Multivariate analyses indicated that the transfusion of fresh-frozen plasma (FFP) was associated with increased mortality, independent of the severity of hypoxemia (Pao2/Fio2), presence of multiple organ system failure or disseminated intravascular coagulation (odds ratio = 1.08, 95% confidence interval = 1.00-1.17, p = 0.04). FFP transfusion was analyzed as a continuous variable, so that for each milliliter of FFP transfused per kilogram patient body weight per day, the odds of death increased by 1.08. There was a trend toward an association of the transfusion of FFP with a fewer number of days of unassisted ventilation (regression coefficient = -0.21, 95% confidence interval = -0.42-0.01, p = 0.06).

CONCLUSIONS

The transfusion of FFP is associated with an increased risk of mortality in children with ALI. The association between FFP and mortality in children with ALI should be investigated further.

Tracheobronchial injury

Tracheobronchial injuries (TBI) can be challenging to diagnose, manage, and definitively treat. They encompass a heterogeneous group of injuries that are often associated with other injuries. Although relatively rare, diagnosis and treatment of TBI often requires skillful and creative airway management, careful diagnostic evaluation, and operative repairs that are often resourceful and necessarily unique to the given injury. An experienced surgeon with a high level of suspicion and the liberal use of bronchoscopy constitute the major tools necessary for diagnosing and treating these injuries. Most TBI can be repaired primarily using a tailored surgical approach and techniques specific to the injury. Associated injuries are common, and surgeons must be knowledgeable in treating a wide variety of physiologic abnormalities, especially those involving the chest wall and lung parenchyma, if a successful outcome is to be achieved in the management of these often challenging patients.

Clinical features of children infected with different strains of influenza B in southern Taiwan

BACKGROUND

This study was designed to determine the clinical characteristics of children infected with different strains of influenza B viruses isolated in southern Taiwan. The clinical features were compared with influenza A infection occurring in the same period.

METHODS

All children enrolled in the study had laboratory-confirmed infection with influenza A or B viruses. Influenza B speciation was performed by RNA extraction, cDNA synthesis, and amplification by polymerase chain reaction and sequencing. Demographic data, clinical findings, diagnoses, and outcomes were obtained.

RESULTS

During the study period, 163 strains of influenza A and 118 strains of influenza B were isolated. The Yamagata-like strains were most prevalent in 2001. New reassortant strains were identified since 2002 and became predominant in 2005 and 2006. Children with influenza B were more likely than those with influenza A to be diagnosed as upper respiratory tract infection, myositis, and gastroenteritis (P < 0.05). Children infected with Yamagata-like strains were more likely to develop lower respiratory tract infection (P < 0.05) and accounted for all cases of invasive disease. Children infected with the Victoria-like group had the longest hospital stays associated with severe bacterial superinfection.

CONCLUSIONS

Currently new reassortant influenza B viruses are the predominant strains circulating in southern Taiwan. There is considerable similarity of clinical features between influenza A and B in children. The Yamagata-like strains were associated with more invasive infections. Continuous influenza virus surveillance is essential particularly in Taiwan where pandemic strains tend to appear earlier than in other countries.

The lung and pediatric trauma

Thoracic trauma is relatively frequent in children and causes considerable mortality. This is mainly due to the multiorganic nature of the trauma. The lung is more often affected even in the absence of rib fractures because of the considerable pliability of the chest wall that allows direct transfer of energy to this organ. Injuries to the heart, the aorta, the esophagus, and the diaphragm are rare. Lung contusion and laceration cause parenchymal hemorrhage and consolidation sometimes accompanied by pneumothorax and/or hemothorax. Tracheobronchial disruption is rare but life-threatening. Most traumatic lung injuries may be treated with rest, respiratory support, and eventually intercostal drainage. Large hemorrhage may require thoracotomy, and persistent pneumothorax (indicative of tracheobronchial disruption) may require intubation with fiberoptic bronchoscopic assistance and eventually reparative or ablative surgery. Adult respiratory distress syndrome is very rarely seen in children with thoracic trauma, but it remains highly lethal.

Pyogenic sacroiliitis and adult respiratory distress syndrome: a case report

Staphylococcus aureus sacroiliitis is uncommon and may lead to bacteraemia, sepsis, and death if diagnosis and treatment are delayed. Its association with pulmonary symptoms has not been reported. We report a 36-year-old Thai woman who presented with a 4-day history of right buttock pain, aggravated by walking, which came on after having a traditional foot massage. She later developed adult respiratory distress syndrome. She was treated with open drainage, respiratory support, and antibiotics.

