Are serial hematocrit measurements sensitive enough to predict intra-abdominal injuries in blunt abdominal trama?

Objective: Routine serial hematocrit measurements are a component of the trauma evaluation for patients without serious injury identified on initial evaluation. We sought to determine whether serial hematocrit testing was useful in predicting the probable injuries in blunt abdominal trauma.

Materials and method: We performed a prospective study of trauma patients admitted in our observation unit over a 12-month period. Patients routinely underwent serial hematocrit testing in 6-hour intervals (two hematocrit levels). We compared trauma patients with a hematocrit drop of 5 and 10 points or more to those without a significant hematocrit drop.

Results: Five hundred forty-two isolated blunt abdominal trauma patients were admitted to observation unit, and 468 patients (86.35%) had serial hematocrit during their 6-hour stay. Of these patients, 36.11% had a hematocrit drop of 5 or more and 12.61% a drop of 10 or more. Of patients with the hematocrit drop >10, 50.8% have had diagnostic manifestations of intra-abdominal injury in both ultrasonographic and computed tomography scanning ( P <0.001). There was no significant correlation between hematocrit drop >5 and positive imaging.

Conclusion: Although serial hematocrit testing may be useful in specific situations, routine use of serial hematocrit testing in trauma patients at a level I trauma center's observation unit did not significantly aid in the prediction of occult injuries.