Antibiotic prophylaxis in clean-contaminated head and neck oncological surgery

Evidence-Based Medicine: Systemic Perioperative Antibiotic Prophylaxis for Prevention of Surgical-Site Infections in Plastic and Reconstructive Surgery

BACKGROUND

After nearly a decade of new data, the Evidence-Based Consensus Conference Statement from the American Association of Plastic Surgeons was updated for prophylactic systemic antibiotics to prevent surgical-site infections (SSI). Pharmacotherapeutic concepts using antimicrobial stewardship were applied for clinical interpretation and management to optimize patient outcomes and minimize resistance.

METHODS

PRISMA, Cochrane, and GRADE certainty of evidence guidelines were implemented for the structure and synthesis of the review. PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases were systematically and independently searched for randomized controlled trials (RCTs). The authors included patients who had plastic and reconstructive surgery and were treated with prophylactic systemic antibiotics administered perioperatively (preoperatively, intraoperatively, or postoperatively). Comparisons were made between active interventions and nonactive interventions (placebo) at different prespecified durations to determine the development of an SSI. Meta-analyses were performed.

RESULTS

The authors included 138 RCTs that met eligibility criteria. RCTs consisted of 18 breast, 10 cosmetic, 21 hand/peripheral nerve, 61 pediatric/craniofacial, and 41 reconstructive studies. The authors examined bacterial data extracted from studies for patients who did or did not take prophylactic systemic antibiotics for prevention of SSI. Clinical recommendations were provided using level I evidence.

CONCLUSIONS

Surgeons have long been overprescribing systemic antibiotic prophylaxis in plastic and reconstructive surgery. Evidence supports antibiotic prophylaxis to prevent SSI for specific indications and durations. Prolonged antibiotic use has not been linked to reductions in SSIs, and misuse may increase the bacterial diversity of infections. Greater efforts should focus on transitioning from practice-based to pharmacotherapeutic evidence-based medicine.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Antibiotic prophylaxis in clean and clean-contaminated plastic surgery: A critical review

Antibiotic prophylaxis is frequently used in plastic surgery procedures, despite the generally low rates of infection and few guidelines on the practice. The increasing prevalence of bacterial resistance to antibiotics calls for a reduction in unnecessary antibiotic use. The aim of this review was to create an updated summary of the available data on the effectiveness of antibiotic prophylaxis in reducing the postoperative infection in clean and clean-contaminated plastic surgery. A systematic literature search was performed on the databases Medline, Web of Science, and Scopus, limited to articles published January 2000 onward. Randomized controlled trials (RCTs) were included in the primary review, whereas older RCTs and other studies were sought if 2 or fewer relevant RCTs were identified. Overall, 28 relevant RCTs, 2 nonrandomized trials, and 15 cohort studies were identified. Although the number of studies for each type of surgery is limited, the data suggest that prophylactic systemic antibiotic may be unnecessary in noncontaminated facial plastic surgery, reduction mammaplasty, and breast augmentation. In addition, no benefit is apparent from extending the antibiotic prophylaxis over 24 h in rhinoplasty, aerodigestive tract reconstruction, and breast reconstruction. No studies assessing the necessity of antibiotic prophylaxis in abdominoplasty, lipotransfer, soft tissue tumor surgery, or gender affirmation surgery were identified. In conclusion, limited data are available on the effectiveness of antibiotic prophylaxis in clean and clean-contaminated plastic surgery. More studies on this topic are needed before strong recommendations can be made on the use of antibiotics in this setting.

The formulation of an enhanced recovery programme for patients undergoing laryngectomy

Objective

Enhanced recovery programmes have been widely adopted in other surgical disciplines but are not commonplace in head and neck surgery. The authors of this study created a pathway for post-operative laryngectomy patients.

Method

A multidisciplinary working group reviewed the literature and agreed standards of care. A retrospective audit was conducted to measure current practice against our new pathway; after programme implementation our performance was reaudited in two prospective cycles, with an education programme and review after the first prospective cycle.

Results

Statistically significant improvement in performance was realised in catheter and surgical drain removal, opiate analgesia use, mobilisation, and timeliness of swallow assessment. The rate of hospital acquired pneumonia reduced from 23.1 to 9.5 per cent and length of stay reduced by a median of 5.2 days to 14.8 days (non-significant).

Conclusion

The programme improved consistency of patient care across most areas that were measured. Improving patient stoma training needs to be prioritised.

Post-Operative Infections in Head and Neck Cancer Surgery: Risk Factors for Different Infection Sites

Background: Post-operative infections in head and neck cancer (HNC) surgery represent a major problem and are associated with an important increase in mortality, morbidity, and burden on the healthcare system. The aim of this retrospective observational study was to evaluate post-operative infections in HNC surgery and to analyze risk factors, with a specific focus on different sites of infection. Methods: Clinical data about 488 HNC patients who underwent surgery were recorded. Univariate and multivariate analyses were performed to identify risk factors for post-operative infections. Results: Post-operative infections were observed in 22.7% of cases. Respiratory and surgical site infections were the most common. Multiple site infections were observed in 3.9% of cases. Considering all infection sites, advanced stage, tracheotomy, and higher duration of surgery were risk factors at multivariate analysis. Median hospital stay was significantly longer in patients who had post-operative infection (38 vs. 9 days). Conclusions: Post-operative infections may negatively affect surgical outcomes. A correct identification of risk factors may help the physicians to prevent post-operative infections in HNC surgery.

Antimicrobial Prophylaxis in Neonates and Children Undergoing Dental, Maxillo-Facial or Ear-Nose-Throat (ENT) Surgery: A RAND/UCLA Appropriateness Method Consensus Study

Surgical site infections (SSIs) represent a potential complication in surgical procedures, mainly because clean/contaminated surgery involves organs that are normally colonized by bacteria. Dental, maxillo-facial and ear-nose-throat (ENT) surgeries are among those that carry a risk of SSIs because the mouth and the first respiratory tracts are normally colonized by a bacterial flora. The aim of this consensus document was to provide clinicians with recommendations on surgical antimicrobial prophylaxis in neonates (<28 days of chronological age) and pediatric patients (within the age range of 29 days−18 years) undergoing dental, maxillo-facial or ENT surgical procedures. These included: (1) dental surgery; (2) maxilla-facial surgery following trauma with fracture; (3) temporo-mandibular surgery; (4) cleft palate and cleft lip repair; (5) ear surgery; (6) endoscopic paranasal cavity surgery and septoplasty; (7) clean head and neck surgery; (8) clean/contaminated head and neck surgery and (9) tonsillectomy and adenoidectomy. Due to the lack of pediatric data for the majority of dental, maxillo-facial and ENT surgeries and the fact that the recommendations for adults are currently used, there is a need for ad hoc studies to be rapidly planned for the most deficient areas. This seems even more urgent for interventions such as those involving the first airways since the different composition of the respiratory microbiota in children compared to adults implies the possibility that surgical antibiotic prophylaxis schemes that are ideal for adults may not be equally effective in children.

