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

Accuracy of tidal volume delivery by paediatric intensive care ventilators: A bench-model study

BACKGROUND

Tidal volume (Vt) delivery during mechanical ventilation is influenced by gas compression, humidity, and temperature.

OBJECTIVES

This bench study aimed at assessing the accuracy of Vt delivery by paediatric intensive care ventilators according to the humidification system. Secondary objectives were to assess the following: (i) the accuracy of Vt delivery in ventilators with an integrated Y-piece pneumotachograph and (ii) the ability of ventilators to deliver and maintain a preset positive end-expiratory pressure.

METHODS

Six latest-generation intensive care ventilators equipped with a paediatric mode were tested on the ASL5000 test lung in four simulated paediatric bench models (full-term neonate, infant, preschool-age chile, and school-age child), under volume-controlled mode with a heated humidifier (HH) or a heat moisture exchanger, with various loading conditions. Three ventilators equipped with a Y-piece pneumotachograph were tested with or without the pneumotachograph in the neonatal and infant models. "Accurate Vt" delivery was defined as a volume error (percentage of the preset Vt under body temperature and pressure and saturated water vapour conditions) being ≤10 % of the absolute preset value.

RESULTS

Vt accuracy varied significantly across ventilators but was acceptable in almost all the ventilators and all the models, except the neonatal model. The humidification system had an impact on Vt delivery in the majority of the tested conditions (p < 0.05). The use of an HH was associated with a better Vt accuracy in four ventilators (V500, V800, R860, and ServoU) and allowed to achieve an acceptable level of volume error in the neonatal model as compared to the use of heat moisture exchanger. The use of an integrated pneumotachograph was associated with lower volume error in only one ventilator (p < 0.01). All the tested ventilators were able to maintain adequate positive end-expiratory pressure levels.

CONCLUSION

The humidification system affects Vt accuracy of paediatric intensive care ventilators, especially in the youngest patients for whom the HH should be preferred.

Infant feeding and criticality in children

BACKGROUND

Data support the protective effects of human breast milk (HBM) feeding in acute illness but little is known about the impact of HBM feeding on the criticality of infants.

AIM

To explore the relationship between early HBM feeding and severity of illness and recovery in critically ill children requiring intubation and mechanical ventilation for acute respiratory failure (ARF).

STUDY DESIGN

Prospective cohort study of mothers of patients aged 1-36 months who participated in the acute and follow-up phases of the Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE) clinical trial. Participants completed a survey describing HBM dose fed during their infant's first month of life.

RESULTS

Of 138 patients, 70 (51%) received exclusive HBM feedings (90%-100% total feeds) and 68 (49%) did not. We found no group differences in severity of illness on paediatric intensive care unit (PICU) admission or severity of paediatric acute respiratory distress syndrome (PARDS) within the first 24-48 h of intubation/mechanical ventilation (Pediatric Risk of Mortality [PRISM] III-12 score median: 5 vs. 5, p = .88; moderate/severe PARDS: 53% vs. 54%, p = .63). While median time to recovery from ARF was reduced by 1 day in patients who received exclusive HBM feedings, the difference between groups was not statistically significant (median 1.5 vs. 2.6 days, hazard ratio 1.40 [95% confidence interval, 0.99-1.97], p = .06).

CONCLUSIONS

Human breast milk dose was not associated with severity of illness on PICU admission in children requiring mechanical ventilation for ARF.

RELEVANCE TO CLINICAL PRACTICE

Data support the protective effects of HBM during acute illness and data from this study support a clinically important reduction in time to recovery of ARF. Paediatric nurses should continue to champion HBM feeding to advance improvements in infant health.

Pediatric Acute Respiratory Distress Syndrome Severity and Health-Related Quality of Life Outcomes: Single-Center Retrospective Cohort, 2011-2017

OBJECTIVES

To determine factors associated with health-related quality of life (HRQL) decline among pediatric acute respiratory distress syndrome (PARDS) survivors.

DESIGN

Retrospective cohort study.

SETTING

Academic children's hospital.

PATIENTS

Three hundred fifteen children 1 month to 18 years old with an unplanned PICU admission from December 2011 to February 2017 enrolled in the hospital's Outcomes Assessment Program.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pre-admission baseline and median 6-week post-discharge HRQL were assessed using the Pediatric Quality of Life Inventory or the Functional Status II-R. Patients meeting retrospectively applied Second Pediatric Acute Lung Injury Consensus Conference criteria for PARDS were identified, and PARDS severity was classified using binary (mild/moderate, severe) and trichotomous (mild, moderate, severe) categorization for noninvasive ventilation and invasive mechanical ventilation (IMV). PARDS occurred in 41 of 315 children (13.0%). Clinically important HRQL decline (≥ 4.5 points) occurred in 17 of 41 patients (41.5%) with PARDS and 64 of 274 without PARDS (23.4%). On multivariable generalized linear regression adjusted for age, baseline Pediatric Overall Performance Category, maximum nonrespiratory Pediatric Logistic Organ Dysfunction score, diagnosis, length of stay, and time to follow-up, PARDS was associated with HRQL decline (adjusted relative risk [aRR], 1.70; 95% CI, 1.03-2.77). Four-hour and maximum PARDS severity were the only factors associated with HRQL decline. HRQL decline occurred in five of 18 patients with mild PARDS at 4 hours, five of 13 with moderate PARDS (aRR 2.35 vs. no PARDS [95% CI, 1.01-5.50]), and seven of ten with severe PARDS (aRR 2.56 vs. no PARDS [95% CI, 1.45-4.53]). The area under the receiver operating characteristic curve for discrimination of HRQL decline for IMV patients was 0.79 (95% CI, 0.66-0.91) for binary and 0.80 (95% CI, 0.69-0.93) for trichotomous severity categorization.

CONCLUSIONS

HRQL decline is common among children surviving PARDS, and risk of decline is associated with PARDS severity. HRQL decline from baseline may be an efficient and clinically meaningful endpoint to incorporate into PARDS clinical trials.

Can Noninvasive Oxygen Saturation Index Match Invasive Oxygenation Index to Monitor Respiratory Disease in Critically Ill Children?-A Prospective Study

Respiratory illnesses are common indications for mechanical ventilation in children. The adequacy of ventilatory support for oxygenation is measured using arterial blood gas analysis and calculation of oxygenation index (OI). Due to invasive nature of arterial blood sampling needed to calculate OI, several researchers have replaced blood gas-derived partial pressure of oxygen values with oxygen saturation (SpO 2 ) obtained from pulse oximetry. This noninvasive index called oxygen saturation index (OSI) is found to be useful in neonates. Studies in pediatric population are lacking. In this prospective study on mechanically ventilated children, both OI and OSI were determined and compared against alveolar-arterial oxygen difference (AaDO 2 ). A total of 29 children were studied. Both OSI and OI had good correlation of 0.787 and 0.792 with AaDO 2 , respectively. OSI of 7.3 and 9.4 had good sensitivity and specificity for AaDO 2 cutoffs of 344 and 498, which represents moderate and severe respiratory illness, respectively. The correlation coefficients of both OSI and OI are similar against AaDO 2 . OSI can be used instead of OI for constant monitoring of children on mechanical ventilation. Arterial blood gas analysis and calculation of OI can be reserved for situations where SpO 2 measurement is unreliable.

Noninvasive Surrogate for Physiologic Dead Space Using the Carbon Dioxide Ventilatory Equivalent: Testing in a Single-Center Cohort, 2017-2023

OBJECTIVES

We sought to evaluate the association between the carbon dioxide (co2) ventilatory equivalent (VEqco2 = minute ventilation/volume of co2 produced per min), a marker of dead space that does not require a blood gas measurement, and mortality risk. We compared the strength of this association to that of physiologic dead space fraction (VD/Vt = [Paco2-mixed-expired Pco2]/Paco2) as well as to other commonly used markers of dead space (i.e., the end-tidal alveolar dead space fraction [AVDSf = (Paco2-end-tidal Pco2)/Paco2], and ventilatory ratio [VR = (minute ventilation × Paco2)/(age-adjusted predicted minute ventilation × 37.5)]).

DESIGN

Retrospective cohort data, 2017-2023.

SETTING

Quaternary PICU.

PATIENTS

One hundred thirty-one children with acute respiratory distress syndrome.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All dead space markers were calculated at the same 1-minute timepoint for each patient within the first 72 hours of using invasive mechanical ventilation. The 131 children had a median (interquartile range, IQR) age of 5.8 (IQR 1.4, 12.6) years, oxygenation index (OI) of 7.5 (IQR 4.6, 14.3), VD/Vt of 0.47 (IQR 0.38, 0.61), and mortality was 17.6% (23/131). Higher VEqco2 (p = 0.003), VD/Vt (p = 0.002), and VR (p = 0.013) were all associated with greater odds of mortality in multivariable models adjusting for OI, immunosuppressive comorbidity, and overall severity of illness. We failed to identify an association between AVDSf and mortality in the multivariable modeling. Similarly, we also failed to identify an association between OI and mortality after controlling for any dead space marker in the modeling. For the 28-day ventilator-free days outcome, we failed to identify an association between VD/Vt and the dead space markers in multivariable modeling, although OI was significant.

