Do all trauma patients need early crossmatching for blood?

Trauma patients frequently have blood drawn for type and crossmatch. The majority of these units are held for 48 hours and never used for that patient. We conducted a retrospective review and followed with a prospective protocol, attempting to identify a variable that would predict the need for blood transfusion, thus decreasing cost and blood waste. In the 180 patients studied retrospectively, we found that 61% of patients with prehospital hypotension (BP < 100 mm Hg) required transfusion, whereas only 11% of patients without prehospital hypotension required transfusion (P < .0001). We prospectively evaluated prehospital hypotension as a predicator of blood usage in 136 patients. Patients with prehospital systolic blood pressure > or = 100 mm Hg had only a type and screen ordered unless clinical judgment dictated otherwise. Of the 136 patients, 109 had no history of prehospital hypotension, and 81 of these were managed with a type and screen. Only 8 patients without prehospital hypotension received a transfusion, 6 because of operative procedures. No patient received uncrossmatched blood, and there were no complications. Implementation of this protocol decreased our units crossmatched for each unit transfused from 3.8 to 2.8. Prehospital blood pressure is a useful adjunct to clinical judgement in identifying major trauma patients who can be initially managed safely without crossmatching.