Have changes in ventilation practice improved outcome in children with acute lung injury?

OBJECTIVES

To describe the changes that have occurred in mechanical ventilation in children with acute lung injury in our institution over the last 10-15 yrs and to examine the impact of these changes, in particular of the delivered tidal volume on mortality.

DESIGN

Retrospective study.

SETTING

University-affiliated children's hospital.

PATIENTS

The management of mechanical ventilation between 1988 and 1992 (past group, n = 79) was compared with the management between 2000 and 2004 (recent group, n = 85).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The past group patients were ventilated with a significantly higher mean tidal volume (10.2 +/- 1.7 vs. 8.1 +/- 1.4 mL.kg actual body weight, p < .001), lower levels of positive end-expiratory pressure (6.1 +/- 2.7 vs. 7.1 +/- 2.4 cm H2O, p = .007), and higher mean peak inspiratory pressure (31.5 +/- 7.3 vs. 27.8 +/- 4.2 cm H2O, p < .001) than the recent group patients. The recent group had a lower mortality (21% vs. 35%, p = .04) and a greater number of ventilator-free days (16.0 +/- 9.0 vs. 12.6 +/- 9.9 days, p = .03) than the past group. A higher tidal volume was independently associated with increased mortality (odds ratio 1.59; 95% confidence interval 1.20, 2.10, p < .001) and reduction in ventilation-free days (95% confidence interval -1.24, -0.77, p < .001).

CONCLUSIONS

The changes in the clinical practice of mechanical ventilation in children in our institution reflect those reported for adults. In our experience, mortality among children with acute lung injury was reduced by 40%, and tidal volume was independently associated with reduced mortality and an increase in ventilation-free days.

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.

Outcome of pulmonary function in Lemierre's disease-associated acute respiratory distress syndrome

Pulmonary function in acute respiratory distress syndrome (ARDS) survivors typically returns to normal with the exception of a persistent reduction in carbon monoxide diffusion capacity (DL(co)). Septic thrombophlebitis of the internal jugular vein, (Lemierre's syndrome or postanginal sepsis) is a well-described, albeit uncommon cause of ARDS in which metastatic pulmonary thromboemboli precipitate respiratory failure requiring ventilatory support. We describe convalescent pulmonary function in two survivors of Lemierre's disease-associated ARDS, suggesting that the subset of Lemierre's syndrome induced ARDS survivors have an excellent long-term pulmonary prognosis.

Ventilatory strategies and adjunctive therapy in ARDS

Acute respiratory distress syndrome, a diagnosis based on physiologic and radiological criteria, occurs commonly in critical care setting. A major challenge in evaluating therapies that may improve survival in ARDS is that it is not a single disease entity but, rather, numerous different diseases that result in endothelial injury, where the most obvious manifestation is within the lung resulting in pulmonary oedema. It has been shown that poor ventilatory technique that is injurious to the lungs can propagate systemic inflammatory response and adversely affect the mortality. The current data suggest that high tidal volumes with high plateau pressures are deleterious and a strategy of ventilation with lower tidal volumes and lower plateau pressure is associated with lower mortality. There may be a role for recruitment manoeuvres as well. Other forms of respiratory support still require further research. The present understanding of optimal ventilatory management and other adjunctive therapies are reviewed.

Infection in Pediatric Acute Respiratory Distress Syndrome

Pediatric acute respiratory distress syndrome (ARDS) is a severe lung injury caused by pneumonia, sepsis, and trauma. ARDS results from inflammation and pulmonary capillary leak causing major changes in lung architecture and function. It has a low incidence, but its severity and duration cause major morbidity, mortality, and use of resources. Any organism can cause ARDS. Susceptible populations develop the syndrome more often and have worse outcomes. Aggressive diagnosis and intensive treatment are essential to good outcomes in ARDS caused by infection. The prognosis for survival is good, but morbidity after the syndrome is a major burden.