CONCLUSIONS

VEqco2 performs similarly to VD/Vt and other surrogate dead space markers, is independently associated with mortality risk, and may be a reasonable noninvasive surrogate for VD/Vt.

Inflammatory and tissue injury marker dynamics in pediatric acute respiratory distress syndrome

BACKGROUNDThe molecular signature of pediatric acute respiratory distress syndrome (ARDS) is poorly described, and the degree to which hyperinflammation or specific tissue injury contributes to outcomes is unknown. Therefore, we profiled inflammation and tissue injury dynamics over the first 7 days of ARDS, and associated specific biomarkers with mortality, persistent ARDS, and persistent multiple organ dysfunction syndrome (MODS).METHODSIn a single-center prospective cohort of intubated pediatric patients with ARDS, we collected plasma on days 0, 3, and 7. Nineteen biomarkers reflecting inflammation, tissue injury, and damage-associated molecular patterns (DAMPs) were measured. We assessed the relationship between biomarkers and trajectories with mortality, persistent ARDS, or persistent MODS using multivariable mixed effect models.RESULTSIn 279 patients (64 [23%] nonsurvivors), hyperinflammatory cytokines, tissue injury markers, and DAMPs were higher in nonsurvivors. Survivors and nonsurvivors showed different biomarker trajectories. IL-1α, soluble tumor necrosis factor receptor 1, angiopoietin 2 (ANG2), and surfactant protein D increased in nonsurvivors, while DAMPs remained persistently elevated. ANG2 and procollagen type III N-terminal peptide were associated with persistent ARDS, whereas multiple cytokines, tissue injury markers, and DAMPs were associated with persistent MODS. Corticosteroid use did not impact the association of biomarker levels or trajectory with mortality.CONCLUSIONSPediatric ARDS survivors and nonsurvivors had distinct biomarker trajectories, with cytokines, endothelial and alveolar epithelial injury, and DAMPs elevated in nonsurvivors. Mortality markers overlapped with markers associated with persistent MODS, rather than persistent ARDS.FUNDINGNIH (K23HL-136688, R01-HL148054).

Severe pediatric COVID-19: a review from the clinical and immunopathophysiological perspectives

BACKGROUND

Coronavirus disease 2019 (COVID-19) tends to have mild presentations in children. However, severe and critical cases do arise in the pediatric population with debilitating systemic impacts and can be fatal at times, meriting further attention from clinicians. Meanwhile, the intricate interactions between the pathogen virulence factors and host defense mechanisms are believed to play indispensable roles in severe COVID-19 pathophysiology but remain incompletely understood.

DATA SOURCES

A comprehensive literature review was conducted for pertinent publications by reviewers independently using the PubMed, Embase, and Wanfang databases. Searched keywords included "COVID-19 in children", "severe pediatric COVID-19", and "critical illness in children with COVID-19".

RESULTS

Risks of developing severe COVID-19 in children escalate with increasing numbers of co-morbidities and an unvaccinated status. Acute respiratory distress stress and necrotizing pneumonia are prominent pulmonary manifestations, while various forms of cardiovascular and neurological involvement may also be seen. Multiple immunological processes are implicated in the host response to COVID-19 including the type I interferon and inflammasome pathways, whose dysregulation in severe and critical diseases translates into adverse clinical manifestations. Multisystem inflammatory syndrome in children (MIS-C), a potentially life-threatening immune-mediated condition chronologically associated with COVID-19 exposure, denotes another scientific and clinical conundrum that exemplifies the complexity of pediatric immunity. Despite the considerable dissimilarities between the pediatric and adult immune systems, clinical trials dedicated to children are lacking and current management recommendations are largely adapted from adult guidelines.

CONCLUSIONS

Severe pediatric COVID-19 can affect multiple organ systems. The dysregulated immune pathways in severe COVID-19 shape the disease course, epitomize the vast functional diversity of the pediatric immune system and highlight the immunophenotypical differences between children and adults. Consequently, further research may be warranted to adequately address them in pediatric-specific clinical practice guidelines.

Positive end-expiratory pressure in the pediatric intensive care unit

Application of positive end-expiratory pressure (PEEP) targeted towards improving oxygenation is one of the components of the ventilatory management of pediatric acute respiratory distress syndrome (PARDS). Low end-expiratory airway pressures cause repetitive opening and closure of unstable alveoli, leading to surfactant dysfunction and parenchymal shear injury. Consequently, there is less lung volume available for tidal ventilation when there are atelectatic lung regions. This will increase lung strain in aerated lung areas to which the tidal volume is preferentially distributed. Pediatric critical care practitioners tend to use low levels of PEEP and inherently accept higher FiO2, but these practices may negatively affect patient outcome. The Pediatric Acute Lung Injury Consensus Conference (PALICC) suggests that PEEP should be titrated to oxygenation/oxygen delivery, hemodynamics, and compliance measured under static conditions as compared to other clinical parameters or any of these parameters in isolation in patients with PARDS, while limiting plateau pressure and/or driving pressure limits.

Decrease in lipid metabolic indexes in infants with neonatal respiratory distress syndrome

Incomplete pulmonary function and insufficient production of pulmonary surfactant in premature infants may affect alveolar relaxation, inducing neonatal respiratory distress syndrome (NRDS). The present study was a retrospective comparison of lipid metabolism indexes and clinic information between NRDS and non-NRDS infants. Data on general information, pregnancy, clinical symptoms, family history as well as plasma biochemical and lipid metabolic indexes were retrospectively collected and statistically analyzed from 79 patients with NRDS and 44 non-NRDS infants. Infants in the NRDS group showed lower body weight (2,055 vs. 3,225 g) and gestation age (33.39 vs. 38.53 weeks) than those in the non-NRDS group (P<0.05). Baseline information was corrected by the inverse probability of treatment weighting (IPTW) analysis. The weighted adjusted median age was the same in both groups and there was no significant difference between two groups in birth weight. The IPTW analysis revealed that the levels of plasma triglyceride (TG), total cholesterol, low-density lipoprotein, free triiodothyronine, free thyroxine, glucose, calcium (Ca2+) and phosphorus in the NRDS infants were significantly lower compared with those in the non-NRDS infants. Additionally, NRDS infants had significantly higher incidence rates of pneumonia, sepsis, brain injury infection, preterm birth, patent foramen ovale, patent ductus arteriosus and premature rupture of membranes compared with the non-NRDS infants (P<0.05). Multivariate logistic analysis showed that TG and Ca2+ were risk factors associated with NRDS (P<0.05). Infants with NRDS have significantly lower levels of plasma lipid indexes. The results of the present study provide data to guide the clinical management of NRDS.

Mechanical power and normalized mechanical power in pediatric acute respiratory distress syndrome

Background

Mechanical power (MP) refers to the energy transmitted over time to the respiratory system and serves as a unifying determinant of ventilator-induced lung injury. MP normalization is required to account for developmental changes in children. We sought to examine the relationship between mechanical energy (MEBW), MP normalized to body weight (MPBW), and MP normalized to respiratory compliance (MPCRS) concerning the severity and outcomes of pediatric acute respiratory distress syndrome (pARDS).

Method

In this retrospective study, children aged 1 month to 18 years diagnosed with pARDS who underwent pressure-control ventilation for at least 24 h between January 2017 and September 2020 were enrolled. We calculated MP using Becher's equation. Multivariable logistic regression analysis adjusted for age, pediatric organ dysfunction score, and oxygenation index (OI) was performed to determine the independent association of MP and its derivatives 24 h after diagnosing pARDS with 28-day mortality. The association was also studied for 28 ventilator-free days (VFD-28) and the severity of pARDS in terms of OI.

Results

Out of 246 admitted with pARDS, 185 were eligible, with an overall mortality of 43.7%. Non-survivors exhibited higher severity of illness, as evidenced by higher values of MP, MPBW, and MEBW. Multivariable logistic regression analysis showed that only MEBW but not MP, MPBW, or MPCRS at 24 h was independently associated with mortality [adjusted OR: 1.072 (1.002-1.147), p = 0.044]. However, after adjusting for the type of pARDS, MEBW was not independently associated with mortality [adjusted OR: 1.061 (0.992-1.136), p = 0.085]. After adjusting for malnutrition, only MP at 24 h was found to be independently associated. Only MPCRS at 1-4 and 24 h but not MP, MPBW, or MEBW at 24 h of diagnosing pARDS was significantly correlated with VFD-28.

Conclusions

Normalization of MP is better related to outcomes and severity of pARDS than non-normalized MP. Malnutrition can be a significant confounding factor in resource-limited settings.

Correlation and Prediction of Oxygen Index from Oxygen Saturation Index in Neonates with Acute Respiratory Failure

OBJECTIVE

The aim of this article was to evaluate the correlation between the oxygen index (OI) and the oxygen saturation index (OSI, measured by pulse oximetry and noninvasively) in neonates with acute respiratory failure and to predict the OI from the OSI.

STUDY DESIGN

A retrospective cohort study was conducted in neonates requiring invasive mechanical ventilation who had arterial blood gas between 2018 and 2019 at a neonatal intensive care unit. The correlation between OI and OSI was analyzed by using the Pearson correlation coefficient.

