Washington, Feb 4 : A new study on mice has found that chronic alcohol consumption can result in a severe form of pneumonia after a surgery.
The study indicated that people who have a consistent drinking habit might have immune-function problem following surgery. They may even have a two- to five-fold greater chance of post-operation infection complications.
The authors of the study have suggested that patients considering surgery should control their drinking habits, and also be very honest with their doctors about their drinking habits, prior to surgery.
Claudia Spies, medical associate director of the department of anesthesiology and intensive care medicine at the University Hospital Charite, Universitaetsmedizin Berlin, said that surgery can be scheduled or the result of an accident, and in either case, complications can arise because of prior alcohol consumption.
"A significantly high rate of complications can develop in patients who consume alcohol at levels that are less than excessive. Some 20 percent of the adult population admitted to a general hospital drinks three beers or two glasses of wine on a daily basis for a prolonged period. These patients can exhibit a higher rate of pneumonia after surgery, a higher rate of cardiomyopathy or heart muscle disease, a higher rate of confusion post surgery, and significant increased bleeding complications. In addition, some 50 percent of patients who are committed to hospitals after an accident suffered their injuries under the influence of alcohol. Consequently, the rate of immune-system complications in emergency medicine is also very high," explained Spies.
"More alcohol abusers die of pulmonary infections than liver cirrhosis. Although a good deal of clinical and experimental evidence suggests that chronic alcohol exposure is detrimental to the health of the subject, only recently has it been suggested that acute alcohol exposure has comparable effects on immune responses to an infectious challenge. By acute alcohol exposure, I mean a single exposure at binge levels - greater than four drinks in a female or greater than five drinks in a male - or multi-day binge drinking," added Elizabeth J. Kovacs, director of the Alcohol Research Program at Loyola University Medical Center.
In the study, 32 female mice were given either alcohol (3.8 mg/kg body weight) or saline for eight days. All mice underwent abdominal surgery on the eighth day. And n the 10th day, the mice were nasally exposed to either K. pneumoniae or saline (referred to as "sham infection").
This resulted into four groups: alcohol/infection, alcohol/sham infection, saline/infection, saline/sham infection. Two days later, the mice were euthanized: their lungs, spleen and liver were extracted for assessment, and levels of cytokines interleukin-6 (IL-6) and IL-10 were measured.
IL-6 is a pro-inflammatory cytokine, this implies that it initiates or perpetuates an inflammatory response, seen after an overwhelming infection. IL-10 is an anti-inflammatory cytokine, activated in order to turn off the pro-inflammatory response. Tissue damage may be possible if the inflammation is not turned off.
The results indicated worse clinical outcomes among the alcohol-exposed mice than the saline-exposed mice. More specifically, they had greater tissue destruction and higher levels of both IL-6 and IL-10, which indicates a severe pulmonary infection with K. pneumoniae.
"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," said Spies.
"These data are consistent with other observations showing that alcohol impairs immunity after infection. The observation that cytokines are produced at higher levels in the lung following the combined insult of alcohol exposure and infection suggest that the return to homeostasis or normality may be delayed in this group of subjects," said Kovacs.
Spies added: "These same high levels of the mediators, interleukin 6 and 10, have been seen in patients with severe pneumonia. We know already that patients with particularly nasty pneumonias are often medium to high alcohol users. Patients who are considering surgery should definitely control their drinking habits in advance."
Kovacs wholeheartedly concurred: "Don't drink in excess before surgery, after surgery, or for that matter ever," she said.
Spies said: "Furthermore, individuals should - in addition to monitoring their alcohol habits with a view to surgery - be honest about the level of their drinking when asked by a doctor. The information could be potentially lifesaving, because knowing about the elevated risk, the anaesthetist and the surgeon can take precautions. And doctors should make it a rule to question each and every patient about their drinking habits. That means they should not only ask them if they drink, but also specifically what amounts per day."
Results of this study are published in the recent issue of Alcoholism: Clinical and Experimental Research.