 The study will be conducted in the intensive care unit ICU of the University Hospital Risoleta Tolentino Neves of the Federal University of Minas Gerais, Brazil. This is a 30-bed ICU with medical and surgical patients. All patients with suspected severe sepsis or septic shock admitted to the ICU will be assessed for eligibility. Patients developing severe sepsis or septic shock during their ICU stay will be also considered for enrollment. 