Defining Acute Respiratory Distress Syndrome (Again): A Plea for Honesty

[Comparison of hospitalized patients with SARS-CoV-2 infection in two time periods of the pandemic]

OBJECTIVE

The aim of the investigation was to compare patients hospitalized with SARS-CoV-2 infection during 2020/2021 and 2022 with respect to the reason for hospitalization as well as severity of disease at admission, during follow-up and clinical outcomes.

METHODS

The data of all patients patients hospitalized with SARS-CoV-2 infection during the periods of interest were collected. Severity of disease at admission and during follow-up was compared in all patients who were hospitalized because of SARS-CoV-2 infection.

RESULTS

During the period of 2020 to 2021, overall n=1281 patients with SARS-CoV-2 infection were hospitalized as compared to n=580 in 2022. Of these, 90% and 42%, respectively, were admitted because of SARS-CoV-2 infection. The rates of nosocomial transmission increased from 5 to 18%. Severity of disease at admission and during follow-up was higher across all age groups in the first period. More patients were admitted to the ICU (25 versus 4%). Accordingly, hospital mortality was higher (17 versus 10%). Intubated patients had a high mortality of 74 and 80%, respectively, in both periods.

CONCLUSIONS

The severity at admission and during follow-up was much higher in the first period. In the second period, the burden of health care systems was only in part driven by disease severity but more by the need for isolation and nosocomial infections. Mortality of intubated patients was high.

Post-pandemic acute respiratory distress syndrome: A New Global Definition with extension to lower-resource regions

Acute respiratory distress syndrome (ARDS), first described in 1967, is characterized by acute respiratory failure causing profound hypoxemia, decreased pulmonary compliance, and bilateral CXR infiltrates. After several descriptions, the Berlin definition was adopted in 2012, which established three categories of severity according to hypoxemia (mild, moderate and severe), specified temporal aspects for diagnosis, and incorporated the use of non-invasive ventilation. The COVID-19 pandemic led to changes in ARDS management, focusing on continuous monitoring of oxygenation and on utilization of high-flow oxygen therapy and lung ultrasound. In 2021, a New Global Definition based on the Berlin definition of ARDS was proposed, which included a category for non-intubated patients, considered the use of SpO2, and established no particular requirement for oxygenation support in regions with limited resources. Although debates persist, the continuous evolution seeks to adapt to clinical and epidemiological needs, and to the search of personalized treatments.

ARDS: hidden perils of an overburdened diagnosis

A diagnosis of ARDS serves as a pretext for several perilous clinical practices. Clinical trials demonstrated that tidal volume 12 ml/kg increases patient mortality, but 6 ml/kg has not proven superior to 11 ml/kg or anything in between. Present guidelines recommend 4 ml/kg, which foments severe air hunger, leading to prescription of hazardous (yet ineffective) sedatives, narcotics and paralytic agents. Inappropriate lowering of tidal volume also fosters double triggering, which promotes alveolar overdistention and lung injury. Successive panels have devoted considerable energy to developing a more precise definition of ARDS to homogenize the recruitment of patients into clinical trials. Each of three pillars of the prevailing Berlin definition is extremely flimsy and the source of confusion and unscientific practices. For doctors at the bedside, none of the revisions have enhanced patient care over that using the original 1967 description of Ashbaugh and colleagues. Bedside doctors are better advised to diagnose ARDS on the basis of pattern recognition and instead concentrate their vigilance on resolving the numerous hidden dangers that follow inevitably once a diagnosis has been made.