A patient about to undergo major surgery may assume that once the procedure is complete, the hard part is over. Unfortunately, for many patients, the development of a surgical site infection (SSI) may make recovery very difficult. Surgical site infections are infections that occur where an incision has been made during surgery. SSIs can affect any part of the body that was affected by the surgery, including the skin and organs. SSIs can cause fever, swelling and redness, and in serious cases, they can cause sepsis and death. These complications are not uncommon. Of the 30 million surgical procedures that take place in the US each year, more than 2% develop a surgical site infection. For the patient, a SSI can mean longer hospital stays, difficult recovery, and increased treatment costs.

Fortunately, there are effective ways to help prevent SSIs. For nearly 40 years it has been known that giving antimicrobials (agents used to kill or inhibit microorganisms that cause infection) shortly before surgery helps to prevent the development of infections after surgery. Surgical guidelines for the use of antibiotics to prevent site infection have been available since 1993 and were most recently (2004) summarized and ammended by the National Surgical Infection Project. To be safe and effective, antibiotics must be given in a very specific manner: the correct agent must be administered no more than 60 minutes before surgery begins, and antibiotic treatment must stop within 24 hours after surgery.

Despite strong evidence for the effectiveness of proper antimicrobial use, guidelines for the prevention of SSIs are not always followed. A study published in the February 2005 issue of Archives of Surgery investigated the current use of antimicrobial prophylaxis for patients undergoing major surgery.

About the Study

This study evaluated the medical records of 34,133 Medicare patients at nearly 3,000 hospitals across the nation. All patients had undergone one of five serious surgical procedures, such as a coronary artery bypass or a hip replacement between January and November 2001. Guidelines explicitly recommend antibiotic prevention for each of these procedures.

The main outcomes for the study were based on the published guidelines for SSI prevention. Each patient case was evaluated for three measures:

  • If the patient was given antimicrobial prophylaxis within one hour before surgery
  • If the patient was given a regimen consistent with published guidelines
  • If therapy was discontinued 24 hours after surgery when it was no longer needed

The researchers also collected information on the type of antibiotics given, the route and duration of treatment, and complications after surgery for each patient.

The Findings

This study found that only 56% of the patients in the study received preventative antimicrobials within the hour before their surgery. In nearly 10% of the cases, patients received the medication almost four hours after surgery, when it was unlikely that it would have a benefit.

The suggested regimens for prevention of infection were not always followed. Vancomycin, a very potent antibiotic, is used as a preventative primarily in patients that have allergies to other medications. Yet, this study found that half of the patients who received vancomycin did not have an allergy to other medications.

Additionally, many patients continued to receive therapy for longer than 24 hours after surgery, even when it was no longer needed.

The authors concluded that there are substantial opportunities to improve the use of preventative antimicrobials for patients undergoing major surgery.

How Does This Affect You?

SSIs are a serious, and common, complication of surgery. This study found that surgical site infections tripled a patient’s risk of death and lengthened hospital stays by a week. SSIs also added an economic burden, increasing the average hospital bill by $3,000 or more. The results of this study are similar to an earlier study of the impact of SSIs, which found that patients who develop SSIs have longer and costlier hospitalizations than patients who do not develop such infections. These patients are nearly twice as likely to die, 60% more likely to spend time in an ICU, and more than five times more likely to be readmitted to the hospital.

Some of the medical errors observed by the study have the potential to cause additional problems, for instance, bacterial resistance. When bacteria become resistant to antibiotics, more and more potent drugs are needed to fight infection. Two of the practices seen in this study are known contributers to bacterial resistance: (1) administering extremely strong antibiotics, like vancomycin unnecessarily, and (2) giving antimicrobials for longer than 24 hours after surgery

Prevention of SSIs is an almost universally accepted practice. There are a number of published guidelines available describing the optimal regimens for prophylaxis, including guidelines published by the Centers for Disease Control and Prevention (CDC). Yet, it is apparent from this study that they are not always followed. This study shows that hospitals, by administering the correct prophylaxis for SSIs, have an opportunity to reduce surgical complications and decrease treatment costs.

A significant finding of this study is that the timing and choice of drug used to prevent infection are vitally important. If you are undergoing a surgical procedure, it is important to talk with your doctor to understand your regimen for preventing an infection after surgery. You should ask your surgeon whether prophylactic antibiotics will be given and what antibiotics he or she recommends for you. You could ask if the hospital tracks use of pre-operative antibiotics as one of its quality indicators and if so, whether you might review data on how effectively this hospital actually follows guidelines for preventing surgical site infection.