Antibiotic Prophylaxis Prescribing Practice in Head and Neck Tumor Resection and Free Flap Reconstruction

Background

Adherence to guidelines for antibiotic prophylaxis is often poor and is an important target for antimicrobial stewardship programs. Prescribing audits that suggested poor adherence to guidelines in a plastic surgery department led to a targeted education program to bring antibiotic prescriptions in line with hospital guidelines. We reviewed whether this intervention was associated with changed perioperative prescribing and altered surgical outcomes, including the rate of surgical site infections, specifically looking at clean-contaminated head and neck tumor resections with free flap reconstruction.

Methods

A retrospective cohort study was performed on 325 patients who underwent clean-contaminated head and neck tumor resection and free flap reconstruction from January 1, 2013, to February 19, 2019. Patients were divided into 2 groups, those before (pre-intervention) and after (postintervention) the education campaign. We analyzed patient demographic and disease characteristics, intraoperative and postoperative factors, and surgical outcomes.

Results

Patients pre-intervention were prescribed longer courses of prophylactic antibiotics (median [interquartile range], 9 [8] vs 1 [1]; P < .001), more topical chloramphenicol ointment (21.82% vs 0%; P < .001), and more oral nystatin (36.9% vs 12.2%; P < .001). Patients postintervention had higher rates of recipient infections (36.11% vs 17.06%; P < .001) and donor site infections (6.94% vs 1.19%; P = .006).

Conclusions

Following the education campaign, patients were prescribed shorter courses of prophylactic antibiotics, more of the recommended cefazolin-metronidazole regimen, and fewer topical antibiotics. However, patients also had a higher rate of surgical site infections.

Impact of the practical guideline on appropriate usage of antimicrobial treatments for surgical site infections in reconstructive surgery of head and neck cancer

OBJECTIVES

In 2016, Japanese Society of Chemotherapy and Japan Society for Surgical Infection presented the practical guideline for appropriate usage of antimicrobial agents to prevent postoperative infections. This study aims to exhibit the validity of the guideline as a series of effective strategies for prevention of surgical site infections (SSIs) during reconstructive surgery of the head and neck cancer.

METHODS

We retrospectively evaluated patients who underwent head and neck reconstructive surgery with free or pedicle flaps in a single institute in Japan between July 2010 and July 2020. We evaluated the incidence of SSIs, patient backgrounds, and microbiological characteristics on the basis of antimicrobial prophylaxis recommended by the guideline.

RESULTS

Enrolled in this study were 102 patients in our institution who underwent head and neck reconstructive surgery with free or pedicle flaps between July 2010 and July 2020. In the period between January 2018 to July 2020 after the SSI guideline was advocated (SSI guideline period), the ratio of administration of sulbactam/ampicillin (SBT/ABPC) was significantly higher (P < 0.001) and the duration of prophylactic antimicrobial treatment was significantly shorter than in the period between July 2010 to December 2017 before the SSI guideline was advocated (Pre-SSI guideline period) (P < 0.001). Incidence of SSIs were similar, even when antibiotic use was changed to be short-term single-agent administration in accordance with the practical guideline.

CONCLUSIONS

Adherence to the current Japanese practical guideline on appropriate antimicrobial prophylaxis for SSIs can shorten the duration of usage of antimicrobial treatment without increasing the risk for occurrence of SSIs.

Antibiotic prophylaxis in head and neck cancer surgery: Systematic review and Bayesian network meta-analysis

Postoperative surgical site infections (SSI) are worrisome complications after head and neck cancer surgery. Due to the lack of direct comparisons, it is difficult to indicate the best antibiotic in the setting of SSI prophylaxis for patients with head and neck cancer. For this reason, we decided to conduct a Bayesian network meta-analysis of clinical studies evaluating various antibiotic classes for SSI prophylaxis; thus, we directly and indirectly compared all the available antibiotics in the setting of head and neck oncological surgery. We performed a systematic review and a network meta-analysis according to the PRISMA-NMA checklist. Regarding inclusion criteria, we included articles with retrospective or prospective design recruiting adult participants with head and neck neoplasm of any subsite that compared different antibiotics or that compared different antibiotic treatment duration with sample sizes of more than 10 patients. Overall, 310 citations were identified by the search on all databases. Of these, 250 were excluded based on title and abstract, leaving 60 publications for full text examination. Finally, 20 papers were included for data extraction and analysis. In total, 8627 patients were evaluated across the included studies. Results of the Bayesian network meta-analysis showed that when compared to clindamycin short course, the antibiotics effective in preventing SSI were ampicillin/sulbactam or other penicillin short course (OR: 0.37, 95%CrI: 0.19-0.72), cefazolin/metronidazole short course (OR: 0.26, 95%CrI: 0.06-0.93), cefazolin (OR: 0.36, 95%CrI: 0.17-0.79), ampicillin/sulbactam long course (OR: 0.20, 95%CrI: 0.04-0.91), cefazolin/metronidazole long course (OR: 0.27, 95%CrI: 0.09-0.64), cefoperazone (OR: 0.05, 95%CrI: 0.002-0.89), cefotaxime (OR: 0.04, 95%CrI: 0.002-0.85). There was no significant difference between clindamycin and no antibiotic (OR: 2.3, 95%CrI: 0.59-9.9). Clindamycin plus aminoglycoside seemed to give a slight protection from SSI compared to clindamycin alone (OR: 0.30, 95%CrI: 0.09-0.99) or no antibiotic (OR: 0.13, 95%CrI: 0.02-067). Antibiotic prophylaxis is important in preventing SSI in head and neck cancer setting. Current evidence suggests that penicillins and cephalosporins are the best choice. Moreover, long duration course does not give any advantage compared to short course prophylaxis. Finally, it is important to implement appropriate antibiotic prophylaxis in patients that are labeled as penicillin allergic, in this regard clindamycin seems to be ineffective and, for this reason, further research is needed to provide a better care for this subset of patients.

