Contribution of arterial redox potential measurement to the care of critically ill patients.

175 arterial and 122 urinary samples from 20 patients admitted in ICU for organ system failure (OSF) were analysed. Besides arterial blood gases and lactate, electrolyte concentrations, pH, rH2 and specific resistance (R) in blood and urine were measured. Redox potential (E) and base excess were calculated from these data. Patients were defined as having MOSF if their organ systems met failure criteria during their ICU stay. Data were classified with corresponding number of OSF developed in the patients when samples were obtained. Acid-base balance or base excess alone could not be used to predict the severity of illness as assessed by increasing number of organ system failures. Significant elevations in blood lactate concentrations were observed only in patients with four, five or six OSF. A lack of correlation between blood lactate and severity of OSF indicates that blood lactate is not valid as a guide to ultimate outcome of the patients. Arterial redox potentials progressively decreased with increasing number of OSF, therefore, it can be stated that the serial measurements of arterial redox potential are useful in assessing the patient's status or predicting their ultimate outcome.