The peripheral smear.

The CBC "with differential" presently includes a blood smear that is examined by the medical technologist and is available for the physician. With increased familiarity of the technique for blood smear preparation and interpretation, the emergency physician must include peripheral blood smear review as part of the emergency department evaluation of bleeding disorders, anemia, infectious disorders, and suspected leukemia. Knowing the variations in morphology of blood cells in specific disease states should help the physician to intelligently order and meaningfully interpret the peripheral blood smear. It is a test commonly available but awaits full use by physicians in emergency medicine.