Adequacy of antibiotic prophylaxis and incidence of surgical site infections in neck surgery

Health care-related infections are frequent and among them surgical site infection (SSI) are the most frequent in hospitals. The objective was to evaluate the adequacy of antibiotic prophylaxis in patients undergoing neck surgery and its relationship with the incidence of surgical site infection (SSI). Prospective cohort study. The adequacy of antibiotic prophylaxis in patients undergoing neck surgery was evaluated. Antibiotic prophylaxis was considered adequate when it conformed to all items of the protocol (antibiotic used, time of administration, administration route, dose and duration). The cumulative incidence of SSI was calculated, and the relationship between SSI and antibiotic prophylaxis adequacy was determined using adjusted relative risk (RR). Antibiotic prophylaxis was administered in 63 patients and was adequate in 85.7% (95% CI 75.0–92.3) of them. The cumulative incidence of SSI was 6.4% (95% CI 3.4–11.8). There was no significant relationship between antibiotic prophylaxis inadequacy and the incidence of SSI (RR = 2.4, 95% CI 0.6–10.6). Adequacy of antibiotic prophylaxis was high and it did not affect the incidence of SSIs.

Predictors of surgical site infection and pneumonia following oral cavity tumor surgery

BACKGROUND

To identify risk factors for surgical site infection (SSI) and pneumonia following oral cavity tumor surgery.

METHODS

Retrospective chart review of a consecutive series of patients undergoing oral cavity resection. Several clinicopathologic variables were tested for their association with SSI and pneumonia.

RESULTS

Three hundred and forty-four cases in 330 patients were included. Incidence of SSI and pneumonia was 67 (19.5%) and 38 (11%), respectively. On multivariate analysis, marginal mandibulectomy and segmental mandibulectomy were independent risk factors for SSI, whereas time under anesthesia (TUA) was an independent risk factor for pneumonia. Receiver operating characteristic curve identified 390 min as the cutoff above which pneumonia was predicted with a high degree of accuracy.

CONCLUSIONS

In oral cavity resections, mandibulectomy predisposes to SSI. Further, prolonged TUA (>390 min) is a powerful predictor for pneumonia. As it is a modifiable risk factor, reduction in TUA might correspondingly lower the incidence of postoperative pneumonia.

Designing and integrating a quality management program for patients undergoing head and neck resection with free-flap reconstruction

Background

Care pathways (CPs) offer a proven method of systematically improving patient care. CPs are particularly helpful in complex clinical conditions where variation in care is a problem such as patients undergoing major head and neck resection with free flap reconstruction. Although CPs have been used to manage this patient group, most CPs are implemented as part of relatively short-term quality improvement projects. This paper outlines a detailed methodology for designing and delivering a quality management program sustained for 9 years.

Methods

We describe a change management approach informed by Kotter’s “8 Step Process” that provided a useful framework to guide program development and implementation. We then provide a detailed, step by step description of how such a program can be implemented as well as a detailed summary of time and costs for design, implementation and sustainability phases. An approach to design and delivery of a measurement, audit and feedback system is also provided.

Results

We present a summary of resources needed to design and implement a head and neck surgery quality management program. The primary result of this study is a design for a sustainable quality management program that can be used to guide and improve care for patients undergoing major head and neck resection with free flap reconstruction.

Conclusions

A change management approach to design and delivery of a head and neck quality management program is practical and feasible.

The impact of a quality management program for patients undergoing head and neck resection with free-flap reconstruction: longitudinal study examining sustainability

BACKGROUND

Care pathways (CPs) are helpful in reducing unwanted variation in clinical care. Most studies of CPs show they improve clinical outcomes but there is little known about the long-term impact of CPs as part of a sustained quality management program. Head and neck (HN) surgery with free flap reconstruction is complex, time-consuming and expensive. Complications are common and therefore CPs applied to this patient population are the focus of this paper. In this paper we report outcomes from a 9 year experience designing and using CPs in the management of patients undergoing major head and neck resection with free flap reconstruction.

METHODS

The Calgary quality management program and CP design is described the accompanying article. Data from CP managed patients undergoing major HN surgery were prospectively collected and compared to a baseline cohort of patients managed with standard care. Data were retrospectively analyzed and intergroup comparisons were made.

RESULTS

Mobilization, decannulation time and hospital length of stay were significantly improved in pathway-managed patients (p = 0.001). Trend analysis showed sustained improvement in key performance indicators including complications. Return to the OR, primarily to assess a compromised flap, is increasing.

CONCLUSIONS

Care pathways when deployed as part of an ongoing quality management program are associated with improved clinical outcomes in this complex group of patients.

Microbiology of wound infection after oral cancer surgery

INTRODUCTION

The aim of present study is to investigate the most common infection pathogen found in the postoperative wounds, following surgical treatment of oral and oropharyngeal cancer, in order to identify the most suitable antibiotic treatment.

PATIENTS AND METHODS

We analyzed patients with squamous cell cancer of oral and oropharyngeal region. In patients who developed postoperative wound infection, wound swabs were taken from three different sites: the cannula, wounds on the neck and wounds in the oral cavity.

RESULTS

In total 195 patients were included. The postoperative wound infection was detected in 115 patients (59%). In average, the swabs were taken 8 days after the surgery. The similar bacterial species from all three sites were detected in 24 patients (12,3%). In comparison, we found that there was statistically significant difference in the bacteria abundance from all three sites (p=0,031). There were significantly more bacteria in the wounds of the neck than cannula (p=0,007) and in the wounds in the oral cavity than cannula (p=0,002). No statistically significant difference between the wound on the neck and in the oral cavity was found. The most frequently isolated bacterial family was Enterobacteriaceae. Other more commonly isolated bacteria species were Staphylococcus spp. (G+), Pseudomonas aeruginosa (G-), Corynebacteruim spp. (G +) and Acinetobacter baumanii (G-).

CONCLUSION

Based on the most commonly isolated groups of pathogens we concluded that probably the best empiric antibiotic treatment of wound infections until antibiogram is completed might be achieved from the group of aminoglycosides or quinolones. Antibiotic therapy should be reviewed if necessary when antibiogram is completed.

