Surgical Protocol Significantly Cuts Shunt Infection Rate

Pauline Anderson

July 05, 2011

July 5, 2011 — A standardized protocol for shunt surgery in children with hydrocephalus reduces the risk for cerebrospinal fluid shunt infection by 36%, according to a new study.

The analysis suggests that double gloving by surgical team members and using antibiotic-impregnated sutures significantly lowers the risk for infection, whereas the use of Bioglide catheters and antiseptic cream instead of doing a formal scrub significantly raises the risk for infection.

"The basic principle is that if you standardize things and everybody does it the same way and you reduce variation, you usually improve outcomes as well as improve efficiency and other things. I'm not sure that the content, the steps, are as important as the fact that everybody does it the same — within reason," lead study author John R. W. Kestle, MD, chief of pediatric neurosurgery, Primary Children's Medical Center, University of Utah, Salt Lake City, told Medscape Medical News.

The study is published in the July issue of the Journal of Neurosurgery: Pediatrics.

Wide Variation in Perioperative Techniques

In the past, pediatric neurosurgical centers used perioperative techniques that varied from center to center. The Hydrocephalus Clinical Research Network (HCRN), a collaboration of 4 such centers, used current literature to develop a standardized, 11-step protocol in an effort to reduce the risk for shunt infection.

To test the protocol, researchers entered all children at each HCRN center into a study when the youngsters underwent a shunt insertion or shunt revision operation. They evaluated patients for infection at the time of routine clinical follow-up, emergency department visits, or hospital admission.

The primary endpoint of the study was shunt infection, which was determined using cultures or was apparent through shunt erosion, which was defined as a wound breakdown with visible shunt hardware.

Researchers also gathered data from each center on shunt infection rates for the 12 months preceding introduction of the protocol. They noted that the preprotocol data may have underestimated the infection rate because they didn't include shunt erosion in the definition of infection.

The analysis included results from 1571 shunt procedures performed by 21 surgeons on 1004 children from June 1, 2007, to February 28, 2009. The median age of the patients was 5.2 years, and there was a mean of 20.5 weeks from shunt insertion.

The most common procedure was shunt revision (61%) followed by shunt insertion (26%).

Rethinking Antiseptic Creams

Fifteen surgeons performed 40 or more procedures. These surgeons accounted for 92.4% of the procedures. Surgeon-specific infection rates varied from 0% to 12.9% and did not appear to correlate with surgeon procedure.

The study showed that the infection rate during the study was 5.7% compared with 8.8% before introduction of the protocol. This represents an absolute risk reduction of 3.2% but a relative risk reduction of 36%.

The procedure with the highest risk for infection (11%) was shunt insertion after treatment of an infection, but this was substantially lower than a previously reported rate of 26%.

"This disparity may indicate that the protocol is particularly effective for procedures at the highest risk of infection," the study authors write.

The investigators found that the most important risk factor for infection was the lack of proper handwashing technique involving the use of a scrub brush to clean under nails and sponges with betadine or chlorhexidine. The infection rate with proper handwashing was 5.61% compared with 20% without.

The study appeared to counter current thinking about antiseptic cream that is now in most hospital operating rooms (ORs).

"After being introduced a few years ago, all of a sudden these squirt bottles show up on the wall on the side where you scrub your hands, and we’re told by the OR that it’s okay to use it instead of scrubbing," said Dr. Kestle.

Double Gloving

Other factors associated with significantly lowering the risk for infection included double gloving by the surgical team, which was linked to an infection rate of 5.60% compared with 14.71% when such a step was missing; preoperative patient hair washing with chlorhexidine shampoo; and the use of antibiotic-impregnated sutures.

Compliance with the protocol was good, with perfect compliance improving during the study. Among the 1512 procedures with accurate compliance data, all 11 steps of the protocol were completed in 74.5%.

Among the most commonly missed steps were injecting vancomycin and gentamicin into the shunt reservoir and positioning the patient with the operative site away from the main OR door, the idea being that if the wound is kept as far as possible from traffic, opportunities for infection are minimized.

Dr. Kestle said he was pleasantly surprised by the compliance rate, considering that a multicenter study of an OR checklist, carried out by the World Health Organization, showed a much lower compliance rate among surgeons. "Probably the simpler the protocol, the better the compliance," he said.

Simpler Is Better

The infection rate reduction was observed at 3 of the 4 centers; the protocol had no apparent effect at the fourth center. The study authors noted that this center was the only one to use BioGlide shunt catheters that have been associated with a near doubling of infection risk.

The part of the shunt that goes in the brain has been taken off the market — for a different reason — but not the tubing that runs from the head to the abdomen, which still has BioGlide on it, said Dr. Kestle.

Developing the protocol was easier than expected, said Dr. Kestle.

"We started at our own center with 4 of us agreeing and then we started adding other centers. We had to give and take a little, but it wasn’t too bad." Hospitals that didn’t have one of the prep solutions had to approve that product and get it stocked, which slowed the process somewhat, he said.

The HCRN has expanded to include 7 centers with data on more than 3000 patients now collected. "It looks like the low infection rate has continued," said Dr. Kestle.

The next step is to simplify the protocol and perhaps remove parts that may not be beneficial. "But once you’ve got the protocol, you can add one step or delete one step and modify it," he said.

Another possibility is to test shunts that are impregnated with an antibiotic. "We decided not to include those in the protocol because they’re expensive; injecting the antibiotics is a lot cheaper," said Dr. Kestle

Note for Neurosurgeons

Commenting on the study for Medscape Medical News, Paul Graham Fisher, MD, professor, neurology and pediatrics, and chief, Division of Child Neurology, Stanford University and Lucile Packard Children's Hospital, Palo Alto, California, said the study was encouraging.

"One of the take-home messages is that quality improvement is not just for general pediatricians and general surgeons; it’s for neurosurgeons, too," he said.

Another important point illustrated by the findings is that it's the simple things that ring true, he added.

"You can keep pushing the science and the technology, which we will, but you can never forget the fundamentals like handwashing. It’s intuitive, but it’s important to point out and to remember."

The importance of handwashing in the OR appears to have gone full circle. "That was sort of the standard of business and then all these gels and creams have come on."

Now, many hospitals are beginning to monitor handwashing behavior, with some even getting patients to reveal whether or not their physician washed his or her hands, he added.

The study was funded by private philanthropy and the National Institute of Neurological Disorders and Stroke. One of the authors, Dr. Simon, is supported by award K23NS062900 from the National Institute of Neurological Disorders and Stroke and by funding to the Pediatric Research in Inpatient Settings Network Executive Council provided by the Child Health Corporation of America. Dr. Simon’s work was supported in part by a Primary Children’s Medical Center Innovative Research Grant and the Children’s Health Research Center at the University of Utah.

J Neurosurg Pediatr. 2011;8:22-29.

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