Abstract
Background
Brain oedema is a major cause of early death after stroke. A 10% solution of glycerol is a hyperosmolar agent that is claimed to reduce brain oedema.
Objectives
To determine whether intravenous glycerol treatment in acute stroke, either ischaemic or haemorrhagic, influences death rates and functional outcome in the short or long term, and whether the treatment is safe.
Search methods
The Cochrane Stroke Group trials register was searched (January 2003), and some trialists were personally contacted.
Selection criteria
All completed, randomised and quasi-randomised, controlled, published and unpublished comparisons, evaluating clinical outcome in which intravenous glycerol treatment was initiated within the first days after stroke onset.
Data collection and analysis
Two reviewers independently applied the inclusion criteria, assessed trial quality and extracted data and this was checked with all co-reviewers. Death from all causes, functional outcome, and adverse effects were analysed.
Main results
Eleven completed, randomised trials comparing intravenous glycerol and control were considered. Analysis of death during the scheduled treatment period for acute ischaemic and/or haemorrhagic stroke was possible in 10 trials where 482 glycerol treated patients were compared with 463 control patients. Glycerol was associated with a non-significant reduction in the odds of death within the scheduled treatment period (odds ratio (OR) 0.78, 95% confidence intervals (CI) 0.58 to 1.06). Among patients with definite or probable ischaemic stroke, glycerol was associated with a significant reduction in the odds of death during the scheduled treatment period (OR 0.65, 95% CI 0.44 to 0.97). However, at the end of the scheduled follow-up period, there was no significant difference in the odds of death (OR 0.98, 95% CI 0.73 to 1.31). Functional outcome was reported in only two studies but there were non-significantly more patients who had a good outcome at the end of scheduled follow up (OR 0.73, 95% CI 0.37 to 1.42). Haemolysis seems to be the only relevant adverse effect of glycerol treatment.
Authors’ conclusions
This systematic review suggests a favourable effect of glycerol treatment on short term survival in patients with probable or definite ischaemic stroke but the confidence intervals were wide and the magnitude of the treatment effect may be only minimal. Due to the relatively small number of patients, and that the trials were performed in the pre-CT era, the results must be interpreted cautiously. The lack of evidence of benefit in long term survival does not support the routine or selective use of glycerol treatment in patients with acute stroke.
Plain language summary
Glycerol for acute stroke
There is not enough evidence to show if glycerol can reduce the disabling effects of brain swelling due to acute stroke. Brain swelling (or oedema) is a major cause of early death and long-term disability after stroke (a sudden catastrophe in the brain either because an artery to the brain blocks, or because an artery in or on the brain ruptures and bleeds). A 10% solution of glycerol might reduce brain swelling and therefore reduce the risk of death and long-term disability after a stroke. The review found some evidence that glycerol improves the short term survival after stroke, but there was not enough evidence to decide whether glycerol helps avoid disability after stroke. Adverse effects of glycerol treatment did not happen often, but a small number of treated patients were found to have blood in their urine (this disappeared after the glycerol treatment was stopped). More research is needed.
