Background: Early use of fresh frozen plasma (FFP) in haemorrhagic shock is associated with improved outcome. This effect may partly be due to protection of the endothelial glycocalyx and/or secondary to a superior efficacy of FFP as a plasma volume expander compared to crystalloids. The objective of the present study was to investigate if protection of the glycocalyx by FFP can be demonstrated when potential differences in plasma volume (PV) following resuscitation are accounted for.
Methods: Rats were subjected to a volume-controlled haemorrhage (30 ml/kg). At 2.5 h after haemorrhage, animals were randomized to resuscitation with FFP (37.5 ml/kg), albumin (30 ml/kg) or Ringer's acetate (RA) (135 ml/kg, 4.5 times the bleed volume). PV was measured 2 h after completion of resuscitation using (125)I-albumin and effects on endothelial glycocalyx were evaluated by measuring circulating heparan sulphate and syndecan-1. Hemodynamic effects of resuscitation were evaluated by measuring lactate and mean arterial pressure (MAP).
Results: Resuscitation with FFP or albumin resulted in plasma volume expansion equalling the blood loss (to 55 ± 5 ml/kg and 54 ± 4 ml/kg (mean ± S.D.), respectively), whereas plasma volume expansion in RA group was lower (to 42 ± 7 ml/kg). Plasma concentration of heparan sulphate was lower in the FFP and albumin groups than in the RA group at 2 h after resuscitation. After correcting for differences in plasma volume, no significant difference in circulating amount of heparan sulphate was detected between the FFP and albumin groups (2879 ± 1075 μg/kg and 3318 ± 1814 μg/kg, respectively, P = 0.4) and the RA group (3731 ± 777 μg/kg). No differences between the groups in plasma concentration or amount of circulating syndecan-1 were detected after resuscitation. After resuscitation, MAP was higher in the FFP and albumin groups than in the RA group. Lactate did not differ between the FFP and RA groups after resuscitation.
Conclusions: Improved outcome in trauma by FFP could in part be explained by better plasma volume expansion compared to crystalloids. The decrease in plasma concentration of markers of glycocalyx degradation after resuscitation with FFP are largely secondary to differences in plasma volume and may not accurately reflect effects of FFP on the glycocalyx.
Keywords: Fresh frozen plasma; Haemorrhage; Heparan sulphate; Resuscitation; Syndecan-1.