Management of hospitalized patients with diabetic foot infections.

C L I N I C A L F E AT U R E S

Management of Hospitalized Patients With Diabetic Foot Infections

Hospital Practice Downloaded from informahealthcare.com by Dalhousie University on 04/13/15 For personal use only.

DOI: 10.3810/hp.2014.10.1148

Mazen S. Bader, MPH, MD 1 Afsaneh Alavi, MD 2 Hamilton Health Sciences, Juravinski Hospital and Cancer Centre, and Department of Medicine, Division of Infectious Diseases, Hamilton, Ontario, Canada; 2Consultant Dermatologist, Department of Medicine (Dermatology), University of Toronto, Toronto, Ontario, Canada 1

Abstract: Diabetic foot infections (DFIs), which present with a variety of clinical manifestations, are commonly encountered by clinicians. They are associated with a high morbidity, a high amputation rate, a high mortality, and increased health care costs. An effective management of DFIs requires a multidisciplinary approach with a strong collaboration among all involved health care providers as well as patient involvement. Diagnosing DFIs appropriately requires consideration of the clinical symptoms and signs of infection in addition to supplementary laboratory testing such as inflammatory markers and imaging studies. The comprehensive patient assessment should include the predisposing risk factors for infection; the type, severity, and extent of the infection; and the assessment of neurologic and vascular status, comorbid conditions, and psychosocial factors. The comprehensive management of DFIs include not only effective antibiotic therapy but also surgical debridement, pressure offloading, wound care and moisture, maintaining good vascular perfusion, control of edema and pain, correction of metabolic abnormalities such as hyperglycemia, and addressing psychosocial and nutritional issues. Discharge planning that addresses full medical and social needs along with suitable follow-up, patient education and counseling, and clear communication with outpatient providers are critical for ensuring a safe and successful transition to outpatient management of hospitalized patients with DFIs. Keywords: diabetic foot infections; diabetic foot ulcers; diabetic foot osteomyelitis

Introduction

Correspondence: Mazen S. Bader, MPH, MD, Juravinski Hospital and Cancer Centre, Department of Medicine, 711 Concession Street, Hamilton, Ontario L8V1C3, Canada. Tel: 905-527-4322 ext. 42813 Fax: 905-389-0108 E-mail: [email protected]

Diabetes mellitus is a complex group of metabolic disorders associated with impaired insulin secretion and variable degrees of peripheral insulin resistance. It is associated with several complications and increased risk of morbidity, mortality, hospitalization, and prolonged hospitalization once admitted.1,2 Diabetic foot problems are one of the most common complications. Recent studies found that the complication rate and hospitalization of skin and soft tissue infections (SSTIs) are 5 and 4 times higher, respectively, among patients with diabetes than among patients without diabetes. These studies also found that diabetes is associated with a longer hospital stay among hospitalized patients with SSTIs. The SSTI-associated hospitalizations accounted for 4.9% of the hospitalizations of patients with diabetes.3–5 Foot complications usually start with neuropathy and subsequent diabetic foot ulcers (DFUs) that have a prevalence as high as 25% in all patients with diabetes mellitus.6 The DFUs frequently become infected; in fact, more than half of them are infected at the time of clinical presentation.7 Diabetic foot infections (DFIs) are defined clinically as a soft tissue or joint/bone infections anywhere distal to the malleolus. The most commonly affected sites are the toes followed by the midfoot. The progression from

© Hospital Practice, Volume 42, Issue 4, October 2014, ISSN – 2154-8331 111 ResearchSHARE®: www.research-share.com • Permissions: [email protected] • Reprints: [email protected] Warning: No duplication rights exist for this journal. Only JTE Multimedia, LLC holds rights to this publication. Please contact the publisher directly with any queries.


Mazen S. Bader and Afsaneh Alavi

DFU colonization to DFIs is influenced by various factors including the type and depth of the ulcer, the blood supply, the immune function of the patient, the quantity and virulence of colonizing organisms, and the appropriateness of prevention and treatment.8 Factors related to the increased risk of DFIs include chronic ulcers (. 30 days), recurrent ulcers, trauma, penetrating ulcers to bone, presence of peripheral arterial disease (PAD), diabetes-related immunologic dysfunction, and chronic renal failure.6 The mortality and morbidity of DFIs depends on the severity of the infection, the presence of associated limb ischemia, and proper management.9 An infected ulcer precedes . 85% of nontraumatic lower extremities amputations, one of the most serious complications of diabetes. In a study of hospitalized patients with DFIs, minor amputation was significantly higher in patients with osteomyelitis than in patients with SSTIs (59.4% vs 13.8%).10 Prior amputation is associated with increased risk of hospitalization.11 Minor amputations alter the architecture of the foot and make the patient prone to further ulceration. The risk of ipsilateral amputation or a contralateral lower extremity amputation is significantly increased.12,13 The subsequent limitations in physical activity, due to amputation, decrease the quality of life and may lead to the worsening of glycemic control.12,14–16 This article provides a stepwise approach to the evaluation and management of hospitalized patients with DFIs based on recently published guidelines.17–21

Diagnostic Approach

A consistent and thorough diagnostic approach is essential for early diagnosis and treatment of DFIs (Table 1). Once infection develops, it can spread to deep soft tissue and bony structures, which is a major causal factor for lowerlimb amputation with subsequent increased morbidity and mortality. Diagnosis of the infection in a diabetic foot is mainly clinical, based on the presence of symptoms and signs of inflammation. Infection can also manifest as purulent discharge, delayed healing, friable, or discolored granulation tissue, foul odor, and wound breakdown.8,17 The clinical symptoms and signs of infection can be dampened due to immunopathy and an impaired neuroinflammatory response due to C-fiber dysfunction and ischemia.7 Diabetic foot infections do not always present with systemic symptoms and signs such as fever and chills, and their presence may indicate a moderate to severe infection such as deep space infection (Figure 1), cellulitis, acute septic arthritis, or acute 112