RESULTS

A total of 636 measurements from 68 neonates (35 preterm and 33 terms) were recruited into the study. There was a strong correlation between the OI and the OSI (r = 0.90) in all neonates. The correlation between the OI and the OSI in persistent pulmonary hypertension of the newborn, congenital cyanotic heart disease, and other causes of respiratory failure also showed a strong correlation (r = 0.88, 0.93, and 0.88, respectively). The correlation was strong in neonates with an oxygen saturation less than 85% (r = 0.88), those with oxygen saturation ranging from 85 to 95% (r = 0.87), and also in preterm and term infants (gestational age < 28, 28 - 34, 34 - 36, and ≥37 weeks, r = 0.87, 0.92, 0.89, and 0.90, respectively). There were strong accuracy measures of the OI for OI cutoffs of 5, 10, 15, and 20 (area under the curve > 0.85). The equation relating the OI and OSI was represented by: OI = (2.3 × OSI) - 4.

CONCLUSION

The OSI has a strong correlation with the OI, is a reliable assessor of the severity of respiratory failure in neonates without arterial sampling, and has high accuracy when the OI is less than 40.

KEY POINTS

· OSI is calculated as (FiO2 × mean airway pressure × 100)/SpO2.. · OSI is as effective tool as OI for assessing the severity of pediatric acute respiratory distress syndrome.. · OSI has a strong correlation with OI in neonatal respiratory failure..

Comparison of 16 Pediatric Acute Respiratory Distress Syndrome-Associated Plasma Biomarkers With Changing Lung Injury Severity

OBJECTIVES

Pediatric acute respiratory distress syndrome (PARDS) is a source of substantial morbidity and mortality in the PICU, and different plasma biomarkers have identified different PARDS and ARDS subgroups. We have a poor understanding of how these biomarkers change over time and with changing lung injuries. We sought to determine how biomarker levels change over PARDS course, whether they are correlated, and whether they are different in critically ill non-PARDS patients.

DESIGN

Two-center prospective observational study.

SETTING

Two quaternary care academic children's hospitals.

PATIENTS

Subjects under 18 years of age admitted to the PICU who were intubated and met the Second Pediatric Acute Lung Injury Consensus Conference-2 PARDS diagnostic criteria and nonintubated critically ill subjects without apparent lung disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma samples were obtained on study days 1, 3, 7, and 14. The levels of 16 biomarkers were measured using a fluorometric bead-based assay. Compared with non-PARDS subjects, on day 1 PARDS subjects had increased concentrations of tumor necrosis factor-alpha, interleukin (IL)-8, interferon-γ, IL17, granzyme B, soluble intercellular adhesion molecule-1 (sICAM1), surfactant protein D, and IL18 but reduced matrix metalloproteinase 9 (MMP-9) concentrations (all p < 0.05). Day 1 biomarker concentrations and PARDS severity were not correlated. Over PARDS course, changes in 11 of the 16 biomarkers positively correlated with changing lung injury with sICAM1 ( R = 0.69, p = 2.2 × 10 -16 ) having the strongest correlation. By Spearman rank correlation of biomarker concentrations in PARDS subjects, we identified two patterns. One had elevations of plasminogen activator inhibitor-1, MMP-9, and myeloperoxidase, and the other had higher inflammatory cytokines.

CONCLUSIONS

sICAM1 had the strongest positive correlation with worsening lung injury across all study time points suggesting that it is perhaps the most biologically relevant of the 16 analytes. There was no correlation between biomarker concentration on day 1 and day 1 PARDS severity; however, changes in most biomarkers over time positively correlated with changing lung injury. Finally, in day 1 samples, 7 of the 16 biomarkers were not significantly different between PARDS and critically ill non-PARDS subjects. These data highlight the difficulty of using plasma biomarkers to identify organ-specific pathology in critically ill patients.

Categorizing Acute Respiratory Distress Syndrome with Different Severities by Oxygen Saturation Index

The oxygen saturation index (OSI), defined by FIO2/SpO2 multiplied by the mean airway pressure, has been reported to exceed the Berlin definition in predicting the mortality of acute respiratory distress syndrome (ARDS). The OSI has served as an alternative to the Berlin definition in categorizing pediatric ARDS. However, the use of the OSI for the stratification of adult ARDS has not been reported. A total of 379 invasively ventilated adult ARDS patients were retrospectively studied. The ARDS patients were classified into three groups by their incidence rate of mortality: mild (OSI < 14.69), moderate (14.69 < OSI < 23.08) and severe (OSI > 23.08). OSI-based categorization was highly correlated with the Berlin definition by a Kendall's tau of 0.578 (p < 0.001). The Kaplan-Meier curves of the three OSI-based groups were significantly different (p < 0.001). By the Berlin definition, the hazard ratio for 28-day mortality was 0.58 (0.33-1.05) and 0.95 (0.55-1.67) for the moderate and severe groups, respectively (compared to the mild group). In contrast, the corresponding hazard ratio was 1.01 (0.69-1.47) and 2.39 (1.71-3.35) for the moderate and severe groups defined by the OSI. By multivariate analysis, OSI-based severe ARDS was independently associated with 28-D or 90-D mortality. In conclusion, we report the first OSI-based stratification for adult ARDS and find that it serves well as an alternative to the 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.

Assessment of the Clinical Course of Human Rhinovirus/Enterovirus Infections in Pediatric Intensive Care

BACKGROUND

This study aims to evaluate the clinical course of human rhinovirus/enterovirus (HRV/EV) infections in the pediatric intensive care unit.

METHODS

The study was conducted as a multicenter, prospective observational study from September 2022 to December 2022. Cases with positive polymerase chain reaction testing for HRV/EV of nasopharyngeal swab samples within the first 24 hours of pediatric intensive care unit admission were recorded. There were 2 groups: 1-24 months and >24 months.

RESULTS

A total of 75 cases (39 male) were included in the study. The median age for all cases was 21 months. The highest polymerase chain reaction positivity rates were observed in October (37.33%). Among the cases, 32 (42.67%) presented with bronchopneumonia/pneumonia, 24 (32%) presented with acute bronchiolitis/bronchitis and 7 (9.33%) presented with sepsis/septic shock. The frequency of pediatric acute respiratory distress syndrome was found to be 6.67%. In the age group of 1-24 months, mean lymphocyte and liver enzyme levels were higher, while in the age group of >24 months, mean hemoglobin and mean kidney function test levels were higher ( P ≤ 0.05). Continuous oxygen therapy was provided to 65.3% of the cases, noninvasive ventilation to 33.3%, high-flow nasal cannula-oxygen therapy to 32% and invasive mechanical ventilation to 16%.

CONCLUSIONS

HRV/EV infections primarily affect the respiratory system and generally exhibit a clinical course with low mortality rates (1, 1.3%). In cases with underlying chronic diseases, more severe clinical conditions such as pediatric acute respiratory distress syndrome and septic shock may occur.

Surfactant status assessment and personalized therapy for surfactant deficiency or dysfunction

Surfactant is a pivotal neonatal drug used both for respiratory distress syndrome due to surfactant deficiency and for more complex surfactant dysfunctions (such as in case of neonatal acute respiratory distress syndrome). Despite its importance, indications for surfactant therapy are often based on oversimplified criteria. Lung biology and modern monitoring provide several diagnostic tools to assess the patient surfactant status and they can be used for a personalized surfactant therapy. This is desirable to improve the efficacy of surfactant treatment and reduce associated costs and side effects. In this review we will discuss these diagnostic tools from a pathophysiological and multi-disciplinary perspective, focusing on the quantitative or qualitative surfactant assays, lung mechanics or aeration measurements, and gas exchange metrics. Their biological and technical characteristics are described with practical information for clinicians. Finally, available evidence-based data are reviewed, and the diagnostic accuracy of the different tools is compared. Lung ultrasound seems the most suitable tool for assessing the surfactant status, while some other promising tests require further research and/or development.

Opportunity for invasive mechanical ventilation in NRDS: a retrospective cohort study in China

PURPOSE

Mechanical ventilation, as a critical breathing support, plays a critical role in the treatment of neonatal respiratory distress syndrome (NRDS). We aim to describe the clinical characteristics of NRDS and give suggestions about when to start mechanical ventilation.

METHODS

We conducted a retrospective cohort study, enrolling 95 neonates between December 2016 and October 2021. Diagnosis of NRDS was according to the Berlin definition. Spearman's and ROC analysis was used to determine the variables correlated with hospital stay and optimal opportunity for mechanical ventilation.

RESULTS

Ninety-five subjects with NRDS were included. Lower PaO₂ and higher PaCO₂ in arterial blood gas prompt longer discharge time after mechanical ventilation and total in-hospital stay (p < .05), in which significant correlations were identified in Spearman's analysis. ROC analysis illustrated that mechanical ventilation starting when PaO₂ was 52.5 mmHg contributed to the shortest discharge time and in-hospital stay. PaCO₂ of 45.4 mmHg was another optimal cut-off value for the initiation of mechanical ventilation with an AUC of 0.636 (sensitivity 91.5%, specificity 29.2%, p = .022).

CONCLUSION

PaO₂ and PaCO₂ were significantly correlated with discharge time and in-hospital stays. When PaO₂ was reduced to 52.5 mmHg or PaCO₂ increased to 45.5 mmHg, mechanical ventilation was strongly recommended.

