Critical care lessons from severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS) is a new disease that caused large outbreaks in several countries in the first half of 2003, resulting in infection in more than 8000 people and more than 900 deaths. During that time, a large body of literature rapidly emerged describing the clinical disease, the etiologic viral agent, and management options. This paper reviews the current status of this knowledge base, with particular reference to the critically ill patient.

Case series of patients from Hong Kong, China, Singapore, and Toronto have characterized the disease with remarkable uniformity. A similarly consistent picture of the SARS patient with respiratory failure has emerged from studies from Toronto and Singapore. Worldwide collaboration led to the rapid identification and gene sequencing of the etiologic virus, SARS-CoV.

SARS is a predominantly respiratory illness, spread through droplets from respiratory secretions and possibly via a fecal-oral route. A small number of "super-spreaders" appear to have contributed to the rapid proliferation of the disease. Infection control precautions are an essential component of management. Approximately 20% of patients develop progressive pulmonary infiltrates and respiratory failure, and the mortality rate is as high as 10%. Treatment strategies with antiviral agents such as ribavirin have not clearly demonstrated a benefit, but high-dose corticosteroids appear to be beneficial in patients with progressive disease. The recent outbreaks highlighted the potential for this disease to overwhelm critical care resources, by the volume of patients and loss of healthcare workers to illness and quarantine.