osteomyelitis that is present in 25% of cases.21 Fever does not occur in chronic osteomyelitis unless accompanied with skin and soft tissue infections. The clinical presentation of DFIs varies widely, ranging from infected ulcer, cellulitis, necrotizing cellulitis, and necrotizing fasciitis, to deep tissue infection involving the bones. Osteomyelitis may be present in up to 20% of mild to moderate DFI and in 50% to 60% of severe infection.20,21 Diagnostic process of DFIs begins with clinical assessment through a comprehensive history and physical examination followed by laboratory testing, microbiology assessment, and diagnostic imaging if deemed necessary.16 The history should include general medical, diabetic, and foot history. A head-to-toe physical examination should be performed on every patient with DFIs on admission (Table 1). Once the diagnosis of a DFI is suspected or established, the next step is to assess its severity, which is important for determining the need for hospitalization, selecting the appropriate empiric antibiotic regimen and its route of administration, and evaluating the potential need for surgical intervention. In the Infectious Disease Society of America classification, DFIs are categorized, based on their severity, as mild (superficial tissue and limited in size and depth), moderate (deeper or more extensive), or severe (associated with systemic signs or metabolic abnormalities)8 (Table 2). This classification has been prospectively validated as a predictor of lower extremities amputation and hospitalization.22 Systemic inflammatory response syndrome might help differentiate between moderate and severe DFIs. However, this syndrome is not present in 50% of patients with deep DFIs, leading to delayed diagnosis and further risk of amputation. Severe DFIs are associated with a higher risk of major amputation, a higher prevalence of gangrene, and a longer hospital stay compared with moderate DFIs.23 Laboratory and radiologic tests help to establish the depth of involvement and type of infection and to differentiate infectious versus noninfectious bone and soft tissue changes (Table 3). Laboratory tests should be interpreted within the whole clinical context because no marker is sufficiently sensitive and specific to confirm the diagnosis of DFIs, and these tests are sometimes misleading, even in the case of severe infection. The role of imaging in DFIs is to establish an early and reliable diagnosis; localize, characterize, and define the depth of involvement; and assess treatment response. The most commonly used imaging modalities for the diagnosis and management of DFIs include plain radiography, computed tomography, nuclear medicine scintigraphy, magnetic

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Table 1. Elements of Clinical Assessment of Hospitalized Patients With Diabetic Foot Infections Element

Assessment Methods

Presence of infection

Infection exists with the presence of $ 2 classic symptoms or signs of inflammation (erythema, warmth, tenderness, pain, or induration) or purulent secretions. Debride any necrotic material or callus, then gently probe the wound to look for any abscesses, sinus tracts, foreign bodies, or evidence of bone or joint involvement. Imaging with plain radiograph is always recommended for all patients with DFIs and additional imaging such as MRI might be required if osteomyelitis is suspected. Type of wound, location, size, duration, depth, quantity and quality of drainage, existing tissue type(s), character of wound base (granular, fibrous, or necrotic) and periwound area. Use IDSA classification (see Table 2). It can be initially assessed through history, physical examinationa and noninvasive testing such as ABPIb with pulse volume recordings and Doppler waveform analysis if necessary. An ABPI . 1.3 is indicative of arterial calcification and other tests should be performed in consultation with a vascular surgeon. Vascular imaging with duplex ultrasonography, computed angiography, magnetic resonance angiography, or digital subtraction angiographyc should be performed if noninvasive testing is abnormal or inconclusive in consultation with a vascular surgeon. It can be assessed through history, physical examination,d and, if needed, imaging with duplex ultrasonography. It can be assessed by testing light-touch sensation using a 10-g Semmes-Weinstein monofilament in addition to 1 of the following techniques: pinprick sensation, vibration perception with a 128-Hz tuning fork, ankle deep tendon reflexes, or vibration perception threshold testing. It can be assessed by inspection and palpation to look for deformities such as Charcot arthropathy, claw or hammer toes, bunions, or callosities. Assess mobility, gait, and walking capacity. Assess the attitude and posture of the lower extremities and foot. Assess the joint active and passive mobility. Tendon assessment by looking for Achilles contractures, equines, and foot drop. Muscle group strength testing and plantar pressure assessment. Previous history of ulcers/wounds, infection, and their treatment course. Look for skin appearance such as color, texture, dry skin, calluses, heel fissures, cracking, nail appearance such as onychomycosis, dystrophic atrophy, hypertrophy, paronychia, and presence of tinea pedis. Duration of diabetes, current and past glycemic drugs, and complications such prior ulcers, nephropathy, retinopathy. Glycemic control can be assessed by intermittent glucose monitoring and HbA1c. Assess the presence of acute complications of diabetes such diabetes ketoacidosis or hypoglycemia. Such as congestive heart failure, and renal dysfunction. Medications include antibiotics (current, recent) and allergy history. Social factors such as use of tobacco or alcohol, quantity of weight-bearing and ambulation level, diet and exercise, home support network, quality of life, occupation and income source. Psychiatric disorders such as depression and personality and anxiety disorders. It can be assessed by using a nutritional screening tool such as the Mini-Nutritional Assessment (MNA) and measurement of serum albumin, prealbumin, cholesterol, and lymphocyte count.

Extent of the infection (depth and involved tissue) Wound


Severity of the infection Arterial circulation

Venous insufficiency Protective sensation

Biomechanical problems Musculoskeletal status

Other foot issues

Diabetes and glycemic control

Comorbid conditions/medications Psychosocial conditions

Nutritional status

An evaluation of the flow signals from both foot arteries (dorsalis pedis and posterior tibials) should be performed for every patient with a hand-held Doppler. The ABPI is the ratio of systolic blood pressure in the ankle to that in the brachial artery in the arm. An ABPI of 0.60–0.89, 0.40– 0.59, and , 0.40 suggests mild, moderate, and severe PAD, respectively. c Computed tomography angiography, MRI angiography, and digital subtraction angiography cannot be used in cases of allergy to contrast media or renal failure. Computed tomography angiography and MRI angiography are unreliable in small-caliber vessels such as the ones below the knee. Computed tomography angiography is also unreliable in the presence of arterial calcification, whereas MRI angiography is also unreliable in the presence of intraluminal stents. Digital subtraction angiography defines the anatomic involvement of the tibial and peroneal arteries and foot vessels in diabetic patients requiring revascularization necessary to heal extensive tissue loss. All these studies do not provide hemodynamic information and, therefore, cannot be used to establish the diagnosis of critical ischemia in patients with DFIs. d Signs of venous insufficiency include varicose veins, hyperpigmentation, brawny induration, and scarring. Adapted from Bader MS. Diagnostic Approach to Diabetic Foot Infections. In: Bader MS, Armstrong D, Alavi A, Sibbald G, Wu S, Giovinco N, ed. Diabetic foot infections. First ed. Gurgaon, India: Macmillan. 2014:41–68. Abbreviations: ABPI, ankle-brachial pressure index; CPO2, transcutaneous oxygen pressure; CT, computed tomography; DFIs, diabetic foot infections; HbA1c, glycosylated hemoglobin; IDSA, Infectious Diseases Society of America; MRI, magnetic resonance imaging; PAD, peripheral arterial disease. a

b

resonance imaging (MRI), ultrasonography, and positron emission tomography (Table 3). However, each of these modalities has limitations and should be ordered and interpreted within the whole clinical context and after consultation with the appropriate services.24–28

