Zinc Therapy in Critical Illness

Sepsis is a clinical syndrome often caused by a bloodstream infection that results in a common set of symptoms termed systemic inflammatory response syndrome (SIRS). Severe sepsis (sepsis with organ failure) is the leading cause of death in critically ill patients in the US. Most patients with severe sepsis need to be treated in the intensive care unit with mechanical ventilation and intravenous antibiotics. Between 30 to 50% of all severe sepsis patients die and quality of life in survivors is substantially reduced. New therapies are needed to improve clinical outcomes in patients with sepsis. A new area of interest in the treatment of critical illness is pharmaconutrition, in which micronutrients (like zinc) are studied and administered to determine if they affect the inflammatory response or immunologic processes in critical illness. The FDA does not regulate micronutrients and does not require rigorous pharmacokinetic (the study of how a drug or nutrient is metabolized in the body) testing so it is not clear how to dose micronutrients in critically ill patients. It is also not clear if critically ill patients would metabolize these micronutrients differently than healthy people and would need different dosing levels. This is true of zinc, the focus of this research study. Zinc is essential for normal immune function, oxidative stress response, and wound healing, and its homeostasis is tightly regulated. Zinc deficiency occurs in \>10% of Americans and leads to loss of innate and adaptive immunity and increased susceptibility to infections. The symptoms of zinc deficiency are similar to many of the symptoms of SIRS and there is strong biologic rationale to suggest that the zinc deficiency seen in nearly all sepsis patients may contribute to the development of sepsis syndrome and to the "immunoparalysis" common in sepsis patients This study has three specific aims, 1) to perform a phase I dose-finding study of intravenous zinc in mechanically ventilated patient