Perioperative Antibiotics in Clean-Contaminated Head and Neck Surgery: A Systematic Review and Meta-Analysis

Background

The optimal evidence-based prophylactic antibiotic regimen for surgical site infections following major head and neck surgery remains a matter of debate.

Methods

Medline, Cochrane, and Embase were searched for the current best evidence. Retrieved manuscripts were screened according to the PRISMA guidelines. Included studies dealt with patients over 18 years of age that underwent clean-contaminated head and neck surgery (P) and compared the effect of an intervention, perioperative administration of different antibiotic regimens for a variable duration (I), with control groups receiving placebo, another antibiotic regimen, or the same antibiotic for a different postoperative duration (C), on surgical site infection rate as primary outcome (O) (PICO model). A systematic review was performed, and a selected group of trials investigating a similar research question was subjected to a random-effects model meta-analysis.

Results

Thirty-nine studies were included in the systematic review. Compared with placebo, cefazolin, ampicillin–sulbactam, and amoxicillin–clavulanate were the most efficient agents. Benzylpenicillin and clindamycin were clearly less effective. Fifteen studies compared short- to long-term prophylaxis; treatment for more than 48 h did not further reduce wound infections. Meta-analysis of five clinical trials including 4336 patients, where clindamycin was compared with ampicillin–sulbactam, implied an increased infection rate for clindamycin-treated patients (OR = 2.73, 95% CI 1.50–4.97, p = 0.001).

Conclusion

In clean-contaminated head and neck surgery, cefazolin, amoxicillin–clavulanate, and ampicillin–sulbactam for 24–48 h after surgery were associated with the highest prevention rate of surgical site infection.

Perioperative Antibiotics in Clean-Contaminated Head and Neck Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

The optimal evidence-based prophylactic antibiotic regimen for surgical site infections following major head and neck surgery remains a matter of debate.

METHODS

Medline, Cochrane, and Embase were searched for the current best evidence. Retrieved manuscripts were screened according to the PRISMA guidelines. Included studies dealt with patients over 18 years of age that underwent clean-contaminated head and neck surgery (P) and compared the effect of an intervention, perioperative administration of different antibiotic regimens for a variable duration (I), with control groups receiving placebo, another antibiotic regimen, or the same antibiotic for a different postoperative duration (C), on surgical site infection rate as primary outcome (O) (PICO model). A systematic review was performed, and a selected group of trials investigating a similar research question was subjected to a random-effects model meta-analysis.

RESULTS

Thirty-nine studies were included in the systematic review. Compared with placebo, cefazolin, ampicillin-sulbactam, and amoxicillin-clavulanate were the most efficient agents. Benzylpenicillin and clindamycin were clearly less effective. Fifteen studies compared short- to long-term prophylaxis; treatment for more than 48 h did not further reduce wound infections. Meta-analysis of five clinical trials including 4336 patients, where clindamycin was compared with ampicillin-sulbactam, implied an increased infection rate for clindamycin-treated patients (OR = 2.73, 95% CI 1.50-4.97, p = 0.001).

CONCLUSION

In clean-contaminated head and neck surgery, cefazolin, amoxicillin-clavulanate, and ampicillin-sulbactam for 24-48 h after surgery were associated with the highest prevention rate of surgical site infection.

Assessing antibiotic stewardship using the surgical site infection prevention bundle

BACKGROUND:

Antibiotic prophylaxis is crucial in head and neck surgery to prevent infection from clean contaminated wounds. Scottish Intercollegiate Guidelines Network (SIGN) guidance, the gold standard of practice, recommends that administration of broad spectrum antibiotics is discontinued after 24 hours post-operation. A three-audit cycle quality improvement project was conducted to assess clinical practice against SIGN guidance at a large London teaching hospital.

METHODS:

Three change initiatives were implemented to improve antibiotic stewardship. First, an update of Trust guidelines with an associated poster campaign to educate staff and improve awareness. Second, introduction of a specific 'prophylactic antibiotics in head and neck surgery' bundle on the electronic hospital-wide prescribing system. Third, an update to an antibiotic prescribing guide (Microguide).

RESULTS:

Over a 3-year study period the number of patients receiving antibiotics beyond 24 hours declined significantly (88% in 2015, 76% in 2016, 25% in 2018), demonstrating improved compliance with SIGN guidelines overall. Despite this, staff documentation of indications for extended antibiotic use remains suboptimal (58% in 2016 and 44% in 2018) as does the number of specimens sent for microbiological analysis (52% in 2016 and 0% in 2018).

CONCLUSIONS:

Appropriate prophylactic antibiotic prescribing can improve morbidity and mortality rates in head and neck cancer patients. Three change initiatives have been demonstrated which can help to improve prescribing compliance in line with SIGN guidance. Ongoing auditing is required to maintain the longevity of improvements made and encourage staff documentation of indications for extended antibiotic use and microbiology specimen analysis.

Systematic review of international guidelines for perioperative antibiotic prophylaxis in Head & Neck Surgery. A YO-IFOS Head & Neck Study Group Position Paper

BACKGROUND

Surgical site infection (SSI) is defined as an infection that occurs after a surgical incision or organ manipulation during surgery. The frequency reported for clean head and neck surgical procedures without antimicrobial prophylaxis is <1%. In contrast, infection rates in patients undergoing complicated cancer surgery are high, ranging from 24% to 87% of patients without antimicrobial prophylaxis.

METHODS

Guidelines and recommendations about the use of antibiotics in head and neck surgery from 2004 to 2019 were reviewed.

RESULTS

Four guidelines from Oceania, 5 from South America, 5 from North America, 2 from the United Kingdom, 11 from Europe, 1 from Africa, 1 from the Middle East, and 3 from Asia were included. A total of 118 papers were included for analysis and recommendation.

CONCLUSION

Antibiotic prophylaxis can decrease the incidence of SSI. However, the risks associated with antibiotic exposure and the risk of antibiotic resistance need to be taken into consideration.

Perioperative Care of Free Flap Patients

Microvascular free tissue transfer is an indispensable reconstructive option in head and neck reconstruction. Flap failure is relatively rare, but it is nonetheless very morbid and psychologically devastating to patients when it does occur. Further, complications after free tissue transfer to the head and neck remain common. There are numerous ongoing debates about various facets of preoperative, intraoperative, and postoperative care of patients undergoing free flap reconstruction of the head and neck, all ultimately searching for the optimal treatment algorithm to further improve flap success, minimize complications, and maximize patient outcomes. Herein, the authors review current literature surrounding optimal preoperative nutritional support, intraoperative vasopressor use, perioperative fluid management, use of antithrombotic agents, antibiotic use, and other facets of the care of head and neck free flap patients to provide a guide to surgeons.

