[1] Univ Western Ontario, Dept Clin Neurol Sci, Program Crit Care, London, ON, Canada
[2] Univ Western Ontario, Dept Anesthesia & Perioperat Med, Program Crit Care, London, ON, Canada
[3] King Faisal Specialist Hosp & Res Ctr, Dept Med, Riyadh 11211, Saudi Arabia