February 2011

IDSA Releases First Guidelines On MRSA

By Brian McCurdy, Senior Editor

Recognizing the rise of methicillin resistant Staphylococcus aureus (MRSA) and its role in infections acquired in the hospital and community, the Infectious Diseases Society of America (IDSA) has released its first guidelines on treating MRSA.

   The IDSA recommends that for hospitalized patients with complicated skin and soft tissue infections (cSSTI), along with surgical debridement and broad-spectrum antibiotics, one should consider empirical therapy for MRSA. Warren Joseph, DPM, notes this is a major point as the IDSA recommends that “pretty much all” patients with cSSTIs should begin anti-MRSA treatment. He says the guidelines do not give any leeway for local or regional variations in MRSA incidence.

    “Frankly, in the past six months to a year, most of our admitted patients are not growing MRSA at this point,” says Dr. Joseph, who is affiliated with the Roxborough Memorial Hospital in Philadelphia. “I have actually started going back to escalation (no MRSA empiric coverage) therapy in some cases.”

   Noting MRSA’s high prevalence, Mark Kosinski, DPM, says it is prudent to use an MRSA active agent as part of empiric therapy for severe infections. He notes that based on the culture results and clinical response, one can decide to continue or discontinue use of the antibiotic.

   “Those first few days, when you are waiting for the culture and sensitivity report to come back, can be the most critical,” says Dr. Kosinski, a Fellow of the IDSA. “Time can’t be wasted giving the wrong antibiotic. Failure to cover MRSA in a serious infection could lead to worsening of the infection and result in loss of life or limb.”

What The Guidelines Say About Vancomycin Dosing

For patients with normal renal function, the IDSA recommends IV vancomycin 15 to 20 mg/kg (actual body weight) every eight to 12 hours, and not to exceed 2 g per dose. For seriously ill patients with suspected MRSA, the guidelines call for a loading dose of 25 to 30 mg/kg (actual body weight).

   In addition, the IDSA notes trough vancomycin concentrations are the most accurate and practical method to guide vancomycin dosing. One should obtain serum trough concentrations after achieving steady state conditions, prior to the fourth or fifth dose, according to the guidelines, which do not recommend monitoring of peak vancomycin concentrations. The guidelines suggest vancomycin trough concentrations of 15 to 20 µg/mL for serious infections, such as bacteremia, infective endocarditis, osteomyelitis, meningitis, pneumonia and severe SSTI like necrotizing fasciitis due to MRSA.

    “There is essentially no good evidence to support bumping vancomycin dose/levels that high in lower extremity infections,” says Dr. Joseph, a Fellow of the IDSA.

   Dr. Joseph has a concern that many practitioners are significantly increasing vancomycin doses and maintaining troughs of 15 of 20 µg/mL despite little evidence of increased efficacy and good evidence of increased renal toxicity. He supports troughs between 10 and 15 µg/mL.

   Similarly, Dr. Kosinski questions whether vancomycin trough dosing at 15 to 20 µg/mL will cause an increase in adverse events, most notably nephrotoxicity. “This in itself may be sufficient reason to start using the host of other MRSA active agents available,” he says. “It’s time to be iconoclastic and disrupt the vancomycin gold standard status quo.”

   For further reading, see Dr. Joseph’s Handbook of Lower Extremity Infections blog at www.leinfections.com/ . Dr. Joseph also blogs for Podiatry Today at http://www.podiatrytoday.com/blogs/warren-s-joseph-dpm-fidsa.

Can The Semmes Weinstein Monofilament Help Predict Ulcer Risk?

By Brian McCurdy, Senior Editor

A small monofilament is an effective predictor of ulceration and amputation in patients with diabetes, according to a recent systematic review published in the Journal of Vascular Surgery.

   Researchers surveyed the literature and identified nine relevant studies of 11,007 patients with diabetes. The studies concluded that the risk of diabetic foot ulcers for patients with positive Semmes Weinstein results was 2.5 to five times higher than for those with negative monofilament results. In addition, authors note patients with positive Semmes Weinstein tests were 1.5 to 15 times more likely to have a lower extremity amputation than those with negative Semmes Weinstein exams.

   Calling the Semmes Weinstein a “godsend,” Kathleen Satterfield, DPM, cites advantages that the monofilament is inexpensive, portable and anyone can be trained in its use. However, she notes downsides in that the devices are so malleable they can easily deform and one must replace them frequently.

    “There are some quality sets that last longer but we often turn to the free ones that come attached to a piece of folded paper,” says Dr. Satterfield, an Associate Professor in the College of Podiatric Medicine at the Western University of Health Sciences in Pomona, Calif. “They are so flimsy that I suspect that they are not meant for more than just a couple of patient exams.”

   Dr. Satterfield used the Semmes Weinstein monofilament on all patients with diabetes. She notes that unlike some more expensive screening examinations such as the vibrometer, tuning fork or the electromyography (EMG)/nerve conduction velocity (NCV) test, it is less expensive and more effective for the physician to take 30 seconds to perform a Semmes Weinstein test.

    “Through this testing for neuropathy, I have captured patients who had diabetes and who did not have a clue,” maintains Dr. Satterfield. “It is fast, free and without any complications. You cannot ask for a better overall test.”

How Can DPMs Predict Return To Activity After Achilles Surgeries?

By Brian McCurdy, Senior Editor

A recent retrospective review in the Journal of Foot and Ankle Surgery evaluated the efficacy of three criteria in determining when Achilles surgery patients should return to activity postoperatively.

   For the review, researchers looked at 219 patients who underwent Achilles tendon surgery from 1990 to 2005. Researchers evaluated three criteria: the patients’ ability to perform five sets of 25 concentric heel raises on a single leg; symmetry of calf girth; and ankle range of motion. Fourteen patients who did not meet all three criteria experienced a delayed return to activity, according to the study. The authors of the review note the time for return to activity ranged from an average of 6.5 weeks for patients with peritenolysis to an average of 31.6 weeks after repair of a chronic tendon rupture.

   To predict return to activity, Kent Sweeting, B.Hlth.Sc.(Pod)(Hons), uses the heel raise test and studies heel raise endurance in comparison to the unaffected side. His patients also take a hopping test in which he assesses the height of a hop, control of the whole kinetic chain and hopping endurance, and compares all results to the unaffected side.

   While stretching and eccentric exercises may be effective pre-surgery and possibly after surgical procedures like peritenolysis, lead study author Amol Saxena, DPM, says they are “not useful and possibly detrimental” after most other Achilles procedures such as insertional repair, retrocalcaneal exostectomies and ruptures.

    “In fact, some therapists find that when patients cannot do a concentric heel raise, they’ll have them do an eccentric exercise program and then patients get worse,” says Dr. Saxena, the Fellowship Director in the Department of Sports Medicine at the Palo Alto Medical Foundation in Palo Alto, Calif.

   Dr. Saxena emphasizes that patients should only start on eccentric exercises when they can achieve concentric heel raises. To help with concentric heel raises, he suggests patients use a pool or an AlterG anti-gravity treadmill (AlterG).

   Dr. Sweeting also uses stretching and eccentric exercises. In the middle and latter stages of recovery (not the early phases), Dr. Sweeting has patients wear night splints to hold the ankle in varying degrees of dorsiflexion. During stretching, his patients isolate both the gastrocnemius muscles (leg straight) and soleus muscle and Achilles tendon (leg bent).

   Other physical therapy options in his Australian practice include dry needling and ankle mobilizations, which are useful in restoring normal ankle range of motion, according to Dr. Sweeting, a Research Fellow in the School of Medicine at the Logan and Gold Coast campuses of Griffith University in Australia.

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