Osmotic therapies added to antibiotics for acute bacterial meningitis

Osmotic therapies added to antibiotics for acute bacterial meningitis

Plain language summary

What is the aim of this review?

The aim of this Cochrane Review is to collect and analyse trials evaluating osmotic therapies given orally or intravenously to people with acute bacterial meningitis. Cochrane authors collected and analysed all relevant studies to answer this question; they found five relevant studies.

Key messages

Giving glycerol, an osmotic diuretic, probably has little or no effect on death (moderate-certainty evidence), but may reduce subsequent deafness (moderate-certainty evidence) or neurological disability (low-certainty evidence). The evidence is current to 17 February 2017.

What was studied in the review?

In meningitis, the cerebrospinal fluid that surrounds the brain and spinal cord is infected, usually as a result of spread from the blood. Any form of meningitis can result in death or severe disability, but acute bacterial meningitis is rapidly fatal without treatment. Even with antibiotics, 10% to 15% of children with bacterial meningitis die in high-income countries with much higher rates in low-income settings. The infection causes the brain to swell, and this is thought to contribute to death and to long-term brain damage in survivors. Osmotic therapies increase the concentration of the blood by exerting an osmotic pressure across a semi-permeable membrane (such as a cell wall or blood vessel lining in the brain). This draws water from the brain into the blood, thereby reducing pressure in the brain. Potentially osmotic therapies could increase the rate of survival, or they could do harm.

What are the main results of the review?

We included five trials that compared glycerol with placebo in a total of 1451 patients with bacterial meningitis. In the studies steroids were often given as well, but this did not appear to modify any of the effects seen with glycerol.

This review detected no benefit from glycerol relating to death. There appeared to be marginal protection against deafness and against neurological disability. No effect on epileptic seizures at follow-up was noted. Glycerol was not associated with any severe adverse effects. The number of trials included was small and only two tested a large number of participants. All trials were from different healthcare settings and examined either adults or children.