<qa>  What is the primary endpoint of plasma and urine catecholamine levels?Secondary endpoints include plasma and urine catecholamine levels, heart rate and blood pressure variability, responses to autonomic cold pressor testing, assessments of coma, sedation, and agitation, sedative requirements, analgesic use, antipsychotic medication use, coma-free days, ventilator-free days, Intensive Care Unit ICU length of stay, and survival. Also, neuropsychological outcomes will be measured at ICU discharge, 3 months, and 12 months. 