Daily Ards Research Analysis
Analyzed 8 papers and selected 3 impactful papers.
Summary
Analyzed 8 papers and selected 3 impactful articles.
Selected Articles
1. Defining the Resolution of Acute Respiratory Distress Syndrome: A Delphi Consensus Study.
Using a modified Delphi process, experts agreed that ARDS resolution requires sustained improvement in oxygenation (PaO2/FiO2 > 300 or SpO2/FiO2 > 315 for >24 hours) and normalization of respiratory support tailored to the prior maximum modality. This definition provides standardized criteria for trials and observational studies.
Impact: First consensus definition for ARDS resolution addresses a critical gap for outcome harmonization across studies and may refine clinical endpoints. It can enable consistent reporting and facilitate meta-analyses and benchmarking.
Clinical Implications: The criteria can guide de-escalation decisions and define endpoints for liberation from support, though clinical validation is needed before routine adoption.
Key Findings
- Consensus defined ARDS resolution as PaO2/FiO2 > 300 or SpO2/FiO2 > 315 sustained for >24 hours.
- Normalization of respiratory support was required, including PEEP ≤ 5 cm H2O and no adjunctive interventions if intubated, and no longer requiring CPAP/NIV, HFNC, or standard oxygen depending on prior maximal support.
- A priori 70% agreement threshold was met after three Delphi rounds with contributions from 16 of 19 experts in the final round.
Methodological Strengths
- Pre-specified Delphi methodology with a priori agreement threshold and iterative item refinement
- Operational definitions tailored to varying levels of respiratory support increase usability and reproducibility
Limitations
- Expert consensus without external validation or patient-level outcome testing
- Limited panel size may not capture all global practice variations
Future Directions: Validate the definition in diverse ARDS cohorts, assess predictive validity for clinical outcomes, and explore integration into trial endpoints and electronic health records.
OBJECTIVES: There are no established criteria to define the resolution of acute respiratory distress syndrome (ARDS). We aimed to develop an expert consensus definition of ARDS resolution. DESIGN: Modified Delphi consensus study with three iterative rounds. SETTING: Electronic surveys. SUBJECTS: A panel of 19 ARDS experts participated in the Delphi process. Experts were identified using prespecified criteria. INTERVENTIONS: The Delphi process was conducted over three rounds. Item generation was performed in round 1 with all panelists invited to suggest defining characteristics for resolution of ARDS with corresponding operational definitions, which were then voted on by the panel. Item refinement in rounds 2 and 3. Thresholds for agreement were specified a priori and set at 70%. MEASUREMENTS AND MAIN RESULTS: Nineteen panelists submitted complete responses to the first round with 16 panelists contributing to the final definition that met a priori consensus criteria after the third round questionnaire. The panel agreed on the following elements: 1) resolution of hypoxemia, defined as ratio of Pao2/Fio2 greater than 300 (or ratio of oxygen saturation to Fio2 > 315) for more than 24 hours and 2) normalization of level of respiratory support, defined as "if still intubated, this is for primarily nonrespiratory reasons (e.g. altered mental state, ICU-acquired weakness) and ventilatory assistance is minimal (i.e., positive end-expiratory pressure less than or equal to 5 cm H2O, and no adjunctive interventions); if maximal respiratory support was continuous positive airway pressure (CPAP) or noninvasive ventilation (NIV), then no longer requiring CPAP or NIV; if maximal respiratory support was oxygen via high-flow nasal cannula (HFNC), then no longer requiring HFNC; and if maximal respiratory support was standard oxygen, then longer receiving oxygen." CONCLUSIONS: A high level of consensus was achieved on criteria defining the resolution of ARDS. Future work is required to explore the epidemiology and performance characteristics of this definition.
2. Effects of High-Flow Nasal Cannula and Helmet Continuous Positive Airway Pressure in Acute Hypoxemic Respiratory Failure.
