Serum Vasopressin Levels and Severe Hemorrhagic Shock

For humans suffering trauma and severe hemorrhagic shock, no randomized controlled studies of
the effect of exogenous vasopressin use exist, although case reports have suggested it may be
of benefit. Even some moribund patients with "irreversible" shock survived severe hemorrhagic
shock after administration of vasopressin. This suggests that at least some patients
suffering severe trauma could benefit from AAVP administration. Recently, many clinicians and
notable research consortiums have suggested that AVP shows promise for human resuscitation
and have called for further human studies.

This is a prospective, single-center observational study designed to evaluate (1) whether
vasopressin is depleted in severe, but not minor, trauma; and (2) the degree to which
endogenous vasopressin levels predict the occurrence of ARDS, sepsis, or death. To test the
first hypothesis, serum vasopressin levels (continuous independent variable) will be assessed
at enrollment (time 0), 6, 12, 18, and 24 hours later, and correlated with the two levels of
trauma (categorical dependent variable). To test the second hypothesis, serum vasopressin
levels (now a continuous dependent variable) will be correlated with each of three
outcomes-death, ARDS, and sepsis.

Inclusion Criteria:

Patients with a minor injury or injuries, defined as:

1. no episodes of systolic blood pressure < 90 mmHg between occurrence of injury and
admission;

2. no blood transfusion requirement;

3. base deficit < 5 mEq/L;

4. no requirement for mechanical ventilation other than transiently during orthopedic
surgery.

Exclusion Criteria:

1. Pregnancy

2. corticosteroid use,

3. prisoners, and/or

4. head trauma as determined by computed tomography (head trauma may itself induce
diabetes insipidus, a marker of pituitary damage and vasopressin deficiency), and/or

5. evidence of spinal cord injury (another cause of vasodilatory shock).

Patients will also be excluded if pre-hospital provider information cannot be obtained, or
indicates that the trauma occurred more than one 1 hour prior to emergency department
admission.