Cultures should be obtained, not to diagnose the infection, but rather to determine which organism is causing the infection, thus guiding antibiotic selection. The majority of DFUs get contaminated and colonized and the presence of bacteria does not confirm a diagnosis of infection. Wound contamination




Figure 1. Diabetic foot infection with deep soft tissue involvement, moderate by Infectious Disease Society of America classification. Courtesy of David Armstrong.

is the presence of nonreplicating bacteria on wound surface, and wound colonization is the presence of replicating bacteria without tissue injury or immune response. Critical colonization involves the replication of bacteria in the superficial wound base with tissue damage. As host resistance weakens, the bacteria invade the wound margins and base where a critical threshold of 105 bacteria per gram of tissue is often associated with tissue damage by the inflammatory cytokines.29,30

The differentiation among the wound spectra from colonization to infection can be challenging. However, clinical symptoms and signs of infections, inflammatory markers, procalcitonin, and a semiquantitative tissue culture sampled by curettage or biopsy are helpful in confirming the diagnosis of DFIs.31 Proper sampling technique for culture is very important. A routine superficial swab for culture from an undebrided and noncleansed wound identifies only the superficial bacteria and may miss the true pathogen. Multiple studies, particularly on diabetic foot osteomyelitis (DFO), demonstrated that a superficial swab culture does not correlate with the deep tissue samples.32,33 If bacterial swabs are to be performed, the Levine method (rotate the swab over a 1 cm2 area with gentle pressure to express fluid from the wound tissue) is preferred after the wound is cleaned and debrided.34 The bacterial swab may detect resistant organisms and help redirect antibiotic therapy if patients do not respond to empiric therapy.35–37 Most laboratories process specimens for culture in a semiquantitative fashion and provide results using such terms as scant, mild, moderate, or heavy growth. The presence of heavy growth indicates . 105 colony forming units per gram of tissue.17,38 The latest guidelines from the Infectious Disease Society of America encourage clinicians to obtain bone biopsy in

Table 2. Infectious Diseases Society of America and International Working Group on the Diabetic Foot Classifications of Diabetic Foot Infection Clinical Manifestation of Infection

PEDIS Grade

IDSA Infection Severity

No symptoms or signs of infection Infection present, as defined by the presence of $ 2 of the following items: • Local swelling or induration • Erythema • Local tenderness or pain • Local warmth • Purulent discharge (thick, opaque to white or sanguineous secretion) Local infection involving only the skin and the subcutaneous tissue (without involvement of deeper tissues and without systemic signs as described below). If erythema, must be . 0.5 cm to # 2 cm around the ulcer. Exclude other causes of an inflammatory response of the skin (eg, trauma, gout, acute Charcot neuroosteoarthropathy, fracture, thrombosis, venous stasis). Local infection (as described above) with erythema . 2 cm, or involving structures deeper than skin and subcutaneous tissues (eg, abscess, osteomyelitis, septic arthritis, fasciitis), and no systemic inflammatory response signs (as described below). Local infection (as described above) with the signs of SIRS, as manifested by $ 2 of the following: • Temperature . 38°C or , 36°C • Heart rate . 90 beats/min • Respiratory rate . 20 breaths/min or PaCO2 , 32 mm Hg • White blood cell count . 12 000 or , 4000 cells/μL or $ 10% immature (band) forms

1

Uninfected

2

Mild

3

Moderate

4

Severea

Ischemia may increase the severity of any infection, and the presence of critical ischemia often makes the infection severe. Systemic infection may sometimes manifest with other clinical findings, such as hypotension, confusion, vomiting, or evidence of metabolic disturbances, such as acidosis, severe hyperglycemia, and new-onset azotemia. Adapted from 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis. 2012;54(12):e132–e173. Abbreviations: IDSA, Infectious Diseases Society of America; PaCO2, partial pressure of arterial carbon dioxide; PEDIS, perfusion, extent/size, depth/tissue loss, infection, and sensation; SIRS, systemic inflammatory response syndrome. a

114




Table 3. Recommended Laboratory and Diagnostic Tests of Hospitalized Patients With Diabetic Foot Infections Test

Indication(s)

Comments

Complete blood count, serum electrolytes, creatinine, and glucose ESR, CRP

All hospitalized patients with DFIs

Wound culture

All hospitalized patients with moderate and severe DFIs

Blood culture

Any patient with DFIs and systemic signs and symptoms of infection such as fever or severe DFIs When the diagnosis of DFO is uncertain despite clinical and imaging evaluations

They are helpful in the assessment of the severity of the infection, response to treatment, and glycemic control and monitoring for adverse effects of drugs such as antibiotics. They are helpful in the diagnosis of DFO and septic arthritis. They may predict outcome of DFO (high levels associated with worse outcome). They are helpful in assessment of response to therapy. The wound should be cleansed and debrided before culturing. The appropriate culture is the one taken from deep tissue, obtained by biopsy, curettage, or scraping from the ulcer base using a dermal curette or sterile scalpel blade, and aspiration of any purulent secretions using a sterile needle and syringe. The specimen should be routinely processed for a Gram-stained smear, aerobic and anaerobic cultures, and susceptibility testing. Bacteremia usually occurs in patients with severe DFIs.

Bone biopsy

Any patient with suspected a deep infection such as DFO or septic arthritis

Plain radiograph of the affected foot

All patients with DFIs

MRI

All patients when the diagnosis of osteomyelitis remains uncertain despite plain radiograph All patients with suspected deep abscess Patients undergoing for bone biopsy Patients undergoing surgical treatment of osteomyelitis All patients when the diagnosis of DFO remains uncertain, particularly forefoot osteomyelitis, despite plain radiograph and the MRI is either contraindicated or unavailable

Nuclear imaging (bone scan, white blood cell–labeled indium-111, technetium-99 m, HMPAO, and sulfur colloid marrow scan)

It is more valuable in midfoot or hindfoot DFO because of higher yield of microbiologic diagnosis. $ 2 specimens should be obtained: 1 to be sent for histopathology, and 1 for microbiology. It is indicated to look for bony abnormalities (deformity, destruction), soft tissue gas, radiopaque foreign bodies, and evidence of osteomyelitis. Classic changes suggestive of osteomyelitis are cortical erosion, periosteal reaction, mixed lucency, and sclerosis. It has a low sensitivity (40%–60%), it may take several weeks to a few months since onset for osteomyelitis to become evident on plain radiographs, and specificity (68%, false-positive mainly occurs with neuro-osteoarthropathy or fracture) for osteomyelitis. Characteristic findings of osteomyelitis are decreased signal intensity of affected bone on T1-weighted images, increased intensity on T2-weighted and postcontrast images, and high bone marrow signal in short tau inversion recovery sequences.

