Disruptions in 24-hour profile of hemodynamic parameters in severe sepsis and septic shock

Objective: To describe circadian disruptions in septic patients and their relation to clinical outcome. Methods: In this work we performed an individual analysis of hemodynamic variables (cardiac frequency and mean blood pressure) in three groups of patients: severe sepsis, septic shock and individuals housed in the same intensive care unit by causes other than inflammation or infection, as controls, during the first and the last 24 hours of their permanency in the critical care unit. Results: Although the cosinor analysis showed no difference in the proportion of patients that expressed a statistically significant circadian rhythm, during the first 24 hours, the phase of the variations were disrupted in both septic groups, being almost in anti-phase as compared to control individuals. During the last 24 hours, this variation was present only for mean blood pressure. No association of these changes could be related to outcome (surveillance). Conclusion: We conclude that disruptions in circadian rhythms in patients during severe stages of sepsis are related to phase better than presence/absence of variation, which could be crucial to time scheduled therapies.