['To compare total plasma antioxidant capacity and selected individual antioxidants in patients with varying degrees of severity of sepsis.', 'A prospective, observational, consecutive case study.', 'A 16-bed intensive care unit (ICU) in a university teaching hospital.', 'None.', 'Forty-six healthy controls, ten ICU patients, nine patients with systemic inflammatory response syndrome (SIRS), 11 septic patients, and 14 septic shock patients. Plasma was obtained in healthy patients scheduled for minor surgery immediately before anesthesia and in ICU patients within 24 hrs of admittance to the unit or diagnosis of SIRS, sepsis, or septic shock.', 'Using the total peroxyl radical trapping method, we found plasma antioxidant capacity to be lower in septic patients but higher in septic shock patients, as compared with controls. Bilirubin was the greatest contributor to the increase with shock, followed by uric acid. Neopterin also correlated with the peroxyl radical trapping antioxidant parameter values.'] Is total plasma antioxidant capacity always decreased in sepsis?