Journal Reviews
Marinella MA, Pierson C, Chenoweth C, et al. The stethoscope: A potential source of nosocomial infection? Arch Intern Med 1997; 157:786-790.
Health care workers should clean stethoscopes regularly with isopropyl alcohol swabs to decrease bacterial colonization that could lead to cross-transmission between patients, the authors advise.
"There is enough evidence from our study to conclude that stethoscopes can be heavily colonized with potential pathogens and that simple cleaning significantly decreases bacterial load," they state. "Isopropyl alcohol seems to be the most effective, economical, and convenient agent to significantly decrease bacterial counts on the diaphragm and under the rim of stethoscopes. Since we have shown that the stethoscope is capable of supporting the survival of numerous types of bacteria that can potentially be transferred to patients, we recommend that all health care personnel regularly clean their stethoscopes with isopropyl alcohol swabs."
Knowing that stethoscope diaphragms have been shown to harbor potentially pathogenic bacteria, the authors sought to assess bacterial contamination on the diaphragm and under the plastic rim that secures the diaphragm of the stethoscopes of physicians, nurses, medical students, and house staff in an intensive care unit and a general medical ward of a large university hospital.
Aerobic and anaerobic bacterial cultures were performed on 40 randomly selected stethoscopes. They also compared the effects of isopropyl alcohol, sodium hypochlorite (bleach), and benzalkonium chloride swabs, as well as soap and water, on reducing bacterial contamination. The transmissibility of Micrococcus luteus inoculated onto a stethoscope diaphragm to clean human skin was also determined.
Overall, 11 different bacterial species were isolated, with coagulase-negative staphylococcus (CNS) present on 100% of stethoscopes and Staphylococcus aureus on 38%. Clostridium difficile was not isolated. Physicians’ stethoscope dia phragms had significantly more colony-forming units of coagulase-negative staphylococci than those of nurses. The most effective cleaning agent was isopropyl alcohol. In addition, M. luteus was transferred from inoculated stethoscopes to human skin, making it likely that more pathogenic bacteria can be transferred as well.
"The transfer of even small numbers of virulent or antibiotic-resistant organisms is of potential significance in the clinical setting," they concluded.
Tacconelli E, Tumbarello M, Pitttiruti M, et al. Central venous catheter-related sepsis in a cohort of 366 hospitalized patients. Eur J Clin Infect Dis 1997; 16:203-209.
The question of whether central venous catheters (CVCs) should be changed over a guidewire or removed directly in patients with suspected catheter-related sepsis remains controversial, the authors note. Their data indicate that the incidence of established infection is much lower than that of suspected infection, and that the exchange of CVC by the guidewire technique does not correlate significantly with an increased risk of development of CVC-related sepsis in patients in whom this procedure was routinely performed.
"Although this result could be related to the relatively small number of catheters routinely changed by the guidewire technique in our patients, we suggest a beneficial effect of this method," they concluded.
During the last several years, the management of acutely ill patients or patients requiring long-term intravenous therapy has changed because of the widespread use of CVCs. The major medical complication associated with the use of intravascular devices is infection, with CVC-related sepsis being the most common, often underestimated, and frequently incorrectly managed infectious complication. To underscore the problem, the authors of this Italian study cite U.S. data showing that 2% to 12% of CVCs cause sepsis, with an average of 100,000 patients affected annually.
The authors studied 502 central venous catheters inserted in 366 patients over a one-year period to determine the frequency and risk factors associated with catheter-related sepsis. For study purposes, in cases in which catheter infection was suspected but the initial blood cultures were negative, the catheters were replaced by guidewire technique; otherwise, the catheters were routinely changed after 21 days by guidewire technique. A catheter-related infection was suspected in 190 cases (190/502, 38%). A diagnosis of catheter-related sepsis was established in 50 patients, which represents 10% of the total number of lines (502). Catheter replacement over a guidewire was no more likely to be associated with sepsis than was percutaneous catheter insertion.
"In conclusion, although the incidence of established catheter infection is much lower than the incidence of suspected infection, in most cases of suspected infection it is wise to change the catheter with the guidewire technique and wait for culture of the tip, rather than remove the catheter immediately," they state. "Such a policy may help reduce the number of unnecessary catheter removals."
Subscribe Now for Access
You have reached your article limit for the month. We hope you found our articles both enjoyable and insightful. For information on new subscriptions, product trials, alternative billing arrangements or group and site discounts please call 800-688-2421. We look forward to having you as a long-term member of the Relias Media community.