Comparison of Prevalence and Outcomes of Pediatric Acute Respiratory Distress Syndrome Using Pediatric Acute Lung Injury Consensus Conference Criteria and Berlin Definition

Pediatric Acute Respiratory Distress Syndrome in South African PICUs: A Multisite Point-Prevalence Study

OBJECTIVES

To describe the prevalence of pediatric acute respiratory distress syndrome (pARDS) and the characteristics of children with pARDS in South African PICUs.

DESIGN

Observational multicenter, cross-sectional point-prevalence study.

SETTING

Eight PICUs in four South African provinces.

PATIENTS

All children beyond the neonatal period and under 18 years of age admitted to participating PICUs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Clinical and demographic data were prospectively collected on a single day of each month, from February to July 2022, using a centralized database. Cases with or at risk of pARDS were identified using the 2015 Pediatric Acute Lung Injury Consensus Conference criteria. Prevalence was calculated as the number of children meeting pARDS criteria/the total number of children admitted to PICU at the same time points. Three hundred ten patients were present in the PICU on study days: 166 (53.5%) male, median (interquartile range [IQR]) age 9.8 (3.1-32.9) months, and 195 (62.9%) invasively mechanically ventilated. Seventy-one (22.9%) patients were classified as being "at risk" of pARDS and 95 patients (prevalence 30.6%; 95% CI, 24.7-37.5%) fulfilled pARDS case criteria, with severity classified as mild (58.2%), moderate (25.3%), and severe (17.6%). Median (IQR) admission Pediatric Index of Mortality 3 risk of mortality in patients with and without pARDS was 5.6 (3.4-12.1) % versus 3.9 (1.0-8.2) % ( p = 0.002). Diagnostic categories differed between pARDS and non-pARDS groups ( p = 0.002), with no difference in age, sex, or presence of comorbidities. On multivariable logistic regression, increasing admission risk of mortality (adjusted odds ratio [aOR] 1.02; 95% CI, 1.00-1.04; p = 0.04) and being admitted with a respiratory condition (aOR 2.64; 95% CI, 1.27-5.48; p = 0.01) were independently associated with an increased likelihood of having pARDS.

CONCLUSIONS

The 30.6% prevalence of pARDS in South Africa is substantially higher than reports from other sociogeographical regions, highlighting the need for further research in this setting.

The Modified Clinical Progression Scale for Pediatric Patients: Evaluation as a Severity Metric and Outcome Measure in Severe Acute Viral Respiratory Illness

OBJECTIVES

To develop, evaluate, and explore the use of a pediatric ordinal score as a potential clinical trial outcome metric in children hospitalized with acute hypoxic respiratory failure caused by viral respiratory infections.

DESIGN

We modified the World Health Organization Clinical Progression Scale for pediatric patients (CPS-Ped) and assigned CPS-Ped at admission, days 2-4, 7, and 14. We identified predictors of clinical improvement (day 14 CPS-Ped ≤ 2 or a three-point decrease) using competing risks regression and compared clinical improvement to hospital length of stay (LOS) and ventilator-free days. We estimated sample sizes (80% power) to detect a 15% clinical improvement.

SETTING

North American pediatric hospitals.

PATIENTS

Three cohorts of pediatric patients with acute hypoxic respiratory failure receiving intensive care: two influenza (pediatric intensive care influenza [PICFLU], n = 263, 31 sites; PICFLU vaccine effectiveness [PICFLU-VE], n = 143, 17 sites) and one COVID-19 ( n = 237, 47 sites).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Invasive mechanical ventilation rates were 71.4%, 32.9%, and 37.1% for PICFLU, PICFLU-VE, and COVID-19 with less than 5% mortality for all three cohorts. Maximum CPS-Ped (0 = home at respiratory baseline to 8 = death) was positively associated with hospital LOS ( p < 0.001, all cohorts). Across the three cohorts, many patients' CPS-Ped worsened after admission (39%, 18%, and 49%), with some patients progressing to invasive mechanical ventilation or death (19%, 11%, and 17%). Despite this, greater than 76% of patients across cohorts clinically improved by day 14. Estimated sample sizes per group using CPS-Ped to detect a percentage increase in clinical improvement were feasible (influenza 15%, n = 142; 10%, n = 225; COVID-19, 15% n = 208) compared with mortality ( n > 21,000, all), and ventilator-free days (influenza 15%, n = 167).

CONCLUSIONS

The CPS-Ped can be used to describe the time course of illness and threshold for clinical improvement in hospitalized children and adolescents with acute respiratory failure from viral infections. This outcome measure could feasibly be used in clinical trials to evaluate in-hospital recovery.

Clinical characterization of human bocavirus 1 infection in infants hospitalized in an intensive care unit for severe acute respiratory tract disease

Acute respiratory infections represent the leading cause of morbimortality in children and viruses are the main etiological agents. Here we describe the clinical characteristics and evolution of infants admitted to intensive care unit with severe acute respiratory infection (SARI) due to Human Bocavirus 1 mono-infection in patients without previous comorbidity. We also compared them with respiratory syncytial virus (RSV) cases. Of 141 cases included (age 5.43 ± 4.54 months, 52% male), 80% had at least 1 virus detected. RSV was the most frequent in the series (71.6%) followed by HBoV1 (28%). Five cases of HBoV1 mono-detection were identified. Pediatric acute respiratory distress syndrome was present in both groups, HBoV1 and RSV. The clinical presentation and evolution of HBoV1 single infection was similar to RSV. HBoV1 should be included among the agents investigated in cases of SARI in infants.

Interrater Reliability of the 2015 Pediatric Acute Lung Injury Consensus Conference Criteria for Pediatric ARDS

BACKGROUND

Diagnostic guidelines for pediatric ARDS (PARDS) were developed at the 2015 Pediatric Acute Lung Injury Consensus Conference (PALICC). Although this was an improvement in creating pediatric-specific diagnostic criteria, there remains potential for variability in identification of PARDS.

RESEARCH QUESTION

What is the interrater reliability of the 2015 PALICC criteria for diagnosing moderate to severe PARDS? What clinical criteria and patient factors are associated with diagnostic disagreements?

STUDY DESIGN AND METHODS

Patients with acute hypoxic respiratory failure admitted from 2016 to 2021 who received invasive mechanical ventilation were retrospectively reviewed by two pediatric ICU physicians. Reviewers evaluated whether the patient met the 2015 PALICC definition of moderate to severe PARDS and rated their diagnostic confidence. Interrater reliability was measured using Gwet's agreement coefficient.

RESULTS

Thirty-seven of 191 encounters had a diagnostic disagreement. Interrater reliability was substantial (Gwet's agreement coefficient, 0.74; 95% CI, 0.65-0.83). Disagreements were caused by different interpretations of chest radiographs (56.8%), ambiguity in origin of pulmonary edema (37.8%), or lack of clarity if patient's current condition was significantly different from baseline (27.0%). Disagreement was more likely in patients who were chronically ventilated (OR, 4.66; 95% CI, 2.16-10.08; P < .001), had a primary cardiac admission diagnosis (OR, 3.36; 95% CI, 1.18-9.53; P = .02), or underwent cardiothoracic surgery during the admission (OR, 4.90; 95% CI, 1.60-15.00; P = .005). Reviewers were at least moderately confident in their decision 73% of the time; however, they were less likely to be confident if the patient had cardiac disease or chronic respiratory failure.

INTERPRETATION

The interrater reliability of the 2015 PALICC criteria for diagnosing moderate to severe PARDS in this cohort was substantial, with diagnostic disagreements commonly caused by differences in chest radiograph interpretations. Patients with cardiac disease or chronic respiratory failure were more vulnerable to diagnostic disagreements. More guidance is needed on interpreting chest radiographs and diagnosing PARDS in these subgroups.

Prevalence and Incidence of Pediatric Acute Respiratory Distress Syndrome in a Tertiary Academic PICU in South Africa

OBJECTIVES

To determine the prevalence and incidence of pediatric acute respiratory distress syndrome (pARDS) among infants and children admitted to the PICU.

DESIGN

A single-center descriptive point prevalence study with twice weekly data collection over a 6 months (August 2020 to February 12, 2021).

SETTING

Red Cross War Memorial Children's Hospital, Cape Town, South Africa.

