What is the latest discovery in terms of “suspended animation” sustainers? Researchers concluded in a recent study published in the journal Anesthesiology that the best reversible substance for slowing down life processes is hydrogen sulfide (H2S), and for those of you who don’t know what that is…well, it resembles the smell of rotten eggs or sewer gas.

It may sound …smelly…but researchers at Massachusetts General Hospital (MGH) said they’ve reached this conclusion after studying the effects of H2S on mice. The substance was known to have metabolic depressant abilities, but what was amazing to discover was that at the same time, it sustained cardiovascular functions.

“Our research showed that breathing low concentrations of H2S rapidly and reversibly depresses metabolism in mice, yet preserves cardiovascular function,” said Warren Zapol, M.D., Chief of Anesthesia and Critical Care at MGH and co-author to the study. “These properties may be exploitable to protect organ function when supplies of oxygen are limited, such as during or after major trauma or during surgery.”

Researchers established to their surprise that when the H2S was inhaled, the heart rate of the mice fell over 50 percent, but the blood pressure remained the same, which is a key element to maintaining a sufficient blood supply to vital organs, Dr. Zapol explained.

Using hydrogen sulfide could come as an alternative to the hypothermia method, which is currently thought to be the only safe method of decreasing metabolic rate: “the ability to induce a reversible hypometabolic state, avoiding the damaging effects of hypothermia, could be a valuable and novel field tool for treatment of severely injured patient,” Dr. Zapol also said. “It could buy time to transport soldiers to a field hospital for major surgery.”

It may sound like an ‘unpleasant’ alternative to the freezing technique, but in fact scientists consider hydrogen sulfate to have many more positive sides than hypothermia by not altering body temperature and by keeping the essential blood pressure at normal levels.