Objective: To examine retrospectively the amount of blood lost solely for diagnostic purposes in a defined group of patients.
Design: Retrospective medical chart review of a case series.
Setting: Operating theater and surgical intensive care unit in a major tertiary care center.
Patients: Thirty-nine consecutive patients with head and neck cancer undergoing major surgical procedures and requiring overnight intensive care unit monitoring.
Main outcome measures: Patient medical records were analyzed for procedure, starting hematocrit reading, intraoperative estimated blood loss and intravenous fluids, operative time, history of blood product transfusion, blood lost for each phlebotomy encounter, and the immediate cost therefrom.
Results: The mean diagnostic blood loss was 181 mL, which was 36% of estimated blood loss. In the group of 23 nontransfused patients, the average drop in hematocrit was 9.7%. This change in hematocrit correlated most strongly with operating time (P < .02) and the amount of intraoperative intravenous fluid administration (P < .05). The average cost to the patient directly from phlebotomy-associated charges was $542.
Conclusion: Diagnostic blood loss contributes significantly to the overall blood loss in the patient undergoing head and neck surgery.