PATIENTS

All infants and children admitted to the PICU on study days were included.

INTERVENTIONS

Data were captured electronically on a standardized case record form using a Research Electronic Data Capture electronic database.

MEASUREMENTS AND MAIN RESULTS

The Pediatric Acute Lung Injury Consensus Conference criteria were used to define pARDS cases. Prevalence was calculated as the total number of pARDS cases/1,000 PICU bed days. The study included 354 patients (median [interquartile range]) 10.1 months old (1.5-61.3 mo old), with 204 males (57.6%), who occupied 879 bed days. Of these 879 bed days, 266 (30.3%; 95% CI, 27.2-33.3%) were occupied by pARDS cases, with a calculated prevalence and incidence of 302.6 of 1,000 bed days (30.3%) and 29.7% (95% CI, 26.7-32.7%), respectively. Three cases from the cohort were defined using the oxygen saturation index calculation. In cases receiving invasive ventilation ( n = 494; 56.2%), pARDS severity was classified as mild ( n = 143; 16.3%), moderate ( n = 44; 5.0%), and severe ( n = 29, 3.3%). A further 205 beds (23.3%) were occupied by patients classified as being at risk of pARDS.

CONCLUSIONS

The prevalence and incidence of pARDS in a South African PICU appears substantially higher than findings described in international reports. Further investigation of risk factors and outcomes is warranted.

Corticosteroids treatment for pediatric acute respiratory syndrome: A critical review

Approximately 25% of all pediatric consultations are due to respiratory conditions, 10% of which are for asthma. Regarding prevalence, bronchiolitis, acute bronchitis, and respiratory infections are other leading pediatric respiratory illnesses. Compared to the aforementioned diseases, pediatric acute respiratory distress syndrome (PARDS) is rare but lethal in the Intensive Care Unit patients. According to global studies, the mortality in PARDS ranges from 13.3% to 60.7%. Before the Pediatric Acute Lung Injury Consensus Conference (PALICC), adult acute respiratory distress syndrome (ARDS) management guidelines were used for PARDS. The PALICC set new criteria to identify PARDS with a different treatment and management approach. Steroids have been used to treat ARDS in some cases, although their effectiveness in treating pediatric patients is highly debated in the scientific community. This review examines steroid use in treating PARDS, emphasizes current developments in the field, and gives a broad overview of PARDS management.

Comparison of the Montreux definition with the Berlin definition for neonatal acute respiratory distress syndrome

To compare the similarities and differences between the Montreux definition and the Berlin definition in terms of the prevalence, mortality, and complications of neonatal acute respiratory distress syndrome (ARDS). We retrospectively analyzed the data of neonates with respiratory failure treated in a neonatal intensive care unit (NICU) between 1 November 2019 and 31 December 2021. In total, 554 infants had neonatal ARDS (524 infants, Montreux definition; 549 infants, Berlin definition). The prevalence (3.1% vs. 3.3%, p = 0.438) and mortality (18.9% vs.18.0%, p = 0.716) of neonatal ARDS did not differ between the definitions. Among the 519 infants meeting both definitions, key clinical outcomes did not differ between the definitions such as ventilation duration, NICU stay, complication rates, and antibiotic use, except for nitric oxide inhalation. The Montreux and Berlin definitions identified an additional 5 and 30 patients, respectively, not captured by the other definition. The rate of inhaled nitric oxide treatment (20.0% vs. 0%, p = 0.013), air leaks (20.0% vs. 0%, p = 0.013), and invasive ventilation duration (110.00 vs.0.00 h, p = 0.002) significantly differed between the above two groups. Sixty-two patients had moderate and severe ARDS according to the Montreux and Berlin definitions, respectively. The rates of adverse outcomes (e.g., mortality, invasive ventilation time) among these patients were similar to the rates among patients with moderate ARDS according to both definitions than among patients with severe ARDS according to both definitions.  Conclusion: The prevalence, mortality, and most complications of neonatal ARDS were similar between the Montreux and Berlin definitions, which mainly differed in terms of the severity of neonatal ARDS. What is Known: • The Montreux definition was first proposed for the diagnosis of neonatal acute respiratory distress syndrome and was established in 2017. To date, the Montreux definition has not been compared with other diagnostic definitions of ARDS. What is New: • The study suggests that perinatal lung disease need not be excluded in the diagnosis of neonatal ARDS, and that the Montreux definition is more applicable to neonates, taking into account their specific physiological characteristics.

Sivelestat improves clinical outcomes and decreases ventilator-associated lung injury in children with acute respiratory distress syndrome: a retrospective cohort study

BACKGROUND

Sivelestat, a neutrophil elastase inhibitor, is a selective and targeted therapy for acute respiratory distress syndrome (ARDS) in adults; and it is also reported to apply to children with ARDS. However, there is little evidence of its efficacy in children.

METHODS

This study recruited 212 patients ranging in age from 28 days to 18 years old, and who met the diagnostic criteria for pediatric ARDS (PARDS) while hospitalized in the Intensive Care Department of the Affiliated Children's Hospital of Xi'an Jiaotong University. A total of 125 patients (case group) received sivelestat treatment, and 87 were assigned to the control group. There were no significant differences in gender (P=0.445) or age (P=0.521). Control group data were collected from the Electronic Case Information System for pediatric patients diagnosed with ARDS between March 2017 to January 2020. Data for the case group were collected from the Electronic Case Information System between February 2020 to February 2022. Demographic data, clinically relevant indicators, respiratory parameters were recorded. The 28-day mortality was the primary endpoint; the Kaplan-Meier and log-rank tests were used to evaluate cumulative survival rate.

RESULTS

For general demographic and clinical characteristics, no significant differences were observed between the two groups. Compared to the control group, the case group displayed significant improvements in PaO₂/FiO₂ at 48 h (141±45 vs. 115±21, P<0.001) and 72 h (169±61 vs. 139±40, P<0.001) post-admission, and plateau pressure was lower than that in the control group at 24 h (24±3 vs. 28±7, P<0.001), 48 h (21±4 vs. 26±7, P<0.001), and 72 h (20±2 vs. 25±6, P<0.001) post-admission. Interleukin-8 levels were lower in the case group at 48 and 72 h post-admission. Overall, 28-day mortality was 25.47% (54/212). Twenty-five children died in the sivelestat group, 29 children died in the control group. Survival analysis revealed that cumulative survival in the case group was higher than that in the control group (P=0.028).

CONCLUSIONS

ARDS is expected to have high morbidity and mortality in critical care medicine, and precise targeted drugs are lacking. Our study showed that sivelestat improved prognosis and reduces mortality in children with ARDS.

Pediatric Acute Respiratory Distress Syndrome in India: Time for Collaborative Study?

How to cite this article: Solomon R. Pediatric Acute Respiratory Distress Syndrome in India: Time for Collaborative Study? Indian J Crit Care Med 2022;26(8):896–897.

Epidemiology of Acute Respiratory Distress Syndrome in Pediatric Intensive Care Unit: Single-center Experience

Background

Acute respiratory distress syndrome (ARDS) is characterized by dysregulated inflammation resulting in hypoxemia and respiratory failure and causes both morbidity and mortality.

Objectives

To describe the clinical profile, outcome, and predictors of mortality in ARDS in children admitted to the Pediatric intensive care unit.

Materials and methods

This is a single-center retrospective study conducted at a tertiary referral hospital in a 12-bed PICU involving children (1 month to 18 years) with ARDS as defined by Pediatric Acute Lung Injury Consensus Conference (PALICC) guidelines, over a period of 5 years (2016–2020). Demographic, clinical, and laboratory details at onset and during PICU stay were collected. Predictors of mortality were compared between survivors and non-survivors.

Results

We identified 89 patients with ARDS. The median age at presentation was 76 months (12–124 months). The most common precipitating factor was pneumonia (66%). The majority of children (35.9%) had moderate ARDS. Overall mortality was 33% with more than half belonging to severe ARDS group (58%). On Kaplan–Meier survival curve analysis, the mean time to death was shorter in the severe ARDS group as compared to other groups. Multiorgan dysfunction was present in 46 (51.6%) of the cases. Non-survivors had higher mean pediatric logistic organ dysfunction (PELOD2) on day 1. PRISM III at admission, worsening trends of ventilator and oxygenation parameters (OI, P/F, MAP, and PEEP) independently predicted mortality after multivariate analysis.