In mild-to-moderate AHRF, both HFNC and helmet CPAP decreased inspiratory effort and improved oxygenation versus conventional oxygen within 20 minutes. Helmet CPAP at 10 cm H2O did not confer additional effort reduction and increased mechanical power compared with HFNC or CPAP at 5 cm H2O.
Impact: Provides mechanistic evidence to optimize noninvasive support settings in AHRF, highlighting potential harm from excessive PEEP via increased mechanical power.
Clinical Implications: Supports preferential use of HFNC or helmet CPAP with moderate PEEP (e.g., 5 cm H2O) to reduce effort and improve gas exchange, while avoiding unnecessary escalation to higher PEEP that may increase lung stress.
Key Findings
- HFNC and helmet CPAP (5 or 10 cm H2O) reduced minute ventilation and inspiratory esophageal pressure swings compared with conventional oxygen (p < 0.001).
- Both modalities improved PaO2/FiO2 compared with conventional oxygen (p < 0.001).
- Helmet CPAP at 10 cm H2O worsened mechanical power compared with HFNC and helmet CPAP at 5 cm H2O.
Methodological Strengths
- Randomized order crossover design with within-subject comparisons
- Direct measurement of inspiratory effort using esophageal manometry and comprehensive physiologic endpoints
Limitations
- Short observation windows (20 minutes per condition) limit assessment of longer-term clinical outcomes
- Single-center study with modest sample size may limit generalizability
Future Directions: Test whether physiologic benefits translate into reduced intubation rates and improved outcomes in pragmatic multicenter trials; refine PEEP titration strategies using mechanical power targets.
HEADINGS: The effects of high-flow nasal cannula (HFNC) and continuous positive airway pressure (CPAP) in patients with acute hypoxemic respiratory failure (AHRF) on respiratory mechanics and inspiratory efforts are not entirely understood. OBJECTIVES: To compare the physiologic effects of HFNC and helmet CPAP with respect to conventional oxygen therapy (COT) in terms of respiratory mechanics, inspiratory effort, gas exchange, and hemodynamics during AHRF. DESIGN: Crossover study. SETTING: General surgical-medical ICU of San Paolo University Hospital, Milan, Italy. PATIENTS: Thirty-three adult patients with AHRF, defined as an Pao2 less than 60 mm Hg or an Pao2/Fio2 less than 300 with a positive end-expiratory pressure (PEEP) level greater than or equal to 5 cm H2O, along with an Paco2 less than 45 mm Hg. INTERVENTIONS: After support with COT, three types of respiratory support were applied in random order: HFNC with 60 L/min of flow and helmet CPAP with 5 or 10 cm H2O of PEEP. MEASUREMENTS AND MAIN RESULTS: Tidal volume, respiratory rate, inspiratory esophageal (ΔPes), and airway pressure swings were measured and an arterial blood gas analysis, along with hemodynamic data, was obtained after 20 minutes from the application of each respiratory support device. The application of HFNC and helmet CPAP at both 5 and 10 cm H2O of PEEP reduced minute ventilation (9.2 ± 3.2, 8.8 ± 2.3, and 9.3 ± 2.7 vs. 10.9 ± 3.3 L/min; p < 0.001) and ΔPes (-6.0 cm H2O [-7.8 to -4.0 cm H2O], -5.8 cm H2O [-7.2 to -4.5 cm H2O], and -5.9 cm H2O [-8.0 to -4.0 cm H2O] vs. -7.5 cm H2O [-10.8 to -6.5 cm H2O]; p < 0.001) while increasing Pao2/Fio2 (188 ± 57, 208 ± 62, and 213 ± 69 vs. 129 ± 32; p < 0.001) with respect to COT; the application of 10 cm H2O of PEEP with helmet CPAP did not reduce inspiratory effort indices or increased oxygenation, but worsened mechanical power compared with HFNC and helmet CPAP with 5 cm H2O of PEEP. CONCLUSIONS: In patients with mild and moderate AHRF, HFNC and helmet CPAP ameliorated minute ventilation and respiratory rate, reduced inspiratory effort, and increased oxygenation compared with COT; the application of 10 cm H2O of PEEP during CPAP support worsened mechanical power.
