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Effectiveness of chlorhexidine alone, clindamycin for invasive strep, and more.

Solo chlorhexidine not as efficacious as many believe, researchers say

Chlorhexidine by itself is not as efficacious for skin antisepsis as many believe, according to a recent systematic review.

The researchers became concerned when they noticed that several clinical study and review authors had concluded chlorhexidine was superior to povidone-iodine, though the studies/reviews themselves had pitted a combination of chlorhexidine and alcohol against povidone-iodine. They did a systematic review of studies that looked at skin antisepsis performed before blood culture collection, before vascular catheter insertion and during catheter maintenance, and before surgery. They studied the clinical outcomes as well as the articles' conclusions to see if incorrect attributes were “carried over into the tertiary literature,” they said.

While the researchers found solid evidence that chlorhexidine/ alcohol was superior to povidone-iodine for all 3 applications, they didn't find superiority when comparing the former to combinations of alcohol with substances other than chlorhexidine. Also, they found no evidence that chlorhexidine without alcohol was effective for preventing surgical site infections, blood culture contamination, and catheter-related bloodstream infections. They did find chlorhexidine was superior to povidone-iodine for preventing catheter colonization, however. Results were published in the Aug. 8 Journal of Antimicrobial Chemotherapy.

In looking at the conclusions of the articles they reviewed, the authors found that between 29% and 43% incorrectly attributed the efficacy of chlorhexidine/alcohol solely to chlorhexidine, and in an additional 8% to 35%, the attribution was ambiguous. The result is “a potentially mistaken rejection of alternative antiseptics...on the basis that they do not contain chlorhexidine...and...unsubstantiated recommendations in major clinical guidelines,” the authors wrote. In addition, caregivers may incorrectly use chlorhexidine on its own, thus exposing patients to a higher risk of infection, they said.

Clindamycin may lower death risk from severe invasive group A streptococcal infection

Patients with severe invasive group A streptococcal (iGAS) infections who received clindamycin were less likely to die than those who didn't, a recent study found.

Australian researchers conducted a prospective, population-based, active surveillance study of iGAS infections in the state of Victoria from March 2002 through August 2004. Their primary analysis assessed the effect of any clindamycin treatment, while in secondary analysis, the clindamycin group was divided into those who did or did not also receive intravenous immunoglobulin (IVIG). In 2005, they also attempted to ascertain the number of household contacts of each iGAS patient who had survived and provided consent and contact information. Results were published in the Aug. 1 Clinical Infectious Diseases.

Three hundred thirty-three people had confirmed iGAS disease during the study period, of which 84 met the definition for severe iGAS disease (streptococcal toxic shock syndrome [STSS], necrotizing fascitis, septic shock, or GAS cellulitis with shock). Clindamycin was used in 63% of cases (n=53) and IVIG was used in 17% (n=14). All patients who received IVIG also received clindamycin. Although patients treated with clindamycin had more severe disease than those who didn't get the drug, they had lower mortality (15% vs. 39%; odds ratio, 0.28; P=0.014). Those who received IVIG along with clindamycin had a fatality rate of 7%, but this was not significantly different from the clindamycin-only death rate. Three cases of iGAS infection were reported to have occurred in household contacts of index cases, all within 8 days of the index case, making the incidence rate of iGAS in household contacts 2,011 times higher than the population incidence of Victoria.

There is ongoing debate as to whether clindamycin should be used only for patients with STSS, the authors noted. However, this study suggests clindamycin should be used with beta lactam antibiotics in all severe iGAS disease, whether or not STSS is present, they wrote. “Until further studies provide more evidence as to which patients will benefit from clindamycin, we suggest that our definition of severe iGAS disease (STSS, necrotizing fascitis, septic shock or cellulitis with hypotension and evidence of GAS infection) may be an appropriate basis for clinical guidelines,” they wrote.

As for the risk to household contacts of those with severe iGAS disease, “given the rarity, severity and high case fatality of iGAS disease, we believe that antibiotic prophylaxis is warranted for household contacts and poses little risk from the use of additional antibiotics,” they added.

IDSA guidelines call for accurate diagnoses, fewer antibiotics for skin and soft-tissue infections

Skin and soft-tissue infections (SSTIs), even those caused by methicillin-resistant Staphylococcus aureus (MRSA), are often minor and either heal on their own or can be easily treated without antibiotics, according to updated practice guidelines.

The guidelines, issued by the Infectious Diseases Society of America, are meant to help physicians make the correct diagnosis, establish the source and cause of the infection, determine its severity, and help physicians know when antibiotics are and are not necessary.