Conclusion

High PRISM score predicts poor outcome, and worsening trends of ventilator and oxygenation parameters (OI, P/F, MAP, and PEEP) are associated with mortality.

How to cite this article

Pujari CG, Lalitha AV, Raj JM, Kavilapurapu A. Epidemiology of Acute Respiratory Distress Syndrome in Pediatric Intensive Care Unit: Single-center Experience. Indian J Crit Care Med 2022;26(8):949–955.

Paediatric acute respiratory distress syndrome: consider the role of lymphatics

We present a case of a 7-day-old male infant with severe respiratory disease requiring venoarterial extracorporeal membrane oxygenation therapy with evidence of lymphangiectasia on lung biopsy. Differentiating primary versus secondary lymphangiectasis in this patient remains a riddle despite extensive investigations including an infective screen, lung biopsy and whole-genome sequencing. In addition to the standard therapies used in paediatric acute respiratory distress syndrome, such as lung-protective ventilation, permissive hypoxaemia and hypercarbia, nursing in the prone position, early use of muscle relaxants, rescue intravenous corticosteroids and broad-spectrum antibiotics, the patient was also given octreotide despite the absence of a chylothorax based on the theoretical benefit of altering the lymphatic flow. His case raises an interesting discussion around the role of lymphatics in the pathophysiology of paediatric and adult respiratory distress syndrome and prompts the exploration of novel agents which may affect lymphatic vessels used as an adjunctive therapy.

ARDS Clinical Practice Guideline 2021

Background

The joint committee of the Japanese Society of Intensive Care Medicine/Japanese Respiratory Society/Japanese Society of Respiratory Care Medicine on ARDS Clinical Practice Guideline has created and released the ARDS Clinical Practice Guideline 2021.

Methods

The 2016 edition of the Clinical Practice Guideline covered clinical questions (CQs) that targeted only adults, but the present guideline includes 15 CQs for children in addition to 46 CQs for adults. As with the previous edition, we used a systematic review method with the Grading of Recommendations Assessment Development and Evaluation (GRADE) system as well as a degree of recommendation determination method. We also conducted systematic reviews that used meta-analyses of diagnostic accuracy and network meta-analyses as a new method.

Results

Recommendations for adult patients with ARDS are described: we suggest against using serum C-reactive protein and procalcitonin levels to identify bacterial pneumonia as the underlying disease (GRADE 2D); we recommend limiting tidal volume to 4–8 mL/kg for mechanical ventilation (GRADE 1D); we recommend against managements targeting an excessively low SpO₂ (PaO₂) (GRADE 2D); we suggest against using transpulmonary pressure as a routine basis in positive end-expiratory pressure settings (GRADE 2B); we suggest implementing extracorporeal membrane oxygenation for those with severe ARDS (GRADE 2B); we suggest against using high-dose steroids (GRADE 2C); and we recommend using low-dose steroids (GRADE 1B). The recommendations for pediatric patients with ARDS are as follows: we suggest against using non-invasive respiratory support (non-invasive positive pressure ventilation/high-flow nasal cannula oxygen therapy) (GRADE 2D), we suggest placing pediatric patients with moderate ARDS in the prone position (GRADE 2D), we suggest against routinely implementing NO inhalation therapy (GRADE 2C), and we suggest against implementing daily sedation interruption for pediatric patients with respiratory failure (GRADE 2D).

Conclusions

This article is a translated summary of the full version of the ARDS Clinical Practice Guideline 2021 published in Japanese (URL: https://www.jsicm.org/publication/guideline.html). The original text, which was written for Japanese healthcare professionals, may include different perspectives from healthcare professionals of other countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-022-00615-6.

ARDS clinical practice guideline 2021

BACKGROUND

The joint committee of the Japanese Society of Intensive Care Medicine/Japanese Respiratory Society/Japanese Society of Respiratory Care Medicine on ARDS Clinical Practice Guideline has created and released the ARDS Clinical Practice Guideline 2021.

METHODS

The 2016 edition of the Clinical Practice Guideline covered clinical questions (CQs) that targeted only adults, but the present guideline includes 15 CQs for children in addition to 46 CQs for adults. As with the previous edition, we used a systematic review method with the Grading of Recommendations Assessment Development and Evaluation (GRADE) system as well as a degree of recommendation determination method. We also conducted systematic reviews that used meta-analyses of diagnostic accuracy and network meta-analyses as a new method.

RESULTS

Recommendations for adult patients with ARDS are described: we suggest against using serum C-reactive protein and procalcitonin levels to identify bacterial pneumonia as the underlying disease (GRADE 2D); we recommend limiting tidal volume to 4-8 mL/kg for mechanical ventilation (GRADE 1D); we recommend against managements targeting an excessively low SpO₂ (PaO₂) (GRADE 2D); we suggest against using transpulmonary pressure as a routine basis in positive end-expiratory pressure settings (GRADE 2B); we suggest implementing extracorporeal membrane oxygenation for those with severe ARDS (GRADE 2B); we suggest against using high-dose steroids (GRADE 2C); and we recommend using low-dose steroids (GRADE 1B). The recommendations for pediatric patients with ARDS are as follows: we suggest against using non-invasive respiratory support (non-invasive positive pressure ventilation/high-flow nasal cannula oxygen therapy) (GRADE 2D); we suggest placing pediatric patients with moderate ARDS in the prone position (GRADE 2D); we suggest against routinely implementing NO inhalation therapy (GRADE 2C); and we suggest against implementing daily sedation interruption for pediatric patients with respiratory failure (GRADE 2D).

CONCLUSIONS

This article is a translated summary of the full version of the ARDS Clinical Practice Guideline 2021 published in Japanese (URL: https://www.jrs.or.jp/publication/jrs_guidelines/). The original text, which was written for Japanese healthcare professionals, may include different perspectives from healthcare professionals of other countries.

Intravascular Gas Exchange: Physiology, Literature Review, and Current Efforts

Acute respiratory failure with inadequate oxygenation and/or ventilation is a common reason for ICU admission in children and adults. Despite the morbidity and mortality associated with acute respiratory failure, few proven treatment options exist beyond invasive ventilation. Attempts to develop intravascular respiratory assist catheters capable of providing clinically important gas exchange have had limited success. Only one device, the IVOX catheter, was tested in human clinical trials before development was halted without FDA approval. Overcoming the technical challenges associated with providing safe and effective gas exchange within the confines of the intravascular space remains a daunting task for physicians and engineers. It requires a detailed understanding of the fundamentals of gas transport and respiratory physiology to optimize the design for a successful device. This article reviews the potential benefits of such respiratory assist catheters, considerations for device design, previous attempts at intravascular gas exchange, and the motivation for continued development efforts.

Venovenous vs. Venoarterial Extracorporeal Membrane Oxygenation in Infection-Associated Severe Pediatric Acute Respiratory Distress Syndrome: A Prospective Multicenter Cohort Study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been increasingly used as rescue therapy for severe pediatric acute respiratory distress syndrome (PARDS) over the past decade. However, a contemporary comparison of venovenous (VV) and venoarterial (VA) ECMO in PARDS has yet to be well described. Therefore, the objective of our study was to assess the difference between VV and VA ECMO in efficacy and safety for infection-associated severe PARDS patients.

METHODS

This prospective multicenter cohort study included patients with infection-associated severe PARDS who received VV or VA ECMO in pediatric intensive care units (PICUs) of eight university hospitals in China between December 2018 to June 2021. The primary outcome was in-hospital mortality. Secondary outcomes included ECMO weaning rate, duration of ECMO and mechanical ventilation (MV), ECMO-related complications, and hospitalization costs.

RESULTS

A total of 94 patients with 26 (27.66%) VV ECMO and 68 (72.34%) VA ECMO were enrolled. Compared to the VA ECMO patients, VV ECMO patients displayed a significantly lower in-hospital mortality (50 vs. 26.92%, p = 0.044) and proportion of neurologic complications, shorter duration of ECMO and MV, but the rate of successfully weaned from ECMO, bleeding, bloodstream infection complications and pump failure were similar. By contrast, oxygenator failure was more frequent in patients receiving VV ECMO. No significant intergroup difference was observed for the hospitalization costs.

