Nonpulmonary Treatments for Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

An overview of patient-ventilator asynchrony in children

INTRODUCTION

Mechanically ventilated children often have patient-ventilator asynchrony (PVA). When a ventilated patient has spontaneous effort, the ventilator attempts to synchronize with the patient, but PVA represents a mismatch between patient respiratory effort and ventilator delivered breaths.

AREAS COVERED

This review will focus on subtypes of patient ventilator asynchrony, methods to detect or measure PVA, risk factors for and characteristics of patients with PVA subtypes, potential clinical implications, treatment or prevention strategies, and future areas for research. Throughout this review, we will provide pediatric specific considerations.

EXPERT OPINION

PVA in pediatric patients supported by mechanical ventilation occurs frequently and is understudied. Pediatric patients have unique physiologic and pathophysiologic characteristics which affect PVA. While recognition of PVA and its subtypes is important for bedside clinicians, the clinical implications and risks versus benefits of treatment targeted at reducing PVA remain unknown. Future research should focus on harmonizing PVA terminology, refinement of automated detection technologies, determining which forms of PVA are harmful, and development of PVA-specific ventilator interventions.

Biomarker-Based Risk Stratification Tool in Pediatric Acute Respiratory Distress Syndrome: Single-Center, Longitudinal Validation in a 2014-2019 Cohort

OBJECTIVES

The Pediatric Acute Respiratory Distress Syndrome Biomarker Risk Model (PARDSEVERE) used age and three plasma biomarkers measured within 24 hours of pediatric acute respiratory distress syndrome (ARDS) onset to predict mortality in a pilot cohort of 152 patients. However, longitudinal performance of PARDSEVERE has not been evaluated, and it is unclear whether the risk model can be used to prognosticate after day 0. We, therefore, sought to determine the test characteristics of PARDSEVERE model and population over the first 7 days after ARDS onset.

DESIGN

Secondary unplanned post hoc analysis of data from a prospective observational cohort study carried out 2014-2019.

SETTING

University-affiliated PICU.

PATIENTS

Mechanically ventilated children with ARDS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between July 2014 and December 2019, 279 patients with ARDS had plasma collected at day 0, 266 at day 3 (11 nonsurvivors, two discharged between days 0 and 3), and 207 at day 7 (27 nonsurvivors, 45 discharged between days 3 and 7). The actual prevalence of mortality on days 0, 3, and 7, was 23% (64/279), 14% (38/266), and 13% (27/207), respectively. The PARDSEVERE risk model for mortality on days 0, 3, and 7 had area under the receiver operating characteristic curve (AUROC [95% CI]) of 0.76 (0.69-0.82), 0.68 (0.60-0.76), and 0.74 (0.65-0.83), respectively. The AUROC data translate into prevalence thresholds for the PARDSEVERE model for mortality (i.e., using the sensitivity and specificity values) of 37%, 27%, and 24% on days 0, 3, and 7, respectively. Negative predictive value (NPV) was high throughout (0.87-0.90 for all three-time points).

CONCLUSIONS

In this exploratory analysis of the PARDSEVERE model of mortality risk prediction in a population longitudinal series of data from days 0, 3, and 7 after ARDS diagnosis, the diagnostic performance is in the "acceptable" category. NPV was good. A major limitation is that actual mortality is far below the prevalence threshold for such testing. The model may, therefore, be more useful in cohorts with higher mortality rates (e.g., immunocompromised, other countries), and future enhancements to the model should be explored.

