Current medical management of diabetic foot infections

Foot infections are a serious complication of diabetes associated with substantial morbidity and occasional mortality. Antibiotic therapy for mild infections in patients who have not recently received antibiotic therapy can often be directed at just staphylococci and streptococci. Empiric therapy for infections that are chronic, moderate or severe, or that occur in patients who have failed previous antibiotic treatment, should usually be more broad spectrum. Bone infection also complicates a substantial percentage of diabetic foot wounds and increases the likelihood of treatment failure, requiring lower extremity amputation. An increasing body of evidence supports the effectiveness of nonsurgical treatment of diabetic foot osteomyelitis in selected patients, although the optimal choice of agent, route of administration and duration of therapy have yet to be defined. This article examines the potential role of standard and newer antibiotics that may be appropriate for treating diabetic foot infections, including ertapenem, vancomycin, moxifloxacin, daptomycin, telavancin and tigecycline, as well as several investigational agents, such as dalbavancin, ceftobiprole and nemonoxacin.     

Current medical management of diabetic foot infections

Foot infections are a serious complication of diabetes associated with substantial morbidity and occasional mortality. Antibiotic therapy for mild infections in patients who have not recently received antibiotic therapy can often be directed at just staphylococci and streptococci. Empiric therapy for infections that are chronic, moderate or severe, or that occur in patients who have failed previous antibiotic treatment, should usually be more broad spectrum. Bone infection also complicates a substantial percentage of diabetic foot wounds and increases the likelihood of treatment failure, requiring lower extremity amputation. An increasing body of evidence supports the effectiveness of nonsurgical treatment of diabetic foot osteomyelitis in selected patients, although the optimal choice of agent, route of administration and duration of therapy have yet to be defined. This article examines the potential role of standard and newer antibiotics that may be appropriate for treating diabetic foot infections, including ertapenem, vancomycin, moxifloxacin, daptomycin, telavancin and tigecycline, as well as several investigational agents, such as dalbavancin, ceftobiprole and nemonoxacin.     

Diabetic foot infection

Foot infections are common in patients with diabetes and are associated with high morbidity and risk of lower extremity amputation. Diabetic foot infections are classified as mild, moderate, or severe. Gram-positive bacteria, such as Staphylococcus aureus and beta-hemolytic streptococci, are the most common pathogens in previously untreated mild and moderate infection. Severe, chronic, or previously treated infections are often polymicrobial. The diagnosis of diabetic foot infection is based on the clinical signs and symptoms of local inflammation. Infected wounds should be cultured after debridement. Tissue specimens obtained by scraping the base of the ulcer with a scalpel or by wound or bone biopsy are strongly preferred to wound swabs. Imaging studies are indicated for suspected deep soft tissue purulent collections or osteomyelitis. Optimal management requires aggressive surgical debridement and wound management, effective antibiotic therapy, and correction of metabolic abnormalities (mainly hyperglycemia and arterial insufficiency). Treatment with antibiotics is not required for noninfected ulcers. Mild soft tissue infection can be treated effectively with oral antibiotics, including dicloxacillin, cephalexin, and clindamycin. Severe soft tissue infection can be initially treated intravenously with ciprofloxacin plus clindamycin; piperacillin/tazobactam; or imipenem/cilastatin. The risk of methicillin-resistant S. aureus infection should be considered when choosing a regimen. Antibiotic treatment should last from one to four weeks for soft tissue infection and six to 12 weeks for osteomyelitis and should be followed by culture-guided definitive therapy.     