CONCLUSION

These positive findings showed the conferred survival advantage and safety of VV ECMO compared with VA ECMO, suggesting that VV ECMO may be an effective initial treatment for patients with infection-associated severe PARDS.

Correlation Between the Ratio of Oxygen Saturation to Fraction of Inspired Oxygen and the Ratio of Partial Pressure of Oxygen to Fraction of Inspired Oxygen in Detection and Risk Stratification of Pediatric Acute Respiratory Distress Syndrome

Objective: To measure the correlation between the ratio of oxygen saturation to fraction of inspired oxygen [SpO₂/FiO₂ (SF)] and the ratio of partial pressure of oxygen to fraction of inspired oxygen [PaO₂/FiO₂ (PF)] among children diagnosed with acute respiratory distress syndrome (ARDS).

Methodology: A cross-sectional study was conducted at the pediatric intensive care unit (PICU), National Institute of Child Health (NICH), Karachi, a tertiary care government hospital, from November 2020 to July 2021. One hundred twenty children (of either gender) having the age range of 2 months to 16 years, admitted to PICU with acute onset of respiratory distress, were included in the study. We measured SpO₂, PaO₂, FiO₂ and calculated SF and PF ratios. SPSS (version 23) (Armonk, NY: IBM Corp) was used to analyze data, and the Spearmen's correlation test was applied to measure the relationship between SF and PF ratios.

Results: A total of 120 children were included, the mean age was 40.58±38.88 months and 67 (55.8%) were males. The mean FiO₂ was 76.33%, the mean PaO₂ and SpO₂ were 100.35 mmHg and 94.37%, respectively. The mean PF ratio was 156.34, and the mean SF ratio was 156.45. There was a strong correlation between the SF ratio and the PF ratio (r=0.688; p=0.001).

Conclusion: This study has shown that there is a strong correlation between the SF and PF ratios, and a statistically substantial agreement has been observed.

Performance of acute respiratory distress syndrome definitions in a high acuity paediatric intensive care unit

BACKGROUND

For years, paediatric critical care practitioners used the adult American European Consensus Conference (AECC) and revised Berlin Definition (BD) for acute respiratory distress syndrome (ARDS) to study the epidemiology of paediatric ARDS (PARDS). In 2015, the paediatric specific definition, Paediatric Acute Lung Injury Consensus Conference (PALICC) was developed. The use of non-invasive metrics of oxygenation to stratify disease severity were introduced in this definition, although this potentially may lead to a confounding effect of disease severity since it is more common to place indwelling arterial lines in sicker patients. We tested the hypothesis that PALICC outperforms AECC/BD in our high acuity PICU, which employs a liberal use of indwelling arterial lines and high-frequency oscillatory ventilation (HFOV).

METHODS

We retrospectively collected data from children < 18 years mechanically ventilated for at least 24 h in our tertiary care, university-affiliated paediatric intensive care unit. The primary endpoint was the difference in the number of PARDS cases between AECC/BD and PALICC. Secondary endpoints included mortality and ventilator free days. Performance was assessed by the area under the receiver operating characteristics curve (AUC-ROC).

RESULTS

Data from 909 out of 2433 patients was eligible for analysis. AECC/BD identified 35 (1.4%) patients (mortality 25.7%), whereas PALICC identified 135 (5.5%) patients (mortality 14.1%). All but two patients meeting AECC/Berlin criteria were also identified by PALICC. Almost half of the cohort (45.2%) had mild, 33.3% moderate and 21.5% severe PALICC PARDS at onset. Highest mortality rates were seen in patients with AECC acute lung injury (ALI)/mild Berlin and severe PALICC PARDS. The AUC-ROC for Berlin was the highest 24 h (0.392 [0.124-0.659]) after onset. PALICC showed the highest AUC-ROC at the same moment however higher than Berlin (0.531 [0.345-0.716]). Mortality rates were significantly increased in patients with bilateral consolidations (9.3% unilateral vs 26.3% bilateral, p = 0.025).

CONCLUSIONS

PALICC identified more new cases PARDS than the AECC/Berlin definition. However, both PALICC and Berlin performed poorly in terms of mortality risk stratification. The presence of bilateral consolidations was associated with a higher mortality rate. Our findings may be considered in future modifications of the PALICC criteria.

Efficacy of human immunoglobulin injection and effects on serum inflammatory cytokines in neonates with acute lung injury

The present study aimed to explore the efficacy of intravenous immunoglobulin (IVIG) injection in neonates with acute lung injury (ALI) and assess its effects on serum inflammatory cytokine levels. The research subjects were 140 neonates with ALI who were evenly distributed into a control group (COG) and a study group (STG). The COG patients were treated routinely, whereas patients in the STG were administered IVIG in addition to the standard treatment received by the COG. The arterial partial pressure of oxygen (PaO₂), PaO₂/fraction of inspired oxygen (FIO₂), mechanical ventilation time and hospitalization time were compared between the two groups. ELISA was used to determine the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the patients before treatment and at 12, 24 and 36 h after treatment. The Kaplan-Meier method was used to analyze the survival of the patients, including their survival for 30 days after treatment. The patients were divided into high and low cytokine expression groups based on their mean expression levels of serum IL-6 and TNF-α before treatment. After treatment, PaO₂ and PaO₂/FiO2 were significantly higher and mechanical ventilation and hospitalization time were reduced in the STG in comparison with the COG (all P<0.001). At 12, 24 and 36 h after treatment, serum IL-6 and TNF-α levels in the STG were lower than those in the COG (both P<0.05). The 30-day survival rate after treatment was not significantly different between the two groups (P>0.05). The 30-day survival rate in the high IL-6 and high TNF-α expression COG was lower than that in the low IL-6 and low TNF-α expression COG (both P<0.05). The results of the present study indicate that IVIG may improve pulmonary gas exchange, shorten the course of disease and reduce the inflammatory response in neonates with ALI.

Paediatrics: how to manage acute respiratory distress syndrome

Background

Acute respiratory distress syndrome (ARDS) is a significant cause of mortality and morbidity amongst critically ill children. The purpose of this narrative review is to provide an up-to-date review on the evaluation and management of paediatric ARDS (PARDS).

Methods

A PubMed search was performed with Clinical Queries using the key term "acute respiratory distress syndrome". The search strategy included clinical trials, meta-analyses, randomized controlled trials, observational studies and reviews. Google, Wikipedia and UpToDate were also searched to enrich the review. The search was restricted to the English literature and children.

Discussion

Non-invasive positive pressure ventilation, lung-protective ventilation strategies, conservative fluid management and adequate nutritional support all have proven efficacy in the management of PARDS. The Pediatric Acute Lung Injury Consensus Conference recommends the use of corticosteroids, high-frequency oscillation ventilation and inhaled nitric oxide in selected scenarios. Partial liquid ventilation and surfactant are not considered efficacious based on evidence from clinical trials.

Conclusion

PARDS is a serious but relatively rare cause of admission into the paediatric intensive care unit and is associated with high mortality. Non-invasive positive pressure ventilation, lung-protective ventilation strategies, conservative fluid management and adequate nutrition are advocated. As there has been a lack of progress in the management of PARDS in recent years, further well-designed, large-scale, randomized controlled trials in this field are urgently needed.

Comparison of the OI and PaO2 /FiO2 score in evaluating PARDS requiring mechanical ventilation

AIM

To examine the differences between oxygenation index (OI) and arterial partial pressure of oxygen to the fraction of inspired oxygen (PaO₂ /FiO₂ , [P/F]) in evaluating the severity of pediatric acute respiratory distress syndrome (PARDS).

METHODS

The severity of PARDS was graded by using the OI score and P/F ratio, respectively. The data including clinical indexes and prognosis indicators were recorded and analyzed.

RESULTS

During the 3-year study period, there were significant differences between OI and P/F scores in the severity grading of PARDS patients (p < .05). However, in severe diseases, both the scorings of OI and P/F were consistent (24.6% vs. 25.6%). The OI scores appeared more accurate when compared with P/F in the correlation between them and the pediatric critical illness score, multiple organ dysfunction syndromes (MODS), pressure indexes of ventilators and patients' prognosis. In the receiver operating characteristic curve, the critical values of OI and P/F were 8.42 and 144.71. Area under the curve of them were 0.839 and 0.853. The sensitivity values were both 0.854. The specificity values were 0.584 and 0.602.