Multicenter Assessment of Antibiotic Prophylaxis Spectrum on Surgical Infections in Head and Neck Cancer Microvascular Reconstruction

Objective

To characterize and identify risk factors for 30-day surgical site infections (SSIs) in patients with head and neck cancer who underwent microvascular reconstruction.

Study Design

Cross-sectional study with nested case-control design.

Setting

Nine American tertiary care centers.

Subjects and Methods

Hospitalized patients were included if they underwent head and neck cancer microvascular reconstruction from January 2003 to March 2016. Cases were defined as patients who developed 30-day SSI; controls were patients without SSI at 30 days. Postoperative antibiotic prophylaxis (POABP) regimens were categorized by Gram-negative (GN) spectrum: no GN coverage, enteric GN coverage, and enteric with antipseudomonal GN coverage. All POABP regimens retained activity against anaerobes and Gram-positive bacteria. Thirty-day prevalence of and risk factors for SSI were evaluated.

Results

A total of 1307 patients were included. Thirty-day SSI occurred in 189 (15%) patients; median time to SSI was 11.5 days (interquartile range, 7-17). Organisms were isolated in 59% of SSI; methicillin-resistant Staphylococcus aureus (6%) and Pseudomonas aeruginosa (9%) were uncommon. A total of 1003 (77%) patients had POABP data: no GN (17%), enteric GN (52%), and antipseudomonal GN (31%). Variables independently associated with 30-day SSI were as follows: female sex (adjusted odds ratio [aOR], 1.6; 95% CI, 1.1-2.2), no GN POABP (aOR, 2.2; 95% CI, 1.5-3.3), and surgical duration ≥11.8 hours (aOR, 1.9; 95% CI, 1.3-2.7). Longer POABP durations (≥6 days) or antipseudomonal POABP had no association with SSI.

Conclusions

POABP without GN coverage was significantly associated with SSI and should be avoided. Antipseudomonal POABP or longer prophylaxis durations (≥6 days) were not protective against SSI. Antimicrobial stewardship interventions should be made to limit unnecessary antibiotic exposures, prevent the emergence of resistant organisms, and improve patient outcomes.

Antibiotic prophylaxis in clean-contaminated head and neck cases with microvascular free flap reconstruction: A systematic review and meta-analysis

BACKGROUND

Optimal antibiotic prophylaxis duration in head and neck clean-contaminated free-flap cases is unknown.

METHODS

A systematic review/meta-analysis was conducted using PubMed/MEDLINE, Cochrane Library, Web-of-Science, and Scopus databases.

RESULTS

Of the 3755 searched articles, 5 articles were included for a total of 861 patients. The recipient surgical site infection risk was significantly higher in patients receiving prophylactic antibiotics for ≤24 hours compared to >24 hours (relative risk [RR] 1.56; 95% confidence interval [CI] 1.13-2.14). In the post hoc multivariate analysis based on available individual-level data on 697 patients from 3 studies, the risk of surgical site infection for ≤24 hours versus >24 hours was not significant after adjusting for antibiotic type (RR 1.09; 95% CI 0.78-1.55). When compared to ampicillin-sulbactam, patients who received clindamycin prophylaxis had an increased likelihood of recipient surgical site infection (RR 2.85; 95% CI 1.95-4.17).

CONCLUSION

Less than or equal to 24 hours of antibiotic prophylaxis in head and neck clean-contaminated free-flap is likely sufficient but a strong conclusion remains elusive. Clindamycin prophylaxis increases the risk of recipient surgical site infection. Further prospective trials are necessary to clarify.

Considerations for antibiotic prophylaxis in head and neck cancer surgery

Peri/post-operative antibiotic prophylaxis (POABP) has become standard practice for preventing surgical site infections (SSI) in head and neck cancer patients undergoing microvascular reconstruction, but few data exist on optimal POABP regimens. Current surgical prophylaxis guideline recommendations fail to account for the complexity of microvascular reconstruction relative to other head and neck procedures, specifically regarding wound classification and antibiotic duration. Selection of POABP spectrum is also controversial, and must balance the choice between too narrow, risking subsequent infection, or too broad, and possible unwanted effects (e.g. antibiotic resistance, Clostridium difficile-associated diarrhea). POABP regimens should retain activity against bacteria expected to colonize the upper respiratory/salivary tracts, which include Gram-positive organisms and facultative anaerobes. However, Gram-negative bacilli also contribute to SSI in this setting. POABP doses should be optimized in order to achieve therapeutic tissue concentrations at the surgical site. Antibiotics targeted towards methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa are not warranted for all patients. Prolonged POABP durations have shown no differences in SSI when compared to short POABP durations, but prolonged durations provide unnecessarily antibiotic exposure and risk for adverse effects. Given the lack of standardization behind antibiotic POABP in this setting and the potential for poor patient outcomes, this practice necessitates an additional focus of surgeons and antimicrobial stewardship programs. The purpose of this review is to provide an overview of POABP evidence and discuss pertinent clinical implications of appropriate use.

Methods to reduce postoperative surgical site infections after head and neck oncology surgery

Head and neck cancer surgery is often a complex multi-step procedure that includes major resections, vascularised tissue reconstruction, and extensive neck dissection. The upper aerodigestive tract mucosal lining is often disrupted during surgery, which requires the management of a clean-contaminated field and the need to reconstruct the mucosal lining. With bacterial contamination, surgical site infections (SSI) are a serious complication that can result in delayed wound healing, wound breakdown, fistula formation, and compromised tissue reconstruction. Methods to reduce SSI in patients with head and neck cancer have been intensely researched, yielding evolving and varied practice patterns. In this Review, we outline the data supporting perioperative antibiotic prophylaxis for clean-contaminated surgeries, which suggest that clindamycin is an inadequate prophylactic antibiotic therapy in the reduction of SSI, and that prolonged antibiotic courses have no established benefit. For salvage laryngectomy after radiotherapy with or without chemotherapy, reconstruction with vascularised tissue reduces the frequency and severity of pharyngocutaneous fistula formation. These evidence-based recommendations have been shown to reduce the chance of SSI after head and neck surgery.