Dual Delivery of Tetramethylpyrazine and miR-194-5p Using Soft Mesoporous Organosilica Nanoparticles for Acute Lung Injury Therapy

Background

The respiratory system is intensely damaged by acute lung injury (ALI). The anti-inflammatory effects of tetramethylpyrazine (TMP) against ALI have been confirmed, but it exhibits a short half-life. miR-194-5p could directly target Rac1, but the internalization rate of miRNA cells was low.

Purpose

To explore the potential of the soft mesoporous organic silica nanoplatform (NPs) as carriers for delivery of TMP and miR-194-5p through the tail vein.

Methods

NPs@TMP and NPs@PEI@miR-194-5p were added to the HUVEC cell-lines, in vitro, to observe the cell uptake and cytotoxic effects. In vivo experiments were conducted by injecting fluorescently labeled NPs through the tail vein and tracking distribution. Therapeutic and toxic side-effects were analyzed systemically.

Results

In vitro study exhibited that NPs have no toxic effect on HUVECs within the experimental parameters and have excellent cellular uptake. The IVIS Spectrum Imaging System shows that NPs accumulate mainly in the lungs. NPs@TMP treatment can improved oxidative stress and inflammation levels in ALI mice and inhibited the TLR4/NLRP3/caspase 1 pathway. NPs@PEI@miR-194-5p can inhibit the Rac1/ZO-1/occludin pathway and improved endothelial cell permeability in ALI mice. The co-treatment of NPs@TMP and NPs@PEI@miR-194-5p can significantly improved the survival rates of the mice, reduced pulmonary capillary permeability and improved pathological injury in ALI mice.

Innovation

This study combined traditional Chinese medicine, bioinformatics, cellular molecular biology and nanobiomedicine to study the pathogenesis and treatment of ALI. The rate of cellular internalization was improved by changing the shape and hardness of nanoparticles. NPs@TMP and NPs@PEI@miR-194-5p combined application can significantly improve the survival condition and pathological injury of mice.

Conclusion

NPs loaded with TMP and miR-194-5p showed a greater therapeutic effect in ALI mice.

Development and validation of a predictive model for early diagnosis of neonatal acute respiratory distress syndrome based on the Montreux definition

Objective

Based on the Montreux definition, we aim to develop and validate a predictive model for the early diagnosis of neonatal acute respiratory distress syndrome (ARDS).

Methods

A retrospective analysis of clinical data on 198 neonates with respiratory distress from January 2018 to January 2022 was conducted. Neonates meeting Montreux definition were classified as ARDS group (n = 79), while the rest were non-ARDS group (n = 119). Univariate analysis identified indicators for neonatal ARDS, followed by logistic regression to construct a predictive model for early diagnosis. The ability of predictors and models to predict neonatal ARDS was evaluated using area under the curve (AUC), and model performance was estimated through bootstrap resampling.

Results

Maternal prenatal fever, abnormal fetal heart beat, meconium-stained amniotic fluid (MSAF), white blood cell (WBC), absolute neutrophil count (ANC), neutrophil percentage (NE%), platelet count (PLT), C-reactive protein (CRP), procalcitonin (PCT), creatine kinase (CK), activated partial thromboplastin time (APTT), serum calcium (Ca) and sodium (Na)exhibited significant differences between the ARDS group and the non-ARDS group (P < 0.05). MSAF (OR=5.037; 95% CI: 1.523-16.657; P < 0.05), ANC (OR = 1.324; 95% CI: 1.172-1.495; P < 0.05), PLT (OR = 0.979; 95% CI: 0.971-0.986; P < 0.05), Ca (OR = 0.020; 95% CI: 0.004-0.088; P < 0.05) emerged as independent risk factors for the development of ARDS. The respective AUC values for MSAF, ANC, PLT, Ca, and the combined prediction models were 0.606, 0.691, 0.808, 0.761 and 0.931. Internal validation showed that the C-index for the model was 0.931.

Conclusions

Early application of the model combining MSAF, ANC, PLT and Ca may have a good predictive effect on the early diagnosis of neonatal ARDS.

Interesting effects of interleukins and immune cells on acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a medical condition characterized by widespread inflammation in the lungs with consequent proportional loss of gas exchange function. ARDS is linked with severe pulmonary or systemic infection. Several factors, including secretory cytokines, immune cells, and lung epithelial and endothelial cells, play a role in the development and progression of this disease. The present study is based on Pubmed database information (1987-2022) using the words "Acute respiratory distress syndrome", "Interleukin", "Cytokines" and "Immune cells". Cytokines and immune cells play an important role in this disease, with particular emphasis on the balance between pro-inflammatory and anti-inflammatory factors. Neutrophils are one of several important mediators of Inflammation, lung tissue destruction, and malfunction during ARDS. Some immune cells, such as macrophages and eosinophils, play a dual role in releasing inflammatory mediators, recruitment inflammatory cells and the progression of ARDS, or releasing anti-inflammatory mediators, clearing the lung of inflammatory cells, and helping to improve the disease. Different interleukins play a role in the development or inhibition of ARDS by helping to activate various signaling pathways, helping to secrete other inflammatory or anti-inflammatory interleukins, and playing a role in the production and balance between immune cells involved in ARDS. As a result, immune cells and, inflammatory cytokines, especially interleukins play an important role in the pathogenesis of this disease Therefore, understanding the relevant mechanisms will help in the proper diagnosis and treatment of this disease.

The perinatal period should be considered in neonatal acute respiratory distress syndrome: comparison of the Montreux definition vs. the second pediatric acute lung injury consensus conference definition

Background

The recently developed Montreux definition for neonatal acute respiratory distress syndrome (ARDS) partially differs from the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2) definition. Here, we compare the Montreux and PALICC-2 definitions regarding morbidity, mortality, and prognosis of neonatal cases of ARDS in order to evaluate which definition is more appropriate for newborns.

Methods

Neonates admitted to our neonatal intensive care unit between 1 January 2018 and 30 September 2019 who met the Montreux or PALICC-2 definition of neonatal ARDS were retrospectively analyzed (n = 472). One comparison was made between application of the Montreux and PALICC-2 definitions to neonates outside the perinatal period (> 7 d after birth). A second comparison was made between a diagnosis of neonatal ARDS within (≤ 7 d of birth) and outside (> 7 d after birth) the perinatal period using the Montreux definition.

Results

No significant differences in morbidity, mortality, severity, therapies, or prognosis were observed between neonates in the extra perinatal group according to the Montreux and PALICC-2 definitions. However, epidemiology, clinical course, and prognosis of neonatal ARDS within the perinatal period did differ from those outside the perinatal period according to the Montreux definition.

Conclusion

Neonates with ARDS within the perinatal period have unique triggers, epidemiology, clinical course, and prognosis, yet a similar pathobiology pattern, to neonates at other ages. Therefore, it may be essential to consider the perinatal period when defining neonatal ARDS.

Effect of different ventilation methods combined with pulmonary surfactant on neonatal acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome precipitates is widespread pulmonary injury in impacted individuals, the neonatal respiratory distress syndrome (NRDS), primarily observed in preterm infants, represents a prevalent critical condition in neonatal clinical settings.

AIM

To investigate the clinical efficacy of various ventilation strategies combined with pulmonary surfactant (PS) therapy in the treatment of NRDS.

METHODS

A total of 20 neonates diagnosed with respiratory distress syndrome, admitted between May 2021 and June 2022, were randomly assigned to either a research group or a control group. Neonates in the research group received treatment involving high-frequency oscillatory ventilation (HFOV) in conjunction with PS. In contrast, neonates in the control group were administered either controlled mechanical ventilation or synchronous intermittent mandatory ventilation, combined with PS. Arterial blood samples from the neonates in both groups were collected before treatment, as well as 6 h, 12 h, 24 h, and 48 h post-treatment. These samples underwent blood gas analysis, with measurements taken for pH value, partial pressures of oxygen (O2) and carbon dioxide. Concurrently, data was collected on the duration of ventilator use, length of hospitalization time, O2 treatment time, treatment outcomes, and complications of the ventilator.

RESULTS

From 6-48 h post-treatment, both groups demonstrated significant improvements in arterial blood pH and oxygen partial pressure, along with a significant decrease in carbon dioxide partial pressure compared to pre-treatment values (P < 0.05). Although these changes progressed over time, there were no significant differences between the two groups (P > 0.05). However, the research group had significantly lower X-ray scores, shorter hospitalization time, and less time on O2 therapy compared to the control group (P < 0.05). Mortality rates were similar between the two groups (P > 0.05), but the research group had a significantly lower incidence of complications (P < 0.05).

CONCLUSION

The integration of HFOV combine with PS has proven to effectively expedite the treatment duration, decrease the occurrence of complications, and secure the therapeutic efficacy in managing NRDS.

Noninvasive Ventilation for Pediatric Acute Respiratory Distress Syndrome: Experience From the 2016/2017 Pediatric Acute Respiratory Distress Syndrome Incidence and Epidemiology Prospective Cohort Study

OBJECTIVES

The worldwide practice and impact of noninvasive ventilation (NIV) in pediatric acute respiratory distress syndrome (PARDS) is unknown. We sought to describe NIV use and associated clinical outcomes in PARDS.

DESIGN

Planned ancillary study to the 2016/2017 prospective Pediatric Acute Respiratory Distress Syndrome Incidence and Epidemiology study.

SETTING

One hundred five international PICUs.