3. Outcome of Severe Adenoviral Respiratory Infection Supported With Extracorporeal Membrane Oxygenation: A Multicenter PICU Study From Colombia (2018-2022).
Among 205 pediatric ECMO cases for severe viral respiratory infections, adenovirus etiology was not associated with worse 28-day survival. Mortality risk increased with pre-ECMO acidosis, high vasoactive-inotropic requirements, and delays >13 hours from meeting ECMO criteria to cannulation.
Impact: Identifies modifiable process-of-care factor (cannulation delay) alongside physiologic severity markers, guiding quality improvement and triage in pediatric severe respiratory failure requiring ECMO.
Clinical Implications: Prioritize timely ECMO cannulation once criteria are met, aggressively correct acidosis, and monitor patients with high VIS closely; anticipate bleeding risk in younger children and prolonged ECMO or CRRT.
Key Findings
- No difference in 28-day survival between adenovirus and other viral etiologies among pediatric ECMO patients (77.6% vs 73.6%; p = 0.513).
- Pre-ECMO risk factors for mortality: VIS > 15 (aOR 3.18), arterial pH < 7.2 (aOR 3.79), and delay >13 hours from meeting ECMO criteria to cannulation (aOR 4.04).
- Hemorrhagic complications occurred in 40% overall; higher odds with age <36 months, prior SARS-CoV-2 infection, ECMO >10 days, and concurrent CRRT.
Methodological Strengths
- Multicenter cohort across seven PICUs with a relatively large sample size for pediatric ECMO
- Adjusted analyses identifying independent risk factors with reported aORs and 95% CIs
Limitations
- Retrospective design with potential residual confounding and selection bias
- Conducted in a single country, which may limit generalizability to other health systems
Future Directions: Prospective validation of timing thresholds and integration into ECMO activation protocols; evaluate interventions to reduce cannulation delays and bleeding complications.
OBJECTIVES: To compare survival, clinical characteristics, complications, and duration of extracorporeal membrane oxygenation (ECMO) support in pediatric patients with severe adenoviral respiratory infections vs. those with other viral respiratory infections. DESIGN: Multicenter, retrospective observational study. SETTING: Seven PICUs in Colombia, South America. PATIENTS: Children 1 month to 18 years old who received ECMO support between January 2018 and December 2022. The primary outcome was survival in children with severe adenoviral infection requiring ECMO, compared with those with ECMO due to other viral respiratory infections. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 205 patients were included; 39% (80/205) had adenoviral infections and 61% (125/205) had other viral respiratory infections. We failed to find an association between the adenovirus group, vs. the nonadenovirus group, and 28-day survival (62/80 [77.6%] vs. 92/125 [73.6%]; p = 0.513). Independent pre-ECMO factors associated with greater odds (adjusted odds ratio [aOR], 95% CI) of mortality across both groups included Vasoactive-Inotropic Score (VIS > 15; aOR, 3.18 [95% CI, 1.08-7.45]), arterial pH less than 7.2 (aOR, 3.79 [95% CI, 1.75-5.52]), and time from meeting ECMO criteria to actual cannulation greater than 13 hours (aOR, 4.04 [95% CI, 1.72-7.21]). Hemorrhagic complications occurred in 81 of 205 (40%) of all patients, and CNS hemorrhage and cannulation site bleeding were the most common locations of bleeding. Greater odds of hemorrhagic complication were associated with age younger than 36 months, previous severe acute respiratory syndrome coronavirus 2 infection, ECMO duration greater than 10 days, and use of continuous renal replacement therapy during ECMO. CONCLUSIONS: In pediatric patients with severe adenoviral infections requiring ECMO support, compared with those with other viral infections requiring ECMO, we failed to identify associated greater odds of mortality. Key factors associated with greater odds of mortality included pre-ECMO acidosis, high VIS, and greater than 13-hour delay in initiating ECMO support.