Immunoparalysis is an immunosuppressed state that occurs after a wide variety of insults including sepsis and cardiopulmonary bypass surgery. Due to the impaired infection fighting ability, patients with immunoparalysis are at risk of subsequent infection which can increase mortality. Immunoparalysis can be measured by two methods: 1) ex vivo endotoxin stimulation and 2) blood monocyte HLA-DR levels. Since sepsis is also a known complication of Acute Kidney Injury(AKI), the investigators hypothesize that AKI is a risk factor for immunoparalysis. The investigators plan to look at these blood factors of immune function from patients before and 3 days following cardiac surgery. Urine will also be collected from the patients before their surgery as well as the 3 days following for AKI biomarker measurement. This prospective cohort will enroll 300 patients and determine the duration and severity of immunoparalysis among patients who develop AKI and those who do not develop AKI.