PATIENTS

Patients with newly diagnosed PARDS admitted during 10 study weeks.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Children were categorized by their respiratory support at PARDS diagnosis into NIV or invasive mechanical ventilation (IMV) groups. Of 708 subjects with PARDS, 160 patients (23%) received NIV at PARDS diagnosis (NIV group). NIV failure rate (defined as tracheal intubation or death) was 84 of 160 patients (53%). Higher nonrespiratory pediatric logistic organ dysfunction (PELOD-2) score, Pa o2 /F io2 was less than 100 at PARDS diagnosis, immunosuppression, and male sex were independently associated with NIV failure. NIV failure was 100% among patients with nonrespiratory PELOD-2 score greater than 2, Pa o2 /F io2 less than 100, and immunosuppression all present. Among patients with Pa o2 /F io2 greater than 100, children in the NIV group had shorter total duration of NIV and IMV, than the IMV at initial diagnosis group. We failed to identify associations between NIV use and PICU survival in a multivariable Cox regression analysis (hazard ratio 1.04 [95% CI, 0.61-1.80]) or mortality in a propensity score matched analysis ( p = 0.369).

CONCLUSIONS

Use of NIV at PARDS diagnosis was associated with shorter exposure to IMV in children with mild to moderate hypoxemia. Even though risk of NIV failure was high in some children, we failed to identify greater hazard of mortality in these patients.

Predictors of Failure of Noninvasive Ventilation in Critically Ill Children

Noninvasive ventilation (NIV) is a common modality employed to treat acute respiratory failure. Most data guiding its use is extrapolated from adult studies. We sought to identify clinical predictors associated with failure of NIV, defined as requiring intubation. This single-center retrospective observational study included children admitted to pediatric intensive care unit (PICU) between July 2014 and June 2016 treated with NIV, excluding postextubation. A total of 148 patients was included. Twenty-seven (18%) failed NIV. There was no difference between the two groups with regard to age, gender, comorbidities, or etiology of acute respiratory failure. Those that failed had higher admission pediatric risk of mortality ( p  = 0.01) and pediatric logistic organ dysfunction ( p  = 0.002) scores and higher fraction of inspired oxygen (FiO 2 ; p  = 0.009) at NIV initiation. Failure was associated with lack of improvement in tachypnea. At 6 hours of NIV, the failure group had worsening tachypnea with a median increase in respiratory rate of 8%, while the success group had a median reduction of 18% ( p  = 0.06). Multivariable Cox's proportional hazard models revealed FiO 2 at initiation and worsening respiratory rate at 1- and 6-hour significant risks for failure of NIV. Failure was associated with a significantly longer PICU length of stay (success [2.8 days interquartile range (IQR): 1.7, 5.5] vs. failure [10.6 days IQR: 5.6, 13.2], p  < 0.001). NIV can be successfully employed to treat acute respiratory failure in pediatric patients. There should be heightened concern for NIV failure in hypoxemic patients whose tachypnea is unresponsive to NIV. A trend toward improvement should be closely monitored.

CNP-miR146a Decreases Inflammation in Murine Acute Infectious Lung Injury

Acute respiratory distress syndrome (ARDS) has approximately 40% in-hospital mortality, and treatment is limited to supportive care. Pneumonia is the underlying etiology in many cases with unrestrained inflammation central to the pathophysiology. We have previously shown that CNP-miR146a, a radical scavenging cerium oxide nanoparticle (CNP) conjugated to the anti-inflammatory microRNA(miR)-146a, reduces bleomycin- and endotoxin-induced acute lung injury (ALI) by decreasing inflammation. We therefore hypothesized that CNP-miR146a would decrease inflammation in murine infectious ALI. Mice were injured with intratracheal (IT) MRSA or saline followed by treatment with IT CNP-miR146a or saline control. Twenty-four hours post-infection, bronchoalveolar lavage fluid (BALF) and whole lungs were analyzed for various markers of inflammation. Compared to controls, MRSA infection significantly increased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1β; p < 0.05), BALF proinflammatory cytokines (IL-6, IL-8, TNFα, IL-1β; p < 0.01), and inflammatory cell infiltrate (p = 0.03). CNP-miR146a treatment significantly decreased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1β; p < 0.05), bronchoalveolar proinflammatory protein leak (IL-6, IL-8, TNFα; p < 0.05), and inflammatory infiltrate (p = 0.01). CNP-miR146a decreases inflammation and improves alveolar-capillary barrier integrity in the MRSA-infected lung and has significant promise as a potential therapeutic for ARDS.

ESICM guidelines on acute respiratory distress syndrome: definition, phenotyping and respiratory support strategies

The aim of these guidelines is to update the 2017 clinical practice guideline (CPG) of the European Society of Intensive Care Medicine (ESICM). The scope of this CPG is limited to adult patients and to non-pharmacological respiratory support strategies across different aspects of acute respiratory distress syndrome (ARDS), including ARDS due to coronavirus disease 2019 (COVID-19). These guidelines were formulated by an international panel of clinical experts, one methodologist and patients' representatives on behalf of the ESICM. The review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence and grade recommendations and the quality of reporting of each study based on the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) network guidelines. The CPG addressed 21 questions and formulates 21 recommendations on the following domains: (1) definition; (2) phenotyping, and respiratory support strategies including (3) high-flow nasal cannula oxygen (HFNO); (4) non-invasive ventilation (NIV); (5) tidal volume setting; (6) positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM); (7) prone positioning; (8) neuromuscular blockade, and (9) extracorporeal life support (ECLS). In addition, the CPG includes expert opinion on clinical practice and identifies the areas of future research.

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.

RNA Sequencing Analysis of CD4+ T Cells Exposed to Airway Fluid From Children With Pediatric Acute Respiratory Distress Syndrome

CD4⁺ T cells contribute to lung inflammation in acute respiratory distress syndrome. The CD4⁺ T-cell response in pediatric acute respiratory distress syndrome (PARDS) is unknown.

OBJECTIVES

To identify differentially expressed genes and networks using a novel transcriptomic reporter assay with donor CD4⁺ T cells exposed to the airway fluid of intubated children with mild versus severe PARDS.

DESIGN

In vitro pilot study.

SETTING

Laboratory-based study using human airway fluid samples admitted to a 36-bed university-affiliated pediatric intensive care unit.

PATIENTS/SUBJECTS

Seven children with severe PARDS, nine children with mild PARDS, and four intubated children without lung injury as controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We performed bulk RNA sequencing using a transcriptomic reporter assay of CD4⁺ T cells exposed to airway fluid from intubated children to discover gene networks differentiating severe from mild PARDS. We found that innate immunity pathways, type I (α and β), and type II (γ) interferon response and cytokine/chemokine signaling are downregulated in CD4⁺ T cells exposed to airway fluid from intubated children with severe PARDS compared with those with mild PARDS.

CONCLUSIONS

We identified gene networks important to the PARDS airway immune response using bulk RNA sequencing from a novel CD4⁺ T-cell reporter assay that exposed CD4⁺ T cells to airway fluid from intubated children with severe and mild PARDS. These pathways will help drive mechanistic investigations into PARDS. Validation of our findings using this transcriptomic reporter assay strategy is needed.

International Consensus Recommendation Guidelines for Subcutaneous Infusions of Hydration and Medication in Adults: An e-Delphi Consensus Study

Infusion of fluids and medications is traditionally performed intravenously. However, venous depletion in patients has led to the quest for vessel health preservation. A safe, effective, acceptable, and efficient alternative is the subcutaneous route. A lack of organizational policies may contribute to the slow uptake of this practice. This modified e-Delphi (electronic) study aimed to derive international consensus on practice recommendations for subcutaneous infusions of fluids and medications. A panel of 11 international clinicians, with expertise in subcutaneous infusion research and/or clinical practice, rated and edited subcutaneous infusion practice recommendations from evidence, clinical practice guidelines, and clinical expertise within an Assessment, Best Practice, and Competency (ABC) domain guideline model. The ABC Model for Subcutaneous Infusion Therapy provides a systematic guideline of 42 practice recommendations for the safe delivery of subcutaneous infusions of fluids and medications in the adult population in all care settings. These consensus recommendations provide a guideline for health care providers, organizations, and policy makers to optimize use of the subcutaneous access route.

Elevated Diaphragmatic Tonic Activity in PICU Patients: Age-Specific Definitions, Prevalence, and Associations

OBJECTIVES

Tonic diaphragmatic activity (tonic Edi, i.e., sustained diaphragm activation throughout expiration) reflects diaphragmatic effort to defend end-expiratory lung volumes. Detection of such elevated tonic Edi may be useful in identifying patients who need increased positive end-expiratory pressure. We aimed to: 1) identify age-specific definitions for elevated tonic Edi in ventilated PICU patients and 2) describe the prevalence and factors associated with sustained episodes of high tonic Edi.

DESIGN

Retrospective study using a high-resolution database.

SETTING

Single-center tertiary PICU.

