Gram-positive and Gram-negative Sepsis: Two Disease Entities?

Sepsis and its sequelae are the leading causes of death among critically ill patients in non-coronary intensive care units (ICUs). Paradoxically, despite a fall in the mortality rate, the incidence of sepsis has increased, with about 750,000 cases annually resulting in about 215,000 deaths a year [1, 2]. This is, in part, a consequence of increased provision of intensive care facilities in the UK and elsewhere [3]. Many factors contribute to the increasing incidence of sepsis and its sequelae including improved chemotherapy for malignancies leading to greater numbers of immunosuppressed patients; more organ transplantations and cardiac surgery; and also the increased use of internal devices such as prostheses, chest drains and endotracheal tubes [3]. Moreover, 40–60 % of patients with severe sepsis develop acute lung injury (ALI) or its extreme manifestation, acute respiratory distress syndrome (ARDS), which is associated with a particularly high mortality [4, 5].