Authors' objectives:

The aim of this overview is to assess the usefulness of hydroxyethyl starch (HES) in plasma expansion.

Authors' results and conclusions: Colloids vs crystalloids: 4 systematic reviews were found on the subject. A Cochrane review Alderson et al included 37 studies comparing the different types of colloids and crystalloids in patients with shock. No statistically significant differences were found in both group's mortality. Another study published by Choi et al which included 814 patients showed no statistically significant differences in the mortality of both groups, except for the polytraumatized patient subgroup which showed a death RR of 0,39 (CI95% 0,17-0,89) which favored crystalloids. Neither differences were found in both groups in the systematic review published by Velanovich et al. In March 1998, a systematic review was published comparing resuscitation with colloids or crystalloids in critically ill patients. This study included 37 controlled randomized trials and showed a combined death RR of 1,29 (95% 0,94-1,77) with a trend to higher mortality in colloids and an increase in absolute risk of death of 4%. One study which compared HES vs jellies showed that 3,5% of patients who received HES presented a RR of 4 after transfusion without improvement in the plasma expansion parameters. Comparison against Albumin A systematic review published by Cochrane in 2004 showed a significant increase in the mortality of critical patients with burns treated with albumin and with a RR of 2,4 (1,11-5,29) and no difference in global mortality between both groups. In a trial conducted by Altman et al, no statistically significant differences were observed in clinical and laboratory parameters in cirrhotic patients receiving HES or Albumin except for a higher weight loss in the HES group. A study published by Boldt et al, assessed the effects of volume replacement with HES vs. albumin. No differences were found in mortality nor in hemodynamic parameters, consequently HES was proposed as a cheaper alternative than albumin. Adverse effects: The adverse effects (AE) related to the use of HES have been mainly abnormal clotting and kidney function disorders. HES solutions mainly differ in their physical and chemical features (Molecular weight and Substitution degree). These differences determine the AE. A multicenter controlled randomized trial conducted in France showed a RR of 1,82 for renal failure and a RR of 1,51 of oliguria in patients who received HES as compared to those treated with jelly. There were no statistically significant differences in mortality, probably due to the fact that patients were few. In August, 2003, the FDA recommended not to use HES in heart surgeries with extracorporeal circulation due to the increase in clotting and bleeding abnormalities. Wilkes et al conducted a meta-analysis which included 653 patients who received HES during cardiovascular surgeries. Those patients who received HES had more significant blood loss than those who received albumin. (33% vs 19%). Note that these adverse effects were observed in high molecular weight and high degrees of substitution HES. According to the review carried out by Boldt et al there should not be any contraindication for current HES (molecular weight 70-130 200 kd) and with low degree of substitution (0,4-0,5) in patients with kidney failure. Patients with kidney function impairment should use other types of expanders.

Authors' recommendations: No clinical differences were found between colloids and crystalloids in most of the studies analyzed. Given the significant difference in costs between both groups of expanders and in light of the currently available evidence, crystalloids should be used as first-choice expanders. If a colloid has to be chosen, HES could be a cheaper substitute than albumin in most cases; though its benefits have not been proven over jellies, it is the cheapest choice. The main adverse effects shown in HES were with older molecules with high molecular weight and high degree of substitution and not with the newer ones, such as Voluven, however given the evidence available, the use of HES in patients with kidney function impairment should be avoided.

Authors' methods: Overview

Project Status: Completed

URL for project: http://www.iecs.org.ar/

Year Published: 2006

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Argentina

Organisation Name: Institute for Clinical Effectiveness and Health Policy

Contact Address: Dr. Emilio Ravignani 2024, Buenos Aires - Argentina, C1414 CABA

Contact Name: info@iecs.org.ar

Contact Email: info@iecs.org.ar

Copyright: Institute for Clinical Effectiveness and Health Policy (IECS)