The sensitivity of 3-phase bone scans is 80% for DFO. Radiolabeled white blood cells scans (usually using either technetium-99 m or indium-111) are more specific than bone scans for diagnosing DFO. Technetium-99m HMPAO and sulfur colloid marrow scan can differentiate osteomyelitis from Charcot neuroarthropathy by specifying bone marrow reactivation and neutrophil production and not affected by antibiotic therapy. They are less specific (false positive with trauma, surgery, neuroarthropathy, and tumor) than MRI for diagnosis of DFO. They lack the anatomical resolution to localize and characterize the site of infection.

Adapted from Bader MS. Diagnostic Approach to Diabetic Foot Infections. In: Bader MS, Armstrong D, Alavi A, Sibbald G, Wu S, Giovinco N, ed. Diabetic foot infections. First ed. Gurgaon, India: Macmillan. 2014:41–68. Abbreviations: CRP, C-reactive protein; DFI, diabetic foot infection; DFO, diabetic foot osteomyelitis; ESR, erythrocyte sedimentation rate; HMPAO, hexamethylpropyleneamine oxime; MRI, magnetic resonance imaging.

patients with suspected or confirmed DFO, particularly with midfoot or hindfoot involvement. The treatment failure rate with subsequent major amputation is much higher in midfoot or hindfoot than in forefoot osteomyelitis.16,39 The sample for bone biopsy can be taken during an open procedure or with imaging guidance percutaneously. Transcutaneous bone biopsy

is a safe procedure, and its accuracy improves with imaging guidance. It should be performed outside wounds or ulcers to avoid contamination by the colonizing organisms. The isolation of an organism from a reliably obtained bone sample with histologic findings of inflammatory cells and osteonecrosis is considered a definitive diagnosis of DFO.16,20




It is essential to assess both arterial and venous circulation in all patients with DFIs (Table 1). Approximately half of the patients with DFUs/DFIs have evidence of PAD. It is associated with impaired wound healing, infection, and amputation, and it decreases the ability to fight infection due to poor delivery of oxygen, nutrients, and antibiotics to infected area.21,40,41 Diagnosing DFO is often a challenge in patients with DFIs because clinical signs (pus in bone at surgery, detached bone in ulcer, or visible cancellous/cortical bone) and laboratory tests (elevated inflammatory markers) are highly variable. The International Working Group on the Diabetic Foot has proposed consensus criteria for diagnosing DFO that are neither simple nor practical and remain to be validated in a properly designed trial.29 Grayson et al,42 in a study on 75 hospitalized patients with DFUs, found that probing to bone or exposed bone is likely to be consistent with osteomyelitis (positive predictive value 89%).43 Lavery et al44 performed a study on 247 outpatients with DFUs and reported that wounds not probed to bone were unlikely to have osteomyelitis present (negative predictive value = 98%). It should be noted that the value of the probe-to-bone test for the diagnosis of DFO depends on the experience of the clinician performing the test and the prevalence of osteomyelitis in DFIs in that setting.45 Combining the probe-to-bone test with plain radiography of the affected foot can improve the diagnosis of DFO.46 Magnetic resonance imaging is the most accurate available imaging for the diagnosis of osteomyelitis, with sensitivity of 90% and specificity of 79%. It provides an excellent definition of soft tissue infection, including detecting sinus tracts, deep tissue necrosis, and deep abscesses, and is helpful in assessing bone viability within sequestered bone. It may be difficult to distinguish osteomyelitis from Charcot’s neuroarthropathy in the diabetic foot using MRI alone.24 Bone scans are an alternative to MRI for the diagnosis of DFO.16,17 A study by Chow et al47 found that MRI was more cost-effective, with better sensitivity and specificity compared with 3-phase bone scan. If imaging is inconclusive, a diagnostic bone biopsy for histology and bacterial culture is the gold standard for diagnosing osteomyelitis, with the bacterial culture providing an opportunity to identify the causative bacterial agent and antibiotic sensitivities. The sensitivity of bone biopsy for the diagnosis of DFO ranges from 67.7% to 93%.48 A negative culture of bone biopsy does not exclude the diagnosis of DFO since one fourth of them may develop osteomyelitis within 2 years.49 A false-negative culture is due to sampling errors, prior antibiotic therapy, or a failure to isolate fastidious organisms. 116

Treatment

The management of hospitalized patients with DFIs requires a multidisciplinary approach by a team of health care professionals to provide both medical and surgical interventions.17 A multidisciplinary team approach is associated with better outcomes, with a significant decrease in amputation rates.50,51 Hospitals with a sufficient volume of patients with DFIs should have simple and well-defined clinical pathways to manage DFIs. A recent guideline strongly called for development of effective, systematic, interdisciplinary teams that focus on skills for inpatient management of DFIs as a priority.18 The aim of the multidisciplinary team is to focus on comprehensive evaluation, risk assessment, prevention, treatment, and coordination of discharge planning of hospitalized patients with DFIs.18,19 The ultimate goal of the treatment of DFIs should be individualized based on several factors such as the severity of the infection and the patient’s comorbid conditions and functional status. However, every effort should be exerted to maximize the function of the patient and activities of daily living; the goal of treatment is an ulcer-free foot.18,19 Appropriate management of DFIs should address all elements of diagnostic workup mentioned previously (Table 4).52 Improper management of DFIs is usually associated with poor wound healing, progressive tissue destruction, amputation, and even increased mortality.

Antibiotic Therapy

Antibiotic therapy is one of the main treatment arms of DFIs and usually is started empirically. An institution-specific antibiotic guideline for the treatment of DFIs is advised. All infected wounds should be appropriately cultured, except in mild DFIs, before initiating empiric antibiotic therapy to help with the selection of a targeted antibiotic therapy. However, broad-spectrum antibiotics should be started as early as possible, even before taking appropriate cultures, in patients with severe infection and hemodynamic instability. Empiric antibiotic therapy for suspected DFO should not be delayed while waiting for MRI or nuclear testing.16–19 The choice of empiric antibiotic therapy should be based on the severity and extent of infection; the risk factors for resistant organisms; the recent use of an antibiotic and the response to it; previously isolated organisms and their susceptibility testing; the local prevalence of pathogens, especially antibiotic-resistant strains; drug allergy; comorbid condition, particularly kidney and liver disease; drug interactions; frequency of administration; and cost.16,17



Table 4. General Principles of the Treatment of Hospitalized Patients With Diabetic Foot Infections Principle

