ObjectiveTo demonstrate if daily Multiple Organ Dysfunction scoring could describe outcome groups in septic shock better than daily Acute Physiology and Chronic Health Evaluation (APACHE) II and Organ Failure scores.DesignA prospective cohort study.SettingA medical and surgical adult intensive care unit (ICU) at a tertiary referral center.Measurements and Main ResultsDaily data collection over a 14-month period was performed on 368 ICU patients, 39 of whom developed septic shock while in the ICU. These data were entered into a computer programmed to calculate APACHE II, Organ Failure, and Multiple Organ Dysfunction scores. The admission Multiple Organ Dysfunction scores for nonsurvivors and survivors of septic shock in the ICU was 6.5 +/- 2.7 and 6.6 +/- 2.8 (SD), respectively. These patients deteriorated due to the development of septic shock during their ICU stay resulting in a maximum Multiple Organ Dysfunction score of 12.2 +/- 3.7 in nonsurvivors and 9.4 +/- 2.7 in survivors (p < .05). The difference between the maximum and initial Multiple Organ Dysfunction scores (delta score) was also significantly greater in nonsurvivors than in survivors (5.6 +/- 4.7 vs. 2.8 +/- 3.0) (p < .05). There were no significant differences between the maximum and delta scores in the outcome groups using the APACHE II and Organ Failure scoring systems. These results were mirrored by 2.3 +/- 0.7 and 1.7 +/- 0.5 organ failures in nonsurvivors and survivors, respectively (p < .01). For all 368 patients, the initial and maximum Multiple Organ Dysfunction scores were 3.5 +/- 2.5 and 10.5 +/- 3.6, respectively.ConclusionMaximum and delta Multiple Organ Dysfunction scores mirrored organ dysfunction and could accurately describe the outcome groups, whereas daily APACHE II and Organ Failure scores could not. (Crit Care Med 1999;27:741-744)