PATIENTS

Four hundred thirty-one children admitted between 2015 and 2020 with continuous Edi monitoring.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We characterized our definition of tonic Edi using data from the recovery phase of respiratory illness (i.e., final 3 hr of Edi monitoring, excluding patients with significant persistent disease or with diaphragm pathology). High tonic Edi was defined as population data exceeding the 97.5th percentile, which for infants younger than 1 year was greater than 3.2 μV and for older children as greater than 1.9 μV. These thresholds were then used to identify patients with episodes of sustained elevated tonic Edi in the first 48 hours of ventilation (acute phase). Overall, 62 of 200 (31%) of intubated patients and 138 of 222 (62%) of patients on noninvasive ventilation (NIV) had at least one episode of high tonic Edi. These episodes were independently associated with the diagnosis of bronchiolitis (intubated patients: adjusted odds [aOR], 2.79 [95% CI, 1.12-7.11]); NIV patients: aOR, 2.71 [1.24-6.0]). There was also an association with tachypnea and, in NIV patients, more severe hypoxemia.

CONCLUSIONS

Our proposed definition of elevated tonic Edi quantifies abnormal diaphragmatic activity during expiration. Such a definition may help clinicians to identify those patients using abnormal effort to defend end-expiratory lung volume. In our experience, high tonic Edi episodes are frequent, especially during NIV and in patients with bronchiolitis.

Stratifying Severity of Acute Respiratory Failure Severity in Cyanotic Congenital Heart Disease

Hypoxemia is used to stratify severity in acute respiratory failure (ARF) but is less useful in cyanotic congenital heart disease (CCHD) due to an inability to differentiate hypoxemia from lung injury versus cardiac shunting. Therefore, we aimed to determine whether variables related to respiratory mechanics were associated with outcomes to assist in stratifying ARF severity in pediatric CCHD. We performed a retrospective cohort study from a single cardiac intensive care unit enrolling children with CCHD with ARF requiring mechanical ventilation between 2011 and 2019. Time-averaged ventilator settings and oxygenation data in the first 24 h of ARF were screened for association with the primary outcome of 28-day mortality. Of 344 eligible patients, peak inspiratory pressure (PIP) and driving pressure (ΔP) were selected as candidate variables to stratify ARF severity. PIP (OR 1.10, 95% CI 1.02-1.19) and ΔP (1.11, 95% CI 1.01-1.24) were associated with higher mortality and fewer ventilator-free days (VFDs) at 28 days after adjusting for age, severity of cardiac history, and FiO₂. A three-level (mild, moderate, severe) severity stratification was established for both PIP (≤ 20, 21-29, ≥ 30) and ΔP (≤ 16, 17-24, ≥ 25), showing increasing mortality (both P < 0.01), decreasing VFDs and increasing ventilator days in survivors (all P < 0.05) across increasing pressures. Overall, we found that higher PIP and ΔP were associated with mortality and duration of ventilation across a three-level severity stratification system in pediatric CCHD with ARF, providing a practical method to prognosticate in subjects with multifactorial etiologies for hypoxemia.

The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study

BACKGROUND

The end-tidal alveolar dead space fraction (AVDSf = [PaCO₂-P_ETCO₂]/PaCO₂) is a metric used to estimate alveolar dead space. Higher AVDSf on the first day of mechanical ventilation is associated with mortality and fewer ventilator-free days. It is not clear if AVDSf is associated with length of ventilation in survivors, how AVDSf performs for risk stratification beyond the first day of ventilation, or whether AVDSf adds predictive value to oxygenation (oxygenation index [OI]) or severity of illness (Pediatric Risk of Mortality [PRISM III]) markers.

METHODS

Retrospective single-center observational cohort study of children and young adults receiving invasive mechanical ventilation. In those with arterial or capillary blood gases, AVDSf was calculated at the time of every blood gas for the first week of mechanical ventilation.

RESULTS

There were 2335 children and young adults (median age 5.8 years [IQR 1.2, 13.2]) enrolled with 8004 analyzed AVDSf values. Higher AVDSf was associated with mortality and longer length of ventilation in survivors throughout the first week of ventilation after controlling for OI and PRISM III. Higher OI was not associated with increased mortality until ≥ 48 h of ventilation after controlling for AVDSf and PRISM III. When using standardized variables, AVDSf effect estimates were generally higher than OI for mortality, whereas OI effect estimates were generally higher than AVDSf for the length of ventilation in survivors. An AVDSf > 0.3 was associated with a higher mortality than an AVDSf < 0.2 within each pediatric acute respiratory distress syndrome severity category. The maximum AVDSf within 12 h of intensive care unit admission demonstrated good risk stratification for mortality (AUC 0.768 [95% CI 0.732, 0.803]). AVDSf did not improve mortality risk stratification when added to PRISM III but did improve mortality risk stratification when added to the gas exchange components of PRISM III (minimum 12-h PaO₂ and maximum 12-h PCO₂) (p < 0.00001).

CONCLUSIONS

AVDSf is associated with mortality and length of ventilation in survivors throughout the first week of invasive mechanical ventilation. Some analyses suggest AVDSf may better stratify mortality risk than OI, whereas OI may better stratify risk for prolonged ventilation in survivors than AVDSf.

Understanding clinical and biological heterogeneity to advance precision medicine in paediatric acute respiratory distress syndrome

Paediatric acute respiratory distress syndrome (PARDS) is a heterogeneous clinical syndrome that is associated with high rates of mortality and long-term morbidity. Factors that distinguish PARDS from adult acute respiratory distress syndrome (ARDS) include changes in developmental stage and lung maturation with age, precipitating factors, and comorbidities. No specific treatment is available for PARDS and management is largely supportive, but methods to identify patients who would benefit from specific ventilation strategies or ancillary treatments, such as prone positioning, are needed. Understanding of the clinical and biological heterogeneity of PARDS, and of differences in clinical features and clinical course, pathobiology, response to treatment, and outcomes between PARDS and adult ARDS, will be key to the development of novel preventive and therapeutic strategies and a precision medicine approach to care. Studies in which clinical, biomarker, and transcriptomic data, as well as informatics, are used to unpack the biological and phenotypic heterogeneity of PARDS, and implementation of methods to better identify patients with PARDS, including methods to rapidly identify subphenotypes and endotypes at the point of care, will drive progress on the path to precision medicine.

Definition, Incidence, and Epidemiology of Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

In 2015, the Pediatric Acute Lung Injury Consensus Conference (PALICC) provided the first pediatric-specific definitions for acute respiratory distress syndrome (pediatric acute respiratory distress syndrome [PARDS]). These definitions have since been operationalized in cohort and interventional PARDS studies. As substantial data have accrued since 2015, we have an opportunity to assess the construct validity and utility of the initial PALICC definitions. Therefore, the Second PALICC (PALICC-2) brought together multiple PARDS experts and aimed to identify and summarize relevant evidence related to the definition and epidemiology of PARDS and create modifications to the definition of PARDS.

DATA SOURCES

MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

We included studies of subjects with PARDS, or at risk for PARDS, excluding studies pertaining primarily to adults except as specified for identifying age-specific cutoffs.

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development, and Evaluation approach was used to identify and summarize evidence and develop recommendations. A total of 97 studies were identified for full-text extraction addressing distinct aspects of the PARDS definition, including age, timing, imaging, oxygenation, modes of respiratory support, and specific coexisting conditions. Data were assessed in a Patient/Intervention/Comparator/Outcome format when possible, and formally summarized for effect size, risk, benefit, feasibility of implementation, and equity. A total of 17 consensus-based definition statements were made that update the definition of PARDS, as well as the related diagnoses of "Possible PARDS" and "At-Risk for PARDS." These statements are presented alongside a summary of the relevant epidemiology.

CONCLUSIONS

We present updated, data-informed consensus statements on the definition for PARDS and the related diagnoses of "Possible PARDS" and "At-Risk for PARDS."

Executive Summary of the Second International Guidelines for the Diagnosis and Management of Pediatric Acute Respiratory Distress Syndrome (PALICC-2)

OBJECTIVES

We sought to update our 2015 work in the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2) guidelines for the diagnosis and management of pediatric acute respiratory distress syndrome (PARDS), considering new evidence and topic areas that were not previously addressed.

DESIGN

International consensus conference series involving 52 multidisciplinary international content experts in PARDS and four methodology experts from 15 countries, using consensus conference methodology, and implementation science.

SETTING

Not applicable.

PATIENTS

Patients with or at risk for PARDS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eleven subgroups conducted systematic or scoping reviews addressing 11 topic areas: 1) definition, incidence, and epidemiology; 2) pathobiology, severity, and risk stratification; 3) ventilatory support; 4) pulmonary-specific ancillary treatment; 5) nonpulmonary treatment; 6) monitoring; 7) noninvasive respiratory support; 8) extracorporeal support; 9) morbidity and long-term outcomes; 10) clinical informatics and data science; and 11) resource-limited settings. The search included MEDLINE, EMBASE, and CINAHL Complete (EBSCOhost) and was updated in March 2022. Grading of Recommendations, Assessment, Development, and Evaluation methodology was used to summarize evidence and develop the recommendations, which were discussed and voted on by all PALICC-2 experts. There were 146 recommendations and statements, including: 34 recommendations for clinical practice; 112 consensus-based statements with 18 on PARDS definition, 55 on good practice, seven on policy, and 32 on research. All recommendations and statements had agreement greater than 80%.

CONCLUSIONS

PALICC-2 recommendations and consensus-based statements should facilitate the implementation and adherence to the best clinical practice in patients with PARDS. These results will also inform the development of future programs of research that are crucially needed to provide stronger evidence to guide the pediatric critical care teams managing these patients.

