An assessment of laboratory changes during autologous whole blood transfusion training: A prospective, observational...

Hemorrhage is the leading cause of death after trauma. Blood transfusions are used to restore physiology but are stored in citrate preservative which can bind electrolytes, particularly calcium, leading to hypocalcemia. Few data exist on the changes that occur in humans because of whole blood donation/transfusion. We sought to determine the electrolyte changes that occur during whole blood donation/reinfusion.

We conducted a prospective observational study of military personnel that served as donor/recipient for personnel performing autologous whole blood transfusion training. Trained research staff analyzed whole blood samples collected pre-donation, post-donation, and post-reinfusion of one autologous unit of whole blood. We used the i-STAT laboratory analyzer. Laboratory data are reported using means and standard deviations.

We prospectively enrolled 40 participants. The median age was 22 years (interquartile range [IQR] 20-26), and 95% were male. The median body mass index was 25.3 (IQR 23.0-29.1). There were four participants that reported use of dietary supplements: three reported taking creatine, and the other one reported taking fish oil, magnesium, multivitamin, creatine, caffeine, and beetroot powder. Mean iCa was 1.25 mmol/L (standard deviation [SD] 0.04) pre-donation, 1.26 (SD 0.04) post-donation, and 1.12 (SD 0.14) post-reinfusion. Comparatively, the mean potassium values were 3.90 mEq/L (SD 0.36), 4.10 (SD 0.62), and 4.09 (SD 0.72). Hemoglobin levels decreased by 0.34 g/dL (p < .001) from post-donation to post-reinfusion. Other labs had no significant changes.

We noted a decrease in ionized calcium measurements post-reinfusion. Future studies should assess changes after larger volume transfusions and assess repletion methods.