Emergency department visits due to SSTIs nearly tripled from 1.2 million in 1995 to 3.4 million in 2005, much of the increase driven by MRSA, the guideline noted. SSTIs account for more than 6 million visits to doctors' offices every year. The guidelines appeared in the July 15 Clinical Infectious Diseases.

About half of SSTIs are caused by staph bacteria and are purulent, typically red, swollen, hot to the touch, and painful. Purulent infections are usually no larger than a few inches, have a focal point of infection, and are filled with pus. Most will clear on their own or should be treated with incision and draining alone, not antibiotics, the guidelines said.

Specifically, the guidelines recommend performing a Gram stain and culture of pus from carbuncles and abscesses, but treatment without these studies is reasonable in typical cases (evidence: strong, moderate). It is not recommended to perform a Gram stain and culture of pus from inflamed epidermoid cysts (evidence: strong, moderate). The guidelines recommend incision and drainage for inflamed epidermoid cysts, carbuncles, abscesses, and large furuncles (evidence: strong, high).

Use of antibiotics for S. aureus as an adjunct to incision and drainage should be based on whether there are symptoms of systemic inflammatory response syndrome, such as temperature higher than 38° C or less than 36° C, tachypnea more than 24 breaths per minute, tachycardia more than 90 beats per minute, or white blood cell count greater than 12,000 or less than 4,000 cells/µL (evidence: moderate). An antibiotic active against MRSA is recommended for patients with carbuncles or abscesses who have failed initial antibiotic treatment or have markedly impaired host defenses or in patients with SIRS and hypotension.

Other SSTIs are caused by non-staph bacteria such as group A streptococcus, which produce toxins instead of pus and are more likely to be severe and even deadly, causing serious infections such as cellulitis, necrotizing fasciitis, or gangrene, the guideline stated. Non-purulent SSTIs do not have a focal point and continue to spread. Even mild or moderate non-purulent cases typically require antibiotic treatment, sometimes provided intravenously. These infections require speedy diagnosis, surgery to remove the infection, and antibiotic treatment. In the case of severe non-purulent SSTIs such as necrotizing fasciitis or group A streptococcus gangrene, the infected material should be removed surgically.

The guidelines contain a chart to help physicians quickly diagnose and treat the SSTI based on whether or not it is purulent; determine whether the infection is mild, moderate or severe; and recommend appropriate treatment. Again, physicians should be most concerned when a patient with any SSTI, whether purulent or not, has a fever higher than 38° C, a high white blood cell count, or a rapid heart rate; is breathing fast; or is immunocompromised.

The updated IDSA guidelines also provide extensive recommendations for:

  • treating SSTIs in immunocompromised patients, including those with HIV/AIDS or those who have had an organ transplant,
  • treating recurrent skin abscesses and cellulitis,
  • providing preferred management of surgical-site infections, and
  • treating animal bite wounds.

High-value care program shows initial promise

A high-value care program launched by hospitalists at a large academic center is yielding promising results, including a more than 50% decrease in nebulizer use, researchers have reported.

Hospitalists and other staff at the University of California, San Francisco, kicked off their high-value care program in March 2012 on a single medical ward, with the following goals: Identify areas of wasted resources within the hospital medicine service, promote interventions that improve care and value, and increase cost awareness among staff. They targeted 6 areas in their first year, including reducing overuse and inappropriate use of gastric stress ulcer prophylaxis; decreasing by 25% the units of blood transfused for a hemoglobin >8.0 g/dL; decreasing by 15% the number of patients (with length of stay >48 hours) who are on telemetry until discharge; reducing by >25% over 6 months the number of ionized calcium labs drawn on the medicine service; and decreasing by 25% inappropriate repeat transthoracic echocardiograms (TTEs).

The sixth aim, and the flagship project, was to reduce by >15% over 9 months the unnecessary use of nebulized bronchodilator therapies (nebulizers), improve transitions from nebulizers to metered dose inhalers (MDIs), and improve patient self-administration of MDIs. The estimated annual cost for the whole program is between $50,000 and $75,000, the authors wrote. Results were published online July 1 by the Journal of Hospital Medicine.

The program has led to a decrease in nebulizer rates of more than 50% on a high-acuity floor and a savings of about $250,000, the researchers reported. Data from the other 5 areas are forthcoming, they said. The program also has supported the development and use of practice guidelines on gastric stress ulcer prophylaxis, which led to a decrease in the use of this prophylaxis in ICU patients from 19% to 6.6% in the first month of implementation, they added.

The initial success of the program provides “a framework to guide physician-led initiatives to identify and address areas of healthcare waste,” the authors wrote. Since implementing the program, they added, the authors have anecdotally noticed more discussion of testing costs: “It is common now to hear ward teams on morning rounds consider the costs of testing or discuss the need for prophylactic proton pump inhibitors,” they wrote.