[Diagnostic blood losses in severe trauma patients]. / Pérdidas sanguíneas diagnósticas en pacientes con trauma grave.

OBJECTIVE: To analyze diagnostic (blood drawings) and iatrogenic (Continuous Renal Replacement Therapy, CRRT) blood losses (BL) in severe trauma patients. METHOD: A one-year descriptive, prospective and observational study. We included patients over 15 years of age, admitted with severe trauma and who had a score of > or =16 on the Injury Severity Index (ISS). Those patients in whom limitation of therapeutic effort had been indicated were excluded. A total of 225 patients with 1619 days of evolution were analyzed for volume of BL/day/patient, type of diagnostic test, clinical outcome and utilization of CRRT. The variables were described as mean +/- standard deviation with the Student's T test. RESULTS: Average blood loss of patient per day was 55.5+/-32.2 cc. Statistically significant differences were found between the blood volume drawn when the first day was compared to the second day, 73.5+/-32.2 vs. 56.3+/-21.9 (p<0.001); clinical outcome (alive vs death) 54.8+/-33 vs. 60.7+/-24.9 (p<0.05); severity (ISS<31 or > or =31) 54.65+/-20 vs. 61.5+/-28.5 (p<0.001), No RRT vs RRT: 50.9+/-18.9 vs. 97.2+/-72.6 (p<0.001). CONCLUSIONS: The greatest diagnostic BL occurs during the resuscitation phase, in the patients who die, in those with greater severity and those undergoing CRRT.