Practice Recommendation

Hemodynamic assessment and support

Monitoring of blood pressure and other vitals. Volume resuscitation with parenteral fluids and vasopressor agents if needed. Support of oxygenation and ventilation if needed. Glycemic control (with diet, oral hypoglycemic agents, and insulin). Treatment of diabetic ketoacidosis or hyperosmolar hyperglycemic syndrome (with intravenous fluids and insulin). Acute kidney injury (with intravenous fluids if due to volume depletion, diuresis if due to volume overload, discontinuation of nephrotoxic agents, and avoidance of iodinated contrast imaging). Correction of electrolytes abnormalities such as hypokalemia or hyponatremia. Lipid control (with diet and lipid lowering agents). Topical therapy with cleansing agents such as saline and topical antimicrobials such as iodine, chlorhexidine-, silver-, and honey-based compounds. Systemic antibiotics adjusted per kidney and liver function if indicated (see Table 5). Surgery such as incision and drainage, debridement, and amputation. Topical therapy. Appropriate dressings (films/membrane, hydrogels, acrylics, hydrocolloids, calcium alginates, hydrofibers, foams, composite, and collagen based dressings). Incision and drainage, debridement, and removal of debris. Autolytic debridement for healable wounds and can be facilitated by dressings containing calcium alginates and hydrogels. It is contraindicated in deep infected or nonhealing wounds. Surgical sharp debridement by a scalpel or a curette is required for abscess, extensive bone or joint involvement, necrotizing fasciitis, and callus to reduce overall peak plantar pressure. This method is a good choice for the infected wounds. It is contraindicated for ischemic tissue and patients with bleeding disorder. Mechanical debridement with wound irrigation (pulsed lavage), hydrotherapy (whirlpool), and dry to wet gauze. It is contraindicated in wounds with mature or healthy granulation tissue because it may damage the wound bed. Biological debridement with sterile maggots either placed directly in the wound or contained in a device. It is contraindicated for ischemic and deep-tunneling wounds, bleeding disorders, and psychological distress. Enzymatic debridement with the use of topical chemicals and proteolytic enzymes such as collagenase. It is a good choice for patients who are not candidates for surgical debridement. All patients with DFIs and manifestations of PAD should be referred urgently for further investigation. Ischemia can be treated by open bypass surgery or endovascular surgical techniques. Encouraging the patient to be nonambulatory, using supportive aids such as wheelchairs, crutches, walkers, felt plantar unloading pads, cerclages at the knee or ankle joint. Providing an appropriate off-loading device and therapeutic footwear (full-contact foot inserts or custommolded shoes such as total contact cast, removable walker, and half shoe). Surgery (callus removal, Achilles tendon lengthening, silicone injections, elimination of skin callosities, bone surgery, metatarsal head resection, osteotomies, arthroplasties, ostectomies, exostectomy, external fixations). Treatment of the underlying cause such as congestive heart failure with diuretics. External compression therapy. Surgical excision of ulcers, arthroplasties, metatarsal head resections, hammer toe repair, metatarsal osteotomies, plantar exostectomies, Achilles tendon lengthening, and complicated Charcot surgery. Screening and assessment of nutritional status for each individual with infection and referral to a dietitian for further assessment and intervention of nutritional problems if necessary. Assessment and management of other medical conditions such as cardiac, renal diseases, anemia, or hypertension. Perioperative assessment and management if the patient will undergo surgery for the treatment of DFIs. Determination of the cause and type pain and treatment with local or systemic analgesic agents and use of off-loading devices. Consultation with physical or occupational therapy services to establish the need for prosthetic devices, rehabilitation, and general conditioning. Counselling and education of patients and caregivers and involvement of patients in the treatment plan. Involvement of social worker. Treatment of anxiety and depression with drugs if needed.

Diabetes and metabolic control


Inflammation and infection control

Wound bed preparation

Debridement

Restoration or maintenance of blood flow Pressure control and off-loading therapy

Control of edema Correction of foot deformities Nutritional assessment Comorbid conditions

Pain Mobility and functional status Psychosocial issues

(Continued) © Hospital Practice, Volume 42, Issue 4, October 2014, ISSN – 2154-8331 117 ResearchSHARE®: www.research-share.com • Permissions: [email protected] • Reprints: [email protected] Warning: No duplication rights exist for this journal. Only JTE Multimedia, LLC holds rights to this publication. Please contact the publisher directly with any queries.


Table 4. (Continued) Principle

Practice Recommendation

Counseling and education (patient, caregiver)

Adherence to individualized treatment plan. Wound care and dressing change including vascular access care if present. Foot care including proper shoes. Review of medications (potential side effects, why indicated, need for adherence). What to do if foot condition worsens or patient develops possible side effects to medications and treatment upon discharge. Diabetes, its complications, importance of glycemic control. Diet/weight reduction (if indicated). Physical activity. Smoking cessation if applicable. Need to keep follow-up appointments upon discharge. Comprehension and competence related to DFIs- and diabetes self-management activities. The patient should meet all criteria for discharge: the patient is clinically stable; all urgently needed surgical treatments are performed; both glucose levels and pain are controlled; the patient tolerated the prescribed antibiotics; the patient has good home and social support systems; there is a well-defined plan that includes an appropriate antibiotic regimen, off-loading strategy, specific wound care instructions to which the patient will adhere, and appropriate outpatient follow-up. Consultation with medical specialists (infectious disease, hospital medicine, and endocrinology), surgical specialists (podiatry, plastic surgery, orthopedic surgery, and vascular surgery), radiologists, wound care specialists, diabetes educators, physical and occupational therapists, orthotists, nutritionists, nursing staff, and case management and social services specialists. Infection prevention practices for wound care include meticulous hand hygiene by health care providers, single-use or appropriately cleaned and reprocessed devices and equipment, barriers, using no-touch technique, sterile materials and supplies, and maintaining a clean field. Hands should be washed with soap and water, for 10 seconds, or as an alternative, an antiseptic, waterless hand rub product, prior to and after any contact with the patient, and before wearing after the removal of gloves. Gloves must be worn when hands touch the wound or wound drainage. Aseptic technique must be used during dressing changes, wound irrigation, and debridement procedures. Gowns, masks, and eye protection should be worn by health care provider when splash or spray from wound drainage is anticipated. Contact precautions must be followed in the hospital for all patients known to be colonized or infected with a resistant organism such as MRSA and VRE.


Hospital discharge planning

Multidisciplinary approach

Infection prevention and control

Abbreviations: DFI, diabetic foot infections; MRSA, methicillin-resistant Staphylococcus aureus; PAD, peripheral arterial disease;VRE, vanco mycin-resistant Enterococcus.