Serious and lethal respiratory tract infections of viral etiology in children

Viruses may lead to serious and lethal pulmonary infections in immunocompetent and immunocompromised children. Series of children with acute respiratory distress syndrome and series of children requiring extracorporeal membrane oxygenation, as well as reported series of nosocomial viral illness, offer an insight into the extent of serious viral disease documented in the medical literature. Series of children with specific viral respiratory illness also will be reviewed, as will the means of diagnosis in these groups of patients. Copyright © 2000 by W.B. Saunders Company

A history of pediatric critical care medicine

Critical care medicine developed out of other subspecialties' need to provide care for their most critically ill patients. Advanced technologies, the understanding of the pathophysiology of critical illness, and the development of the multidisciplinary team have made this care possible. Pediatric critical care medicine emerged in the 1960s and has expanded dramatically since then. The field has made major advances in the areas of lung injury, sepsis, traumatic brain injury, and postoperative care. We review here the evolution of modern pediatric critical care medicine from its roots in general pediatric and cardiac surgery, adult respiratory care medicine, neonatology, and pediatric anesthesiology to its current state as a unique discipline.

Acute respiratory distress syndrome in children with severe motor and intellectual disabilities

We report 13 severely disabled children with acute respiratory distress syndrome, who were treated at the Department of Pediatrics, Niigata City General Hospital between 1995 and 2002. The children ranged in age from 1 year to 16 years. All were non-ambulant. Chronic aspiration and gastro-esophageal reflux were recognized in 12 patients. Patients had the rapid onset of dyspnea refractory to oxygen therapy. Diffuse bilateral lung infiltrates were present on chest X-ray. Predisposing events included sepsis (3 patients), pneumomia (7 patients), pancreatitis (1 patient) and two children with other infections. All required mechanical ventilation for periods of 3-26 days and received oxygen for 5-64 days. Steroid therapy and surfactant therapy were given to eight and three patients, respectively. Only one patient developed an air leak complication. Despite intensive care, three children died, one underwent tracheostomy and nine recovered completely. Acute respiratory distress syndrome is a commonly recognized cause of acute respiratory failure following a variety of insults. It is characterized by the acute onset of dyspnea refractory to oxygen therapy, and diffuse lung infiltrates. Children with severe motor and intellectual disabilities had various complications. In this study, chronic aspiration and gastro-esophageal reflux are considered to be one of predisposing factors triggering acute respiratory distress syndrome in children with severe motor and intellectual disabilities. Although acute respiratory distress syndrome was considered to be a not infrequent occurrence, its mortality rate might be low despite the severity of the disease in children with severe motor and intellectual disabilities. Acute respiratory distress syndrome can be a complication seen in severely disabled children.

Kinetic therapy improves oxygenation in critically ill pediatric patients

OBJECTIVE

To compare changes in oxygenation after manual turning and percussion (standard therapy) and after automated rotation and percussion (kinetic therapy).

DESIGN

Randomized crossover trial.

SETTING

General and cardiac pediatric intensive care units.

PATIENTS

Intubated and mechanically ventilated pediatric patients who had an arterial catheter and no contraindications to using a PediDyne bed.

INTERVENTIONS

Patients were placed on a PediDyne bed (Kinetic Concepts) and received 18 hrs blocks of standard and kinetic therapy in an order determined by randomization.

MEASUREMENTS AND MAIN RESULTS

Arterial blood gases were measured every 2 hrs during each phase of therapy. Oxygenation index and arterial-alveolar oxygen tension difference [P(A-a)O(2)] were calculated. Indexes calculated at baseline and after each 18-hr phase of therapy were analyzed. Fifty patients were enrolled. Data from 15 patients were either not collected or not used due to reasons that included violation of protocol and inability to tolerate the therapies in the study. Indexes of oxygenation were not normally distributed and were compared using Wilcoxon signed rank testing. Both therapies led to improvements in oxygenation, but only those from kinetic therapy achieved statistical significance. In patients receiving kinetic therapy first, median oxygenation index decreased from 7.4 to 6.19 (p = .015). The median P(A-a)O(2) decreased from 165.2 to 126.4 (p = .023). There were continued improvements in oxygenation after the subsequent period of standard therapy, with the median oxygenation index decreasing to 5.52 and median P(A-a)O(2) decreasing to 116.0, but these changes were not significant (p = .365 and .121, respectively). When standard therapy was first, the median oxygenation index decreased from 8.83 to 8.71 and the median P(a-a)o(2) decreased from 195.4 to 186.6. Neither change was significant. Median oxygenation index after the subsequent period of kinetic therapy was significantly lower (7.91, p = .044) and median P(A-a)O(2) trended lower (143.4, p = .077).

CONCLUSIONS

Kinetic therapy is more efficient than standard therapy at improving oxygenation and produces improvements in oxygenation that are more persistent.

