Given the common incidence of puncture wounds, our roundtable experts continue their discussion (see page 32, November 2006 issue) by sharing key insights on appropriate antibiotic selection and how they prefer to close these wounds. Without further delay, here is what they had to say …
Q: What empiric antibiotics do you prescribe for puncture wounds?
A: For Michael Keller, DPM, the antibiotic selection depends upon three factors: the timing of presentation, the type of puncture and the type of patient.
If the patient presents with a simple but contaminated wound, one should direct antibiotics toward gram-positive organisms such as Staphylococcus spp. and Streptococcus spp., according to Dr. Keller. He notes one can give the patient ancef and nafcillin intravenously, and give cefdinir (Omnicef, Medicis) and cephalexin po. If one sees the patient in the delayed setting and he or she has a gross clinical infection, Dr. Keller says DPMs must have a high index of suspicion for deep space infection. This would require antibiotics as well as adequate incision and drainage, usually in the OR setting, according to Dr. Keller.
If the patient presents with a puncture wound through the plantar aspect of a shoe and there is a distinct possibility of osseous inoculation, Dr. Keller recommends both gram-positive and Pseudomonas spp. coverage. One can use imipenem/cilastin or clindamycin/ aztreonam IV.
Dr. Keller says if the patient has diabetes and is brittle, one should administer a broad-spectrum antibiotic due to the high rate of polymicrobial infection. He suggests amoxicillin/clavulanic acid PO or pipercillin/tazobactam IV. For all metallic or dirty puncture wounds, Dr. Keller advises clinicians to consider appropriate tetanus prophylaxis.
For Molly Judge, DPM, empiric oral antibiotic treatment depends on the nature of the wound. For a wound resulting from stepping on a sharp object in the home (a wound that is otherwise clean), she often prescribes a first-generation cephalosporin and awaits the results of my wound culture. Dr. Judge says the twice-a-day dosing of the oral third-generation cephalosporin, cefdinir, helps improve patient compliance. Dr. Judge notes that cefdinir covers Staph, Strep and E. coli, which can accompany cellulitus due to a foreign body. If the puncture wound involves a substance like soil or grass, she says the odds of having an anaerobe present are higher and amoxicillin-clavulanate is a good choice for an oral agent. For patients allergic to penicillin, Dr. Judge may use clindamycin due to its coverage of anaerobes in addition to Staph and Strep. She advises looking at the Medical Letter (www. medletter.com), which publishes guidelines for the choice of antibacterial drugs every spring.
Lawrence Karlock, DPM, typically prefers gram-positive Staph strips and the majority of these puncture wounds will grow gram-positive organisms.
Q: What antibiotics do you empirically use in a patient with no penicillin allergy? How about a patient with a penicillin allergy?
A: Dr. Judge suggests “keeping in mind that obtaining well-prepared wound cultures is paramount to successful infection management and that empiric antibiotic therapy does have a role.”
When it comes to the empiric use of antibiotics in a patient who is not allergic to penicillin, Dr. Judge calls herself a “purist.” She asserts that the most common pathogens in superficial wounds and ulcerations are Staph and Strep, adding that she will start with a course of cephalexin 500 mg qid, depending on the patient’s age and weight. In certain instances, she will adjust the dosage downward, particularly for an elderly patient, a patient with chronic renal dysfunction or an adult with a very frail size and stature.
Whenever a patient is admitted for inpatient care for an infection, Dr. Judge’s first priority is getting an infectious disease consult. If she encounters a severe ulcer or wound in a patient with diabetes who has several comorbidities and may have suspected poor glycemic control, Dr. Judge will use an agent with a beta lactamase inhibitor such as amoxicillin/ clavulanate for outpatients. For inpatients, she will use an IV variation such as piperacillin/tazobactam or ampicillin/ sulbactam.
“I keep a very close eye on these patients and if there is no evidence of improvement after 72 hours, I need to consider that I have overlooked something,” says Dr. Judge.
For someone with a penicillin allergy, Dr. Judge uses trimethoprim-sulfamethoxazole DS (160/800) bid and clindamycin 300 mg qid as alternatives, noting that one can give both medications via oral or IV routes. As she points out, it seems like a common pattern that some strains of methicillin-resistant Staphylococcus aureus are sensitive to trimethoprim-sulfamethoxazole. Accordingly, Dr. Judge makes this drug her first choice in patients who are allergic to penicillin but not allergic to sulfa.
“Each year, the infection control department gives an annual report for each individual hospital/facility regarding current bacterial strains and resistances,” adds Dr. Judge. “This is a good reference to help prevent the selection of an agent that has proved to be ineffective within a particular facility.”
Q: When do you consider primary closure of these wounds?
A: If the initial injury occurred less than eight hours before irrigation, drainage and debridement of all devitalized tissue, Dr. Keller says one may choose to close the wound primarily. If more than eight hours have elapsed, he suggests leaving the wound open to drain and using packing. If a reexamination of the wound shows no clinical signs of infection, Dr. Keller says one may close the wound five to seven days later.
For a wound that Dr. Judge sees in the “golden period” of a few hours after the injury, she often can clean the wound definitively, get cultures and do a loose primary closure. If she finds any contamination or a lot of tissue damage due to high energy trauma, such as a gunshot wound, Dr. Judge says it is probably best to debride, irrigate and pack the wound open even if one has treated it within six hours after the injury. As Dr. Judge notes, a delayed primary closure is frequently a good alternative to primary closure since it gives the DPM an opportunity to see the culture and sensitivity report, consider alternate antibiotics if necessary and then pursue a subsequent debridement prior to closure.
Dr. Karlock considers primary closure with acute wounds that have been irrigated thoroughly and are extremely clean. If he has any question as to whether the wound should be closed, Dr. Karlock recommends packing the wound open and performing primary closure later or even letting the wounds granulate in.
Dr. Judge is a Fellow of the American College of Foot and Ankle Surgeons. She completed a three-year surgical residency program in major reconstructive surgery for the leg, foot and ankle. She is board-certified in reconstructive rearfoot and ankle surgery. She has offices in Port Clinton, Ohio and Lambertville, Mich. Dr. Judge is the Official Foot and Ankle Physician for The Jamie Farr Owens Corning LPGA Classic.
Dr. Karlock is a Fellow of the American College of Foot and Ankle Surgeons, and practices in Austintown, Ohio. He is the Clinical Instructor of the Western Reserve Podiatric Residency Program in Youngstown, Ohio. Dr. Karlock is a member of the Editorial Advisory Board for WOUNDS, a Compendium of Clinical Research and Practice.
Dr. Keller is a Fellow of the American College of Foot and Ankle Surgeons. He is the Residency Director of the Benedictine Podiatric Residency Program (PM&S-36). He practices at Hudson Valley Foot Associates in Kingston, N.Y.
For related articles, see “How To Diagnose And Treat Foreign Body Injuries” in the June 2003 issue of Podiatry Today or “How To Treat Bite Injuries” in the May 2003 issue.
For more articles, please visit the archives at www.podiatrytoday.com .