The initial empiric antibiotic therapy must be parenteral, particularly for patients who are critically ill; have a severe infection, critical limb ischemia, or DFO; cannot tolerate oral agents; or are infected with an organism resistant to oral agents. Moderate (deep and surrounding tissue involvement, abscess, gangrene, previously treated infection) and severe DFIs should be treated with a broad-spectrum antibiotic regimen with polymicrobial coverage that has activity against staphylococci, streptococci, gram-negative organisms, and anaerobes.16–18 The initial empiric antibiotic therapy should have activity against certain antibiotic-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas species, Acinetobacter species, extendedspectrum β-lactamases (ESBLs) producing organisms, and Bacteroides fragilis group if the patient has risk factors of infection with these organisms. The prevalence of MRSA in DFIs ranges from 5% to 30%, and it is increasing over 118

time. Diabetic foot infections due to MRSA have been associated with poor wound healing and a higher risk of lower extremity amputation.53–55 An antibiotic with activity against MRSA should be considered in patients with severe infection; patients previously colonized or infected with MRSA; patients on dialysis; patients who failed initial antibiotic therapy, particularly fluoroquinolones; patients with chronic infected large ulcer; and patients in communities where the prevalence of MRSA infection exceeds 10% to 15%.51,53 Moderate to severe DFIs due to MRSA should be treated initially with parenteral vancomycin, linezolid, daptomycin, tigecycline, ceftaroline, or telavancin. Oral trimethoprimsulfamethoxazole, doxycycline/minocycline, clindamycin, or linezolid can be used as a step-down treatment to complete the course of treatment of DFIs due to MRSA.56 Antibiotic against Pseudomonas spp. should be considered in patients with severe infection; patients from develop-



Table 5. Empiric Antibiotic Therapy for Hospitalized Patients With Diabetic Foot Infections Type and Extent of Infection Moderate No risk of MRSA infection (monomicrobial infections such as cellulitis)

High risk of MRSA infectiona


Risk factors for polymicrobial infectionsb

Severe No risk of MRSA infection

High risk of MRSA infectiona

Treatment Regimen Nafcillin/Cloxacillin 1–2 g IV q6h Cefazolin 1–2 g IV q8h Ceftriaxone 1–2 g IV q24h Clindamycin 300–450 mg po q6–8h or clindamycin 600 mg IV q8h Moxifloxacin 400 mg po/IV q24h Levofloxacinc 500 mg po/IV q24h Vancomycin 15 mg/kg IV q12h (use in case of severe reactions to β-lactam antibiotics) Vancomycin 15 mg/kg IV q12h Linezolid 600 mg po/IV q12h Daptomycin 4 mg/kg IV q24h Telavancin 10 mg/kg IV q24h Ceftaroline 600 mg IV q12h Ampicillin/sulbactam 3 g IV q6h Cefazolin 1–2 g IV q8h plus clindamycin 300–450 mg po q6–8h or metronidazole 500 mg po q8–12h Ceftriaxone 1–2 g IV q24h plus clindamycin 300–450 mg po q6–8h or metronidazole 500 mg po q8–12h Levofloxacinc 500 mg po/IV q24 plus clindamycin 300–450 mg po q6–8h or metronidazole 500 mg po q8–12h Moxifloxacin 400 mg po/IV q24h Ceftazidimec 1–2 g IV q 8h plus clindamycin 300–450 mg q6–8h Cefepimec 2 g IV q12h plus clindamycin 300–450 mg po q6–8h or metronidazole 500 mg po q8–12h Piperacillin/tazobactamc 3.375/4.5 g IV q6–8h Ertapenemc 1 g IV q24h Imipenem/cilastinc 500 mg IV q6h Meropenemc 500–1000 mg IV q6–8h Doripenemc 500 mg IV q8h Tigecycline 100 mg IV loading dose followed by 50 mg IV q12h Ceftaroline 600 mg IV q12h Cefepimec 2 g IV q12h plus clindamycin 600 mg IV q8h or metronidazole 500 mg IV q8–12h Ceftazidimec 1–2 g IV q8h plus clindamycin 600 mg IV 8h Piperacillin/tazobactamc 3.375/4.5 g IV q6–8h Imipenem/cilastinc 500 mg IV q6h Meropenemc 500–1000 mg IV q6–8h Doripenemc 500 mg IV q8h Tigecycline 100 mg IV loading dose followed by 50 mg IV q12h Ceftaroline 600 mg IV q12h Cefepimec 2 g IV q12h plus metronidazole 500 mg IV q8–12h plus vancomycin 15 mg/kg IV q12h Ceftazidimec 1–2 g IV q8h plus metronidazole 500 mg IV q8–12h plus Vancomycin 15 mg/kg IV q12h Piperacillin/tazobactamc 3.375/4.5 g IV q6–8h plus vancomycin 15 mg/kg IV q12h Imipenem/cilastinc 500 mg IV q6h plus vancomycin 15 mg/kg IV q12h Meropenemc 500–1000 mg IV q6–8h plus vancomycin 15 mg/kg IV q12h Doripenemc 500 mg IV q8h plus vancomycin 15 mg/kg IV q12h Tigecycline 100 mg IV loading dose followed by 50 mg IV q12h Ceftaroline 600 mg IV q12h

Previous/recent MRSA infection or colonization, communities with high MRSA prevalence, recent/prolonged hospitalization, recent antibiotic use, hemodialysis, recent surgery, residence in a long-term care facility, contact sports, military service, injection drug use, and men who have sex with men. b Chronic wounds, deep space infection, necrotizing fasciitis, recent antibiotic use, hospitalization, surgery, and ischemic wounds. c These antibiotics have activity against Pseudomonas spp. Abbreviations: h, hours; IV, intravenously; MRSA, methicillin-resistant S. aureus; po, orally; q, every. a

ing countries, particularly those in warm climates; patients with chronic ulcer who failed initial antibiotic therapy with no antipseudomonal activity; and patients who have been soaking their feet.16,17

