By Michael Smith, North American Correspondent, MedPage Today Published: May 05, 2011 Reviewed by Dori F. Zaleznik, MD ; Associate Clinical Professor of Medicine, Harvard Medical School, Boston and Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
While attention has been lavished on the infection risks associated with central venous catheters, the risk of bacteremia associated with peripheral venous catheters goes largely unrecognized, researchers reported. In a retrospective, single-institution study, Staphylococcus aureus bacteremia linked to peripheral venous catheters occurred at an estimated rate of 0.07 per 1,000 catheter-days, according to Leonard Mermel, DO, ScM, and colleagues at Rhode Island Hospital in Providence, R.I. While that’s low compared with the rate of S. aureus bacteremia associated with central lines, it works out to more than 10,000 cases a year among adult inpatients in the U.S., Mermel and colleagues reported online in Infection Control and Hospital Epidemiology.
Explain that a study of Staphylococcus aureus bacteremia in patients with peripheral venous catheters found that placement in the antecubital fossa, insertion in the emergency department, and longer duration of catheterization were risk factors.
Note that the study took place in a single institution.
The study "reaffirms the substantial medical burden" associated with such infections, Mermel and colleagues reported.
Infections associated with central lines have been the focus of a concerted prophylactic effort. Indeed, the CDC reported recently that bloodstream infections associated with a central line in intensive care units had fallen 58% over a nine-year period.
But although a large number of inpatients have a peripheral venous catheter (also known as a peripheral IV) inserted at some time during their hospital stay, Mermel and colleagues described S. aureus bacteremia as "an under-recognized complication" of the devices.
To help clarify the matter, they analyzed the records of all adult inpatients at their tertiary care teaching hospital from July 2005 through March 2008. To get a handle on how often peripheral lines were inserted, they conducted a point-prevalence analysis on Jan. 9, 2008.
All told, the study looked at 77,852 adult discharges; records showed 544 cases of S. aureus bacteremia, Mermel and colleagues reported.
The majority of those — some 69% — arose from either soft tissue or bone or a central line, they found. But 24 cases, or 4% of the total, were associated with a peripheral venous catheter.
The point-prevalence analysis showed that 76% of inpatients had a peripheral IV, they reported. In all, there were 451,366 patient-days during the study period, so that there were approximately 343,130 patient-days with a peripheral IV.
In other words, Mermel and colleagues reported, the estimated incidence density of S. aureus bacteremia associated with the devices was 0.07 per 1,000 peripheral line-days.
Analysis of the 24 cases found that patients with peripheral IV-related S. aureus bacteremia were:
More likely to have the IV placed in the antecubital fossa, the so-called "elbow pit." The odds ratio was 6.5, which was significant at P<0.001.
Less likely to have had it placed in the hand or forearm. The odds ratios were 0.23 and 0.37, respectively, and both were significant at P=0.03.
More likely to have had the line inserted in the emergency department. The odds ratio was 6.03, which was significant at P<0.001.
Less likely to have had it inserted on an inpatient medical unit. The odds ratio was 0.17, which was also significant at P<0.001.
The researchers also found that longer duration of catheterization was associated with an increased risk of bacteremia. The median duration for those with infection was three days, compared with one for those without. The difference was significant at P<0.001.
Nearly half of the cases – 10 of the 24, or 42% — encountered complications as a result of the infection, Mermel and colleagues reported.
The researchers cautioned that the comparison group for the study was uninfected patients in the point-prevalence analysis, which may not have been a representative sample.
As well, they noted, the incidence may have been underestimated because of the retrospective design and the tendency of physicians to overlook peripheral IVs as a possible source of bacteremia.
?The study had no external support. Mermel reported financial links with Theravance, Pfizer, CorMedix, Ash Access, Semprus, CareFusion, Bard, and Catheter Connections, although none of these activities involved peripheral intravenous catheters.
Primary source: Infection Control and Hospital Epidemiology Source reference: Trinh TT, et al "Peripheral venous catheter-related Staphylococcus aureus bacteremia" Infect Control Hosp Epidemiol 2011; 32(6): DOI: 10.1086/660099.