Antibiotic Prophylaxis in Clean-Contaminated Head and Neck Surgery: A Systematic Review and Meta-analysis

Objective

To determine the optimal duration and type of antibiotic prophylaxis in patients undergoing clean-contaminated resection for head and neck cancer.

Data Sources

Search strategies were created by a medical librarian, implemented in multiple databases, and completed in June 2016.

Review Methods

The population of interest was adults ≥18 years undergoing clean-contaminated head and neck surgery, intervention was postoperative antibiotic prophylaxis, comparator was duration and types of antibiotics used, outcome was the wound infection rate, and the study design was randomized controlled trials (RCTs). Studies were excluded if not randomized, did not use systemic antibiotics, did not study wound infections, or included children. After excluding duplicates, the search strategy yielded 427 abstracts. After applying inclusion and exclusion criteria, 67 studies were screened, leaving 19 RCTs for review. PRISMA guidelines were followed. A random-effects model was used for meta-analysis.

Results

Meta-analysis of 340 patients in 4 RCTs showed that the pooled relative risk of wound infection was 0.98 (95% confidence interval [CI], 0.58-1.61; P = .718; I2 = 0.0%) in patients receiving 1 day vs 5 days of prophylaxis.

Conclusion

This study provides evidence that there is no difference in the risk of wound infection with 1 day vs 5 days of systemic antibiotic prophylaxis in clean-contaminated head and neck surgery, consistent with existing guidelines. Future large randomized trials are needed to more clearly define the appropriate choice of prophylaxis in penicillin-allergic patients.

Surgical site infection in clean-contaminated wounds after multimodal treatment of advanced oral squamous cell carcinoma

OBJECTIVES

The aim of this study was to assess the incidence rate for surgical site infections (SSI), patient- and therapy-related risk factors in UICC stage III and IV oral squamous cell carcinoma patients treated with preoperative radiochemotherapy, ablative surgery and immediate microvascular free flap reconstruction.

MATERIAL AND METHODS

This retrospective analysis included 85 patients with oral squamous cell carcinoma treated by neoadjuvant radiochemotherapy, tumor surgery and immediate free flap reconstruction. Patient-, therapy-related factors and blood parameters were collected for this selective cohort.

RESULTS

The incidence for SSI was 44.7% and for transplant loss 14.1%. Minor BMI changes (p = 0.010), diabetes (p = 0.003), edentulous status (p = 0.006) and cessation of alcohol consumption (0.034) showed to be significant patient-related risk factors. No therapy-related factors were found to be significantly influencing the risk for SSI. Neutrophil counts (p = 0.027) and GGT (p = 0.002) were found to be significantly linked to SSI.

CONCLUSION

The not so common treatment option for oral squamous cell carcinomas showed no more risk for SSI compared to standard treatment options. Preserving the ability for healthy nutrition has a significant impact on the development of SSI. This applies not only to the presented and particular treatment option.

Surgical prophylaxis with gram-negative activity for reduction of surgical site infections after microvascular reconstruction for head and neck cancer

BACKGROUND

The purpose of this study was to determine the incidence of and risk factors for surgical site infections in microvascular reconstruction for patients with head and neck cancer.

METHODS

One hundred seventeen patients with head and neck cancer undergoing microvascular reconstruction received postoperative surgical infection prophylaxis and were followed for 30 days. Surgical infection prophylaxis was categorized by empiric spectrum of activity. Risk factors for surgical site infection development and cumulative incidence of surgical site infections were characterized.

RESULTS

Thirty-seven patients developed surgical site infection (cumulative surgical site infection incidence of 31.6%). Risk factors identified in logistic regression include alcohol use (odds ratio [OR] = 2.704; 95% confidence interval [CI] = 1.029-7.106), increased surgical duration (OR = 1.403; 95% CI = 1.185-1.661), American Society of Anesthesiologists (ASA) class IV (OR = 3.075; 95% CI = 1.000-9.459), and lack of postoperative gram-negative coverage (OR = 15.139; 95% CI = 3.083-74.347).

CONCLUSION

Alcohol use, longer surgical duration, and lack of gram-negative postoperative prophylactic coverage are modifiable risk factors for surgical site infection development. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-1454, 2016.

Clostridium difficile infection following systemic antibiotic administration in randomised controlled trials: a systematic review and meta-analysis

Antibiotics have been the most important risk factor for Clostridium difficile infection (CDI). However, only data from non-randomised studies have been reviewed. We sought to evaluate the risk for development of CDI associated with the major antibiotic classes by analysing data from randomised controlled trials (RCTs). The PubMed, Cochrane and Scopus databases were searched and the references of selected RCTs were also hand-searched. Eligible studies should have compared only one antibiotic versus another administered systemically. Inclusion of studies comparing combinations of antibiotics was allowed only if the second antibiotic was the same or from the same class or if it was administered in a subset of the enrolled patients who were equally distributed in the two arms. Only a minority of the selected RCTs (79/1332; 5.9%) reported CDI episodes. Carbapenems were associated with more CDI episodes than fluoroquinolones [risk ratio (RR) = 2.44, 95% confidence interval (CI) 1.32-4.49] and cephalosporins (RR = 2.24, 95% CI 1.46-3.42), but not penicillins (RR = 2.53, 95% CI 0.87-7.41). Cephalosporins were associated with more CDIs than penicillins (RR = 2.36, 95% CI 1.32-4.23) and fluoroquinolones (RR = 2.84, 95% CI 1.60-5.06). There was no difference in CDI frequency between fluoroquinolones and penicillins (RR = 1.34, 95% CI 0.55-3.25). Finally, clindamycin was associated with more CDI episodes than cephalosporins and penicillins (RR = 3.92, 95% CI 1.15-13.43). In conclusion, data from RCTs showed that clindamycin and carbapenems were associated with more CDIs than other antibiotics.

Antibiotic Use after Free Tissue Reconstruction of Head and Neck Defects: Short Course vs. Long Course

BACKGROUND

Free tissue reconstruction has become the standard of care for most major defects in the head and neck. Surgical site infection (SSI) can lead to vessel thrombosis and eventual flap loss. The use of antibiotics after free tissue reconstruction has not been studied in the current environment of heightened bacterial antibiotic resistance. We compared the use of short-term and longer-term antibiotics in a series of patients receiving free tissue reconstructions.