Approximately one third to two thirds of the isolated gram-negative organisms in patients with DFIs, mainly from the Indian subcontinent and the Middle East, are ESBL-producing organisms. The risk factors for infection




with ESBL-producing organisms include age . 65 years, hospitalization in the previous year, recurrent urinary tract infection, prior use of fluoroquinolones, and being from developing countries.57 Carbapenems (imipenem, meropenem, doripenem, and ertapenem) are the antibiotic of choice for treatment of moderate and severe DFIs caused by ESBLs and AmpC-producing organisms. Alternative options include fluoroquinolones, tigecycline, polymyxins such as colistin, and aminoglycosides used as monotherapy or part of a combination therapy. Definitive/targeted antibiotic therapy is based on several factors: organism identification, antimicrobial susceptibility, response to initial empiric antibiotic therapy, significance of adverse effects, status of gastrointestinal absorption problems, type of treatment (medical, surgical, or both), site of treatment (outpatient or inpatient), oral bioavailability, tissue penetration, pharmacokinetics of the agent, cost, and other factors of choice of empiric antibiotic therapy. If the infection is responding and the patient is tolerating the empiric antibiotic therapy, there is no need to change, even if some or all of the isolated organisms are resistant to the initial empiric regimen. However, if the infection is not responding to the empiric regimen, it should be modified to cover all isolated organisms including coagulase-negative Staphylococcus spp., Enterococcus spp., and Pseudomonas spp. after excluding other potential causes of failure.58 Based on the results of the treatment studies of DFIs, no single antibiotic or combination of agents appears to be superior to the others.7,16,17,59 The clinical response to antibiotic therapy and the result of appropriate wound culture are the most important factors in choosing the potentially most effective regimen. Oral antibiotics can be used as a stepdown treatment of DFIs when infection has been stabilized, the fever resolves, the leukocyte count is trending toward normal, the isolated organisms and their susceptibility testing are known, and the patient can tolerate taking them without vomiting or diarrhea.58,60 The commonly used effective oral antibiotics to treat patients with DFIs including DFO are ciprofloxacin, levofloxacin, moxifloxacin, clindamycin, metronidazole (should be part of combination antibiotic therapy and it is the drug of choice for anaerobic osteomyelitis), linezolid, doxycycline, rifampin (an adjuvant agent with other antibiotics), and trimethoprim-sulfamethoxazole. These antibiotics not only have high bioavailability but also good penetration in bone, synovia, biofilm, and necrotic tissue.61,62 β-Lactams such as oral amoxicillin-clavulanate or cephalexin should be used with caution to treat DFO because of their 120

low bioavailability and inability to exceed target minimal inhibitory concentration (MIC) of etiologic bacteria in most cases.16,17 Fluoroquinolones should be used with caution for the treatment of DFO due to S. aureus because of potential clinical failure. The increasing prevalence of resistant organisms may limit the role of oral antibiotics in the treatment of DFO.63 Parenteral antibiotics, if deemed necessary after consultation with an infectious diseases specialist, can be continued through outpatient parenteral antimicrobial therapy (OPAT). The preferred parenteral antibiotic for use in the OPAT should be effective for the type of DFIs and isolated organisms according to the response and the results of in vitro susceptibility testing; should be stable in an ambulatory environment; should have a good safety and tolerability profile; should entail only a low risk of phlebitis; should have a long half-life, thus requiring infrequent administration (once daily); should have predictable pharmacokinetics to minimize the requirement for therapeutic drug monitoring; and should be cost-effective. The commonly used antibiotics for DFIs in the OPAT include ceftriaxone, cefazolin, cefepime, piperacillin-tazobactam, ertapenem, meropenem, vancomycin, and daptomycin.64 The duration of treatment of DFIs is determined mainly by the extent and severity of the infection, the type of isolated organism and its susceptibility testing, the patient’s comorbid conditions (such as PAD), the patient’s response to treatment, the presence of residual necrotic tissue, viable or dead bone, and the patient’s adherence to the treatment plan. Moderate and severe DFIs that involve soft tissue infections can be treated for 2 to 4 weeks. The recommended duration of antibiotic therapy for DFO has traditionally been 4 to 6 weeks but can be longer, particularly in the presence of residual dead bone or significant PAD in the involved limb/ foot. However, surgical amputated DFO with no residual infection either in the soft tissue or bone can be treated for 3 to 5 days.16,17 The recommendations for treatment duration of DFIs are not based on strong evidence. Therefore, an individual-based approach is strongly recommended instead of a general one.

The Role of Surgery

Surgical intervention is one of the treatment options of DFIs and DFO. All hospitalized patients with severe and some moderate (with deep and surrounding tissue infection, not with cellulitis or lymphangitis) DFIs require surgical consultation. Early surgical consultation and intervention may decrease the risk of subsequent and major amputation,




improve wound healing, hasten return to activities, and decrease the duration of antibiotic therapy.65–67 Urgent or emergent consultation is required in patients with necrotizing fasciitis, deep soft tissue abscess, or gangrene accompanying osteomyelitis. Surgical treatment options of DFIs include incision and drainage of an abscess; radical debridement of all infected, nonviable necrotic tissue (once or repeated until the wound base is clean and the tissue looks healthy); and amputation. Every effort should be exerted to preserve the limb through the involvement of an experienced and knowledgeable surgeon, and consideration of the vascular supply to the affected limb, wound healing, and biomechanical function. Intraoperative cultures from deep soft tissue and bone should be sent to the lab for microbiologic and histopathologic examination (if osteomyelitis is suspected).16,17 In patients with moderate and severe DFIs with ischemia, debridement should be done first to control the infection and for revascularization thereafter. Revascularization can be performed by either endovascular or surgical procedures. Although the major outcomes are similar for both treatment modalities, recently there is an increasing trend favoring endovascular procedures due to their feasibility and technical efficacy, the reduced number of complications, and the improved limb salvage rates despite their shorter long-term patency and higher restenosis rate compared with open bypass surgery. However, debridement of an infected ischemic foot should be either avoided or performed with extreme caution if revascularization is not amenable.68 Secondary reconstruction and closure of the wound, correction of foot deformities and gait disorders, and arthrodesis should be done after appropriate control of the infection and achieving adequate perfusion. Filling the defect that is created from the infection and surgical debridement can be achieved through split-thickness skin grafting, local rotational or advancement flaps, muscle flaps, or pedicle flaps.69

Topical Therapy

Topical therapy can reduce the surface colonization and inflammation. It consists of cleansing agents such as saline, topical antiseptic agents (eg, silver, povidone iodine, hypochlorite, peroxide, zinc oxide), and topical antimicrobials such as topical antibiotics. None of these agents has been proven to be superior to other nonantiseptic dressings in the treatment of DFUs.70 Moisture balance can be achieved through several types of dressings. There is no robust evidence that any one dressing

Figure 2. A well-debrided noninfected diabetic foot ulcer.

performs significantly better on the diabetic foot than others. However, it is useful if the dressing is easy to remove, absorbent, and able to accommodate pressures of walking without disintegrating.71–74

Pressure Redistribution

Managing pressure offloading from the skin and associated soft tissue is one of the vital strategies for effective treatment of DFIs (Figure 2). Nonprescription or nonadherence to offloading therapy is associated with treatment failure and recurrence of ulcers and infection. There are several off-loading strategies, surgical and nonsurgical, available (Table 6). However, the chosen strategy must be tailored to the age, strength, activity, and home environment of the patient.75–77

