The volume-expanding effects of autologous liquid stored plasma following hemorrhage

Comparative Evaluation of Crystalloid Resuscitation Rate in a Human Model of Compensated Haemorrhagic Shock

Introduction:

The most effective rate of fluid resuscitation in haemorrhagic shock is unknown.

Methods:

We performed a randomized crossover pilot study in a healthy volunteer model of compensated haemorrhagic shock. Following venesection of 15 mL/kg of blood, participants were randomized to 20 mL/kg of crystalloid over 10 min (FAST treatment) or 30 min (SLOW treatment). The primary end point was oxygen delivery (DO₂). Secondary end points included pressure and flow-based haemodynamic variables, blood volume expansion, and clinical biochemistry.

Results:

Nine normotensive healthy adult volunteers participated. No significant differences were observed in DO₂ and biochemical variables between the SLOW and FAST groups. Blood volume was reduced by 16% following venesection, with a corresponding 5% reduction in cardiac index (CI) (P < 0.001). Immediately following resuscitation the increase in blood volume corresponded to 54% of the infused volume under FAST treatment and 69% of the infused volume under SLOW treatment (P = 0.03). This blood volume expansion attenuated with time to 24% and 25% of the infused volume 30 min postinfusion. During fluid resuscitation, blood pressure was higher under FAST treatment. However, CI paradoxically decreased in most participants during the resuscitation phase; a finding not observed under SLOW treatment.

Conclusion:

FAST or SLOW fluid resuscitation had no significant impact on DO₂ between treatment groups. In both groups, changes in CI and blood pressure did not reflect the magnitude of intravascular blood volume deficit. Crystalloid resuscitation expanded intravascular blood volume by approximately 25%.

The half-life of infusion fluids: An educational review

Supplemental Digital Content is available in the text

An understanding of the half-life (T_1/2) of infused fluids can help prevent iatrogenic problems such as volume overload and postoperative interstitial oedema. Simulations show that a prolongation of the T_1/2 for crystalloid fluid increases the plasma volume and promotes accumulation of fluid in the interstitial fluid space. The T_1/2 for crystalloids is usually 20 to 40 min in conscious humans but might extend to 80 min or longer in the presence of preoperative stress, dehydration, blood loss of <1 l or pregnancy.

The longest T_1/2 measured amounts to between 3 and 8 h and occurs during surgery and general anaesthesia with mechanical ventilation. This situation lasts as long as the anaesthesia. The mechanisms for the long T_1/2 are only partly understood, but involve adrenergic receptors and increased renin and aldosterone release. In contrast, the T_1/2 during the postoperative period is usually short, about 15 to 20 min, at least in response to new fluid.

The commonly used colloid fluids have an intravascular persistence T_1/2 of 2 to 3 h, which is shortened by inflammation. The fact that the elimination T_1/2 of the infused macromolecules is 2 to 6 times longer shows that they also reside outside the bloodstream. With a colloid, fluid volume is eliminated in line with its intravascular persistence, but there is insufficient data to know if this is the same in the clinical setting.

The importance of albumin infusion rate for plasma volume expansion following major abdominal surgery - AIR: study protocol for a randomised controlled trial

BACKGROUND

Administration of fluids to restore normovolaemia is one of the most common therapeutic interventions performed peri-operatively and in the critically ill, but no study has evaluated the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid. The present study is designed to test the hypothesis that a slow infusion of resuscitation fluid results in better plasma volume expansion than a rapid infusion.

METHODS/DESIGN

The study is a single-centre, assessor-blinded, parallel-group, randomised prospective study. Patients over 40 years of age admitted to the post-operative care unit after a Whipple procedure or major gynaecological surgery and presenting with signs of hypovolaemia are eligible for inclusion. Patients are randomised in a 1:1 fashion with no stratification to either rapid (30 minutes) or slow (180 minutes) infusion of 5% albumin at a dose of 10 ml/kg ideal body weight. Plasma volume is measured using 125I human serum albumin at baseline (prior to albumin infusion) as well as at 30 minutes and 180 minutes after infusion start. The primary endpoint is change in plasma volume from baseline to 180 minutes after the start of 5% albumin infusion. Secondary endpoints include the integral of plasma volume over time from baseline to 180 minutes after the start of the infusion and transcapillary escape rate of albumin (%/h) from 180 minutes to 240 minutes after the start of albumin infusion. In addition, diuresis, change in central venous oxygen saturation, lactate and blood pressure will be evaluated. A total of 70 patients will be included in the study, and the study has 80% power to detect a difference of 4 ml/kg in plasma volume expansion between the two groups.

DISCUSSION

The present study is the first clinical investigation of the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid.

TRIAL REGISTRATION

EudraCT identifier: 2013-004446-42 . Registration date: 20 December 2013. ClinicalTrials.gov identifier: NCT02728921 . Registration date: 31 March 2016.

Resuscitation with Pooled and Pathogen-Reduced Plasma Attenuates the Increase in Brain Water Content following Traumatic Brain Injury and Hemorrhagic Shock in Rats

Traumatic brain injury and hemorrhagic shock is associated with blood-brain barrier (BBB) breakdown and edema formation. Recent animal studies have shown that fresh frozen plasma (FFP) resuscitation reduces brain swelling and improves endothelial function compared to isotonic NaCl (NS). The aim of this study was to investigate whether pooled and pathogen-reduced plasma (OctaplasLG^® [OCTA]; Octapharma, Stockholm, Sweden) was comparable to FFP with regard to effects on brain water content, BBB permeability, and plasma biomarkers of endothelial glycocalyx shedding and cell damage. After fluid percussion brain injury, hemorrhage (20 mL/kg), and 90-min shock, 48 male Sprague-Dawley rats were randomized to resuscitation with OCTA, FFP, or NS (n = 16/group). Brain water content (wet/dry weight) and BBB permeability (transfer constant for ⁵¹Cr-EDTA) were measured at 24 h. Plasma osmolality, oncotic pressure, and biomarkers of systemic glycocalyx shedding (syndecan-1) and cell damage (histone-complexed DNA) were measured at 0 and 23 h. At 24 h, brain water content was 80.44 ± 0.39%, 80.82 ± 0.82%, and 81.15 ± 0.86% in the OCTA, FFP, and NS groups (lower in OCTA vs. NS; p = 0.026), with no difference in BBB permeability. Plasma osmolality and oncotic pressures were highest in FFP and OCTA resuscitated, and osmolality was further highest in OCTA versus FFP (p = 0.027). In addition, syndecan-1 was highest in FFP and OCTA resuscitated (p = 0.010). These results suggest that pooled solvent-detergent (SD)-treated plasma attenuates the post-traumatic increase in brain water content, and that this effect may, in part, be explained by a high crystalloid and colloid osmotic pressure in SD-treated plasma.

Effects of fresh frozen plasma, Ringer's acetate and albumin on plasma volume and on circulating glycocalyx components following haemorrhagic shock in rats

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 ¹²⁵I-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.