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ne of the many challenges we face today in long-term care is the treatment of nonhealing wounds. As healthcare providers, we are faced with the challenge of providing appropriate antibiotics to treat these wounds. The purpose of this article is to provide guidelines for the use of antibiotics in wound care.
       Wound infections are classified as either superficial non-limb threatening or serious limb or life threatening. Superficial infections commonly present as soft-tissue redness or inflammation with or without purulent drainage. This is commonly referred to as cellulitis. The presence of pus indicates potential abscess formation, which must be drained surgically. Patients are not toxic in appearance, and oral antibiotic therapy for 7 to 14 days is generally sufficient. Treatment based on culture and sensitivity reports is optimal, but the choice of antibiotic is usually made empirically.
       Staphylococcus aureus and streptococcal organisms, such as Group A, B, C, or G, are usually the causes of these superficial infections. Antibiotic therapy with a first generation cephalosporin, such as cephalexin, is the customary empiric therapy in this instance. Cloxacillin, dicloxacillin, clindamycin, and amoxicillin-clavulanate are also useful empiric agents for suspected Staphylococcus or Streptococcal infections. For penicillin-allergic patients or patients with infections due to Gram-negative rods, such as Pseudomonas, therapy with a fluoroquinolone, such as levofloxacin or ciprofloxacin, is appropriate. Methicillin-resistant Staphylococcus aureus (MRSA) infections require intravenous vancomycin, as the aforementioned agents will be inactive against MRSA. Cultures from wounds, especially those obtained from superficial swabs, occasionally reveal Group D Streptococcus (enterococcus), Staph epidermidis (coagulase-negative Staphylococcus), or Candida fungal species. These organisms are frequently wound colonizers and do not require independent antibiotic or antifungal therapy.
       More serious limb- or life-threatening infections usually involve deeper tissue structures, such as tendon, muscle, or bone, and may involve tissue gangrene. Systemic toxicity manifested by fever, chills, leukocytosis, hypotension, tachycardia, and altered mental status may be present. These are indications for rapid hospitalization. These infections are often very aggressive, and surgical debridement is the rule to remove necrotic tissue and control infection. Intravenous (IV) antibiotic therapy is essential. IV therapy provides higher antibiotic tissue levels and eliminates the risk of variable gastrointestinal absorption that can occur with oral antibiotics. Treatment of bone, joint, and deep soft-tissue infections may require up to four to six weeks of IV antibiotics. Specific antibiotic therapy should always be guided by appropriate deep-tissue culture results.
       A myriad of IV antibiotic choices exists for these more serious infections. Often, there are multiple “correct” regiments. Empiric choices pending culture results are based on the need for broad-spectrum coverage of Gram-positive cocci, such as Staphylococcus aureus or Streptococcal organisms. A first-generation cephalosporin, such as cefazolin, or anti-staphylococcal penicillin, such as nafcillin, are the effective choices in this setting. Vancomycin is an appropriate agent when MRSA is a concern until culture results are available.
       In seriously ill patients, patients with diabetes, or the severely immunocompromised, coverage for mixed infections should be utilized. Organisms may include Gram-negative rods, such as Klebsiella or Pseudomonas, and anaerobes, such as Bacteroides. Gram-positive organisms should also be considered. Appropriate broad-spectrum single agents that will cover most pathogens in the compromised patient include extended-spectrum penicillins, such as ticarcillin-clavulanate, piperacillin-sulbactam, and carbapenems, such as imipenem-cilastin, or meropenem. Extended-spectrum cephalosporins, such as ceftriaxone or cefepime, are frequently used in this context. In life-threatening situations, vancomycin is frequently added until MRSA is ruled out by culture. Quinolones, such as levofloxacin, are sometimes added to potentiate Gram-negative rod coverage. Antianaerobic agents, such as clindamycin or metronidazole, are added to enhance anaerobic coverage. However, quinolones and antianaerobic agents should not be utilized as single-agent coverage in most situations unless indicated by the wound cultures.
       Several newer agents for the management of wound infections deserve mention. Ertapenem is a parenterally administered carbapenem with broad-spectrum coverage, excluding Pseudomonas. It has the ease of once-a-day administration and is proving useful in the outpatient and inpatient setting. Linezolid, an oxazolidinone, available orally and parenterally, has activity against vancomycin-resistant enterococcus (VRE) and MRSA. It is particularly useful for patients unable to tolerate vancomycin. Cefepime is a multigenerational parenteral cephalosporin that provides good Staphylococcus aureus (not MRSA) and Pseudomonas coverage in a single drug.
       Patient assessment and monitoring are essential parts of wound care treatment. The dose of antibiotic and the administration interval may have to be adjusted to compensate for the patient’s compromised metabolism. Interpretation of lab values and the patient’s tolerance of the therapy should be addressed. When administering vancomycin, it is important to measure serum levels of the antibiotic to prevent nephrotoxicity and ototoxicity. The rate of administration should also be addressed with vancomycin to prevent “Red Man Syndrome.”
       Chronic wounds do not heal for a variety of reasons. Infection is only one of the obstacles. A multidisciplinary approach is necessary to ensure optimal wound management, including adequate nutrition and control of underlying diseases, such as diabetes. Appropriate antibiotic selection is only a cornerstone.