Typically when infection preventionists (IP) evaluate bloodstream infection rates, their initial thoughts turn to central line compliance. Rarely is there much attention given to the use of multichamber bags versus compounded bags for parenteral nutrition.
But a study that was presented at the Infectious Diseases Society of America's (IDSA) 47th annual meeting October 29–November 1 found that the way in which parenteral nutrition is delivered could affect bloodstream infections among high-risk patients.
Authors of the study focused their research specifically on the oncology unit because patients in that unit are already susceptible to infections, says Robin Turpin, PhD, senior director of health economics in IV nutrition at Baxter Healthcare Corporation in Deerfield, IL.
"In this particular analysis, we were interested in looking at the oncology population because they were high risk," Turpin says. "They already have a compromised immune system, so we had thought they might be at a higher risk [for bloodstream infections]."
By evaluating data among 19,540 patients, Turpin and her colleagues found that patients who were given compounded bags were more likely to have major or extreme illness severity, more days of parenteral nutrition, more days in the ICU, and a longer overall hospital length of stay. After adjusting baseline differences, the study concluded that the adjusted probability for bloodstream infections was 19% higher for compounded bags compared to multichamber bags.
"It has been fairly well documented in literature that parenteral nutrition is a risk factor for bloodstream infections, but we were curious as to, in general, if different types of preparation may have a higher risk versus another," Turpin says. "Because compounding parenteral nutrition is a very different process than a multichamber bag, we were curious."
Compounding is more popular
Compounding parenteral nutrition is a process in which a pharmacist takes the amino acids, dextrose, and perhaps lipids, depending on the physician's prescription, and literally mixes the nutrients in the pharmacy under aseptic conditions. Multichamber bags are dual-chamber bags with premixed solution that can be mixed by rolling the chambers together. Additional vitamins and micronutrients can be added if needed.
For whatever reason, the compounding process has become a standard of practice in the United States, says Turpin. The IDSA study found that more than 18,000 of the 19,540 patients were given compounded parenteral nutrition. Other countries, such as France, favor multichamber bags.
"I don't think there is necessarily clinical evidence for that," Turpin says. "In the U.S., there is just a lot of compounding."
Developing a standardized process
The reason multichamber bags may lead to fewer bloodstream infections is because they involve a much more uniform process. Compounded bags provide a much larger window for human error by breaking a sterile barrier.
"A multichamber bag is really a standardized parenteral nutrition [process], and we believe, and sometimes you see thought leaders that publish this, probably a good number of patients can really be serviced with a standard parenteral nutrition," Turpin says. "Some [patients] certainly would need some customized, which is where compounding is ideal. In other words, there are some patients for which compounding is ideal, then there is a large group of patients where a multichamber bag is great too."
Unlike some infection prevention checklists or processes, there is no cut-and-dry determination for when each approach produces the most favorable results. Because this was a retrospective study, the final numbers produced very limited evidence. Turpin says Baxter does have some prospective studies in the works that may provide much more consistency across all units and populations.
"But it's not just a prospective study within the hospital, we also have a study looking at home care patients as well," Turpin says. "It's looking at various patient populations. [We will know more] assuming we find similar results."
Raising questions
This study is not intended to be the final recommendation for parenteral nutrition use across all hospital units, Turpin says. Although authors of the study had a vast amount of variables and data to work with, they still only focused on the oncology unit, and there are likely many more factors yet to be determined.
Rather, it's a chance for IPs to look at the process that is used at their hospital and consider whether an alternative solution might help in particular instances.
"I think for infection control practitioners, what they love about this is really just raising the issue," Turpin says. "It's providing some more information for people to understand a little bit more about these issues, raise the issue, and say, 'Wait a minute, let's look a little bit more carefully.' "
The study was well received by IDSA meeting attendees. "I think people seemed to be very, very interested in the bloodstream infection issue, and I think people hadn't considered the whole parenteral nutrition piece of it before," Turpin says.
This article was adapted from one that originally appeared in the January 2010 issue of Briefings on Infection Control, an HCPro publication.