Clinical outcomes according to timing to invasive ventilation due to noninvasive ventilation failure in children

OBJECTIVE

Noninvasive ventilation (NIV) failure it has been associated to worst clinical outcomes due to a delay in intubation and initiation of invasive mechanical ventilation (IMV). There is a lack of evidence in pediatric patients regarding this topic. The objective was to deter-mine the association between duration of IMV and length of stay, with duration of NIV prior tointubation/IMV in pediatric patients.

DESIGN

A prospective cohort study since January 2015 to October 2019.

SETTING

A pediatric intensive care unit.

PATIENTS

Children under 15 years with acute respiratory failure who failed to noninvasive ventilation.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Demographic variables, pediatric index of mortality (PIM2), pediatric acute respiratory distress syndrome (PARDS) diagnosis, IMV and NIV duration, PICU LOS were registered and intrahospital mortality.

RESULTS

A total of 109 patients with a median (IQR) age of 7 (3-14) months were included. The main diagnosis was pneumonia (89.9%). PARDS was diagnosed in 37.6% of the sample. No association was found between NIV duration and duration of IMV after Kaplan-Meier analysis (Log rank P = .479). There was no significant difference between PICU LOS (P = .253) or hospital LOS (P = 0.669), when categorized by NIV duration before intubation. PARDS diagnosis was associated to an increased length of invasive ventilation (HR: 0.64 [95% IC: 0.42-0.99]).

CONCLUSIONS

No association was found between NIV duration prior to intubation and duration of invasive ventilation in critical pediatric patients with acute respiratory failure.

Monitoring in Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

Monitoring is essential to assess changes in the lung condition, to identify heart-lung interactions, and to personalize and improve respiratory support and adjuvant therapies in pediatric acute respiratory distress syndrome (PARDS). The objective of this article is to report the rationale of the revised recommendations/statements on monitoring from the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2).

DATA SOURCES

MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

We included studies focused on respiratory or cardiovascular monitoring of children less than 18 years old with a diagnosis of PARDS. We excluded studies focused on neonates.

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development and Evaluation approach was used to identify and summarize evidence and develop recommendations. We identified 342 studies for full-text review. Seventeen good practice statements were generated related to respiratory and cardiovascular monitoring. Four research statements were generated related to respiratory mechanics and imaging monitoring, hemodynamics monitoring, and extubation readiness monitoring.

CONCLUSIONS

PALICC-2 monitoring good practice and research statements were developed to improve the care of patients with PARDS and were based on new knowledge generated in recent years in patients with PARDS, specifically in topics of general monitoring, respiratory system mechanics, gas exchange, weaning considerations, lung imaging, and hemodynamic monitoring.

Impact of extracorporeal membrane oxygenation in immunocompetent children with severe adenovirus pneumonia

BACKGROUND

Severe adenovirus (Adv.) pneumonia can cause significant mortality in young children. There has been no worldwide consensus on the impact of extracorporeal membrane oxygenation (ECMO) in immunocompetent children with severe Adv. pneumonia. This study aimed to assess the impact of ECMO in immunocompetent children with severe Adv. pneumonia.

METHODS

This study evaluated the medical records of 168 hospitalized children with severe Adv. pneumonia at the Guangzhou Women and Children's Medical Center between 2019 and 2020.Nineteen patients in the ECMO group and 149 patients in the non-ECMO group were enrolled.

RESULTS

Between these two groups, there were no differences in host factors such as sex, age (all P > 0.05). Significant differences were observed in shortness of breath/increased work of breathing; cyanosis; seizures; tachycardia; the partial pressure of oxygen in arterial blood (PO₂); the ratio of PaO₂ to the fraction concentration of oxygen in inspired air (FiO₂; P/F); white blood cell, lymphocyte, monocytes, lactate dehydrogenase (LDH), serum albumin, and procalcitonin levels; and, pulmonary consolidation (all P < 0.05). There were significant differences in the parameters of mechanical ventilation (MV) therapy and complications such as respiratory failure, acute respiratory distress syndrome, septic shock, length of hospitalization, and death (all P < 0.05). The maximum axillary temperatures, respiratory rates, heart rates and LDH levels after receiving ECMO were significantly lower than those before ECMO (all P < 0.05). Additionally, SPO₂, PO₂, and P/F were significantly higher than those before ECMO (all P < 0.05). In MV therapy, FiO₂, PIP, and PEEP were significantly lower than those before ECMO (all P < 0.05).

CONCLUSIONS

In our study, the clinical conditions of the patients in the ECMO group were much more severe than those in the non-ECMO group. Our study showed that ECMO might be beneficial for the patients with severe Adv. pneumonia.

Clinical characteristics and outcomes in neonates with perinatal acute respiratory distress syndrome in China: A national, multicentre, cross-sectional study

BACKGROUND

Neonatal acute respiratory distress syndrome (NARDS) was defined in 2017 and the epidemiological data remain unknown. Our objective was to explore aetiological factors, clinical characteristics and outcomes in patients with perinatal NARDS.

METHODS

A multicentre, prospective, cross-sectional study was performed in 58 tertiary neonatal intensive care units in China from Jan 1, 2018 to June 30, 2019. Neonates diagnosed with NARDS were included. Primary outcomes were aetiological factors, clinical characteristics and outcomes. Binary logistic regression and multivariate cox proportional regression were performed to identify independent predictors for bronchopulmonary dysplasia (BPD) and/or death or single death. This study was registered with ClinicalTrials.Gov, NCT03311165.

FINDINGS

Among 70,013 admitted neonates, the incidence of NARDS was 1.44% (1005). The cumulative incidences were 65.6%, 86.7%, 94.1% within one, two and three days after birth. The median gestational age and birth weight were 36.4 weeks and 2700 g. Three main aetiological triggers included pneumonia (58.1%), asphyxia (24.3%) and early-onset sepsis (EOS) (21.3%). BPD and/or death was observed in 213 (21.2%) infants, consisting 104 (10.3%) BPD and 126 (12.6%) deaths. The numbers of mild, moderate and severe NARDS were 537 (53.4%), 286 (28.4%) and 182 (18.2%). Two or more doses of surfactant was associated with increased mortality as compared with one or less doses of surfactant (odds ratio [OR] 1.93, 95% confidence interval [CI] 1.20-3.10, P = 0.006). Similarity also appeared in the comparison between EOS and non-EOS triggers (OR 1.57, 95% CI 1.06-2.33, P = 0.023).

INTERPRETATION

NARDS incidence was 1.44% and the three main aetiologies were pneumonia, asphyxia and EOS. The cumulative incidences were 65.6%, 86.7%, and 94.1% within one, two and three days after birth. Our results suggested that two or more doses of surfactant increased mortality compared with one or less doses of surfactant.

FUNDING

The National Clinical Research Center of China and Clinical Medical Study Program of Children's Hospital of Chongqing Medical University (NCRC-2019-GP-13) and Natural Science Foundation of Chongqing (cstc2020jcyj-msxmX0197).

Clinical practice guidelines: management of severe bronchiolitis in infants under 12 months old admitted to a pediatric critical care unit

PURPOSE

We present guidelines for the management of infants under 12 months of age with severe bronchiolitis with the aim of creating a series of pragmatic recommendations for a patient subgroup that is poorly individualized in national and international guidelines.

METHODS

Twenty-five French-speaking experts, all members of the Groupe Francophone de Réanimation et Urgence Pédiatriques (French-speaking group of paediatric intensive and emergency care; GFRUP) (Algeria, Belgium, Canada, France, Switzerland), collaborated from 2021 to 2022 through teleconferences and face-to-face meetings. The guidelines cover five areas: (1) criteria for admission to a pediatric critical care unit, (2) environment and monitoring, (3) feeding and hydration, (4) ventilatory support and (5) adjuvant therapies. The questions were written in the Patient-Intervention-Comparison-Outcome (PICO) format. An extensive Anglophone and Francophone literature search indexed in the MEDLINE database via PubMed, Web of Science, Cochrane and Embase was performed using pre-established keywords. The texts were analyzed and classified according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. When this method did not apply, an expert opinion was given. Each of these recommendations was voted on by all the experts according to the Delphi methodology.

RESULTS

This group proposes 40 recommendations. The GRADE methodology could be applied for 17 of them (3 strong, 14 conditional) and an expert opinion was given for the remaining 23. All received strong approval during the first round of voting.

CONCLUSION

These guidelines cover the different aspects in the management of severe bronchiolitis in infants admitted to pediatric critical care units. Compared to the different ways to manage patients with severe bronchiolitis described in the literature, our original work proposes an overall less invasive approach in terms of monitoring and treatment.

