Objective: The objective was to assess the effects of pulse indicator continuous cardiac output catheterization on the management of critically ill patients and the alteration of therapy in intensive care units. Methods: One hundred thirty-two patients with primary physiological abnormalities of hypotension or hypoxemia were evaluated. Prior to catheterization, physicians were asked to complete a questionnaire that collected information regarding predictions of the ranges of several hemodynamic variables and plans for therapy. After catheterization, each chart was reviewed by a panel of intensive care attending physicians to determine the possibility of altering the therapy. Results: Overall correct classification of the key variables ranged from 46.0% to 65.4%. Catheterization results prompted alterations in therapy for 45.5% of patients. The fellows were less accurate in predicting hemodynamic values for patients whose diagnoses were unknown, and the primary abnormality was hypotension. There was significant difference in the physicians' abilities to predict the hemodynamics for the subgroups with and without acute myocardial infarction. When the patients were divided into 3 subgroups by Acute Physiology and Chronic Health Evaluation II and Sepsis-related Organ Failure Assessment scores, the fellows had the most difficulty predicting the variables of the moderately ill patients in the middle subgroup, which led to the greatest percentage of therapy alterations for this subgroup; and this difference was significant. Conclusions: The hemodynamic variables obtained from pulse indicator continuous cardiac output catheterization improved the accuracy of bedside evaluations and led to alterations in therapeutic plans, particularly among the moderately ill patients with hypotension or unknown diagnoses. (C) 2014 Elsevier Inc. All rights reserved.