Hamburg, Germany - Even moderate consumption of alcohol before surgery weakens the immune system, slows recovery and increases the risk of complications, a team of German researchers warn. Just one or two drinks before an operation has a serious effect on the body's defences after an operation.
Patients may take longer to recover and become more susceptible to life-threatening infections.
Researchers pointed out that surgery can be scheduled unexpectedly, for instance after an accident. The chances of success will be lower if the patient has been drinking, they stressed.
It was already known that alcohol abusers have immune system problems after surgery and face a two to five-fold greater risk of complications.
The new research conducted on rodents suggests that even moderate drinking before an operation can be dangerous.
The scientists in Germany carried out abdominal surgery on 32 mice given either alcohol or a salt solution for eight days.
Several of the animals were then exposed to pneumonia bugs which infected them via the nose.
Those exposed to alcohol suffered worse lung damage due to pneumonia and produced high levels of two immune system signalling molecules called cytokines.
One of the cytokines, IL-6, promoted potentially damaging inflammation, while the other, IL-10, turned the inflammatory response off. Over-production of both indicated a severe infection.
Professor Claudia Spies, who led the team from Berlin's famed Charite University Hospital, said: "Apparently the immune system of the alcohol-exposed mice tried in vain to fight off the infection and produced excessive amounts of IL-6 and IL-10 in the process.
"The pneumonia was also more severe in the alcohol-exposed mice than in the animals that had only been exposed to the bacteria but not to the alcohol."
She added: "Patients who are considering surgery should definitely control their drinking habits in advance."
Surgery patients should always be honest when questioned in hospital about their drinking habits, said Dr. Spies.
"The information could be potentially life-saving, because knowing about the elevated risk, the anaesthetist and the surgeon can take precautions," she said.
The findings are published in the journal Alcoholism: Clinical & Experimental Research.
