Acute Respiratory Distress Syndrome

Abstract

Since its first description, the acute respiratory distress syndrome (ARDS) has been acknowledged to be a major clinical problem in respiratory medicine. From July 2015 to July 2016 almost 300 indexed articles were published on ARDS. This review summarises only eight of them as an arbitrary overview of clinical relevance: definition and epidemiology, risk factors, prevention and treatment. A strict application of definition criteria is crucial, but the diverse resource-setting scenarios foster geographic variability and contrasting outcome data. A large international multicentre prospective cohort study including 50 countries across five continents reported that ARDS is underdiagnosed, and there is potential for improvement in its management. Furthermore, epidemiological data from low-income countries suggest that a revision of the current definition of ARDS is needed in order to improve its recognition and global clinical outcome. In addition to the well-known risk-factors for ARDS, exposure to high ozone levels and low vitamin D plasma concentrations were found to be predisposing circumstances. Drug-based preventive strategies remain a major challenge, since two recent trials on aspirin and statins failed to reduce the incidence in atrisk patients. A new disease-modifying therapy is awaited: some recent studies promised to improve the prognosis of ARDS, but mortality and disabling complications are still high in survivors in intensive care. Definition and epidemiologySince its first description by ASHBAUGH et al. [1] in 1967, the acute respiratory distress syndrome (ARDS) has been widely recognised as a major clinical problem worldwide, carrying a high morbidity and mortality burden [2][3][4]. Although the recent Berlin definition [5] is probably much better than previous ones, there is still a high variability in both epidemiology and clinical outcomes in diverse healthcare settings [4]. In fact, the incidence of ARDS ranges from 1.5 cases per 100 000 [2] to nearly 79 cases per 100 000 [3], with European countries reporting a lower incidence than USA [6]. Moreover, studies from Brazil reported incidence rates ranging from 1.8 to 31 per 100 000 [7,8].Although the overall survival rate is improving [9, 10], there is a notable difference when considering in-hospital mortality over several observational studies [2][3][4][8][9][10][11]. This may be explained by differences in risk factors, availability of diagnostics, ability to recognise ARDS and some selection biases affecting clinical trials [12]. Recently, a large international observational study (the LUNG SAFE trial) evaluated the incidence of ARDS across 459 intensive care units (ICUs) in 50 countries [13]. To assess the clinical recognition of ARDS according to the latest definition, any patient inclusion into the trial was made through a computer algorithm following the Berlin criteria [5], and then compared to the diagnosis made by the attending physicians. Among 4499 patients who developed acute hypoxaemic respiratory failure, ARDS occurred in 10.4% of t...

High‐dose steroid therapy for acute respiratory distress syndrome lacking common risk factors: predictors of outcome

“…The inclusion criteria specified patients who: were 18 years of age and older; met the Berlin definition of ARDS1 excluding common risk factors; received i.v. MPPT (0.5–1 g/day) for 3 days; underwent chest computed tomography (CT) within 3 calendar days of MPPT; and whose laboratory profiles were analyzed within 24 h of the initiation of MPPT.…”

“…MPPT (0.5–1 g/day) for 3 days; underwent chest computed tomography (CT) within 3 calendar days of MPPT; and whose laboratory profiles were analyzed within 24 h of the initiation of MPPT. In this study, ARDS was diagnosed according to the Berlin definition based on the PaO 2 /F I O 2 (P/F) ratio with a positive end‐expiratory pressure or continuous positive airway pressure of ≥5 cmH 2 O 1. However, patients who did not receive positive‐pressure mechanical ventilation but who had a P/F ratio of ≤300 were included in the present study.…”

“…If the patient was not supported by a mechanical ventilator, the F I O 2 level was calculated as follows: oxygen flow (L/min) × 0.03 + 0.21 10. The common risk factors for ARDS were defined as aspiration, diffuse pulmonary infection, near‐drowning, toxic inhalation, lung contusion, non‐pulmonary sepsis, severe non‐thoracic trauma, pancreatitis, severe burns, non‐cardiogenic shock, drug overdose, hypertransfusion for emergency resuscitation, and cardiopulmonary bypass 1, 2…”

“…The acute respiratory distress syndrome (ARDS) is a life‐threatening inflammatory lung disease with a mortality rate of 40–50% 1, 2. Acute respiratory distress syndrome is defined as acute onset of hypoxemia and bilateral pulmonary infiltrates not attributed to cardiac failure or fluid overload with pulmonary or non‐pulmonary risk factors that trigger lung inflammation 1, 2.…”

“…Acute respiratory distress syndrome is defined as acute onset of hypoxemia and bilateral pulmonary infiltrates not attributed to cardiac failure or fluid overload with pulmonary or non‐pulmonary risk factors that trigger lung inflammation 1, 2. Diffuse alveolar damage (DAD), which is usually resistant to treatment, is the accepted histological hallmark of ARDS 1, 2…”