Oxygenation index predicts outcome in children with acute hypoxemic respiratory failure

To define outcome and time dependence of predictors of outcome in pediatric acute hypoxemic respiratory failure, 131 patients (age range, 1 month to 18 years) were prospectively followed. Parametric models were used to describe time-related events, and competing risks analysis was performed for mortality estimates. Multiple logistic analysis was applied to describe time-related predictors of ventilation time and mortality. Overall mortality was 27%. Peak oxygenation index (OI) measured at any time point (p < 0.001, 91% reliability in bootstrapping, after inverse transformation) and Pediatric Risk of Mortality, or PRISM, score within the first 12 hours of mechanical ventilation (p < 0.001, 63% reliability in bootstrapping, after square transformation) were identified as independent predictors of mortality. Peak OI, younger age, and need for renal replacement therapy were significantly associated with a longer time to extubation. Although OI was less reliable as outcome predictor within the first 12 hours of intubation, it still predicted duration of mechanical ventilation. No clear-cut threshold of OI was identified that could accurately predict mortality. Survival was characterized by a peak rate of extubations at approximately 1 week, with a more gradual decline thereafter, whereas death appeared as a constant risk over time, which exceeded chances of survival at approximately 4 weeks. Severity of oxygenation failure at any point in time during acute hypoxemic respiratory failure correlates with duration of mechanical ventilation and mortality. This is best reflected by the OI, which shows a direct correlation to outcome in a time-independent manner.

Trauma and the paediatric lung

Thoracic injury is a serious cause of morbidity and mortality in paediatric patients. This review will present cases to assist the clinician in the epidemiology, assessment and management of airway injury, pulmonary contusion, rib fracture, musculoskeletal injury and pneumothorax.

The multiply injured child

The treatment of multiple traumas in children requires knowledge of common injury patterns, incidence, mortality, and the consequences and differences between these injuries in children and adult patients. However, epidemiological studies concerning pediatric multiple trauma are rare. To address this, data were collected and analyzed from 682 multiple trauma patients treated at a Level I trauma center. The patients were divided into four age-related groups (< 6 years, 6-12 years, 13-18 years, and 18-40 years) and were evaluated for trauma mechanism, injury distribution, and cause of death. Children aged 6 to 17 years mostly were injured as pedestrians and cyclists whereas infants, preschoolers, and adults more commonly were injured as car passengers. Pediatric patients suffered a significantly higher mortality than adults, with a threefold increased risk of death when injured as passengers in car accidents. Injuries to the head and the legs were most common. A lower incidence of thoracic (28% versus. 62%), abdominal (20% versus 36%), pelvic (22% versus 35%), and upper limb (32% versus 43%) trauma was observed in children (< 18 years) than in adults (18-40 years). Nevertheless, trauma to the thorax, abdomen, and head were associated with a high risk of death in all groups. Spinal cord injuries, especially in the cervical region, also carried a high risk of mortality (36.8 in the group of patients younger than 18 years and 18.9 in the group of patients 18-40 years). Children younger than 6 years had the most severe head injuries. The data show that there are important differences in incidence, mortality, and injury patterns between pediatric and adult patients with multiple traumas.

Pediatric acute lung injury: prospective evaluation of risk factors associated with mortality

RATIONALE

The 1994 American European Consensus Committee definitions of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) have not been applied systematically in the pediatric population.

OBJECTIVES

The purpose of this study was to evaluate prospectively the epidemiology and clinical risk factors associated with death and prolonged mechanical ventilation in all pediatric patients admitted to two large, pediatric intensive care units with ALI/ARDS using Consensus criteria.

METHODS

All pediatric patients meeting Consensus Committee definitions for ALI were prospectively identified and included in a relational database.

MEASUREMENTS AND MAIN RESULTS

There were 328 admissions for ALI/ARDS with a mortality of 22%. Multivariate logistic regression analyses revealed (1) the initial severity of oxygenation defect, as measured by the Pa(O2)/FI(O2) ratio; (2) the presence of nonpulmonary and non-central nervous system (CNS) organ dysfunction; and (3) the presence of CNS dysfunction were independently associated with mortality and prolonged mechanical ventilation. A substantial fraction of patients (28%) did not require mechanical ventilation at the onset of ALI; 46% of these patients eventually required intubation for worsening ALI.

CONCLUSIONS

Mortality in pediatric ALI/ARDS is high and several risk factors have major prognostic value. In contrast to ALI/ARDS in adults, the initial severity of arterial hypoxemia in children correlates well with mortality. A significant fraction of patients with pediatric ALI/ARDS can be identified before endotracheal intubation is required. These patients provide a valuable group in whom new therapies can be tested.