CONCLUSIONS

The OI and P/F were consistent in designating patients with severe PARDS. Among patients with mild to moderate diseases, the P/F could still be used for rapid determination given its simple calculation. Combined with the prognostic factors, the OI score was more accurate.

Longitudinal PEEP Responses Differ Between Children With ARDS and at Risk for ARDS

BACKGROUND

It is unknown whether lung mechanics differ between patients with pediatric ARDS and at risk for ARDS. We aimed to examine the hypothesis that, compared to ARDS, subjects at risk of ARDS are characterized by higher end-expiratory lung volume (EELV) or respiratory system compliance (C_RS) and lower distending pressure (stress) applied on the lung or parenchymal deformation (strain) during mechanical ventilation.

METHODS

Consecutively admitted subjects fulfilling the PALICC ARDS criteria were considered eligible for inclusion in this study. A ventilator with an integrated gas exchange module was used to calculate EELV, C_RS, strain, and stress after a steady state had been achieved based on nitrogen washout/washin technique. All subjects were subjected to incremental PEEP trials at 0, 6, 12, 24, 48, and 72 h.

RESULTS

A total of 896 measurements were longitudinally calculated in 32 mechanically ventilated subjects (n = 15 subjects with ARDS; n = 17 subjects at risk for ARDS). EELV correlated positively with strain or stress in the ARDS group (r = 0.30, P < .001) and the at risk group (r = 0.60, P < .001). C_RS correlated with strain (r = 0.40, P < .001) only in subjects at risk for ARDS. EELV increased over time as PEEP rose from 4 to 10 cm H₂O in subjects with ARDS (P = .001). In the at risk group, EELV only increased at 48 h (P = .001). Longitudinally, C_RS (P = .001) and EELV (P = .002) were lower and strain and stress were higher in subjects with ARDS compared to those at risk for ARDS (P = .002), remaining within safe limits. Strain and stress increased by 24 h but declined by 72 h in subjects with ARDS at a PEEP of 4 cm H₂O (P = .02). In the at risk group, strain and stress declined from 6 h to 72 h at a PEEP of 10 cm H₂O (P = .001).

CONCLUSIONS

Longitudinally, C_RS and EELV were lower and strain and stress were higher in subjects with ARDS compared to subjects at risk for ARDS. These parameters behaved differently over time at PEEP values of 4 or 10 cm H₂O. At these PEEP levels, strain and stress remained within safe limits in both groups.

Dynamic Airway Driving Pressure and Outcomes in Children With Acute Hypoxemic Respiratory Failure

BACKGROUND

Limited adult data suggest that airway driving pressure might better reflect the potential risk for lung injury than tidal volume based on ideal body weight, and the parameter correlates with mortality in ARDS. There is a lack of data about the effect of driving pressure on mortality in pediatric ARDS. This study aimed to evaluate the effect of driving pressure on morbidity and mortality of children with acute hypoxemic respiratory failure.

METHODS

This retrospective cohort study was performed in a tertiary level pediatric ICU. Children who received invasive mechanical ventilation for acute hypoxemic respiratory failure (defined as [Formula: see text] < 300 within 24 h after intubation), in a 2-y period were included. The cohort was divided into 2 groups based on the highest dynamic driving pressure (ΔP, calculated as the difference between peak inspiratory pressure and PEEP) in the first 24 h, with a cutoff value of 15 cm H₂O.

RESULTS

Of the 380 children who were mechanically ventilated during the study period, 101 children who met eligibility criteria were enrolled. Common diagnoses were pneumonia (n = 51), severe sepsis (n = 24), severe dengue (n = 10), and aspiration pneumonia (n = 7). In comparison to the group with high ΔP (ie, ≥ 15 cm H₂O), children in the group with low ΔP (ie, < 15 cm H₂O) had significantly lower median (interquartile range) duration of ventilation (5 [4-6] d vs 8 [6-11] d, P < .001], ICU length of stay (6 [5-8] d vs 12 [8-15] d, P < .001], and more ventilator-free days at day 28 (23 [20-24] vs 17 [0-22] d, P < .001). Logistic regression analysis also suggested driving pressure as an independent predictor of morbidity after adjusting for confounding variables. However, there was no statistically significant difference in mortality between the 2 groups (17% in low ΔP vs 24% in high ΔP, P = .38). Subgroup analysis of 65 subjects who fulfilled ARDS criteria yielded similar results with respect to mortality and morbidity.

CONCLUSIONS

Below a threshold of 15 cm H₂O, ΔP was associated with significantly decreased morbidity in children with acute hypoxemic respiratory failure.

Acute respiratory distress syndrome (ARDS) as an adverse event following immunization: Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration Case Definition of the term “Acute Respiratory Distress Syndrome – ARDS” to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected Expert Reviewers prior to submission. The comments of the reviewers were taken into consideration and edits incorporated in this final manuscript.

Acute viral bronchiolitis as a cause of pediatric acute respiratory distress syndrome

The Pediatric Acute Lung Injury Consensus Conference (PALICC) published pediatric-specific guidelines for the definition, management, and research in pediatric acute respiratory distress syndrome (PARDS). Acute viral bronchiolitis (AVB) remains one of the leading causes of admission to PICU. Respiratory syncytial virus (RSV) is the most common cause of AVB. We aimed to evaluate the incidence of PARDS in AVB and identify the risk of RSV as a trigger pathogen for PARDS. This study is a retrospective single-center observational cohort study including children < 2 years of age admitted to the pediatric intensive care unit at St Mary's Hospital, London, and presented with AVB in 3 years (2016-2018). Clinical and demographic data was collected; PALICC criteria were applied to define PARDS. Data was expressed as median (IQR range); non-parametric tests were used. In this study, 144 infants with acute viral bronchiolitis were admitted to PICU in the study period. Thirty-nine infants fulfilled criteria of PARDS with RSV as the most common virus identified. Bacterial infection was identified as a risk factor for development of PARDS in infants with AVB.Conclusion: AVB is an important cause of PARDS in infants. RSV is associated with a higher risk of PARDS in AVB. Bacterial co-infection is a significant risk factor for development of PARDS in AVB. What is Known: • Bronchiolitis is a common cause of respiratory failure in children under 2 years. • ARDS is a common cause of PICU admission. What is New: • Evaluation of bronchiolitis as a cause of PARDS according to the PALLIC criteria. • Evaluation of different viruses' outcome in PARDS especially RSV as a commonest cause of AVB.

Comparison of Ventilator-free Days at 14 and 28 days as a Clinical Trial Outcome in Low- and Middle-income Countries

Aims and objectives

Reporting ventilator-free days (VFDs) with time frame of 28 days is a popular composite outcome measure (COM) in trials. However, early deaths and shorter pediatric intensive care unit (PICU) stay predominate in low- and middle-income countries (LMICs). A shorter time frame may reduce sample size required. We planned to compute sample size requirements for different effect sizes from datasets of previously conducted prospective studies for 28-day and 14-day time frames (VFD₂₈ vs VFD₁₄) to examine the hypothesis.

Materials and methods

The VFD₂₈ and VFD₁₄ were defined. Datasets of five prospective studies from PICU of our hospital were analyzed to estimate sample sizes for target reductions of 1–9 days in VFDs and other COMs for the two time frames. Reconfirmation of results was done with datasets of two other studies from PICUs of two geographical extremes of the country.

Results

Time-to-event occurred within 14 days in majority of patients. Sample size required for VFD₁₄ is about one-fifth to one-sixth of what is required for VFD₂₈ for target reductions of 1–9 days for all the enrolled studies. The same was true for other COMs as well. The hypothesis was supported by datasets of two other studies used for reconfirmation.

Conclusion

Choice of time frame for assessing VFDs and other COMs in clinical trials should be guided by the clinical context. A shorter time frame may be rewarding in terms of smaller sample size in the prevalent clinical setting of LMICs. Further confirmation with more datasets and prospective studies is desirable.

How to cite this article

Baranwal AK, Kumar MP, Gupta PK. Comparison of Ventilator-free Days at 14 and 28 days as a Clinical Trial Outcome in Low- and Middle-income Countries. Indian J Crit Care Med 2020;24(10):960–966.