METHODS

A retrospective review was performed of 147 patients receiving 149 free flaps who were treated with either short-course (≤2 d; n = 149 [43%]) or long-course (>2 d; n = 85 [57%])) post-operative antibiotics from 2009 to 2014. The outcomes examined were infection, return to the operating room, length of hospital stay, and patient death up to six weeks post-surgery. In addition, risk factors associated with SSI were explored.

RESULTS

Surgical site infection, flap dehiscence, flap loss, and length of stay were not different in the two groups. However, those receiving long-course antibiotics had a significantly higher rate of pneumonia (24.7% vs. 10.9%; p = 0.03), although they had a lower rate of urinary tract infection (0.0% vs 9.4%, respectively; p = 0.01). Body mass index remained a statistically significant risk factor in the multivariable analysis (p = 0.005).

CONCLUSION

Prolonged antibiotic use after free flap reconstruction of head and neck defects does not appear to prevent SSI better than short-course treatment in this population. Moreover, long-course antibiotic use was associated with a higher risk of pneumonia.

Postoperative abnormal response of C-reactive protein as an indicator for infectious complications after oral oncologic surgery with primary reconstruction

Background

C-reactive protein (CRP) screening has been reported to be reliable for detection of infectious complications. Postoperative abnormal response of CRP can predict wound infection in colorectal surgery. This study aimed to determine the efficacy of CRP monitoring to detect infectious complications in oral oncologic surgery.

Methods

One hundred patients who underwent oral cancer resection with primary reconstruction were enrolled. Postoperative kinetics of CRP were classified into a normal or abnormal response.

Results

A normal CRP response after surgery was observed in 61 patients and an abnormal response was observed in 39. There were postoperative infectious complications in 21 patients, with surgical site infections in 13 patients (early onset in six and late onset in seven). Non-wound infections were found in nine patients. Sensitivity, specificity, the positive predictive value, and the negative predictive value for abnormal CRP response as a predictor for early infectious complications were 100%, 70.1%, 35.9%, and 100%, respectively.

Conclusion

Postoperative serial CRP screening is a useful test as an indicator of infectious complications in oral oncologic surgery. Normal CRP responses can rule out almost all early infectious complications.

Retrospective health-care associated infection surveillance in oral and maxillofacial reconstructive microsurgery

In polymorbid or anaemic patients who receive preoperative radiotherapy or undergo long duration surgery involving potentially infectious sites, perioperative antibiotic prophylaxis (PAP) that is effective against normal oral bacterial flora is mandatory and plays an important role in preventing postoperative infection. In a four-year retrospective analysis, the incidence, outcome, and the efficacy of PAP were evaluated in patients treated at the Department of Oral and Maxillofacial Surgery and Otorhinolaryngology at Kecskemét Hospital. The results were compared with data from the literature to determine if the use of PAP was adequate at the Department.During the study period (between 01/09/2007 and 31/01/2011) 108 patients were evaluated. The mean duration of prophylactic antibiotic treatment was 8.3 ± 5.2 days, with cefotaxime+metronidazole being the most commonly used combination. Surgical site infection occurred in 8 patients (7.5%) in the clean-contaminated category.Our results showed that the perioperative antibiotic prophylaxis administered at our Department was efficient and effective against the oral bacterial flora of patients. Its use is recommended in head and neck microsurgery. To avoid development of antibiotic resistance and to reduce costs, it seems that the duration of antibiotic regimen for primary surgery can be reduced from 8.3 ± 5.2 days to 3 days.

Current trends in perioperative antibiotic use: a survey of otolaryngologists

This study describes the patterns of perioperative antimicrobial use by otolaryngologists during common otolaryngologic surgical procedures. Through the American Academy of Otolaryngology--Head and Neck Surgery Infectious Diseases Committee, a survey was developed to assess the current practice patterns regarding the use of perioperative antibiotics in otolaryngology. A total of 6903 surveys were sent out; 458 were fully or partially completed, and a total of 442 responses were included in the final analysis. Most physicians reported routinely prescribing antibiotics either preoperatively or postoperatively for 12 of the 17 procedures included in the questionnaire despite providers agreeing that there is not enough evidence to support their use. The most common procedure for which antibiotics were prescribed was laryngectomy (91.1%). Antibiotic use is a common practice during the perioperative period for otolaryngologic procedures; however, there is a discrepancy between utilization and evidence of benefit.

Surgical site infections among high-risk patients in clean-contaminated head and neck reconstructive surgery: concordance with preoperative oral flora

BACKGROUND

Salivary contamination of surgical wounds in clean-contaminated head and neck surgery with free flap reconstruction remains a major cause of infection and leads to significant morbidity. This study investigates the correlation between intraoral flora and surgical site infections (SSIs) among high-risk head and neck cancer patients undergoing resection and free flap reconstruction.

METHODS

One hundred twenty-nine patients were identified as being at high risk for infective complications based on cancer stage, tumor size, comorbid factors, and extent of reconstruction. All patients had intraoral swab cultures before surgery. Patients with culture-confirmed SSI after surgery were chosen for analysis, using the κ index and its 95% confidence interval for concordance analysis. All patients received clindamycin and gentamicin for antibiotic prophylaxis for 5 days. Antibiotic susceptibility testing of all isolates was obtained and analyzed.

RESULTS

Thirty-seven patients experienced SSI, or an infection rate of 28.3%, occurring at a mean of 9.3 postoperative days. The overall concordance between oral flora and SSI was fair to moderate (κ index of 0.25), but detailed analysis shows a higher concordance for known and opportunistic pathogens, such as Pseudomonas aeruginosa and Enterococcus faecalis, compared to typical oral commensals. Antibiotic susceptibility tests show rapid and significant increases in resistance to clindamycin, indicating a need for a more effective alternative.

CONCLUSIONS

Predicting pathogens in SSI using preoperative oral swabs did not demonstrate a good concordance in general for patients undergoing clean-contaminated head and neck surgery, although concordance for certain pathogenic species seem to be higher than for typical intraoral commensals. The rapid development of resistance to clindamycin precludes its use as a prophylactic agent.

Preoperative topical antimicrobial decolonization in head and neck surgery

OBJECTIVES/HYPOTHESIS

Surgical site infections (SSIs) are an important cause of morbidity and mortality after head and neck surgery. Our primary objective was to determine the efficacy of preoperative topical antimicrobial decolonization before head and neck surgery.

