We thank Kozek-Langenecker et al. 1 and Colomina et al. 2 for addressing evidence-based updated peri-operative guidelines to administer hydroxyethyl starch (HES) colloids and crystalloids. In this dynamic area of medicine, we feel a few comments based on recent results are relevant.
We agree with the recommendation of initial volume-restoring fluid therapy with isotonic crystalloids in a timely and protocol-based manner, yet to avoid postoperative complications, there may be reservation if the fluid excess approaches 2 l. 3 We also agree that compared with crystalloids, haemodynamic stabilisation by iso-oncotic colloids such as human albumin or HES provokes little tissue oedema, but infusion of colloids to patients with severe haemorrhage can aggravate dilutional coagulopathy by effects on fibrin polymerization and platelet aggregation. 1 Also, the chosen colloid seems to influence perioperative bleeding.
In randomised controlled trials, administration of lactated Ringer, HES 130/0.4, Dextran and human albumin were evaluated in 120 patients undergoing resection of the urinary bladder due to cancer. 3 It was concluded that peri-operative haemorrhage is influenced by the chosen fluid therapy with artificial colloids affecting coagulation competence and in turn volume of lost blood (Fig. 1). Infusion of the colloids HES 130/0.4 and Dextran reduces coagulation competence and increases haemorrhage.
These trials were strengthened by a triple-blinded design in regard to the first and third endpoints (coagulation laboratory results and patient outcome during hospitalisation), and double-blinded design in regard to the second endpoint (volume of lost blood), as the patient and the outcome assessor (the surgical nurse) were ignorant of the intervention. 4
Furthermore, the results agree with a systematic review incorporating 2198 patients, 5 showing that administration of HES products compared with administration of crystalloids resulted in a 5% increase in loss of blood and a 10% increased blood loss by infusion of HES compared with human albumin; that is, during severe haemorrhage, albumin may be added to patients refractory to infusion of crystalloid and without risk factors or contraindications. 6 Yet, cost-effectiveness analysis for administration of human albumin to patients in need of a large volume of fluid is in need.
The results are also in line with the randomised trial by Skhirtladze et al. 7 who found HES to affect coagulation competence, induce haemodilution and to be associated with transfusion of more blood products compared with crystalloid use in 240 patients.
We agree with the guidelines from the European Society of Anaesthesiology 1 in using perioperative colloid solutions as supplements. However, new randomised trials seem to show the adverse effects associated with the use of synthetic colloids such as HES 130/0.4 and Dextran on coagulation competence and hence risk of increased haemorrhage.
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2. Colomina MJ, Basora M, Moral V, et al. Crystalloids and hydroxyethyl starches in noncardiac surgical patients. Eur J Anaesthesiol
3. Rasmussen KC. Effect of perioperative colloid and crystalloid fluid therapy on coagulation competence, haemorrhage and outcome (thesis). Dan Med J
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5. Rasmussen KC, Secher NH, Pedersen T. Effect of perioperative crystalloid or colloid fluid therapy on hemorrhage, coagulation competence and outcome. A systematic review and stratified meta-analysis. Medicine (Baltimore)
6. Raiman M, Mitchell CG, Biccard BM, et al. Comparison of hydroxyethyl starch colloids with crystalloids for surgical patients. A systematic review and meta-analysis. Eur J Anaesthesiol
7. Skhirtladze K, Base EM, Lassnigg A, et al. Comparison of the effects of albumin 5%, hydroxyethyl starch 130/0.4 6%, and Ringer's lactate on blood loss and coagulation after cardiac surgery. Br J Anaesth