Physiologic parameters as biomarkers: what can we learn from physiologic variables and variation?

Sepsis generates an overwhelming host response characterized by changes in physiologic parameters. Monitoring these parameters can help identify and stratify septic patients. Recognizing sepsis early and identifying septic patients at risk of worsening are keys to successful treatment. Several studies have analyzed the independent physiologic parameters associated with the diagnosis of sepsis or bacteremia, with the development of severe sepsis or septic shock, and with mortality. Physiologic variability of heart rate and body temperature is reduced in sepsis and measuring the variability of these parameters can be useful for the diagnosis and prognosis of sepsis.