In this study we hope to delineate the typical vasoactive mediator response of trauma patients to shock. We plan to assess serum levels of vasopressin and also catecholamines, angiotensin, and cortisol during resuscitation of trauma patients to delineate high risk populations for vasopressin deficiency.

This is a prospective observational study. The only research-driven procedure will be the removal of blood samples at designated time points(total blood removed 48 cc per patient). Hemodynamic, fluid infusion and agitation/pain data (RAMSEY Score) will prospectively be collected for research purposes. We will collect data from a convenience sample of patients (when research staff is available) over a one year period.

Inclusion Criteria:

• Patient is a male or female patient presumed to be at least 18 years of age;
• Patient has a reported or actual systolic blood pressure < 90 mmHg within 1 hour of arrival to the Emergency Room;
• Patient has clinical evidence of acute traumatic injury;

Exclusion Criteria:

• Patient is asystolic or requires CPR prior to arrival;
• Patient was transferred from an outside facility
• Patient known to be pregnant
• Patient known to be prisoner

observational study - trauma patients admitted to University Hospital