Prehospital Lactate (COMPLETED)

This observational study tests whether blood lactate levels in injured patients in an ambulance predicts the need for emergency surgery, blood transfusions or other complications.

Lactate will be measured in a drop of blood from patients who are being taken to a trauma center by ambulances.  The drop of blood will be taken from the needles used to start an intravenous line.  Only patients who are already getting an intravenous line will be tested.  Paramedics will put the drop of blood on a test strip that measures lactate.  There is no change in patient care, no extra blood drawn, and no change in treatment at the hospital. Most patients will have lactate measured again at the hospital to compare with the results from the paramedic device.  Investigators will track what happens to subjects by reviewing the ambulance and hospital records.

Lactate is a small molecule that accumulates in blood when organs do not have enough blood supply or oxygen.  After a severe injury, patients may lose blood because of internal bleeding.  Normal vital signs such as blood pressure and heart rate may not detect whether this bleeding is severe.  The purpose of this study is to test whether lactate measured in the ambulance can improve the ability of paramedics to recognize those trauma patients who will need emergency surgery or other interventions even before they get to the hospital.

Doctors often measure lactate in the hospital for the same reasons.  This measurement has not been done in the ambulance before because affordable testing machines were not previously available.  The investigators are specifically trying to learn what values of lactate measured in the ambulance in these patients are worrisome and what values are normal.

This is a Resuscitation Outcomes Consortium study (roc.uwctc.org).