Cell studies showed a common anesthetic -- desflurane -- did not cause a build up of amyloid-beta protein, however, when the anesthetic was combined with low oxygen it linked to more production of the proteins associated with Alzheimer's disease.

Bin Zhang, Yuanlin Dong, Rudolph Tanzi, Zhongcong Xie and colleagues at Massachusetts General Institute for Neurodegenerative Disease, Massachusetts General Hospital/Harvard Medical School in Boston said hypoxia said low oxygen -- by itself -- did not have this effect.

The findings, published in the Journal of Biological Chemistry, were produced from human brain cell culture experiments and should next be confirmed by animal models. The preliminary findings suggest it is important to ensure anesthetic patients maintain sufficient brain oxygen, the researchers said.

The study exposed human brain cells to 12 percent desflurane for six hours -- mimicking surgical conditions -- and found no observable changes in either the production of amyloid-beta protein or the rate of cell death.

However, desflurane combined with low oxygen levels of 18 percent could stimulate both of these cellular changes.