Nutritional support in the patient with the systemic inflammatory response syndrome

The syndrome previously known as "sepsis" is now recognized as a generalized response to a number of stimuli that cause systemic activation of inflammatory mediators. The so-called "systemic inflammatory response syndrome" (SIRS) represents a final common endpoint to overwhelming persistent infection, massive tissue injury, prolonged tissue oxygen debt, or any other insult precipitating global inflammation. The metabolic consequences of SIRS are profound but in the past were not fully appreciated because patients died from more immediate causes (e.g., renal failure, pulmonary failure, gastrointestinal hemorrhage). As modern critical care has maintained patients in prolonged phases of recovery, the need for appreciation of the nutritional impact of the hypermetabolic response is taking center stage. The systemic activation of counterregulatory hormones, cytokines, and other mediators of inflammation has complex metabolic effects that are discussed in this review. A rational approach to assessing nutritional needs in patients with SIRS will be presented along with a discussion of how the needs are best met. Finally, the pitfalls encountered in nutritional support of patients with sepsis will be outlined along with a protocol for monitoring tolerance to and effectiveness of metabolic support in SIRS.