<p>Third-Day Oxygenation Index is an Excellent Predictor of Survival in Children Mechanically Ventilated for Acute Respiratory Distress Syndrome</p>

Purpose

The aim of this study was to assess the association between oxygenation index (OI) and outcome in children with acute respiratory distress syndrome (ARDS).

Patients and Methods

Patients (age, >30 days) in the pediatric intensive care unit from April 2011 to March 2016 with ARDS and who were mechanically ventilated were included. Patients were divided into two age groups: infants (<12month) and older children. Lowest PaO₂/FiO₂ and SpO₂/FiO₂ ratios and highest mean airway pressure (MAP) were recorded on the first day of ARDS and after 72 h. OI was calculated on the first and third days of mechanical ventilation (MV) and its association with OI (first and third days) and short-term mortality evaluated at 28 days.

Results

MV was initiated a mean of 2.3 days after admission (median, 1.0 day; maximum 14 days). The average MV duration for all patients was 11.8 (median, 7.0) days. Mean (95% confidence interval (CI)) OI values on the first day of MV were 14.17 (11.94–16.41), 12.72 (10.68–14.75), and 13.24 (11.73–14.74) for infants, older children, and all participants, respectively. In survivors (n=39) mean OI was 11.66 (9.64–13.68) compared with 15.22 (13.03–17.40) in non-survivors (n=31). Logistic regression analysis revealed that OI on day 3 had highly significant prognostic value for mortality (odds ratio, 256.5, 95% CI 27.1–2424, p<0.001), with an AUC of 0.919 (cut-off value, 17; positive predictive value, 0.905; negative predictive value, 0.964; p=0.0001). In contrast, OI on day 1 did not have significant prognostic value (AUC, 0.634; p=0.056) for short-term mortality. Different modes of MV were not significantly associated with outcome (p>0.05).

Conclusion

OI is a simple, highly accurate, and sensitive predictor of the survival (short-term mortality) of children mechanically ventilated for ARDS.

Acute Respiratory Distress Syndrome Following Pediatric Trauma: Application of Pediatric Acute Lung Injury Consensus Conference Criteria

OBJECTIVES

To assess the incidence, severity, and outcomes of pediatric acute respiratory distress syndrome following trauma using Pediatric Acute Lung Injury Consensus Conference criteria.

DESIGN

Retrospective cohort study.

SETTING

Level 1 pediatric trauma center.

PATIENTS

Trauma patients less than or equal to 17 years admitted to the ICU from 2009 to 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We queried electronic health records to identify patients meeting pediatric acute respiratory distress syndrome oxygenation criteria for greater than or equal to 6 hours and determined whether patients met complete pediatric acute respiratory distress syndrome criteria via chart review. We estimated associations between pediatric acute respiratory distress syndrome and outcome using generalized linear Poisson regression adjusted for age, injury mechanism, Injury Severity Score, and serious brain and chest injuries. Of 2,470 critically injured children, 103 (4.2%) met pediatric acute respiratory distress syndrome criteria. Mortality was 34.0% among pediatric acute respiratory distress syndrome patients versus 1.7% among patients without pediatric acute respiratory distress syndrome (adjusted relative risk, 3.7; 95% CI, 2.0-6.9). Mortality was 50.0% for severe pediatric acute respiratory distress syndrome at onset, 33.3% for moderate, and 30.5% for mild. Cause of death was neurologic in 60.0% and multiple organ failure in 34.3% of pediatric acute respiratory distress syndrome nonsurvivors versus neurologic in 85.4% of nonsurvivors without pediatric acute respiratory distress syndrome (p = 0.001). Among survivors, 77.1% of pediatric acute respiratory distress syndrome patients had functional disability at discharge versus 30.7% of patients without pediatric acute respiratory distress syndrome patients (p < 0.001), and only 17.5% of pediatric acute respiratory distress syndrome patients discharged home without ongoing care versus 86.4% of patients without pediatric acute respiratory distress syndrome (adjusted relative risk, 1.5; 1.1-2.1).

CONCLUSIONS

Incidence and mortality associated with pediatric acute respiratory distress syndrome following traumatic injury are substantially higher than previously recognized, and pediatric acute respiratory distress syndrome development is associated with high risk of poor outcome even after adjustment for underlying injury type and severity.

Association between age and acute respiratory distress syndrome development and mortality following trauma

BACKGROUND

Improved understanding of the relationship between patient age and acute respiratory distress syndrome (ARDS) development and mortality following traumatic injury may help facilitate generation of new hypotheses about ARDS pathophysiology and the role of novel treatments to improve outcomes across the age spectrum.

METHODS

We conducted a retrospective cohort study of trauma patients included in the National Trauma Data Bank who were admitted to an intensive care unit from 2007 to 2016. We determined ARDS incidence and mortality across eight age groups for the entire 10-year study period and by year. We used generalized linear Poisson regression models adjusted for underlying mortality risk (injury mechanism, Injury Severity Score, admission Glasgow Coma Scale score, admission heart rate, and admission hypotension).

RESULTS

Acute respiratory distress syndrome occurred in 3.1% of 1,297,190 trauma encounters. Acute respiratory distress syndrome incidence was lowest among pediatric patients and highest among adults aged 35 to 64 years. Acute respiratory distress syndrome mortality was highest among patients 80 years or older (43.9%), followed by 65 to 79 years (30.6%) and 4 years or younger (25.3%). The relative risk of mortality associated with ARDS was highest among the pediatric age groups, with an adjusted relative risk (aRR) of 2.06 (95% confidence interval [CI], 1.72-2.70) among patients 4 years or younger compared with an aRR of 1.51 (95% CI, 1.42-1.62) for the entire cohort. Acute respiratory distress syndrome mortality increased over the 10-year study period (aRR, 1.03 per year; 95% CI, 1.02-1.05 per year), whereas all-cause mortality decreased (aRR, 0.98 per year; 95% CI, 0.98-0.99 per year).

CONCLUSIONS

While ARDS development following traumatic injury was most common in middle-aged adults, patients 4 years or younger and 65 years or older with ARDS experienced the highest burden of mortality. Children 4 years or younger were disproportionately affected by ARDS relative to their low underlying mortality following trauma that was not complicated by ARDS. Acute respiratory distress syndrome-associated mortality following trauma has worsened over the past decade, emphasizing the need for new prevention and treatment strategies.

LEVEL OF EVIDENCE

Prognostic/epidemiological study, level III.

Morbidity and Mortality Among Critically Injured Children With Acute Respiratory Distress Syndrome

OBJECTIVES

To evaluate morbidity and mortality among critically injured children with acute respiratory distress syndrome.

DESIGN

Retrospective cohort study.

SETTING

Four-hundred sixty Level I/II adult or pediatric trauma centers contributing to the National Trauma Data Bank.

PATIENTS

One hundred forty-six thousand fifty-eight patients less than 18 years old admitted to an ICU with traumatic injury from 2007 to 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We assessed in-hospital mortality and need for postdischarge care among patients with and without acute respiratory distress syndrome and hospital resource utilization and discharge disposition among survivors. Analyses were adjusted for underlying mortality risk (age, Injury Severity Score, serious brain or chest injury, and admission heart rate and hypotension) and year, transfer status, and facility trauma level designation. Acute respiratory distress syndrome occurred in 2,590 patients (1.8%). Mortality was 20.0% among acute respiratory distress syndrome patients versus 4.3% among nonacute respiratory distress syndrome patients, with an adjusted relative risk of 1.76 (95% CI, 1.52-2.04). Postdischarge care was required in an additional 44.8% of acute respiratory distress syndrome patients versus 16.0% of patients without acute respiratory distress syndrome (adjusted relative risk, 3.59; 2.87-4.49), with only 35.1% of acute respiratory distress syndrome patients discharging to home versus 79.8% of patients without acute respiratory distress syndrome. Acute respiratory distress syndrome mortality did not change over the 10-year study period (adjusted relative risk, 1.01/yr; 0.96-1.06) nor did the proportion of acute respiratory distress syndrome patients requiring postdischarge care (adjusted relative risk, 1.04/yr; 0.97-1.11). Duration of ventilation, ICU stay, and hospital stay were all significantly longer among acute respiratory distress syndrome survivors. Tracheostomy placement occurred in 18.4% of acute respiratory distress syndrome survivors versus 2.1% of patients without acute respiratory distress syndrome (adjusted relative risk, 3.10; 2.59-3.70).

