You are in: eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > PHARMACOLOGY Antibiotics, Prophylactic Use in Head and Neck SurgeryArticle Last Updated: May 2, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 7
  Author: Jonathan P Lindman, MD, Consulting Staff, Department of Otolaryngology, ENTCare Associates Jonathan P Lindman is a member of the following medical societies: Alpha Omega Alpha, American Academy of Otolaryngology-Head and Neck Surgery, Phi Beta Kappa, and Triological Society Coauthor(s): Remy H Blanchaert, Jr, MD, DDS, Director, OMS Residency Program, Assistant Professor, Department of Oral and Maxillofacial Surgery, University of Maryland Medical Center; Alexander E Pazoki MD, DDS, Director, Postgraduate Program, Baltimore College of Dentistry Editors: William M Lydiatt, MD, Associate Professor, Department of Otolaryngology-Head and Neck Surgery, University of Nebraska Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Karen Hall Calhoun, MD, Chair, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Missouri; Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders; Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine Author and Editor Disclosure Synonyms and related keywords: prophylactic antibiotics, prophylaxis, antibiotic, antimicrobial INTRODUCTIONSection 2 of 7
  Prophylaxis with antimicrobials has decreased the high incidence of wound infection after head and neck operations that involve incisions through oral or pharyngeal mucosa. Prophylactic administration of antibiotics can decrease postoperative morbidity, shorten hospitalization, and reduce overall costs attributable to infections. Principles of prophylaxis include providing effective levels of antibiotics at the time of wound exposure and effective prophylactic regimens. The regimen should be directed against the most likely infecting organisms. Only those organisms commonly cited as pathogens need to be eradicated. Many antimicrobials require a single dose given within 30 minutes of skin incision to provide adequate tissue concentration throughout the operation. Additional doses during the procedure are advisable if surgery is prolonged (ie, > 4 h), major blood loss occurs, or an antimicrobial with a short half-life is used. The aim of prophylaxis is to augment host defense mechanisms at the time of bacterial invasion, thereby decreasing the size of the inoculum. Prophylaxis is an attempt to attack organisms before they have a chance to induce infection. Previous surgery (ie, scarring) and radiation injury decrease host defenses. Likewise, certain medical conditions, such as diabetes mellitus or HIV, predispose the patient to infection because of diminished host response. CHOICE OF ANTIBIOTICS AND SPECTRUMSection 3 of 7
Choosing an antibiotic for prophylaxis is multifactorial and should be based on the following:
In operations in which mucosa is not violated, antimicrobial prophylaxis needs to cover only gram-positive skin flora, primarily Staphylococcus epidermidis and Staphylococcus aureus. In operations that feature postoperative infections with aerobic and anaerobic flora, an antibiotic regimen effective against this broad spectrum of pathogens should be used. The regimen chosen should be compatible with findings from the hospital's infection control wound surveillance report. This regimen is particularly important in hospitals with high incidence of infection with methicillin-resistant organisms (eg, S aureus [MRSA], S epidermidis [MRSE]) or with newly vancomycin-resistant organisms. If a number of drugs appear equally acceptable for prophylaxis, the agent least likely to be used for definitive therapy in postoperative wound infection should be chosen. This strategy should minimize the selection of organisms resistant to valuable therapeutic agents. Consider cost and total expenses, including those of laboratory monitoring, drug administration (eg, supplies, personnel), and treatment of adverse effects. TYPES OF ANTIBIOTICSSection 4 of 7
Penicillin
Cephalosporin
Erythromycin
Clindamycin
Metronidazole (Flagyl)
APPROPRIATE USES OF ANTIBIOTIC PROPHYLAXISSection 5 of 7
Antibiotic prophylaxis is indicated in some surgeries but not in others. The appropriate use of antibiotic prophylaxis in the different types of head and neck surgery is discussed herein. An algorithm of appropriate antibiotic prophylaxis is shown in Image 1. Noncontaminated head and neck surgery Noncontaminated surgery refers to violation of prepared skin only and no mucosal exposure or incision (eg, neck dissection, parotidectomy, thyroidectomy). Clean surgical procedures are those in which no infection exists prior to surgery. During surgery, sterility of the wound is maintained. Following closure of the wound at completion of surgery, the wound is never again exposed to direct contact with bacteria. The risk of postoperative wound infection under these circumstances is less than 5%. The inefficacy of antibiotics administrated to patients undergoing clean operations of the head and neck was demonstrated in a study by Johnson et al. Contaminated head and neck surgery Contaminated surgery refers to transmucosal operations (eg, composite resection, glossectomy, maxillectomy). In a study by Johnson et al, organisms involving oropharyngeal flora included anaerobic organisms (Bacteroides, 76%), gram-negative rods (eg, Escherichia coli and Klebsiella, Serratia, and Proteus species), and gram-positive organisms (ie, Staphylococcus, Streptococcus). Saliva contains 108 bacteria per milliliter, 90% of which are anaerobic. Ninety-six percent of wound infections in the head and neck are polymicrobial. Aerobic gram-negative bacilli commonly colonize the oropharynx of hospitalized patients within days of admission. Isolation of aerobic gram-negative bacilli and fungi from postoperative wounds after head and neck surgery is generally representative of colonization. Therefore, antimicrobial prophylaxis for these microorganisms is usually unnecessary. Clindamycin (600 mg PO/IV q8h for 4 doses) is the recommended antibiotic to prevent anaerobic wound contamination in extensive surgeries of the head and neck. Appropriate antibiotic choices also include a combination of ampicillin and sulbactam (3 g IV followed by 1.5 g q8h for 3 doses) and a combination Ancef and Flagyl. As an oral mouth rinse, use of clindamycin (75-mg caps stirred in 8 oz of tap water) or chlorhexidine (Peridex) provides rapid and sustained reductions in the concentrations of aerobic and anaerobic oral flora. The optimum duration of prophylaxis has not been determined but is probably 2-7 days. One or two days are all that have been demonstrated effective. Johnson et al, Weber et al, and others have failed to show additional benefit beyond 2 days. A single antibiotic with excellent anaerobic coverage (eg, Clindamycin) is probably as effective as multiple or broad-based spectrum antibiotics covering aerobes and anaerobes. Nasal and sinus surgery Nasal bacterial flora primarily consists of diphtheroids, coagulase-negative cocci, and enterobacteria. Coagulase-positive staphylococcal organisms reside in the nasal cavities of approximately 50% of patients undergoing nasal surgery. The nose is a contaminated field. Prophylactic antibiotics should be used to prevent devastating postoperative infections. Intranasal packing causes sinusitis that can be prevented with antibiotics. Facial fractures Open fractures have an increased incidence of infection in the absence of antibiotic prophylaxis when compared to closed or open fractures treated with prophylactic antibiotics. The infection rates of mandible fractures treated with closed or open reduction are similar, provided that antibiotics are used in the perioperative period. Studies have concluded that antibiotic prophylaxis significantly reduce the incidence of postoperative infections in facial fractures, especially mandible fractures of the body or parasymphyseal region. The infection rates in zygoma fractures, LeFort fractures, and mandibular subcondylar fractures are similar. Disadvantages of antibiotics The use of antibiotics may encourage laxity of good surgical technique. It promotes antibiotic resistance and contributes to superinfection. Antibiotic use is also costly and associated with allergic reactions, toxic reactions, and adverse effects. MULTIMEDIASection 6 of 7
REFERENCESSection 7 of 7
Antibiotics, Prophylactic Use in Head and Neck Surgery excerpt Article Last Updated: May 2, 2007 | |||||||