Association between Age and Mortality in Pediatric and Adult Acute Respiratory Distress Syndrome

Rationale: The epidemiology, management, and outcomes of acute respiratory distress syndrome (ARDS) differ between children and adults, with lower mortality rates in children despite comparable severity of hypoxemia. However, the relationship between age and mortality is unclear.Objective: We aimed to define the association between age and mortality in ARDS, hypothesizing that it would be nonlinear.Methods: We performed a retrospective cohort study using data from two pediatric ARDS observational cohorts (n = 1,236), multiple adult ARDS trials (n = 5,547), and an adult observational ARDS cohort (n = 1,079). We aligned all datasets to meet Berlin criteria. We performed unadjusted and adjusted logistic regression using fractional polynomials to assess the potentially nonlinear relationship between age and 90-day mortality, adjusting for sex, PaO2/FiO2, immunosuppressed status, year of study, and observational versus randomized controlled trial, treating each individual study as a fixed effect.Measurements and Main Results: There were 7,862 subjects with median ages of 4 years in the pediatric cohorts, 52 years in the adult trials, and 61 years in the adult observational cohort. Most subjects (43%) had moderate ARDS by Berlin criteria. Ninety-day mortality was 19% in the pediatric cohorts, 33% in the adult trials, and 67% in the adult observational cohort. We found a nonlinear relationship between age and mortality, with mortality risk increasing at an accelerating rate between 11 and 65 years of age, after which mortality risk increased more slowly.Conclusions: There was a nonlinear relationship between age and mortality in pediatric and adult ARDS.

Diagnostic, Management, and Research Considerations for Pediatric Acute Respiratory Distress Syndrome in Resource-Limited Settings: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

Diagnosis of pediatric acute respiratory distress syndrome (PARDS) in resource-limited settings (RLS) is challenging and remains poorly described. We conducted a review of the literature to optimize recognition of PARDS in RLS and to provide recommendations/statements for clinical practice and future research in these settings as part of 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 related to precipitating factors for PARDS, mechanical ventilation (MV), pulmonary and nonpulmonary ancillary treatments, and long-term outcomes in children who survive PARDS in RLS.

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. Seventy-seven studies were identified for full-text extraction. We were unable to identify any literature on which to base recommendations. We gained consensus on six clinical statements (good practice, definition, and policy) and five research statements. Clinicians should be aware of diseases and comorbidities, uncommon in most high-income settings, that predispose to the development of PARDS in RLS. Because of difficulties in recognizing PARDS and to avoid underdiagnosis, the PALICC-2 possible PARDS definition allows exclusion of imaging criteria when all other criteria are met, including noninvasive metrics of hypoxemia. The availability of MV support, regular MV training and education, as well as accessibility and costs of pulmonary and nonpulmonary ancillary therapies are other concerns related to management of PARDS in RLS. Data on long-term outcomes and feasibility of follow-up in PARDS survivors from RLS are also lacking.

CONCLUSIONS

To date, PARDS remains poorly described in RLS. Clinicians working in these settings should be aware of common precipitating factors for PARDS in their patients. Future studies utilizing the PALICC-2 definitions are urgently needed to describe the epidemiology, management, and outcomes of PARDS in RLS.

Methodology of the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

This article describes the methodology used for The Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2). The PALLIC-2 sought to develop evidence-based clinical recommendations and when evidence was lacking, expert-based consensus statements and research priorities for the diagnosis and management of pediatric acute respiratory distress syndrome (PARDS).

DATA SOURCES

Electronic searches were conducted using PubMed, Embase, and Cochrane Library (CENTRAL) databases from 2012 to March 2022.

STUDY SELECTION

Content was divided into 11 sections related to PARDS, with abstract and full text screening followed by data extraction for studies which met inclusion with no exclusion criteria.

DATA EXTRACTION

We used a standardized data extraction form to construct evidence tables, grade the evidence, and formulate recommendations or statements using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

DATA SYNTHESIS

This consensus conference was comprised of a multidisciplinary group of international experts in pediatric critical care, pulmonology, respiratory care, and implementation science which followed standards set by the Institute of Medicine, using the GRADE system and Research And Development/University of California, Los Angeles appropriateness method, modeled after PALICC 2015. The panel of 52 content and four methodology experts had several web-based meetings over the course of 2 years. We conducted seven systematic reviews and four scoping reviews to cover the 11 topic areas. Dissemination was via primary publication listing all statements and separate supplemental publications for each subtopic that include supporting arguments for each recommendation and statement.

CONCLUSIONS

A consensus conference of experts from around the world developed recommendations and consensus statements for the definition and management of PARDS and identified evidence gaps which need further research.