CONCLUSIONS

Acute respiratory distress syndrome development following traumatic injury in children is associated with significantly increased risk of morbidity and mortality, even after adjustment for injury severity and hemodynamic abnormalities. Outcomes have not improved over the past decade, emphasizing the need for new therapeutic interventions, and prevention strategies for acute respiratory distress syndrome among severely injured children.

Steroids in pediatric acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a complex entity with high potential for harm and healthcare resource utilization. Despite multiple clinical advances in its ventilatory management, ARDS continues to be one of the most challenging disease processes for intensivists. It continues to lack a direct, proven and desperately needed effective therapeutic intervention. Given their biologic rationale, corticosteroids have been widely used by clinicians and considered useful by many in the management of ARDS since its first description. Adult data is abundant, yet contradictory. Controversy remains regarding the routine use of corticosteroids in ARDS. Therefore, widespread evidence-based recommendations for this heterogeneous disease process have not been made. In this article, our aim was to provide a summary of available evidence for the role of steroids in the treatment of ARDS, while giving special focus on pediatric ARDS (PARDS).

What do we know about optimal nutritional strategies in children with pediatric acute respiratory distress syndrome?

Nutrition in pediatric acute respiratory distress syndrome (PARDS) is an essential aspect of therapy, with potential to modify outcomes. The gut is slowly establishing its place as the motor of critical illness, and the 'gut-lung' axis has been shown to be in play in the systemic inflammatory response. Thus, utilizing the gut to modify outcomes in PARDS is an exciting prospect. PARDS is associated with high mortality in low- and middle-income countries (LMIC), where malnutrition is also prevalent and may worsen during hospital stay. Mortality may be higher in this subgroup of patients. At present, the gold standard to estimate resting energy expenditure (REE) in critically ill children is indirect calorimetry. However, it is a cumbersome and expensive procedure, as a result of which its routine practice is limited to very few units across the world. Therefore, predictive equations, which may under- or over-estimate REE, are relied upon to approximate calorie and protein needs of children with PARDS. Despite having target calorie and protein requirements, studies have found that a large proportion of critically ill children do not achieve these levels even at the end of a week in pediatric intensive care unit (PICU). The preferred mode of nutrition delivery is enteral, and if possible, early enteral nutrition (EEN). Immunonutrition has been a lucrative subject of research, and while there have been some strides, no therapy has yet conclusively demonstrated benefit in terms of mortality or reduced length of stay in PICU or the hospital. Probable immunonutrients in PARDS include omega-3 fatty acids, arginine, glutamine and vitamin D, though none are a part of any recommendations yet.

Severity and Mortality Predictors of Pediatric Acute Respiratory Distress Syndrome According to the Pediatric Acute Lung Injury Consensus Conference Definition

OBJECTIVES

The objective of this study was to assess the prevalence, severity, and outcomes of pediatric acute respiratory distress syndrome in a resource-limited country. In addition, we sought to explore the predisposing factors that predicted the initial severity, a change from mild to moderate-severe severity, and mortality.

DESIGN

Retrospective study.

SETTING

PICU in Songklanagarind Hospital, Songkhla, Thailand.

PATIENTS

Children 1 month to 15 years old with acute respiratory failure admitted to the PICU from January 2013 to December 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From a total of 1,738 patients admitted to PICU, 129 patients (prevalence 7.4%) were diagnosed as pediatric acute respiratory distress syndrome using the Pediatric Acute Lung Injury Consensus Conference definition. The patients were categorized by severity. Fifty-seven patients (44.2%) were mild, 35 (27.1%) were moderate, and 37 (28.1%) were severe. After multivariable analysis was performed, factors significantly associated with moderate to severe disease at the initial diagnosis were Pediatric Risk of Mortality III score (odds ratio, 1.08; 95% CI, 1.03-1.15; p = 0.004), underlying oncologic/hematologic disorder (odds ratio, 0.32; 95% CI, 0.12-0.77; p = 0.012), and serum albumin level (odds ratio, 0.46; 95% CI, 0.27-0.80; p = 0.006), whereas underlying oncologic/hematologic disorder (odds ratio, 5.33; 95% CI, 1.33-21.4) and hemoglobin (odds ratio, 0.63; 95% CI, 0.44-0.89) predicted the progression of this syndrome within 7 days. The 30-day all-cause mortality rate was 51.2% (66/129). The predictors of mortality were the Pediatric Risk of Mortality III score (odds ratio, 1.12; 95% CI, 1.02-1.24; p = 0.017), underlying oncologic/hematologic disorder (odds ratio, 7.81; 95% CI, 2.18-27.94; p = 0.002), receiving systemic steroids (odds ratio, 4.04; 95% CI, 1.25-13.03; p = 0.019), having air leak syndrome (odds ratio, 5.45; 95% CI, 1.57-18.96; p = 0.008), and presenting with multiple organ dysfunction (odds ratio, 7.41; 95% CI, 2.00-27.36; p = 0.003).

CONCLUSIONS

The prevalence and mortality rate of pediatric acute respiratory distress syndrome in a developing country are high. The oncologic/hematologic comorbidity had a significant impact on the severity of progression and mortality.

Definition and global epidemiology of pediatric acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) has been known to occur in children since early descriptions of the disease, but pediatric specific diagnostic criteria were first established in 2015 with the Pediatric Acute Lung Injury Consensus Conference (PALICC) definition of pediatric ARDS (PARDS). There were substantial changes proposed with the PALICC definition, including simplification of radiographic criteria, use of pulse oximetry based metrics to define PARDS, specific criteria for non-invasive ventilation, and the use of oxygenation index (OI) instead of PaO2/FiO2 ratio for those on invasive ventilation. While these changes could potentially result in major changes in the reported incidence and outcome of PARDS, review of the recent literature since publication of the PALICC definitions highlight that major elements regarding the contemporary epidemiology of PARDS have remained stable over the past 20 years. This highlights that the PARDS definition is likely catching up to changes in clinical practice, and suggests that this new definition should be used moving forward as it is more reflective of current practice than historical definitions. However, it is also clear that PARDS severity alone (as measured by the PALICC) criteria insufficiently characterizes the risk for mortality or other important clinical outcomes amongst PARDS patients, although there appears to be some association between PARDS severity and outcome, particularly when hypoxemia is severe.

Risk Factors on Hospital Arrival for Acute Respiratory Distress Syndrome Following Pediatric Trauma

OBJECTIVES

To determine risk factors identifiable at hospital arrival associated with acute respiratory distress syndrome development among critically injured children.

DESIGN

Retrospective cohort study.

SETTING

Level I or II adult or pediatric trauma centers contributing to the National Trauma Data Bank from 2007 to 2016.

PATIENTS

Patients less than 18 years admitted to an ICU with traumatic injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We determined associations between patient, injury, and clinical characteristics present at hospital arrival with development of acute respiratory distress syndrome recorded as a hospital complication. Acute respiratory distress syndrome occurred in 1.8% of 146,058 critically injured children (n = 2,590). The only demographic factor associated with higher risk of developing acute respiratory distress syndrome on multivariable analysis was African American race (relative risk, 1.42 vs white; 95% CI, 1.13-1.78). Injury characteristics included firearm injuries (relative risk 1.93; 1.50-2.48) and motor vehicle crashes (relative risk, 1.91; 1.57-2.31) relative to falls; spine (relative risk, 1.39; 1.20-1.60), chest (relative risk, 1.36; 1.22-1.52), or lower extremity injuries (relative risk, 1.26; 1.10-1.44); amputations (relative risk, 2.10; 1.51-2.91); and more severe injury (relative risk, 3.69 for Injury Severity Score 40-75 vs 1-8; 2.50-5.44). Clinical variables included abnormal respiratory status (intubated relative risk, 1.67; 1.23-2.26 and hypopnea relative risk, 1.23; 1.05-1.45 and tachypnea relative risk, 1.26; 1.10-1.44) and lower Glasgow Coma Scale score (relative risk, 5.61 for Glasgow Coma Scale score 3 vs 15; 4.44-7.07).

CONCLUSIONS

We provide the first description of the incidence of and risk factors for acute respiratory distress syndrome among pediatric trauma patients. Improved understanding of the risk factors associated with acute respiratory distress syndrome following pediatric trauma may help providers anticipate its development and intervene early to improve outcomes for severely injured children.

