Anesthetic agent isoflurane may treat intracerebral hemorrhage

The anesthetic agent isoflurane may be a useful treatment for intracerebral hemorrhage (ICH)—a type of stroke caused by bleeding inside the brain, reports a study in the August issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

Based on experiments in mice, "low-dose isoflurane…may be a promising therapeutic option as an acute treatment after ICH injury," concludes the new report, led by Dr. Nikan H. Khatibi of Loma Linda (Calif.) University Medical Center.

Given Three Different Ways, Isoflurane Reduces Brain Damage from ICH

The researchers designed an experiment to assess the protective effects of isoflurane after induced ICH in mice. Intracerebral hemorrhage is the most devastating form of stroke, occurring when a ruptured blood vessel causes bleeding inside the brain. Up to 50 percent of patients die within a month; survivors are left with brain damage leading to functional and behavioral disabilities.

After ICH was induced in the brain, some animals were treated with low-dose (1.5 percent) isoflurane for one or two hours. Another group of animals received no treatment. Isoflurane is widely used as an inhaled anesthetic for surgery. Past studies have suggested that it may have an effect in preventing cell death—including brain cells.

Mice treated with isoflurane showed a significant reduction in the severity of ICH. This included a reduction in brain edema (swelling) as well as evidence of decreased brain cell death.

Isoflurane treatment was also associated with reductions in neurobehavioral abnormalities—behaviors such as walking and climbing. The reduction in cell death was significantly related to the neurobehavioral improvements.

New treatment approaches for ICH are urgently needed. Despite extensive research, "[C]urrently, there are no clinically viable therapeutic options for ICH patients," Dr. Khatibi and coauthors write. One issue is the complex nature of brain edema developing after ICH—swelling can cause up to an eight percent increase in brain volume, causing further damage due to increased intracranial (within the skull) pressure.

Together with previous evidence of the "neuroprotective" effects of isoflurane, the results suggest that this widely used anesthetic should be studied further as a possible new treatment for ICH. By reducing edema and brain cell death, treatment offers a hope of alleviating brain damage and resulting disability. The researchers conclude, "[I]soflurane may be an effective posttreatment therapeutic option for ICH because of its ability to reduce structural damage and subsequently preserve functional integrity."
 
Source: Anesthesia & Analgesia