Identifying Systemic Sepsis
The body develops compensatory mechanisms to prevent systemic inflammation in response to stress and injury. As overwhelming inflammation is rapidly lethal, these mechanisms have a protective effect during the first few hours after injury. However, they become deleterious as nearly all immune functions are compromised.The term “immunoparalysis” describes the global incapacity of the body to mount any kind of immune response; the extent of immunoparalysis is thought to correlate with life-threatening secondary infections and mortality. The hypoimmune state might require proinflammatory therapies to enhance immune function, but establishing the presence of immunodepression is crucial when considering such an approach. This article discusses methods for diagnosing immunoparalysis, in particular measurements of circulating monocyte human leukocyte antigen type DR expression and plasma interleukin-10. Read more
Consensus of Infection Definition
Infection is a major problem in the intensive care unit (ICU), and infection is an integral part of sepsis. Almost any epidemiologic or intervention study that deals with infection or its consequences will need to include definitions of infection at various sites as part of its protocol.Although there are a number of published systems that suggest working definitions of infection that can be used, for instance for infection control purposes, there are no universally agreed upon definitions of infection as they apply to patients with severe sepsis or septic shock in the ICU. Some of the infections that occur in the ICU can easily be included within existing definitions. For instance, the use of the standard microbiological definition of a urinary tract infection as 105 colonyforming units (cfu)/mL of pure growth of an organism is not unreasonable for a noncatheterized ICU patient. However, in many more common and more serious infections that are encountered in the ICU, these “standard” definitions are neither appropriate nor particularly helpful. The most obvious example is pneumonia, which presents particular problems.
It would greatly improve the quality and comparability of clinical trials of sepsis if there were a set of definitions for infection, customized for patients in the ICU, that could find widespread acceptance. Therefore, the International Sepsis Forum (ISF) convened an international consensus conference to formulate a set of definitions of infections that occur commonly in the ICU. The purpose of these proposed definitions is to determine whether the infection is likely to be present in patients who have the clinical syndrome of severe sepsis or septic shock. The definitions have been developed specifically for use in clinical studies of sepsis and thus are intended to maximize specificity and minimize false positives. It is recognized that in clinical practice, a different definition might be used to de- fine who should receive antibiotic therapy, but this type of more sensitive definition will have more false positives.
METHODS Read more