Temporal changes in the epidemiology, management, and outcome from acute respiratory distress syndrome in European intensive care units: a comparison of two large cohorts

Abstract

Background Mortality rates for patients with ARDS remain high. We assessed temporal changes in the epidemiology and management of ARDS patients requiring invasive mechanical ventilation in European ICUs. We also investigated the association between ventilatory settings and outcome in these patients. Methods This was a post hoc analysis of two cohorts of adult ICU patients admitted between May 1–15, 2002 (SOAP study, n = 3147), and May 8–18, 2012 (ICON audit, n = 4601 admitted to ICUs in the same 24 countries as the SOAP study). ARDS was defined retrospectively using the Berlin definitions. Values of tidal volume, PEEP, plateau pressure, and FiO2 corresponding to the most abnormal value of arterial PO2 were recorded prospectively every 24 h. In both studies, patients were followed for outcome until death, hospital discharge or for 60 days. Results The frequency of ARDS requiring mechanical ventilation during the ICU stay was similar in SOAP and ICON (327[10.4%] vs. 494[10.7%], p = 0.793). The diagnosis of ARDS was established at a median of 3 (IQ: 1–7) days after admission in SOAP and 2 (1–6) days in ICON. Within 24 h of diagnosis, ARDS was mild in 244 (29.7%), moderate in 388 (47.3%), and severe in 189 (23.0%) patients. In patients with ARDS, tidal volumes were lower in the later (ICON) than in the earlier (SOAP) cohort. Plateau and driving pressures were also lower in ICON than in SOAP. ICU (134[41.1%] vs 179[36.9%]) and hospital (151[46.2%] vs 212[44.4%]) mortality rates in patients with ARDS were similar in SOAP and ICON. High plateau pressure (> 29 cmH2O) and driving pressure (> 14 cmH2O) on the first day of mechanical ventilation but not tidal volume (> 8 ml/kg predicted body weight [PBW]) were independently associated with a higher risk of in-hospital death. Conclusion The frequency of and outcome from ARDS remained relatively stable between 2002 and 2012. Plateau pressure > 29 cmH2O and driving pressure > 14 cmH2O on the first day of mechanical ventilation but not tidal volume > 8 ml/kg PBW were independently associated with a higher risk of death. These data highlight the continued burden of ARDS and provide hypothesis-generating data for the design of future studies.

Personalized mechanical ventilation in acute respiratory distress syndrome

“…Driving pressure may also be used to set PEEP since the best compromise between overinflation and recruitment is determined at the lowest Δ P [ 17 ]. A study analyzing two randomized ARDS trials found that a decrease in Δ P was associated with lower mortality compared to increased Pa O2 /F i O2 [ 18 ]. Several concerns exist regarding PEEP titration according to Δ P including (1) depending on the V T used, the lowest Δ P may be achieved at different PEEP levels, (2) at higher C RS , compared to lower C RS , higher PEEP levels may achieve a lower Δ P , (3) the decrease in Δ P with PEEP may be associated with greater intratidal recruitment, (4) changes in chest wall compliance may affect the Δ P measurement, and (5) the presence of airway closure may confound the relationship between Δ P and PEEP.…”

Standardizing PaO2 for PaCO2 in P/F ratio predicts in-hospital mortality in acute respiratory failure due to Covid-19: A pilot prospective study

“…The ratio of arterial (PaO2) to inspired (FiO2) partial pressure of oxygen (P/F ratio), is currently utilized to assess the severity of respiratory failure in patients with ARDS [5] and correlates to mortality rate [6][7][8]. P/F ratio has been recently proposed as a prognostic marker in Covid-19 [9,10].…”

Comorbid Diseases, Decreased PaO2/FiO2 Ratio, Increased Ferritin, Decreased Liver and Kidney Function as Risk Factors for Mortality in COVID-19 Patients

“…[38]Other studies have also stated that the PaO2/FiO2 ratio is correlated with mortality, so the PaO2/FiO2 ratio is proposed as a prognostic marker in Covid-19. [4,6] In COVID-19, inflammation and edema in the alveoli are the main causes of hypoxemia in the early stages of the disease, so the P/F ratio is quite related to the severity of decreased diffusion which is characterized by hypoxemia and a decrease in the PaO2/FiO2 ratio. In the development of COVID-19 disease (consolidation phase), intrapulmonary shunt occurs and causes early arterial hypoxaemia which is mainly caused by ventilation/perfusion imbalance and persistent pulmonary blood flow to unventilated alveoli, and there can be a relative failure of pulmonary vasoconstriction.…”

“…[2,3]The ratio of partial pressure of oxygen (PaO2) to a fraction of inspired oxygen (FiO2) (P/F ratio), is currently used to assess the severity of respiratory failure in patients with ARDS and correlates with mortality. [2,4,5] The P/F ratio was recently proposed as a prognostic marker in COVID-19. [6] In one study from China with twenty cases of COVID-19, it was found that individuals with severe disease often presented with elevated serum ferritin levels, with statistically significant differences between the severe and mild categories.…”