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Haemodilution for acute ischaemic strokeAsplund K
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SummaryDilution of the blood to improve compromised brain blood flow in patients with acute stroke is not beneficial.Most strokes are caused by a blood clot that interrupts blood flow to a part of the brain. If blood flow is not restored early, the brain cells will die (brain infarction). Haemodilution (dilution of the blood) improves the flow properties of the blood so that, theoretically, oxygen and nutrient supply to the brain is improved and brain cells threatened to die could survive. This treatment has been shown to reduce brain infarct size in animals with experimental stroke. Haemodilution can be achieved by bloodletting, by giving fluids as an infusion or by a combination of both. The fluids used may be simple salt solutions but so-called colloid solutions are more effective as haemodilution agents. In many countries, haemodilution has been used in routine clinical treatment of patients with acute stroke since the late 1970s when the first studies were published. Since then, a large number of clinical studies on haemodilution in acute stroke have been published. This review shows that when all the studies are taken together there are no benefits from this treatment. There is no evidence that any particular mode of haemodilution, with or without blood-letting, using various kinds of haemodiluting agents, etc. is effective. It is concluded that there is no scientific support for the use of haemodilution in the routine treatment of patients with acute stroke.
This is a Cochrane review abstract and plain language summary, prepared and maintained by The Cochrane Collaboration, currently published in The Cochrane Database of Systematic Reviews 2008 Issue 3, Copyright © 2008 The Cochrane Collaboration. Published by John Wiley and Sons, Ltd.. The full text of the review is available in The Cochrane Library (ISSN 1464-780X).
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October 16. 1995 AbstractBackgroundIschaemic stroke interrupts the flow of blood to part of the brain. Haemodilution is thought to improve the flow of blood to the affected areas of the brain and thus reduce infarct size. ObjectivesThe objective of this review was to assess the effects of haemodilution in acute ischaemic stroke. Search strategyWe searched the Cochrane Stroke Group Trials Register (last searched January 2002), Medline (1966-June 2002) and conference abstracts. We contacted manufacturers and investigators in the field to identify any additional published and unpublished studies. Selection criteriaRandomised trials of haemodilution treatment in people with acute ischaemic stroke. Only trials in which treatment was started within 72 hours of stroke onset were included. Data collection and analysisTwo reviewers assessed trial quality and independently extracted the data. Main resultsEighteen trials were included. A combination of venesection and plasma volume expander was used in eight trials. Ten trials used plasma volume expander alone. The plasma volume expander was dextran 40 in 12 trials, hydroxyethyl starch (HES) in five trials and albumin in one trial. Two trials tested haemodilution in combination with another therapy. Evaluation was blinded in 11 trials. Five trials probably included some patients with intracerebral haemorrhage. Haemodilution did not significantly reduce deaths within the first four weeks (odds ratio 1.09, 95% confidence interval 0.86 to 1.38). Similarly, haemodilution did not influence deaths within three to six months (odds ratio 1.01, 95% confidence interval 0.84 to 1.22), or death and dependency or institutionalisation (odds ratio 0.98, 95% confidence interval 0.84 to 1.15). The results were similar in confounded and unconfounded trials, and in trials of isovolaemic and hypervolaemic haemodilution. No statistically significant benefits were documented for any particular type of haemodiluting agents, but the statistical power to detect effects of HES and albumin was weak. Six trials reported venous thromboembolic events. There was a tendency towards reduction in deep venous thrombosis and/or pulmonary embolism at three to six months follow-up (odds ratio 0.59, 95% confidence interval 0.33 to 1.06). There was no increased risk of serious cardiac events among haemodiluted patients. Authors' conclusionsThe overall results of this review are compatible both with modest benefit and moderate harm of haemodilution therapy for acute ischaemic stroke. This therapy has not been proven to improve survival or functional outcome. |
