Severe acute respiratory syndrome (SARS) is a newly recognized infectious
disease capable of causing severe respiratory failure.
To determine the epidemiological features, course, and outcomes of patients
with SARS-related critical illness.
Design, Setting, and Patients
Retrospective case series of 38 adult patients with SARS-related critical
illness admitted to 13 intensive care units (ICUs) in the Toronto area between
the onset of the outbreak and April 15, 2003. Data were collected daily during
the first 7 days in the ICUs, and patients were followed up for 28 days.
Main Outcome Measures
The primary outcome was mortality at 28 days after ICU admission. Secondary
outcomes included rate of SARS-related critical illness, number of tertiary
care ICUs and staff placed under quarantine, and number of health care workers
(HCWs) contracting SARS secondary to ICU-acquired transmission.
Of 196 patients with SARS, 38 (19%) became critically ill, 7 (18%) of
whom were HCWs. The median (interquartile range [IQR]) age of the 38 patients
was 57.4 (39.0-69.6) years. The median (IQR) duration between initial symptoms
and admission to the ICU was 8 (5-10) days. Twenty-nine (76%) required mechanical
ventilation and 10 of these (34%) experienced barotrauma. Mortality at 28
days was 13 (34%) of 38 patients and for those requiring mechanical ventilation,
mortality was 13 (45%) of 29. Six patients (16%) remained mechanically ventilated
at 28 days. Two of these patients had died by 8 weeks' follow-up. Patients
who died were more often older, had preexisting diabetes mellitus, and on
admission to hospital were more likely to have bilateral radiographic infiltrates.
Transmission of SARS in 6 study ICUs led to closure of 73 medical-surgical
ICU beds. In 2 university ICUs, 164 HCWs were quarantined and 16 (10%) developed
Critical illness was common among patients with SARS. Affected patients
had primarily single-organ respiratory failure, and half of mechanically ventilated
patients died. The SARS outbreak greatly strained regional critical care resources.