The purpose of this study is to develop new triage tool for trauma patients based on HRV. EKG will be prospectively measured in trauma patients in two locations: in the prehospital setting (the field and during transport by helicopter) and in the hospital setting. In each case HRV will be derived from the EKG signal, will be correlated with other non-invasive signals (e.g. near infrared spectroscopy (NIR), and bispectral EEG (BIS)), along with other routinely measured variables (blood pressure, respiratory rate, pulse oximetry, etc), will be correlated with injury severity and day of discharge. An algorithm will be constructed using multiple linear regression. The hypotheses are:

1. reduced HRV in the field correlates with bad outcome;
2. the specificity and efficiency of HRV as a screening tool can be improved by controlling factors such as heart rate, age, gender, respiratory rate, and pulse oxygen saturation;
3. an easy to interpret HRV index can be derived that can be used for trauma triage or diagnosis.

The eligible study population will be comprised of patients who meet level 1 trauma criteria and are transported by helicopter to Ryder Trauma Center or who are already admitted to the trauma center for presumptive traumatic brain injury. In addition to the EKG, trauma patients may also be connected to either an non-invasive NIR Monitor, which provides real-time information about perfusion status and/or a bispectral EEG monitor, which provides real-time information about brain metabolic activity.

Inclusion Criteria:

• Patients who meet level 1 trauma criteria and are transported by helicopter to Ryder Trauma Center
• An additional study population will be comprised of patients already admitted to the trauma center for presumptive Traumtaic Brain Injury

Exclusion Criteria:

• None

All trauma patients

75 patients with complete HRV and trauma registry data

Duration of transport from injury to hospital