Risk factors for foot infections in individuals with diabetes

OBJECTIVE: To prospectively determine risk factors for foot infection in a cohort of people with diabetes. RESEARCH DESIGN AND METHODS: We evaluated then followed 1,666 consecutive diabetic patients enrolled in a managed care-based outpatient clinic in a 2-year longitudinal outcomes study. At enrollment, patients underwent a standardized general medical examination and detailed foot assessment and were educated about proper foot care. They were then rescreened at scheduled intervals and also seen promptly if they developed any foot problem. RESULTS: During the evaluation period, 151 (9.1%) patients developed 199 foot infections, all but one involving a wound or penetrating injury. Most patients had infections involving only the soft tissue, but 19.9% had bone culture-proven osteomyelitis. For those who developed a foot infection, compared with those who did not, the risk of hospitalization was 55.7 times greater (95% CI 30.3-102.2; P < 0.001) and the risk of amputation was 154.5 times greater (58.5-468.5; P < 0.001). Foot wounds preceded all but one infection. Significant (P < 0.05) independent risk factors for foot infection from a multivariate analysis included wounds that penetrated to bone (odds ratio 6.7), wounds with a duration >30 days (4.7), recurrent wounds (2.4), wounds with a traumatic etiology (2.4), and presence of peripheral vascular disease (1.9). CONCLUSIONS: Foot infections occur relatively frequently in individuals with diabetes, almost always follow trauma, and dramatically increase the risk of hospitalization and amputation. Efforts to prevent infections should be targeted at people with traumatic foot wounds, especially those that are chronic, deep, recurrent, or associated with peripheral vascular disease.     

Medical management of diabetic foot infections

Diabetic foot infections (DFIs) are a commonly encountered medical problem. They are associated with an increased frequency and length of hospitalization and risk for lower-extremity amputation. Furthermore, they have substantial economic consequences. Patients with diabetes mellitus are particularly susceptible to foot infections because of neuropathy, vascular insufficiency, and diminished neutrophil function. The approach to managing DFIs starts with determining if an infection exists. If an infection exists, then the type, severity, extent of infection, and risk factors for resistant organisms should be determined through history, physical examination, and additional laboratory and radiological testing. Optimal management requires surgical debridement, pressure offloading, effective antibiotic therapy, wound care and moisture, maintaining good vascular supply, and correction of metabolic abnormalities, such as hyperglycemia, through a multidisciplinary team. Empiric antibiotics for DFIs vary based on the severity of the infection, but must include anti-staphylococcal coverage.     

Are granulocyte colony-stimulating factors beneficial in treating diabetic foot infections?: A meta-analysis

OBJECTIVE: To assess the value of granulocyte colony-stimulating factor (G-CSF) as adjunctive therapy for diabetic foot infections. RESEARCH DESIGN AND METHODS: We systematically searched the medical literature (including Medline, Embase, LookSmart, and the Cochrane Library) for prospective randomized studies that used G-CSF as an adjunct to standard treatment for diabetic foot infections. Using a conventional meta-analysis, we pooled the relative risks (RRs) for outcomes of interest, including resolution of infection, wound healing, duration of antibiotic therapy, and need for various surgical interventions, using a fixed-effects model. RESULTS: Five randomized trials, with a total of 167 patients, met our inclusion criteria. The methodological quality of the studies was satisfactory. The investigators administered various G-CSF preparations parenterally for between 3 and 21 days. The meta-analysis revealed that adding G-CSF did not significantly affect the resolution of infection or the healing of the wounds but was associated with a significantly reduced likelihood of lower extremity surgical interventions (RR 0.38 [95% CI 0.20-0.69], number of patients who needed to be treated: 4.5), including amputation (0.41 [0.17-0.95], number of patients who needed to be treated: 8.6). There was no evidence of heterogeneity among the studies or of publication bias, suggesting that these conclusions are reasonably generalizable and robust. CONCLUSIONS: Adjunctive G-CSF treatment does not appear to hasten the clinical resolution of diabetic foot infection or ulceration but is associated with a reduced rate of amputation and other surgical procedures. The small number of patients who needed to be treated to gain these benefits suggests that using G-CSF should be considered, especially in patients with limb-threatening infections.     

Complicated urinary tract infection in patients with benign prostatic hyperplasia

Complicated urinary tract infection (UTI) is a symptomatic urinary infection accompanied by functional or structural abnormalities of the genitourinary tract. Benign prostatic hyperplasia (BPH) is a major cause of lower urinary tract obstruction in male patients, and bladder outlet obstruction (BOO) secondary to BPH can lead to UTIs in men. However, no evidence has clearly shown that UTI in the aging male population is associated with either post-void residual urine or BOO. Screening for the presence of bacteriuria is recommended prior to any procedure manipulating the urinary tract, and imaging studies of the upper urinary tract are recommended to identify underlying abnormalities. Recurrent or persistent UTI in men with BPH is an indication for surgical treatment. Asymptomatic bacteriuria should be screened for and treated before transurethral resection of the prostate (TURP). In addition, antibiotic prophylaxis reduced the risk of UTI in patients undergoing TURP. The choice of specific antimicrobial for prophylaxis should be based on local pathogen prevalence and individual antibiotic susceptibility. Patients with severe systemic infections require hospitalization, and empirical therapy should include an intravenous antimicrobial regimen. Further prospective studies are needed to refine the treatment process for complicated UTI in patients diagnosed with BPH.     

