Post surgery drugs fuelling drug resistance

According to a latest study, only half of all patients receive appropriately administered antimicrobial infection medication within one hour of major surgery. The figure emphasises just how much patients are at risk from surgical site infections.

In addition, the reluctance to carry out this procedure, which was established in the 1960's, is causing concern amongst scientists, who believe that the lack of proper post-operative treatment is fuelling the blitz of antibiotic-resistant microorganisms.

Surgical site infections (SSIs) are a major contributor to patient injury, mortality and health care costs, increasing mortality rates by two to three times, length of hospital stay by an average of seven days and charges by approximately $3000 (€2270).

The study published in the February issue of Archives of Surgery, one of the JAMA/Archives journals, said: "Antimicrobial prophylaxis (preventive treatment) to prevent SSI is one of the most widely accepted practices in surgery."

The study noted there was evidence that use of new, broad-spectrum antimicrobials and prolonged use of antimicrobials could promote antimicrobial-resistant bacteria and increase the incidence of antibiotic-associated complications, according to the article.

More and more hospital-acquired infections are resistant to the most powerful antibiotics available, methicillin and vancomycin. These drugs are normally reserved to treat only the most intractable infections in order to slow development of resistance to them.

"The results of this study raise additional concerns regarding antimicrobial resistance. Our data suggest that vancomycin continues to be used excessively for surgical prophylaxis," the authors of the study discovered.

According to Centres for Disease Control and Prevention (CDC), nearly two million patients in the United States get an infection in the hospital each year. Of those patients, about 90,000 die each year as a result of their infection-up from 13,300 patient deaths in 1992.

More than 70 per cent of the bacteria that cause hospital-acquired infections are resistant to at least one of the drugs most commonly used to treat them. Persons infected with drug-resistant organisms are more likely to have longer hospital stays and require treatment with second or third choice drugs that may be less effective, more toxic, and more expensive

Dale Bratzler of the Oklahoma Foundation for Medical Quality, Oklahoma City, and colleagues report results of an assessment of antimicrobial use to prevent SSIs for patients undergoing major surgery during 2001.

The study included a random sample of 34,133 patients. Records were examined to see whether SSI's were given within one hour before the surgical incision and the selection of safe and effective antimicrobials consistent with current published guidelines.

Overall, 55.7 per cent of patients received prophylactic antimicrobials during the 60 minutes before incision. Prior studies have demonstrated that timing is critical to the effectiveness of prophylaxis, and current guidelines recommend dosing within one hour before incision.

It noted that 9.6 per cent of the patients in our assessment received their first dose more than four hours after incision when little if any benefit would be expected based on these previously published guidelines.

"Most (92.6 per cent) of the patients in this assessment received a prophylactic antimicrobial regimen consistent with current guidelines," according to the study. "However, only 78.7 per cent received regimens that were limited to the recommended agents, suggesting that a substantial amount of antimicrobials are used unnecessarily."

Substantial opportunities remain to improve the use of prophylactic antimicrobials for patients undergoing major surgery. Achieving high rates of performance for appropriate antimicrobials to prevent SSIs will require the development of systems in which the knowledge from years of research and recommendation from clinical practice guidelines are routinely incorporated into practice.