A patient anticipating surgery usually doesn’t have much say about which anesthesia drug is used. Most of the time, a patient meets with the anesthesiologist just moments before the procedure, and he’s asked only whether he has had any problems with anesthesia in the past. From there, the anesthesiologist decides what to use.

But I urge you to speak up before you’re put under! That’s because, according to a large new study, people who receive one particular anesthesia drug are more likely to die or suffer serious complications in the weeks following surgery than those who get a different drug.

The study: Researchers at the Cleveland Clinic searched the medical records of more than 100,000 patients who had operations requiring general anesthesia at their facility between 2005 and 2009. In 84% of cases, patients got an anesthesia drug called propofol (Diprivan)…8% were given a drug called etomidate (Amidate)…the rest got other drugs or a combination of drugs. The patients who got etomidate were generally older and sicker, so—to level the playing field—the researchers matched each patient who received etomidate with up to three other patients with similar medical profiles who received propofol for the same surgical procedure.

Worrisome findings: Compared with patients who received propofol, those who got etomidate were 2.5 times as likely to die from any cause within 30 days after surgery. They also had a 50% higher risk of experiencing major cardiovascular problems—even though the study included only patients who were having noncardiac surgery. The findings did not vary regardless of the dose of etomidate, meaning that even the smallest amount was associated with increased risk.

Researchers aren’t sure how etomidate, which is a short-acting drug, could affect patients several weeks after surgery. One possible explanation is that even a small dose of etomidate interferes with the function of the adrenal glands, which normally release the hormone cortisol in response to stressful situations (including surgery)—and this suppression increases the risk for shock, seizures, coma and death. Propofol also suppresses cortisol production, but etomidate’s effect in this regard is 1,500 times greater.

Caveat: The researchers were limited to information gleaned from medical records, which did not necessarily include detailed explanations of the factors that led anesthesiologists to choose one drug over another…so there may have been good reasons why certain patients got etomidate. For instance, etomidate has the advantage of working very fast and minimizing the dangerous drop in blood pressure—and accompanying risk for abnormal heart rhythms or cardiac arrest during surgery—that can occur with general anesthesia. This is thought to be particularly important when dealing with critically ill patients. Still, this short-term advantage looks less attractive when you factor in etomidate’s newly discovered longer-term risks…especially considering the fact that the drug’s adrenal-suppressing effects last longer in critically ill patients than in healthier ones.

Self-defense: If you are anticipating surgery that requires general anesthesia, ask your anesthesiologist what type of drug will be used and why…and bring up the concerns about etomidate. Until additional studies shed more light on etidomate’s safety or lack thereof, it’s only prudent to consider using an alternative anesthesia drug.