Infekt nach Arthroskopie

Introduction

Postarthroscopy infections are rare. Because delayed diagnosis can have dramatic consequences, an early enquiry of patient history, blood examinations, and diagnostic puncture or—in case of strong suspicion of infection—intraoperative sampling (without previous antibiotics) is necessary.

Methods

For early-stage infections, arthroscopic therapy has proven valuable. In addition, calculated and antibiogram-adjusted antibiotic therapy is essential. A special case is implant-associated joint infection, which requires a more complex surgical therapy with often longer antibiotic treatment and decisions concerning implant preservation or removal. In this context, interdepartmental cooperation is desired.

Conclusion

If signs of infection are present, the indication for surgical revision should be considered quickly and comprehensively. To prevent joint stiffness, mobilization should be started early and the duration of immobilization should be kept as short as possible.     

糖尿病足溃疡感染多重耐药菌的临床特点及相关因素分析

目的 探讨糖尿病足溃疡(diabetic foot ulcer,DFU)感染多重耐药菌(MDROs)的分布特点、DFU感染MDROs的危险因素及对DFU结局的影响.方法 对我院收治的157例DFU患者临床病例资料进行回顾性分析.以是否感染MDROs分为两组,采用χ2检验,t检验进行MDROs感染及糖尿病足溃疡结局的单因素分析,logistics回归进行MDROs感染的危险因素分析.结果 MDRO阳性组中共分离出MDROs78株,居前三位分别是金黄色葡萄球菌16.7%(13/78)、肠杆菌16.7%(13/78)、铜绿假单孢菌15.4%(12/78).MDROs感染的单因素分析,两组在糖尿病病程、入院前住院次数、入院前抗生素应用时间、溃疡类型、溃疡大小及骨髓炎方面差异有统计学意义,而logistics回归分析,入院前住院次数、入院前抗生素应用时间、溃疡类型、溃疡大小、骨髓炎是MDROs感染的独立危险因素.MDRO阳性组截肢率高于MDRO阴性组(60.9% vs 37.0%,P<0.05).结论 入院前住院次数、入院前抗生素应用时间、溃疡类型、溃疡大小及骨髓炎是DFU感染MDROs 的独立危险因素,感染MDROs影响溃疡的结局,增加截肢的风险,更好的控制MDROs是改善DFU预后的重要途径.     

Optimizing antimicrobial therapy in sepsis and septic shock

Every patient with sepsis and septic shock must be evaluated thoroughly at presentation before the initiation of antibiotic therapy. However, in most situations, an abridged initial assessment focusing on critical diagnostic and management planning elements is sufficient. Intravenous antibiotics should be administered as early as possible, and always within the first hour of recognizing severe sepsis and septic shock. Broad-spectrum antibiotics must be selected with one or more agents active against likely bacterial or fungal pathogens and with good penetration into the presumed source. Antimicrobial therapy should be reevaluated daily to optimize efficacy, prevent resistance, avoid toxicity, and minimize costs. Consider combination therapy in Pseudomonas infections, and combination empiric therapy in neutropenic patients. Combination therapy should be continued for no more than 3 to 5 days and de-escalation should occur following availability of susceptibilities. The duration of antibiotic therapy typically is limited to 7 to 10 days; longer duration is considered if response is slow, if there is inadequate surgical source control, or in the case of immunologic deficiencies. Antimicrobial therapy should be stopped if infection is not considered the etiologic factor for a shock state.     

