Infectious Diseases (Lymphadenopathies, Abscesses, Necrotizing Fasciitis)
Infectious complications following head and neck surgery (HNS) can have devastating consequences for patients. Many major HNS breech the protective mucosa and expose “clean” anatomy to a bacterial inoculate, significantly increasing the risk of postoperative infection. Before the introduction of prophylactic antibiotic regimens, the postoperative infection rates for major HNS ranged from 36 to 87%.1,2 Postoperative infections extend hospitalizations, increase patient-care costs, and limit immediate and long-term patient quality of life.3–5 During a study period from 1977 to 1989, Blair et al5 found postoperative infections resulted in an average increase in hospital stay of 15 days (at an estimated cost of $2,402 per day in 1992 US dollars). More recently, Penel et al4 reported an increase of 16 hospitalization days and 17,000 Euros for surgical site infections (SSI) in HNS. Surgical site infections are a major healthcare cost. In a recent quantification of the costs of SSI, Broex et al6 reported that SSI resulted in approximately double the costs, when compared with a patient without an SSI.
In an attempt to standardize the reporting of postoperative head and neck infections, Johnson et al7 adapted a wound grading system from an American College of Surgeons Manual on control of infection in surgical patients. They defined a postoperative head and neck wound infection as a wound with purulent drainage by incision, spontaneous drainage, or development of a mucocutaneous fistula ( Fig. 27.1 ). Most authors publishing in the head and neck literature subsequently have adopted Johnson′s criteria. The Centers for Disease Control and the American College of Surgeons have adopted the terminology of SSI. This terminology was introduced in 1992 and was revised in 1999.8 The basic schematic of SSI anatomy and appropriate classification is demonstrated in Fig. 27.2 (see Horan et al8 for full details and definitions). In keeping with Johnson′s spirit of standardization, head and neck surgeons may want to adopt/modify the SSI terminology when reporting in the future.
In 1986, Becker stated, “Any method of wound infection control in patients undergoing HNS should address the following question: (1) who is likely to develop a wound infection; (2) what is the likely bacterial flora of the wound infection; (3) which antibiotic, or combination of antibiotics, should be used, and for how long; and (4) which adjunctive methods (other than the perioperative use of antibiotics) will decrease the rate of wound infection?”9 Multiple publications since Becker′s statement have attempted to answer the basic question; what are the major risk factors for SSI after HNS. The results from several of these studies were analyzed and are summarized in Table 27.1 .10–19
As underscored by Becker, substantial reductions in SSI following HNS were seen with the introduction of appropriate antibiotic prophylaxis. We will address the topic of prophylactic antibiotics initially and independently from other factors influencing SSI in HNS.
The role of prophylactic antibiotics in clean (noncontaminated) surgery of the head and neck is limited, and should not be employed routinely.20 The use of prophylactic antibiotics in uncontaminated neck dissections has been controversial. In a review of uncontaminated neck dissections, Carrau et al21 reported a trend that did not reach statistical significance, favoring the efficacy of antibiotic prophylaxis. In 2004, Seven et al22 reported on a prospective study (with historical controls) that reached statistical significance (p = 0.02) for the use of antibiotic prophylaxis in clean neck dissections. Most recently, Man et al23 studied 273 uncontaminated neck dissections, comparing several antibiotic regimens. All wound infections occurred in patients receiving antibiotics. Infections were associated with extent of surgery (radical or extended neck dissections, p = 0.006), flap closure (p < 0.001), and extended length of surgery (p < 0.001). As demonstrated by Man et al,23 it is my opinion that antibiotic prophylaxis for clean surgery of the head and neck should be be individualized based on the presence or absence of the risk factors outlined in Table 27.1 .
In contrast to clean HNS, many studies have demonstrated the efficacy of prophylactic antibiotics in decreasing the incidence of SSI in the setting of clean–contaminated HNS. Burke24 initially demonstrated that the timing of antibiotic delivery relative to bacterial inoculate was critical. Prophylactic antibiotics should be delivered intravenously before incision, and should be redosed according to half-life. Antibiotics delivered even 3 hours after the inoculate are ineffective at the prevention of infection. Rubin, Penel and others have described the polymicrobial nature of SSI after HNS, and prophylactic antibiotic regimens must include activity against gram-negative, aerobic, and anaerobic organisms.14,20,25 Common single agents include cefazolin, cefotaxime, ampicillin, and clindamycin. Combinations with extended coverage are more effective than single agents and are recommended, including, clindamicin/metronidazole, amoxicillin/clavulanic acid, cefuroxime/metronidazole, clindamicin/gentamicin, and ampicillin/sulbactam.20 Multiple studies have attempted to define the optimal duration of perioperative antibiotics. In summary, the literature does not support the continuation of antibiotic coverage for > 24 hours following surgery, even in the setting of complex reconstruction.26–29