Acute blood loss.

Acute blood loss is a common, but often challenging, problem facing emergency physicians. Inadequate or delay in treatment can lead to morbidity or mortality. Standard classifications to quantify blood loss, as well as vital signs alone, are inadequate for guiding therapy. Mechanism of injury, base deficit and blood lactate, central venous oxygen saturation, and oxygen transport parameters should all play a role in deciding the need for further diagnostic studies and resuscitation. Extreme care must be taken to evaluate and resuscitate those with decreased physiologic reserve adequately, such as the elderly. Once bleeding has been identified, expeditious control of bleeding should be accomplished, either operatively or angiographically. Care must be individualized, but adherence to these general guidelines will improve outcome.