Albumin combined with Mannitol impairs whole blood coagulation and platelet function in vitro

The indication of hydroxyethyl starch is currently under critical discussion and albumin 5% (ALB) has an increasing use in the operating theatre. Therefore, ALB is routinely used in neurosurgical procedures and often combined with mannitol 20% (MAN). Purpose of this in-vitro study was to determine the influence of the combination of MAN and ALB on blood coagulation and platelet function.

Twenty-two healthy volunteers were included into this study and 21 analyzed. Blood was obtained and diluted into five groups: 1) 7% dilution with MAN; 2) 10% dilution with ALB; 3) 17% dilution with isotonic balanced electrolyte solution; 4) 17% dilution with MAN+ALB; and 5) undiluted blood as control group (CON). Rotational thrombelastometry via ROTEM^® (EXTEM^™/FIBTEM^™ Test; SABIC, Riyad, Saudi Arabia) and thrombocyte aggregometry via Multiplate^® (Roche Diagnostics, Grenzach-Wyhlen, Germany) (ASPI, ADP and TRAP-test) were used to detect differences within the intervention groups and compared to the control group.

The maximum clot firmness in the FIBTEM^™ Test (SABIC) decreased under the normal range with the combination of MAN+ALB: 8 mm (5.5-11) compared to CON: 15 mm (12.5-20), P<0.05. Platelet function (ADP test) showed significant decreases for ALB: 51 AUC (40-84) and MAN+ALB: 54 AUC (41-68) compared to CON: 92 AUC (75-101), P<0.05. Except in clotting time all other EXTEM^™ tests (SABIC) of MAN+ALB subgroup showed significant impairment on blood coagulation compared to the control group.

In this in-vitro study clinically relevant dilutions of MAN+ALB showed a significant inhibition of blood coagulation and platelet function. Further in-vivo studies are necessary to confirm these results.