Simran Kaur ‘20

Acute respiratory distress syndrome (ARDS) is characterized by the build-up of fluid in the alveoli of the lungs, the main sites of gaseous exchange, causing a lack of oxygen in the body. ARDS is caused by sudden trauma to the lungs, and there currently is no pharmacological treatment for the condition. Researchers in the study sought to determine the efficacy of dexamethasone, an anti-inflammatory corticosteroid, as a possible treatment for ARDS. 

A randomised trial of 277 patients from various intensive care units diagnosed with acute onset of ARDS based on worsening respiratory symptoms following an initial clinical condition such as pneumonia was conducted. Patients were classified by PaO₂/FiO₂ levels, the ratio of arterial partial pressure to inspired oxygen, and were only enrolled in the study with levels below 30 mm Hg, the normal range being 35-45 mm Hg. Patients in the experimental group received an intravenous dose of 20 mg dexamethasone once daily in the first five days, and the dose was decreased 50% for the subsequent five days. All patients received simultaneous intubation, were extubated after 10 days, and then were placed on mechanical ventilation. The efficacy of dexamethasone in alleviating pulmonary symptoms was assessed by the number of the days the patient required mechanical ventilation after initial administration. 

Results showed a significantly greater amount of ventilation-free days in the dexamethasone days (12.3 vs 7.5). Mortality in the dexamethasone group was also significantly less than the control group (21% vs 36%), and patients in the group had lower sepsis rates. Although the study only used the number of ventilation-free days to assess the effects of dexamethasone, these results in combination with lowered mortality in the group demonstrates the possible therapeutic effects of dexamethasone as an early treatment in ARDS. One of the negative effects, however, is the increased occurrence of high blood sugar with the use of corticosteroids like dexamethasone. Nevertheless, future studies are necessary to determine the safety of this treatment for ARDS, because it could be the first treatment drug for the condition on the market. 

References:

1. J. Villar, et al., Dexamethasone Treatment for the Acute Respiratory Distress syndrome: a Multicentre, Randomised Controlled Trial. Lancet Respiratory Medicine, (2020). 
2. Image retrieved from: https://upload.wikimedia.org/wikipedia/commons/0/0f/Bronchial_anatomy.jpg