Pleural and transpulmonary pressures to tailor protective ventilation in children

This review aims to: (1) describe the rationale of pleural (P_PL) and transpulmonary (P_L) pressure measurements in children during mechanical ventilation (MV); (2) discuss its usefulness and limitations as a guide for protective MV; (3) propose future directions for paediatric research. We conducted a scoping review on P_L in critically ill children using PubMed and Embase search engines. We included peer-reviewed studies using oesophageal (P_ES) and P_L measurements in the paediatric intensive care unit (PICU) published until September 2021, and excluded studies in neonates and patients treated with non-invasive ventilation. P_L corresponds to the difference between airway pressure and P_PL Oesophageal manometry allows measurement of P_ES, a good surrogate of P_PL, to estimate P_L directly at the bedside. Lung stress is the P_L, while strain corresponds to the lung deformation induced by the changing volume during insufflation. Lung stress and strain are the main determinants of MV-related injuries with P_L and P_PL being key components. P_L-targeted therapies allow tailoring of MV: (1) Positive end-expiratory pressure (PEEP) titration based on end-expiratory P_L (direct measurement) may be used to avoid lung collapse in the lung surrounding the oesophagus. The clinical benefit of such strategy has not been demonstrated yet. This approach should consider the degree of recruitable lung, and may be limited to patients in which PEEP is set to achieve an end-expiratory P_L value close to zero; (2) Protective ventilation based on end-inspiratory P_L (derived from the ratio of lung and respiratory system elastances), might be used to limit overdistention and volutrauma by targeting lung stress values < 20-25 cmH₂O; (3) P_PL may be set to target a physiological respiratory effort in order to avoid both self-induced lung injury and ventilator-induced diaphragm dysfunction; (4) P_PL or P_L measurements may contribute to a better understanding of cardiopulmonary interactions. The growing cardiorespiratory system makes children theoretically more susceptible to atelectrauma, myotrauma and right ventricle failure. In children with acute respiratory distress, P_PL and P_L measurements may help to characterise how changes in PEEP affect P_PL and potentially haemodynamics. In the PICU, P_PL measurement to estimate respiratory effort is useful during weaning and ventilator liberation. Finally, the use of P_PL tracings may improve the detection of patient ventilator asynchronies, which are frequent in children. Despite these numerous theoritcal benefits in children, P_ES measurement is rarely performed in routine paediatric practice. While the lack of robust clincal data partially explains this observation, important limitations of the existing methods to estimate P_PL in children, such as their invasiveness and technical limitations, associated with the lack of reference values for lung and chest wall elastances may also play a role. P_PL and P_L monitoring have numerous potential clinical applications in the PICU to tailor protective MV, but its usefulness is counterbalanced by technical limitations. Paediatric evidence seems currently too weak to consider oesophageal manometry as a routine respiratory monitoring. The development and validation of a noninvasive estimation of P_L and multimodal respiratory monitoring may be worth to be evaluated in the future.

Clinical characteristics and remission of nine cases with coronavirus disease 2019 infection in Zunyi, Southwest of China: A retrospective study

The outbreak of coronavirus disease 2019 (COVID-19) has become a rock-ribbed public pandemic and caused substantial health concerns worldwide. In addition to therapeutic strategies, the epidemiologic features and clinical characteristics of patients responded to COVID-19 infection are of equal importance. The study aims to systematically evaluate the clinical presentations and remission of cases with COVID-19 infection in Zunyi, Southwest of China, and to determine the similarities and variations for further clinical classification and comprehensive treatment. Herein, we conducted a retrospective study upon 9 patients in Zunyi, southwest of China, including 1 mild (LPA), 5 severe (SPA) and 3 critical (CPA) types of COVID-19 infection. In details, the demographic data, historical epidemiology, previous medical history, clinical symptoms and complications, laboratory examination, chest imaging, treatment and outcomes of the patients were throughout explored. The non-normal distribution of the data was conducted by utilizing the SPSS software, and significant statistical differences were identified when P < .05. By retrospective analysis of the 9 cases, we found there were multifaceted similarities and differences among them in clinical representation. The patients collectively showed negative for nucleic acid test (NAT) and favorable prognosis after receiving comprehensive therapy such as hormonotherapy, hemopruification, and antiviral administration as well as respiratory support. On the basis of the information, we systematically dissected the clinical features and outcomes of the enrolled patients with COVID-19 and the accompanied multiple syndromes, which would serve as new references for clinical classification and comprehensive treatment. Analysis of clinical characteristics and therapeutic effect of 9 cases of novel coronavirus pneumonia (COVID-19), ChiCTR2000031930. Registered April 15, 2020 (retrospective registration).

PRISM III Score Predicts Short-Term Outcome in Children with ARDS on Conventional and High-Frequency Oscillatory Ventilation

Therapeutic recommendations for pediatric acute respiratory distress syndrome (PARDS) include conventional (CMV) and rescue high-frequency oscillatory mode (HFOV) of mechanical ventilation (MV). The pediatric risk of mortality (PRISM) is a frequently used mortality score for critically ill patients. In search of methods to recognize those patients, we analyzed the PRISM III score as a potential predictor of the short-term outcome in MV subjects with PARDS. A retrospective five-year study of PARDS in children on MV was conducted in the Pediatric ICU. Seventy patients were divided into two groups (age group <1 year and age group 1−7 years). The PRISM III score was used to assess the 28-day outcome and possible development of complications. The most common causes of PARDS were pneumonia and sepsis. Male sex, malnourishment, sepsis, and shock were significant indicators of poor outcome. The PRISM III score values were significantly higher in those who died, as well as in subjects requiring HFOV. The score had a significant prognostic value for short-term mortality. There was no significant difference in outcome based on the comparison of two modes of ventilation. A significantly higher score was noted in subjects who developed sepsis and cardiovascular insufficiency. The PRISM III score is a fair outcome predictor during the 28-day follow-up in MV subjects with PARDS, regardless of the ventilation mode.

Evaluating IL-6 and IL-10 as rapid diagnostic tools for Gram-negative bacteria and as disease severity predictors in pediatric sepsis patients in the intensive care unit

Background

To explore the diagnostic performance of interleukin (IL)-6 and IL-10 in discriminating Gram bacteria types and predicting disease severity in intensive care unit (ICU)-hospitalized pediatric sepsis patients.

Method

We retrospectively collected Th1/Th2 cytokine profiles of 146 microbiologically documented sepsis patients. Patients were categorized into Gram-positive (G+) or Gram-negative (G-) sepsis groups, and cytokine levels were compared. Subgroup analysis was designed to eliminate the influence of other inflammatory responses on cytokine levels.

Results

After propensity score matching, 78 patients were matched and categorized according to Gram bacteria types. Compared with G+ sepsis, IL-6 and IL-10 were significantly elevated in G- sepsis (p < 0.05). Spearman test proved the linear correlation between IL-6 and IL-10 (r = 0.654, p < 0.001), and their combination indicators (ratio and differences) were effective in identifying G- sepsis. In the subgroup analysis, such cytokine elevation was significant regardless of primary infection site. However, for patients with progressively deteriorating organ function [new or progressive multiple organ dysfunction syndrome (NPMODS)], differences in IL-6 and IL-10 levels were less significant between G+ and G- sepsis. In the receiver operating characteristic (ROC) curves of the G- sepsis group, the area under the curve (AUC) value for IL-6 and IL-10 was 0.679 (95% CI 0.561-0.798) and 0.637 (95% CI 0.512-0.762), respectively. The optimal cutoff value for diagnosing G- sepsis was 76.77 pg/ml and 18.90 pg/ml, respectively. While for the NPMODS group, the AUC for IL-6 and IL-10 was 0.834 (95% CI 0.766-0.902) and 0.781 (95% CI 0.701-0.860), respectively.

Conclusion

IL-6 and IL-10 are comparably effective in discriminating G+/G- sepsis in pediatric intensive care unit (PICU) patients. The deteriorated organ function observed in ICU patients reveals that complex inflammatory responses might have contributed to the cytokine pattern observed in severe sepsis patients, therefore confounding the discriminating efficacy of Th1/Th2 cytokines in predicting Gram bacteria types.

Pulse oximetry for the diagnosis and management of acute respiratory distress syndrome

The diagnosis of acute respiratory distress syndrome (ARDS) traditionally requires calculation of the ratio of partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2) using arterial blood, which can be costly and is not possible in many resource-limited settings. By contrast, pulse oximetry is continuously available, accurate, inexpensive, and non-invasive. Pulse oximetry-based indices, such as the ratio of pulse-oximetric oxygen saturation to FiO2 (SpO2/FiO2), have been validated in clinical studies for the diagnosis and risk stratification of patients with ARDS. Limitations of the SpO2/FiO2 ratio include reduced accuracy in poor perfusion states or above oxygen saturations of 97%, and the potential for reduced accuracy in patients with darker skin pigmentation. Application of pulse oximetry to the diagnosis and management of ARDS, including formal adoption of the SpO2/FiO2 ratio as an alternative to PaO2/FiO2 to meet the diagnostic criterion for hypoxaemia in ARDS, could facilitate increased and earlier recognition of ARDS worldwide to advance both clinical practice and research.

State-of-the-art management of the acutely unwell child

Children make up around one-fifth of all emergency department visits in the USA and UK, with an increasing trend of emergency admissions requiring intensive care. Anaesthetists play a vital role in the management of paediatric emergencies contributing to stabilisation, emergency anaesthesia, transfers and non-technical skills that optimise team performance. From neonates to adolescents, paediatric patients have diverse physiology and present with a range of congenital and acquired pathologies that often differ from the adult population. With increasing centralisation of paediatric services, staff outside these centres have less exposure to caring for children, yet are often the first responders in managing these high stakes situations. Staying abreast of the latest evidence for managing complex low frequency emergencies is a challenge. This review focuses on recent evidence and pertinent clinical updates within the field. The challenges of maintaining skills and training are explored as well as novel advancements in care.