Diagnosis and management of acute pyelonephritis in adults

There are approximately 250,000 cases of acute pyelonephritis each year, resulting in more than 100,000 hospitalizations. The most common etiologic cause is infection with Escherichia coli. The combination of the leukocyte esterase test and the nitrite test (with either test proving positive) has a sensitivity of 75 to 84 percent and a specificity of 82 to 98 percent for urinary tract infection. Urine cultures are positive in 90 percent of patients with acute pyelonephritis, and cultures should be obtained before antibiotic therapy is initiated. The use of blood cultures should be reserved for patients with an uncertain diagnosis, those who are immunocompromised, and those who are suspected of having hematogenous infections. Outpatient oral antibiotic therapy with a fluoroquinolone is successful in most patients with mild uncomplicated pyelonephritis. Other effective alternatives include extended-spectrum penicillins, amoxicillin-clavulanate potassium, cephalosporins, and trimethoprim-sulfamethoxazole. Indications for inpatient treatment include complicated infections, sepsis, persistent vomiting, failed outpatient treatment, or extremes of age. In hospitalized patients, intravenous treatment is recommended with a fluoroquinolone, aminoglycoside with or without ampicillin, or a third-generation cephalosporin. The standard duration of therapy is seven to 14 days. Urine culture should be repeated one to two weeks after completion of antibiotic therapy. Treatment failure may be caused by resistant organisms, underlying anatomic/functional abnormalities, or immunosuppressed states. Lack of response should prompt repeat blood and urine cultures and, possibly, imaging studies. A change in antibiotics or surgical intervention may be required.     

Recommendations and rationale for the treatment of pelvic inflammatory disease

Pelvic inflammatory disease (PID) is one of the most common serious infections of nonpregnant women of reproductive age. Management of PID is directed at containment of infection. Goals of therapy include the resolution of clinical symptoms and signs, the eradication of pathogens from the genital tract and the prevention of sequelae including infertility, ectopic pregnancy and chronic pelvic pain. The choice of an antibiotic regimen used to treat PID relies upon the appreciation of the polymicrobial etiology of this ascending infection including Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium and other lower genital tract endogenous anaerobic and facultative bacteria, many of which are associated with bacterial vaginosis. Currently available evidence and the CDC treatment recommendations support the use of broad-spectrum antibiotic regimens that adequately cover the above named microorganisms. The outpatient treatment of mild-to-moderate PID should include tolerated antibiotic regimens consisting of an extended-spectrum cephalosporin in conjunction with either azithromycin or doxycycline. Clinically severe PID should prompt hospitalization and imaging to rule out a tubo-ovarian abscess. Parenteral broad-spectrum antibiotic therapy with activity against a polymicrobial flora, particularly Gram-negative aerobes and anaerobes, should be implemented.     

Outcomes analysis of daptomycin use in a community hospital

This study was conducted to assess clinical and cost outcomes associated with the use of daptomycin. This objective was addressed through a consecutive patient chart review of the first 50 inpatients treated with daptomycin. Type of infection, identity of isolated pathogens, prior therapy, duration of therapy, length of hospitalization, cost of antibiotics, adverse events, and outcomes were evaluated. The analysis showed that mean patient age was 64 y, and mean length of hospitalization was 9.2 d. A total of 62% of patients had confirmed methicillin-resistantStaphylococcus aureus infection. The mean duration of daptomycin therapy was 7.5 d; however, in patients given treatment for complicated skin and skin structure infections, the mean duration of therapy was 6.1 d (n=15) and 7.1 d (n=16) for first- and second-line daptomycin therapy, respectively. The average course of daptomycin cost $727 (n=38) and $390 (n=11), respectively, in the subset of patients with renal insufficiency. In patients who did not respond to prior antibiotic treatment for a Gram-positive bacterial infection (n=26), the mean duration of prior therapy with antibiotics was 6.0 d and the cost was $287. For patients who were transitioned to outpatient daptomycin therapy (n=14), hospital charges were reduced by an estimated $102,340. In 48 patients (96%), infection was resolved with daptomycin therapy. Daptomycin was effective in resolving Grampositive infection in this aged patient population. Earlier identification of antibiotic failure, first-line use of daptomycin in patients with complicated skin and skin structure infections, and outpatient daptomycin therapy provided cost savings and improved clinical outcomes at this facility.     

