Related Experiment Video
Updated: Jun 2, 2026

Invasive Hemodynamic Monitoring of Aortic and Pulmonary Artery Hemodynamics in a Large Animal Model of ARDS
Published on: November 26, 2018
Dynamic oxygenation subgroup bringing new insights in ARDS: more predictive of outcomes and response to PEEP than
Yu Bai1, Shengsong Chen2, Haopu Yang3
1National Center for Respiratory Medicine; State Key Laboratory of Respiratory Health and Multimorbidity; National Clinical Research Center for Respiratory Diseases; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences; Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, Beijing, China.
Background:
Acute respiratory distress syndrome (ARDS) is a rapidly evolving condition. Dynamic assessments using patient trajectories may provide novel insights into disease heterogeneity. The primary objective of this study was to develop and validate dynamic oxygenation subgroups of ARDS based on longitudinal arterial oxygen tension/fractional inspired oxygen (PaO2/FiO2) ratios from the day of ARDS diagnosis to day 3. The secondary objective was to determine whether these dynamic physiological subgroups are more effective in predicting patient outcomes and treatment response than the Berlin criteria-defined static oxygenation subgroups.
Methods:
We used group-based trajectory modelling to construct longitudinal oxygenation subgroups over the first 3 days following ARDS diagnosis, based on five ARDS databases. Additionally, we compared these longitudinal subgroups with static Berlin criteria-defined mild, moderate and severe subgroups in terms of clinical characteristics, outcomes and positive end-expiratory pressure (PEEP) responses.
Results:
A total of 814 and 2505 patients with ARDS were included in the training cohort (Chinese ARDS Database) and validation cohorts (FACTT, SAILS, ALVEOLI and MIMIC-IV), respectively. We derived three longitudinal oxygenation subgroups: group 1 (n=406, 49.88%), group 2 (n=302, 37.10%) and group 3 (n=106, 13.02%). The PaO2/FiO2 of the three subgroups exhibited the following trends over time: persistently low, gradually increasing and rapidly improving. The mortality differences across the three longitudinal subgroups (62.59% vs 35.79% vs 17.39%) were significantly greater than those in Berlin criteria-defined subgroups (57.53% vs 41.34% vs 32.18%; χ²=55.65 vs 13.45, p=0.001 for heterogeneity comparison). Additionally, treatment heterogeneity (high vs low PEEP) was more pronounced in longitudinal subgroups (interaction p=0.001) compared with Berlin subgroups (interaction p=0.72). The longitudinal subgroup exhibited variations in patient demographics, PaO2/FiO2 development trajectory and PEEP treatment response, compared with the subgroup defined by the Berlin criteria.
Conclusions:
We identified three longitudinal oxygenation subgroups of ARDS that were more predictive of prognosis and response to PEEP than the subgroups defined by static PaO2/FiO2 ratios in the ARDS Berlin criteria.
More Related Videos
Related Concept Videos
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...
Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:
Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue, improving...
Oxygen Delivering System II: Venturi Mask and Transtracheal Oxygen
Venturi Mask
The Venturi mask, named after the Venturi effect, is designed to deliver precise oxygen concentrations. It consists of a large tube with an oxygen inlet that narrows down, causing a pressure drop that pulls air in through adjustable side ports. The mask is a lightweight,...

