Infections after surgery rare at St. Louis Children’s Hospital, study shows

Infections are one of the most common complications following surgery. They can cause severe illness and are costly to treat, but studies to identify patients most at risk typically include only adults.

Now, doctors at Washington University School of Medicine in St. Louis have documented the risk of infections following surgery in children. Looking at the medical records of children who had surgery at St. Louis Children’s Hospital from 1996-2008, they found that 159 of 16,031 children, or less than 1 percent, developed an infection at the surgical site within 30 days, they report in the Journal of the American College of Surgeons.

By comparison, the rate of surgical site infections in U.S. adults is 2.6 percent. Previous studies in U.S. children, conducted in the 1990s, show infection rates of 2-3.3 percent following surgery.

“The most common post-surgery complication in children is surgical site infections,” says senior author and pediatric surgeon Martin Keller, MD. “While the infection rate at St. Louis Children’s Hospital is very, very low, these infections are still a major concern. This study opens the door to new approaches to reducing post-surgical infections in young patients.”

Surgical site infections are a serious issue for children and their families. While adults generally have infected wounds cleaned and sterile dressings changed at the bedside, many children find the experience scary and painful. They often need additional sedation, sometimes in an operating room setting. Afterward, intravenous antibiotics are usually prescribed for seven to 10 days to fight the infection.

“There’s a huge impact on children and their families,” says first author Brian Bucher, MD, a surgery resident at the School of Medicine. “Many times, children who come back to the hospital with a surgical site infection need to be admitted to get the appropriate care.”

In the study, Keller, Bucher and their colleagues looked at the medical records of children who had orthopedic, plastic or general surgery, including operations on the face, joints, lungs, chest, esophagus and stomach. The researchers did not include patients having procedures in which a high level of bacterial contamination was present before surgery. These include surgeries to remove a perforated appendix or colon, for example.

Compared to children who did not get a surgical site infection, the researchers found that those at highest risk for infection were children admitted to the intensive care unit following surgery. These patients are acutely ill, even if for a relatively short time, but may be more susceptible to surgical site infections, the researchers say. Compared to children discharged to home after surgery, those who were admitted to the hospital also had an elevated risk of infection.

“We know that children admitted to the hospital are exposed to a wide variety of microorganisms, including antibiotic-resistant bacteria, which may increase the risk for surgical site infections,” Bucher says.

Other children who had an increased risk of surgical site infections were newborns, whose immune systems are still developing; children having a urinary catheter inserted, which may indicate these patients were quite ill; and those having a medical device implanted, such as orthopedic pins to set fractures or catheters to deliver medication or intravenous nutrition for an extended time period. These devices may limit the body’s ability to attack microorganisms already present at the surgical site by giving them a surface to cling to and grow on.

Compared to whites, African-American children also had a higher risk of infections following surgery, which the researchers say warrants additional study.

“Whenever you have a disparate outcome between ethnic groups, there’s always a question about whether it is a socioeconomic difference or a genetic difference, which in this case could make some children more susceptible to wound infections,” Keller says.

Overall, pediatric patients who had a surgical site infection stayed in the hospital longer, an average of 13 days, compared to children without an infection, who stayed eight days, on average. Forty-three patients discharged to home following surgery returned to the hospital with a surgical site infection; 28 of these patients (65 percent) were readmitted for treatment.

The researchers also found an increasing incidence of antibiotic-resistant bacteria in surgical site infections during the study, which parallels the trend doctors are seeing among children in the St. Louis community and nationwide. In 1996, all the bacteria cultured in the surgical site infections were sensitive to antibiotics, but by 2008, all the bacteria cultured in the post-surgery infections contained methicillin-resistant Staphylococcus aureus (MRSA), which is especially difficult to treat because it is resistant to most antibiotics.

“This is important data to have because many surgical site infections start with a stitch abscess after children are discharged, and then they come back to the hospital having been prescribed antibiotics that won’t cover MRSA,” Keller says.

While more study is needed, the researchers say the research provides information to help doctors determine which children may need to take antibiotics before surgery, to reduce the risk of infection or need more intensive monitoring after surgery.

Keller and Bucher add that one reason St. Louis Children’s Hospital may have a low rate of surgical site infections is because it is one of the few hospitals nationwide with a unit devoted solely to the treatment of wounds, including surgical site infections. Patients treated there have dedicated caregivers, who do not care for patients in other parts of the hospital, which reduces the spread of infections.

Bucher BT, Guth RM, Elward AM, Hamilton NA, Dillon PA, Warner BW and Keller MS. Risk factors and outcomes of surgical site infection in children. Journal of the American College of Surgeons. June 2011.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.