The Current State of Pediatric Acute Respiratory Distress Syndrome

Pediatric acute respiratory distress syndrome (PARDS) is a significant cause of morbidity and mortality in children. Children with PARDS often require intensive care admission and mechanical ventilation. Unfortunately, beyond lung protective ventilation, there are limited data to support our management strategies in PARDS. The Pediatric Acute Lung Injury Consensus Conference (PALICC) offered a new definition of PARDS in 2015 that has improved our understanding of the true epidemiology and heterogeneity of the disease as well as risk stratification. Further studies will be crucial to determine optimal management for varying disease severity. This review will present the physiologic basis of PARDS, describe the unique pediatric definition and risk stratification, and summarize the current evidence for current standards of care as well as adjunctive therapies.

A prospective investigation of interleukin-8 levels in pediatric acute respiratory failure and acute respiratory distress syndrome

Background

The association of plasma interleukin-8 (IL-8), or IL-8 genetic variants, with pediatric acute respiratory distress syndrome (PARDS) in children with acute respiratory failure at risk for PARDS has not been examined. The purpose of this study was to examine the association of early and sequential measurement of plasma IL-8 and/or its genetic variants with development of PARDS and other clinical outcomes in mechanically ventilated children with acute respiratory failure.

Methods

This was a prospective cohort study of children 2 weeks to 17 years of age with acute airways and/or parenchymal lung disease done in 22 pediatric intensive care units participating in the multi-center clinical trial, Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE). Plasma IL-8 levels were measured within 24 h of consent and 24 and 48 h later. DNA was purified from whole blood, and IL-8 single nucleotide polymorphisms, rs4073, rs2227306, and rs2227307, were genotyped.

Results

Five hundred forty-nine patients were enrolled; 480 had blood sampling. Plasma IL-8 levels ranged widely from 4 to 7373 pg/mL. Highest IL-8 levels were observed on the day of intubation with subsequent tapering. Levels of IL-8 varied significantly across primary diagnoses with the highest levels occurring in patients with sepsis and the lowest levels in those with asthma. Plasma IL-8 was strongly correlated with oxygenation defect and severity of illness. IL-8 was consistently higher in PARDS patients compared to those without PARDS; levels were 4–12 fold higher in non-survivors compared to survivors. On multivariable analysis, IL-8 was independently associated with death, duration of mechanical ventilation, and PICU length of stay on all days measured, but was not associated with PARDS development. There was no association between the IL-8 single nucleotide polymorphisms, rs4073, rs2227306, and rs2227307, and PARDS development or plasma IL-8 level.

Conclusions

When measured sequentially, plasma IL-8 was robustly associated with multiple, relevant clinical outcomes including mortality, but was not associated with PARDS development. The wide range of plasma IL-8 levels exhibited in this cohort suggests that further study into the heterogeneity of this patient population and its impact on individual responses to PARDS treatment is warranted.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2342-8) contains supplementary material, which is available to authorized users.

Outcomes of Children With Critical Bronchiolitis Meeting at Risk for Pediatric Acute Respiratory Distress Syndrome Criteria

OBJECTIVES

New definitions of pediatric acute respiratory distress syndrome include criteria to identify a subset of children "at risk for pediatric acute respiratory distress syndrome." We hypothesized that, among PICU patients with bronchiolitis not immediately requiring invasive mechanical ventilation, those meeting at risk for pediatric acute respiratory distress syndrome criteria would have worse clinical outcomes, including higher rates of pediatric acute respiratory distress syndrome development.

DESIGN

Single-center, retrospective chart review.

SETTING

Mixed medical-surgical PICU within a tertiary academic children's hospital.

PATIENTS

Children 24 months old or younger admitted to the PICU with a primary diagnosis of bronchiolitis from September 2013 to April 2014. Children intubated before PICU arrival were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Collected data included demographics, respiratory support, oxygen saturation, and chest radiograph interpretation by staff radiologist. Oxygen flow (calculated as FIO2 × flow rate [L/min]) was calculated when oxygen saturation was 88-97%. The median age of 115 subjects was 5 months (2-11 mo). Median PICU length of stay was 2.8 days (1.5-4.8 d), and median hospital length of stay was 5 days (3-10 d). The criteria for at risk for pediatric acute respiratory distress syndrome was met in 47 of 115 subjects (40.9%). Children who were at risk for pediatric acute respiratory distress syndrome were more likely to develop pediatric acute respiratory distress syndrome (15/47 [31.9%] vs 1/68 [1.5%]; p < 0.001), had longer PICU length of stay (4.6 d [2.8-10.2 d] vs 1.9 d [1.0-3.1 d]; p < 0.001) and hospital length of stay (8 d [5-16 d] vs 4 d [2-6 d]; p < 0.001), and increased need for invasive mechanical ventilation (16/47 [34.0%] vs 2/68 [2.9%]; p < 0.001), compared with those children who did not meet at risk for pediatric acute respiratory distress syndrome criteria.

CONCLUSIONS

Our data suggest that the recent definition of at risk for pediatric acute respiratory distress syndrome can successfully identify children with critical bronchiolitis who have relatively unfavorable clinical courses.

Paediatric acute respiratory distress syndrome incidence and epidemiology (PARDIE): an international, observational study

BACKGROUND

Paediatric acute respiratory distress syndrome (PARDS) is associated with high mortality in children, but until recently no paediatric-specific diagnostic criteria existed. The Pediatric Acute Lung Injury Consensus Conference (PALICC) definition was developed to overcome limitations of the Berlin definition, which was designed and validated for adults. We aimed to determine the incidence and outcomes of children who meet the PALICC definition of PARDS.

METHODS

In this international, prospective, cross-sectional, observational study, 145 paediatric intensive care units (PICUs) from 27 countries were recruited, and over a continuous 5 day period across 10 weeks all patients were screened for enrolment. Patients were included if they had a new diagnosis of PARDS that met PALICC criteria during the study week. Exclusion criteria included meeting PARDS criteria more than 24 h before screening, cyanotic heart disease, active perinatal lung disease, and preparation or recovery from a cardiac intervention. Data were collected on the PICU characteristics, patient demographics, and elements of PARDS (ie, PARDS risk factors, hypoxaemia severity metrics, type of ventilation), comorbidities, chest imaging, arterial blood gas measurements, and pulse oximetry. The primary outcome was PICU mortality. Secondary outcomes included 90 day mortality, duration of invasive mechanical and non-invasive ventilation, and cause of death.

FINDINGS

Between May 9, 2016, and June 16, 2017, during the 10 study weeks, 23 280 patients were admitted to participating PICUs, of whom 744 (3·2%) were identified as having PARDS. 95% (708 of 744) of patients had complete data for analysis, with 17% (121 of 708; 95% CI 14-20) mortality, whereas only 32% (230 of 708) of patients met Berlin criteria with 27% (61 of 230) mortality. Based on hypoxaemia severity at PARDS diagnosis, mortality was similar among those who were non-invasively ventilated and with mild or moderate PARDS (10-15%), but higher for those with severe PARDS (33% [54 of 165; 95% CI 26-41]). 50% (80 of 160) of non-invasively ventilated patients with PARDS were subsequently intubated, with 25% (20 of 80; 95% CI 16-36) mortality. By use of PALICC PARDS definition, severity of PARDS at 6 h after initial diagnosis (area under the curve [AUC] 0·69, 95% CI 0·62-0·76) discriminates PICU mortality better than severity at PARDS diagnosis (AUC 0·64, 0·58-0·71), and outperforms Berlin severity groups at 6 h (0·64, 0·58-0·70; p=0·01).

INTERPRETATION

The PALICC definition identified more children as having PARDS than the Berlin definition, and PALICC PARDS severity groupings improved the stratification of mortality risk, particularly when applied 6 h after PARDS diagnosis. The PALICC PARDS framework should be considered for use in future epidemiological and therapeutic research among children with PARDS.

FUNDING

University of Southern California Clinical Translational Science Institute, Sainte Justine Children's Hospital, University of Montreal, Canada, Réseau en Santé Respiratoire du Fonds de Recherche Quebec-Santé, and Children's Hospital Los Angeles, Department of Anesthesiology and Critical Care Medicine.