Sequential metabolic changes following induction of systemic inflammatory response in patients with severe sepsis or major blunt trauma

We have recently completed studies in critically ill patients with severe s epsis or major trauma that investigated sequential changes in the metabolic response following admission to the intensive care unit. Protein, water, a nd energy metabolism were measured using in vivo neutron activation analysi s, tracer dilution, dual-energy x-ray absorptiometry, and indirect calorime try. Over the 3-week study period both groups of patients lost 13% of their total body protein. The severe sepsis patients retained twice the volume o f fluid of those with major trauma, and the return to normal hydration in t he sepsis group was correspondingly prolonged, especially for those in the elderly age group. In both groups of patients resting energy expenditure in creased progressively over the first week to around 40% above normal and wa s still elevated 3 weeks from onset of illness. A twofold increase in total energy expenditure occurred in both groups of patients between the first a nd second weeks of critical care admission. The prolonged hypermetabolism t hroughout the study period was not reflected in the concentrations of circu lating proinflammatory cytokines, which fell rapidly over the first week. T he pattern of changes seen in plasma proinflammatory and antiinflammatory c ytokine concentrations is similar for sepsis and trauma. The remarkably sim ilar metabolic sequelae seen in critically ill patients following the onset of severe sepsis or major trauma may constitute a universal response to th e induction of the systemic: inflammatory response syndrome.