Antiobiotic prophylaxis to prevent surgical site infections

Surgical site infections are the most common nosocomial infections in surgical patients, accounting for approximately 500,000 infections annually. Surgical site infections also account for nearly 4 million excess hospital days annually, and nearly $2 billion in increased health care costs. To reduce the burden of these infections, a partnership of national organizations, including the Centers for Medicare and Medicaid Services and the Centers for Disease Control and Prevention, created the Surgical Care Improvement Project and developed six infection prevention measures. Of these, three core measures contain recommendations regarding selection of prophylactic antibiotic, timing of administration, and duration of therapy. For most patients undergoing clean-contaminated surgeries (e.g., cardiothoracic, gastrointestinal, orthopedic, vascular, gynecologic), a cephalosporin is the recommended prophylactic antibiotic. Hospital compliance with infection prevention measures is publicly reported. Because primary care physicians participate in the pre- and postoperative care of patients, they should be familiar with the Surgical Care Improvement Project recommendations.     

Risk factors for recurrence in patients with Staphylococcus aureus infections complicated by bacteremia

Recurrence is a common complication of Staphylococcus aureus infections. A shorter duration of antibiotic treatment for a S. aureus infection has been previously suggested as a possible risk factor for recurrence. We conducted a retrospective cohort study of patients with S. aureus infection complicated by bacteremia who survived their initial treatment (N = 397) at the VA Maryland Health Care System from 1995 to 2004 to determine if 2 weeks or less of antibiotic therapy is significantly associated with a higher rate of recurrence. Recurrence was defined as recurrence of infection because of S. aureus with the same susceptibility to methicillin within 1 year of treatment of the initial bacteremia. Seventeen percent of patients who survived their initial infection had a recurrence of infection. Mean duration of antibiotic therapy in those who recurred was longer than in those who did not recur (21 versus 18 days, P = .18). No evidence was found to support an association between a duration of therapy of 14 days or less and an increased risk for recurrence (RR, 0.68; 95% CI, 0.44-1.04). However, being HIV infected (OR, 4.59; 95% CI, 1.61-13.10), having diabetes (OR, 2.02; 95% CI, 1.13-3.61) and having an infection due to a methicillin-resistant S. aureus (MRSA) (OR, 2.11; 95% CI, 1.17-3.80) were independent risk factors for recurrence. In conclusion, 2 weeks or less of antibiotic therapy was not associated with an increased risk for recurrence. However, patients with diabetes or HIV infection and patients with MRSA infections are at an increased risk for recurrence and should be followed more closely.     

糖尿病足抗生素规范化治疗

糖尿病足（diabeticfoot, DF)是糖尿病最常见的并发症之一,临床表现主要为足部溃疡、感染和坏疽,常常给患者带来巨大痛苦和沉重的经济负担,严重者常导致截肢甚至危及生命。因此, 糖尿病足的治疗需要一个规范化的标准。糖尿病足的发病是多种因素共同作用的结果,包括神经病变、血管病变、感染等,其中感染是较复杂且不易控制的因素,这就涉及到抗生素的应用,本文主要阐述糖尿病足抗生素规范化治疗。     

SIRS Is Valid in Discriminating Between Severe and Moderate Diabetic Foot Infections

OBJECTIVE

This retrospective, single-center study was designed to distinguish severe diabetic foot infection (DFI) from moderate DFI based on the presence or absence of systemic inflammatory response syndrome (SIRS).

RESEARCH DESIGN AND METHODS

The database of a single academic foot and ankle program was reviewed and 119 patients were identified. Severe DFI was defined as local infection associated with manifestation of two or more objective findings of systemic toxicity using SIRS criteria.

RESULTS

Patients with severe DFI experienced a 2.55-fold higher risk of any amputation (95% CI 1.21–5.36) and a 7.12-fold higher risk of major amputation (1.83–41.05) than patients with moderate DFI. The risk of minor amputations was not significantly different between the two groups (odds ratio 1.02 [95% CI 0.51–2.28]). The odds of having a severe DFI was 7.82 times higher in patients who presented with gangrene (2.03–44.81) and five times higher in patients who reported symptoms of anorexia, chills, nausea, or vomiting (2.22–11.25). The mean hospital length of stay for patients with severe DFI was ∼4 days longer than for patients with moderate DFI, and this difference was statistically significant.

