health may be described as a dynamic state of well-being characterized by a potential, which satisfies the demands of a life commensurate with age, culture, and personal responsibility. Life based on a potential that does not fully meet the internal and external requirements for survival means disease. Conclusions: Not all features of the definition of life are needed to discuss human health. The description of health focuses on several other specific relationships and properties, such as the balance between resources and requirements of life, the double nature of the resources, and its orientation toward the future. Thus, both models are consistent with each other, yet their descriptions overlap only in part. http://dx.doi.org/10.1016/j.jcrc.2012.10.018 References [1] Macklem PT, Seely A. Towards a definition of life. Perspect Biol Med 2010;53:330-40. [2] Bircher J. Towards a dynamic definition of health and disease. Med Health Care Philos 2005;8:335-41 and www.psim.ch. Abstract 3 Temperature curve complexity estimated with Tsallis entropy is related with SOFA score of severity of illness in patients with sepsis and septic shock Vasilios Papaioannou a , Ioanna Chouvarda b , Nikos Maglaveras b , Ioannis Pneumatikos a a Democritus University of Thrace, Alexandroupolis Medical School, Xanthi, Greece b Aristotle University of Thessaloniki, Lab of Medical Informatics, Thesaloniki, Greece Objectives: Different studies estimating complexity of temperature curves in critically ill patients have found decreased entropy during severe stress. In this study, a nonextensive entropy measure, Tsallis entropy (TsEn), was undertaken to assess temperature complexity, in a cohort of septic patients and to predict severity of illness, estimated with Sequential Organ Failure Assessment Score (SOFA). Methods: Twenty-one patients were enrolled in the study. Thirteen had sepsis (group 1), and 8 had septic shock (group 2). All temperature curves were analyzed during the first 24 hours of an inflammatory state. A wavelet transformation was applied, decomposing the signal in different frequency components (scales) that have been found to reflect neurogenic and metabolic inputs upon temperature oscillations. Tsallis entropy of the whole signal, per different scales and frequency bands derived from wavelet transformation, was calculated. Statisti- cally significant differences of entropy features were tested between the 2 groups and correlated with SOFA. A regression model was built, after exhaustive regression and many bootstrapping repetitions, for predicting severity of illness. Finally, a Bland-Altman plot was used for estimating agreement between the 2 methods. Results: Patients from group 2 exhibited reduced TsEn values compared with group 1. Tsallis entropy measurements per different scales were proven to correlate with SOFA in the whole group of patients. The regression model included a triple combination of entropy features per high scales, indicating an association between clinical deterioration and reduced metabolic inputs upon temperature oscillations. The R 2 was 0.6171 (P = .0008), whereas bias (mean of differences between SOFA measured and SOFA predicted) was 0.0397; SD of bias was 2.0964, and 95% limits of agreement were 0.0397 ± 4.19. Moreover, Spearman correlation coefficient between model and measured SOFA was found to be 0.785 (P b .005). Conclusions: We suggest that reduced nonextensive TsEn values may reflect severity of illness in septic patients, capturing inherent thermoregulatory dynamics. http://dx.doi.org/10.1016/j.jcrc.2012.10.019 Abstract 4 Coefficient of variation of coarsely sampled heart rate predicts early vasopressor independence in early severe sepsis and septic shock Samuel Brown a,b , Quinn Tate c , Jason Jones d , Kathryn Kuttler a,b , Michael Lanspa a,b , Matthew Rondina a,b , Colin Grissom a,b , V.J. Mathews c a Pulmonary/Critical Care, Intermountain Medical Center, Murray, UT, USA b Pulmonary/Critical Care, University of Utah, Salt Lake City, UT, USA c Computer and Electrical Engineering, University of Utah, Salt Lake City, UT, USA d Research Division, Kaiser Permanente Southern California, Pasadena, CA, USA Objectives: Early resuscitation of severe sepsis and septic shock is important, but hemodynamic predictors of response to therapy and outcome are uncertain. We sought to determine whether variability in heart rate, measure at 30-second intervals, early in the course of severe sepsis and septic shock predicts successful resuscitation. Methods: We sampled heart rate every 30 seconds over the first 6 hours of ICU admission and calculated variability of those measurements. Primary outcome was vasopressor independence at 24 hours; secondary outcome was 28-day mortality. Results: We studied 165 patients. Of these, 97 (59%) achieved vasopressor independence at 24 hours. Overall 28-day mortality was 15%. Significant multivariate predictors of vasopressor indepen- dence at 24 hours included the coefficient of variation of heart rate, age, Acute Physiology and Chronic Health Evaluation II, the number of increases in vasopressor dose, mean vasopressin dose, mean blood pressure, and time-pressure integral of mean blood pressure below 60 mm Hg. Lower sampling frequencies (up to once every 5 minutes) did not affect the findings. Conclusions: Increased variability of heart rate was predictive of vasopressor independence at 24 hours after controlling confounders. Further work should clarify the reason for this finding. The optimal sampling frequency for coarsely granular physiological data may be as infrequent as every 5 minutes, depending on the clinical setting. http://dx.doi.org/10.1016/j.jcrc.2012.10.020 Abstract 5 The principle of maximum entropy production (MEP or MAXEP) Ralph Lorenz Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA Objectives: Initially, a methodology was sought for predicting the equator-to-pole temperature gradient on an arbitrary planet. Methods: Work in the 1970s suggested that the heat flows in the Earth's oceans and atmosphere might conspire to produce entropy at the maximum rate. In steady state, there is a temperature gradient enforced by the uneven distribution of sunlight on a spherical e2 Abstracts