Acute lung injury and acute respiratory distress syndrome

Acute lung injury and acute respiratory distress syndrome are an important challenge for pediatric intensive care units. These disorders are characterized by a significant inflammatory response to a local (pulmonary) or remote (systemic) insult resulting in injury to alveolar epithelial and endothelial barriers of the lung, acute inflammation and protein rich pulmonary edema. The reported rates in children vary from 8.5 to 16 cases / 1000 pediatric intensive care unit (PICU) admissions. The pathological features of ARDS are described as passing through three overlapping phases - an inflammatory or exudative phase (0-7 days), a proliferative phase (7-21 days) and lastly a fibrotic phase (from day 10). The treatment of ARDS rests on good supportive care and control of initiating cause. The goal of ventilating patients with ALI/ARDS should be to maintain adequate gas exchange with minimal ventilator induced lung injury. This can be achieved by use of optimum PEEP, low tidal volume and appropriate FiO2. High frequency ventilation can improve oxygenation but does affect the outcomes. Prone positioning is a useful strategy to improve oxygenation. Pharmacological strategies have not made any significant impact on the outcomes. Preliminary data suggests some role for use of corticosteroids in non-resolving ARDS. The mortality rates have declined over the last decade chiefly due to the advances in supporting critically ill patients.

The effect of opening wedge thoracostomy on thoracic insufficiency syndrome associated with fused ribs and congenital scoliosis

BACKGROUND

Thoracic insufficiency syndrome is the inability of the thorax to support normal respiration or lung growth and is seen in patients who have severe congenital scoliosis with fused ribs. Traditional spinal surgery does not directly address this syndrome.

METHODS

Twenty-seven patients with congenital scoliosis associated with fused ribs of the concave hemithorax had an opening wedge thoracostomy with primary longitudinal lengthening with use of a chest-wall distractor known as a vertical, expandable prosthetic titanium rib. Repeat lengthenings of the prosthesis were performed at intervals of four to six months. Radiographs were analyzed with respect to correction of the spinal deformity, as indicated by a change in the Cobb angle, and lateral deviation of the spine, as indicated by the interpedicular line ratio. Spinal growth was assessed by measuring the change in the length of the spine. Correction of the thoracic deformity and thoracic growth were assessed on the basis of the increase in the height of the concave hemithorax compared with the height of the convex hemithorax (the space available for the lung), the increase in the thoracic spinal height, and the increase in the thoracic depth and width. The thoracic deformity in the transverse plane was measured with computed tomography, and the scans were analyzed for spinal rotation, thoracic rotation, and the posterior hemithoracic symmetry ratio. Clinically, the patients were assessed on the basis of the relative heights of the shoulders and of head and thorax compensation. Pulmonary status was evaluated on the basis of the respiratory rate, capillary blood gas levels, and pulmonary function studies.

RESULTS

The mean age at the time of the surgery was 3.2 years (range, 0.6 to 12.5 years), and the mean duration of follow-up was 5.7 years. All patients had progressive congenital scoliosis, with a mean increase of 15 degrees /yr before the operation. The scoliosis decreased from a mean of 74 degrees preoperatively to a mean of 49 degrees at the time of the last follow-up. Both the mean interpedicular line ratio and the space available for the lung ratio improved significantly. The height of the thoracic spine increased by a mean of 0.71 cm/yr. At the time of the last follow-up, the mean percentage of the predicted normal vital capacity was 58% for patients younger than two years of age at the time of the surgery, 44% for those older than two years of age (p < 0.001), and 36% for those older than two years of age who had had prior spine surgery. In a group of patients who had sequential testing, all increases in the volume of vital capacity were significant (p < 0.0001), but the changes in the percentages of the predicted normal vital capacity were not. There was a total of fifty-two complications in twenty-two patients, with the most common being asymptomatic proximal migration of the device through the ribs in seven patients.

CONCLUSIONS

Opening wedge thoracostomy with use of a chest-wall distractor directly treats segmental hypoplasia of the hemithorax resulting from fused ribs associated with congenital scoliosis. The operation addresses thoracic insufficiency syndrome by lengthening and expanding the constricted hemithorax and allowing growth of the thoracic spine and the rib cage. The procedure corrects most components of chest-wall deformity and indirectly corrects congenital scoliosis, without the need for spine fusion. The technique requires special training and should be performed by a multispecialty team.