February 8, 2010 (Las Vegas, NV)
Paul Wischmeyer, MD, professor of anesthesiology and director of the Nutrition Therapy Services, University of Colorado at Denver School of Medicine, Aurora, and editor-in-chief of the Journal of Parenteral and Enteral Nutrition, reported the study findings here today at the American Society of Parenteral and Enteral Nutrition's 2010 Clinical Nutrition Week.
"These premade multichamber bags have all the components already in the bag," Dr. Wischmeyer noted in a telephone interview with Medscape Critical Care. "The pharmacist doesn't have to put needles into the bag and repeatedly violate the bag to create it. Every time you do that, you increase the risk of the bag being contaminated."
However, it is unclear whether the method of PN preparation affects BSI rates. Therefore, Dr. Wischmeyer and colleagues compared BSI rates and associated hospital costs in 31,129 adult critical care inpatients at 182 US hospitals who received PN between January 2005 and December 2007. All of them had a minimum intensive care unit stay of 3 days. A total of 1464 patients received PN via premixed multichamber bags (the MCB group), whereas 29,665 received similar hospital or outsourced compounded PN (the COM group).
The unadjusted BSI rate was significantly higher in the COM group than the MCB group (43.2% vs 35.1%; P < .001), Dr. Wischmeyer reported.
Patients receiving COM PN were somewhat sicker and more acutely ill than those receiving MCB PN. They were more likely to have major/extreme illness severity (96% vs 93%), more days on PN (9.7 vs 6.3), longer intensive care unit stay (13.4 vs 10.3 days), and longer hospital stay (24.7 vs 21.1 days; P < .001 for all).
After adjusting for these differences, the adjusted probability for BSI was roughly 9% higher with COM PN than with MCB PN (43.1% vs 39.2%; odds ratio, 1.20; 95% confidence interval, 1.12 - 1.67).
There are potential direct and indirect savings from using premade MCB PN, Dr. Wischmeyer said. A cost analysis of the data showed that BSI-related costs were $22,383 per infection. "The outright average daily cost for MCB PN was $119 versus $188 for COM PN, and over the hospitalization period you're looking at a difference of $730 for the multichamber bag vs $1598 for the compounded bag," he noted.
Dr. Wischmeyer noted that although premade multichamber PN bags are used widely in Europe, they are fairly new in the United States. Premade MCB PN is cheaper, he noted, "and it looks like they reduce infection as well."
"With the health care issues that we are faced with, and the enormous cost of parenteral nutrition itself, this is something that we are going to have to move to one way or another," he said.
In a telephone interview with Medscape Critical Care, Marcus Zervos, MD, division head of infectious diseases at Henry Ford Hospital/Henry Ford Health System, Detroit, Michigan, who was not involved in the study, said: "This study has several strengths — a very large number of patients and hospitals, and the use of multivariate analysis — but there are also a lot of important limitations to the study."
For example, because the patients in the COM group were sicker and in the intensive care unit longer "they would be expected to have more bloodstream infections for other reasons not related to the catheters or to whether PN was compounded or not," he noted.
"The rates of bloodstream infections are very high, reflecting infections not related to the parenteral nutrition, one way or the other, but related to the underlying disease," he also said.
Dr. Zervos cautioned against "drawing any sweeping conclusions from this trial," adding, "the findings need to be confirmed by other trials."
The study was supported by Baxter International, Deerfield, Illinois. Dr. Wischmeyer serves as a consultant to Baxter International. Dr. Zervos has disclosed no relevant financial relationships.
American Society of Parenteral and Enteral Nutrition's (ASPEN) 2010 Clinical Nutrition Week: Abstract SP42. Presented February 8, 2010.