CONCLUSIONS

SIRS is valid in distinguishing severe from moderate DFI in hospitalized patients. Patients with severe DFI, as by manifesting two or more signs of systemic inflammation or toxicity, had higher rates of major amputation and longer hospital stays and required more surgery and more subsequent admissions than patients who did not manifest SIRS.In 2004, the Infectious Disease Society of America (IDSA) classified diabetic foot infections (DFIs) as mild, moderate, and severe based on local and systemic manifestations of infection (1). Individuals with mild infections are typically treated as outpatients but some patients with moderate infections and all patients with severe infections require hospitalization and potential surgical intervention. The International Working Group on the Diabetic Foot devised a similar classification system (1). Severe infections are distinguished from moderate infections by the presence of systemic toxicity or metabolic instability (fevers, chills, tachycardia, hypotension, confusion, vomiting, leukocytosis, acidosis, severe hyperglycemia, or azotemia). A validation study of the IDSA classification demonstrated that as infection severity increased, there was an increased risk of amputation and hospitalization (2). Neither the initial guideline nor the validation study precisely defined what constituted leukocytosis, tachycardia, hypotension, severe hyperglycemia, or azotemia (1,2). Recently, the IDSA updated their guidelines and recommended using systemic inflammatory response syndrome (SIRS) as a method for distinguishing between moderate and severe DFI (3). To the best of our knowledge, the use of SIRS has not yet been validated as a method of discriminating between moderate and severe DFI.The aim of this study was to classify infection severity in a group of hospitalized diabetic patients based on the presence or absence of SIRS. The reason for hospitalization in this group of patients was their DFI. Our hypotheses are that patients with DFI who manifest SIRS (i.e., severe infection) will have longer hospital stays and higher rates of major amputation than patients who don’t manifest SIRS (i.e., moderate infection).     

Impact of multidrug resistance on the management of bacterial infections in cirrhosis

Patients with cirrhosis have an increased risk of infection and differently from other complications, that over the years are improving in their outcomes, infections in cirrhotic patients are still a major cause of hospitalization and death (up to 50% in-hospital mortality). Infections by multidrug-resistant organisms (MDRO) have become a major challenge in the management of cirrhotic patients with significant prognostic and cost-related impact. About one third of cirrhotic patients with bacterial infections is infected with MDR bacteria and their prevalence has increased in recent years. MDR infections have a worse prognosis compared to infections by non-resistant bacteria because they are associated with lower rate of infection resolution. An adequate management of cirrhotic patients with infections caused by MDR bacteria depends on the knowledge of some epidemiological aspects, such as the type of infection (spontaneous bacterial peritonitis, pneumonia, urinary tract infection and spontaneous bacteremia), bacteriological profile of antibiotic resistance at each health care unit and site of infection acquisition (community acquired, healthcare associated or nosocomial). Furthermore, regional variations in the prevalence of MDR infections determine that the choice of empirical antibiotic therapy must be adapted to the local microbiological epidemiology. Antibiotic treatment is the most effective measure to treat infections caused by MDRO. Therefore, optimizing antibiotic prescribing is critical to effectively treat these infections. Identification of risk factors for multidrug resistance is essential to define the best antibiotic treatment strategy in each case and the choice of an effective empirical antibiotic therapy and its early administration is cardinal to reduce mortality. On the other hand, the supply of new agents to treat these infections is very limited. Thus, specific protocols that include preventive measures must be implemented in order to limit the negative impact of this severe complication in cirrhotic patients.     

Surgical management of diabetic foot infections and amputations

THE INCIDENCE OF DIABETES with severe foot infections (eg, necrotizing fasciitis, gas gangrene, ascending cellulitis, infection with systemic toxicity or metabolic instability) has risen significantly during the past decade.FOOT INFECTIONS are a major cause of hospitalization and subsequent lower extremity amputation among patients with diabetes mellitus who have a history of a preexisting ulceration.SURGICAL MANAGEMENT often is required to address severe diabetic foot infections because they can be limb- or life-threatening. Critical limb ischemia, neuropathy, and an immunocompromised host, which often are associated with diabetic foot infections, complicate treatment and are associated with a poorer prognosis. AORN J 87 (May 2008) 935-946. © AORN, Inc, 2008.