Blood Loss from Laboratory Tests

Abstract

Background: Laboratory tests can be an important source of blood loss in hospitals, especially for newborns and patients in intensive care. The aim of this study was to quantify blood loss for laboratory diagnostic tests in a large number of patients in a teaching hospital. Methods: We estimated blood loss by multiplying the number and volumes of sampling tubes collected from 2654 adult inpatients. We compared the number of tests per patient for all inpatients and intensive care unit patients during the first period and again in the same time period 1 year later when cumulative blood-loss volumes were being reported to physicians and educational information had been given to decrease blood loss from laboratory tests. Results: For 95% of the patients, blood loss during hospitalization was <196 mL. The largest proportion of the blood samples was used for clinical chemical tests (median, 45%), followed by hematologic (median, 26%) and coagulation (median, 17%) tests. In the surgical and cardiovascular surgical intensive care units, however, blood gas analyses accounted for 19 -34% (medians) of the use. For 5% of the patients, all undergoing intensive care, blood loss was >200 mL and for 0.7% was >600 mL during their hospital stay. Such high blood losses were observed in patients with long-term ventilation, coagulation disorders, and repeated surgery. The largest median blood loss was in patients undergoing cardiovascular surgery (median, 201 mL). The mean number of tests was 44 per inpatient before cumulative blood loss was being reported and 46 when it was being reported.

Reducing unnecessary testing: an intervention to improve resident ordering practices

“…For several reasons, excessive laboratory testing may represent an economic burden for the hospital and an unnecessary risk for patients. The reasons include unnecessary cost to the healthcare system and unnecessary discomfort and blood loss to the patient 14. Although laboratory testing may deliver information to providers about a patient's internal body processes to help identify and treat a wide variety of medical conditions, repeated testing in the setting of clinical stability is not indicated.…”

“…One recent study showed that residents' cost awareness can be increased through comprehensive visual displays 14. However, that study did not specifically address whether increased awareness resulted in residents changing their clinical decision-making habits or their test ordering.…”

Effect of laboratory testing guidelines on the utilization of tests and order entries in a surgical intensive care unit*

“…As patients remain in the ICU and more laboratory tests are obtained, transfusions will be administered that could very likely be spared with a conservative laboratory testing strategy. In a similar analysis, Wisser et al (30) were able to identify subgroups of patients who received sufficient blood tests to have specifically required blood transfusions.…”

Diagnostic blood loss in mechanically ventilated patients

“…[3][4][5][6][7][8][9]12 It is likely that the volume of blood removed from patients with short stays was not clinically significant. One factor in this may have been related to the location of the study in a community hospital rather than the teaching hospital setting.…”