Acute kidney injury (AKI) in critically ill trauma patients has been shown to significantly increase mortality, length of stay, and costs, however detection has proven difficult as markers like elevated creatinine and decreased urine output may take days to manifest and are late indicators of AKI. The combination of two urinary biomarkers, Tissue Inhibitor of Metalloproteinase 2 (TIMP-2) and Insulin-like Growth Factor Binding Protein 7 (IGFBP-7), has been shown to increase within 12 hours following renal insult, allowing assessment of risk for developing acute kidney injury. Therefore, the investigators plan to assess if acute kidney injury in critically ill trauma patients can be determined earlier using urinary TIMP-2 and IGFBP-7 via the NephroCheck testing system. These markers have not been specifically evaluated in trauma patients at risk of AKI.

Inclusion Criteria:

• trauma patients with multiple injuries;
• abdominal injuries;
• crush injuries;
• those who present in shock (systolic blood pressure <90 or mean arterial pressure <65);
• require blood transfusions, vasopressors or mechanical ventilation

Exclusion Criteria:

• known pregnancy;
• patients under 21 years of age;
• known moderate to severe AKI prior to enrollment and end stage renal disease. known moderate to severe AKI prior to enrollment and end stage renal disease

Subjects must be trauma patients with multiple injuries.