Evaluation of a blood conservation strategy in the intensive care unit: a prospective, randomised study

Anemia is a common problem in the ICU population. Most patients are anemic at admission, their hemoglobin concentrations declining further thereafter. The aim of the present study was to evaluate the effect of a combination strategy, involving closed arterial blood gas sampling and the use of pediatric vials for phlebotomy (Group A), on the sampling-induced blood loss and the rate of decline in hemoglobin in adult ICU patients. Combination (Group A) was compared to the current standard technique of arterial line sampling and adult vial phlebotomy (Group B) in a prospective, randomised, ethically-approved trial for the first 72 hours of their ICU stay. Peri-operative, oncology, coagulopathic and uremic patients were excluded. All other ICU patients with arterial cannulae and predicted to stay beyond 3 days, were enrolled.

39 patients entered the study, 20 in Group A, and 19 in Group B. Data collection was complete for all. There was a statistically significant difference in sampling-induced blood loss between the groups over the first 72 hours of treatment (mean +/- standard deviation: 15.16 +/- 5.3 ml Group A vs 45.11 +/- 14 ml Group B, p<0.001). There was a smaller decline in mean hemoglobin level, which was not statistically significant (0.79 +/- 0.6 g/dL vs 1.30 +/- 1.13, p = 0.09).

Overall, this strategy reduced measurable blood losses from phlebotomy. In larger trials it might also preserve hemoglobin levels.