New Rules for Antibiotic Use Before Medical Procedures

Dr. Tallet

For a long time cardiologists have recommended the use of antibiotics for some patients before dental procedures, gastroenterology procedures (for example, colonoscopies) or genitourinary procedures (for example, cystoscopies). You might wonder what these procedures have to do with the health of your heart.

The mouth, the rest of the gastrointestinal tract and the genitourinary tract always have bacteria in them, regardless of good tooth brushing, flossing or general hygiene. It has been demonstrated many times that injury or medical procedures in the mouth, throat, stomach, intestines, urethra, and vagina lead to a temporary rush of bacteria in the blood stream. Healthy people have body defenses that quickly kill these bacteria.

Cardiologists have been concerned that the bacteria in the blood stream might stick to abnormal or damaged heart valves. These bacteria could then infect the heart valves, a potentially fatal condition called endocarditis. Based on the degree of damage to a patient’s heart valves and the likelihood of a significant amount of bacteria in the blood stream after a procedure, cardiologists have recommended antibiotics to some patients with structural heart disease before some types of procedures to prevent endocarditis.

As scientists have gathered more information, however, it has become clearer that the likelihood of a heart valve infection (endocarditis) after these procedures is actually very low. For example, although 94% of patients get bacteria in the blood stream after a dental procedure, only 6-10 people out of a million get endocarditis each year from any cause. In fact, endocarditis is much more likely to result from frequent random exposure of the blood stream to bacteria associated with daily activities, such as brushing your teeth, than from bacteria in the blood stream caused by a procedure. Also, the likelihood of antibiotics preventing these infections is lower than previously thought. So, it seems that using antibiotics routinely before some of these procedures is not useful.

Taking this recent information into account, the American Heart Association has issued new guidelines that significantly reduce the number of patients who need to take antibiotics before dental procedures. The only people who need to take antibiotics before dental procedures are: (1) patients with heart valve replacement or (2) patients who have had a previous episode of endocarditis. Far less common reasons to take antibiotics before dental procedures apply to patients who have received a heart transplant and then developed injury of the valves in the transplanted heart. Another rare group of people who need to take antibiotics before procedures are patients born with heart defects that allow blood to flow from the right side of the heart to the left (if they have not have had surgery to repair the defect or there is still some defect left after surgical repair or within six months of successful complete repair). As always, you do not need antibiotics if you have had coronary artery bypass grafting (CABG), angioplasty, stents, pacemaker, or defibrillator.

The new guidelines also limit the types of procedures for which antibiotics are necessary. You need them for dental procedures (including cleanings) that affect the gums. For the respiratory tract, only procedures that involve cutting the lining of the respiratory tract require antibiotics. These include tonsillectomy, adenoidectomy, and biopsies. Antibiotics are not needed for bronchoscopies without biopsy. Routine antibiotics for prevention of endocarditis are not recommended for gastrointestinal or genitourinary procedures. These procedures include EGD, ERCP, colonoscopy, and cystoscopy. You do not need antibiotics for body piercings, tattoos, vaginal delivery, and hysterectomy.

Remember, these guidelines only apply to antibiotics intended to reduce the risk of endocarditis. Antibiotics used to treat an active infection do not fall under these guidelines and should still be used!

In summary, as more evidence has become available, it appears that the risk of developing an infection of the heart valves after certain medical procedures is less than previously thought. As a consequence, the American Heart Association has issued new guidelines that recommend antibiotics for fewer patients and less types of procedures than before. For the average patient, you only need antibiotics for the prevention of endocarditis if you have had a heart valve replacement or if you have already had endocarditis before. The only types of procedures that need antibiotics for those patients at risk are dental procedures that involve the gums and procedures that involve cutting the lining of the airway such as tonsillectomies, adenoidectomies or biopsies. If you are not sure what to do or if you are not sure whether you need antibiotics before a certain procedure, please ask your cardiologist.