STUDY DESIGN

Prospective, randomized controlled trial.

METHODS

This study was conducted among 84 patients presenting for head and neck surgery requiring admission to an academic medical center. Preoperative cultures were performed to identify Staphylococcus aureus carriers. Patients were randomized to preoperative topical antimicrobial decolonization with a 5-day regimen of chlorhexidine skin rinses and intranasal mupirocin coupled with standard perioperative systemic antimicrobial prophylaxis, versus standard prophylaxis alone. The main outcome was the incidence of SSIs.

RESULTS

Despite a trend suggesting a decrease in SSIs with perioperative topical antimicrobial decolonization (24% vs. 10%), there was no significant difference (odds ratio, 0.34; 95% confidence interval, 0.10-1.18; P = .079). Patients with a higher American Society of Anesthesiologists score (3 vs. 1; P = .02), with more operative blood loss (P = .05), and who required operative takeback (P = .04) had a higher rate of SSIs; there was a trend suggesting a higher rate of SSIs among patients undergoing clean-contaminated surgery compared to clean cases (P = .08) and among those having received prior radiation (P = .07) or chemotherapy (P = .06).

CONCLUSIONS

Preoperative antimicrobial decolonization did not significantly decrease the incidence of SSIs after head and neck surgery, but might be considered for high-risk groups despite the lack of conclusive evidence confirming efficacy. Risk factors for SSIs after head and neck surgery are identified for the first time in a prospective study.

Surgical site infections after gracilis free flap reconstruction for facial paralysis

Compared with other free tissue transfer procedures, the gracilis free muscle transfer (GFMT) for facial reanimation is unique in that the recipient site is typically uninvolved by malignancy or infection. In this study, the authors examined the incidence, bacteriology, and outcomes of surgical site infection (SSI) after gracilis free muscle transfer for facial reanimation. From 2003 to 2011, 105 patients underwent 107 GFMT operations, with 6 SSIs. All cases of infection occurred in patients receiving clindamycin, levofloxacin, and/or cefazolin perioperatively. None of the patients who received ampicillin-sulbactam developed an SSI. Surgical site cultures grew oral flora, including α-hemolytic streptococci, Haemophilus parainfluenzae, Fusobacterium and Neisseria species, and coagulase-negative staphylococci. Notably, there were no methicillin-resistant Staphylococcus aureus (MRSA) infections. These data may have implications for the optimal perioperative antibiotic choice in facial reanimation cases. Further study is needed to determine the ideal antibiotic regimen for this category of free flap surgeries.

Prognostic significance of postoperative wound infections after total laryngectomy

BACKGROUND

In oncologic surgery, the relationship between postoperative wound infections and prognosis remains unclear. The purpose of this study was to establish the prognostic significance of surgical wound infections in laryngectomized patients.

METHOD

We studied 129 consecutive patients with previously untreated laryngeal or hypopharyngeal squamous cell carcinoma who underwent a total laryngectomy. Minimum follow-up was 24 months.

RESULTS

Fifty-seven patients (44%) developed a wound infection. Infections were more frequent in hypopharyngeal tumors (p < .001). Surgical wound infection was associated with a worse disease-specific survival (p = .046), but this association was due to the hypopharyngeal subgroup of cases (p = .024). In multivariate analysis, the only parameters significantly associated with a worse disease-specific survival in these cases were nodal extracapsular invasion (p < .001) and surgical wound infection (p = .02).

CONCLUSION

Our results suggest that the development of a postoperative wound infection is a poor prognostic sign in patients with advanced hypopharyngeal cancers surgically treated.

Prognostic factors in patients with buccal squamous cell carcinoma: 10-year experience

PURPOSE

Squamous cell carcinoma (SCC) of the buccal mucosa accounts for 23% to 37% of all intraoral cancer cases in Taiwan. Because of the high recurrence rate and invasive tumor behavior, the prognosis is generally poor. The aim of this study was to evaluate the prognostic significance of clinicopathologic factors on survival rates for patients with buccal SCC in a medical center in central Taiwan.

MATERIALS AND METHODS

Between March 1995 and December 2002, patients admitted to hospital and diagnosed as having buccal SCC were enrolled in the study. There were 415 patients (406 men and 9 women) 25 to 84 years old (mean age, 51.1 ± 11.4 years). The chart records were retrospectively reviewed. Relevant clinical features in each patient, such as primary tumor size, tumor stage, initial treatment modalities, surgical margin status, cervical nodal metastasis status, and histopathologic grade, were compared for survival analysis.

RESULTS

Three hundred ninety-four patients received surgical intervention. Univariate analysis of relevant prognostic factors showed that positive surgical margin, positive cervical nodal metastasis, positive extracapsular spread, larger tumor, and advanced tumor stage were associated with poor prognosis. Multivariate analysis identified the factors that independently influenced the survival rate as advanced stage disease (stage III: relative risk [RR], 3.09; P = .006; stage IV: RR, 4.64; P < .001), positive surgical margin (RR, 2.02; P = .001), and extracapsular spread of cervical lymph node metastasis (RR, 6.89; P < .001).

CONCLUSIONS

This study represents the largest series in the literature and highlights the importance of tumor stage, surgical margin status, and extracapsular spread of cervical nodal metastasis as the most important prognostic factors in patients with buccal SCC.

Comparative study of two cefazolin prophylactic protocols in oncologic surgery of the larynx: A randomized trial

OBJECTIVE

Patients who need major head and neck surgery like laryngectomy are at risk of postoperative wound infection. Although the role of antibiotics in prophylaxis of clean contaminated head and neck surgery has been well documented, controversy exists in the optimal antibiotic regimen.

METHODS

In two tertiary referral hospitals (Imam Khomeini and Amir Alam hospital), 90 patients undergoing laryngectomy were prospectively randomized into two groups receiving cefazolin perioperative prophylaxis either for 2 days or for 5 days from June 2004 to March 2006. Then patients were blindly examined for the development of wound infection.

RESULTS

No wound infection was detected in either group. Two (4.4%) mucocutaneous fistula occurred in the 2-day group, and 3 (6.7%) in the 5-day group. There was no statistically significant difference in the infection rate between two groups.

CONCLUSION

We conclude that a 2-day perioperative cefazolin prophylaxis is equally effective as longer therapies. The increased morbidity and cost of the latter are in favor of the 2-day prophylactic regimen.