After 24 hours he presented with persistent fever (39.0°C), dry cough and respiratory failure and was admitted to the intensive care unit (ICU). Vital signs were as follows: blood pressure 135/70 mm Hg; heart rate 50 beats per minute; respiratory rate 34 breaths per minute; oxygen saturation 88%, on 50% inspired oxygen. On physical examination rhonchi were detected in the lower lung fields.