Other Management Issues

There are several other modalities that have been used as adjunctive therapy for DFUs and DFIs. These include negative pressure wound healing, hyperbaric oxygen therapy, granulocyte colony-stimulating factor, and maggot debridement therapy. Because their benefit is not widely supported by evidence, their use should be limited after consultation with experts in these fields.78–82



Table 6. Common Plantar Pressure Redistribution Devices Off- Loading Device

Advantages

Disadvantages

Total contact cast (TCC)

Gold standard Reduces pressure under ulcer site between 84%-92% Forced patient adherence to device Can be used for infected wounds Can be made irremovable to become instant total contact cast (ITCC) Transfers pressure to middle and rear foot by eliminating propulsion Low cost Low cost

Requires trained professional to apply Risk of ulceration with improper application Contraindicated for infected or ischemic wounds Less helpful for heel ulcers Removable Patient needs time to learn how to use it Contraindicated for heel ulcers and poor balance Very unstable Contraindicated in patient with gait instability High risk of falls Off-loading property limited Can cause high pressure “edge effect” Requires trained professional to assess and mold/modify Relatively higher cost May require deeper shoe

Removable cast walker (RCW) Half shoe (forefoot) Padding/felted foam


Custom-made orthotics Custom braces ankle foot orthoses

Distributes the pressure under foot evenly May be used with regular footwear Immobilize the foot and ankle to manage wounds

Currently, no studies have evaluated the impact of glycemic control on the outcome of DFIs. However, poor short- and long-term glycemic control are associated with more complications after diabetic foot surgery.83 The guideline from the American Association of Clinical Endocrinologists and the American College of Physicians recommends a glucose level range of 140 to

200 mg/dL (7.8–11.1 mmol/L) in critically ill patients. A blood glucose level , 140 mg/dL (, 7.8 mmol/L) should be avoided because of potential harm. The preprandial blood glucose , 140 mg/d- (, 7.8 mmol/L) in conjunction with random blood glucose values , 180 mg/ dL (, 10.0 mmol/L) should be the targets, with few exceptions, for the majority of noncritically ill hospitalized

Table 7. Diabetic Foot Infections Discharge Checklist Element

Yes

No

Reason not Done

Prescription of discharge drugs: Antibiotics Oral hypoglycemic agents or insulins Aspirin or other antiplatelet therapy Angiotensin-converting enzyme inhibitor Lipid-lowering agent such as statins Final assessment and recommendations by involved health care providers with a comprehensive care plan Prescription of supplies and ancillary devices: Diabetes supplies such as glucose test strips and lancets, glucose monitor kits, insulin needles and syringes, pen needles, and insulin pumps supplies Wound care supplies such as dressings, bandages, tapes, wraps, and wipes Off-loading device or shoes Compression therapy such as stockings Short- or long-term intravenous catheter use Patient evaluation and selection for outpatient parenteral antimicrobial therapy Identifying referring and receiving providers, including home health care Clinical discharge summary dictated and mailed/faxed to appropriate physicians Follow-up laboratory and imaging testing Identifying the responsible health care provider to whom pending laboratory tests and other will be sent Follow-up appointments with health care providers, which include the name of provider, date, address, phone number, and visit purpose Counselling of patient and or caregiver for diabetic foot infections, diabetes, and other comorbid conditions Immunization Pneumococcal vaccine Influenza vaccination Other vaccines if indicated (such as tetanus, varicella-zoster virus vaccine) Any anticipated problems, suggested intervention, and whom to contact

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patients with diabetes mellitus. Patients with DFIs should have their hemoglobin A1c checked at the time of admission unless there is one available within the last 60 days or the patient has a medical condition or has received therapy that would confound the results.84,85 Patients should take an active part in treatment and be given the opportunity to make informed decisions about their care, in partnership with their health care providers. Individualized care plans that address specific patient-centered concerns are most likely to succeed and promote the best outcomes for patients with DFIs. Good communication between health care providers and patients is essential. Patients should be educated not only about DFIs but also about other health-related issues (Table 7). Foot care education as part of multidisciplinary team approach is strongly associated with reduction in foot complications including amputation rates.86 Discharge planning should be started at the time of initial assessment and admission. Discharge decisions should be based not only on clear markers of clinical stabilization and improvement but also on other important factors that are illustrated in Table 3. A clear and well-defined plan should be in place prior to discharge. This requires a team approach, and may involve physicians, nurses, medical assistants, dietitians, case managers, and social workers, as well as a discharge checklist (Table 7). Clear communication with outpatient health care providers either directly or by means of hospital discharge summaries facilitates safe transitions to outpatient care. The patient should be informed about proper care and follow-up. The severity and extent of the infection, the patient’s overall condition, the patient’s environment, and the goals of the plan of care determine the first follow-up visit after discharge.16–19

Conclusion

Diabetic foot infections are a commonly encountered complication of diabetes. They are associated with a significant morbidity and impairment of physical and psychosocial wellbeing. Their management is complex and requires not only simple and well-defined clinical pathways but also involvement of all health care providers with different areas of expertise. The comprehensive assessment and management of DFIs should be clearly defined and practically applied once the patient is admitted to the hospital. Every effort should be exerted to treat the infection, avoid amputation, and preserve the functional status of the patient.

Acknowledgments

This article has not received funding from any agency. We did not receive support from the National Institutes of

Health, the Wellcome Trust, the Howard Hughes Medical, or elsewhere. We certify that the manuscript has not been published and is not being considered for publication elsewhere.

Conflict of Interest Statement

Mazen S. Bader, MPH, MD, and Afsaneh Alavi, MD, have no conflicts of interest to declare.

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Diabetic foot: infections and outcomes in Iranian admitted patients.

Perioperative management of diabetic foot.

Management of the diabetic foot.

Management of the diabetic foot.

Prevalence of Corynebacteria in diabetic foot infections.

Infections of diabetic foot ulcers with methicillin-resistant Staphylococcus aureus.

The microbiologic profile of diabetic foot infections in Turkey: a 20-year systematic review: diabetic foot infections in Turkey.

Association of complement C3 and interleukin-1 with foot infections in diabetic patients.

Population pharmacokinetics and target attainment analysis of moxifloxacin in patients with diabetic foot infections.

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Cognitive functioning among patients with diabetic foot.

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The diabetic foot management - recent advance.

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Self-reported quality of life and diabetic foot infections.

Susceptibility patterns of Staphylococcus aureus biofilms in diabetic foot infections.

Roles of Physical Therapists in Wound Management, Part III: Select Biophysical Technologies and Management of Patients With Diabetic Foot Ulceration.

Daptomycin for methicillin-resistant Staphylococcus aureus diabetic foot infections.

Prognostic Factors in Patients Hospitalized with Diabetic Ketoacidosis.

Do diabetic foot infections with methicillin-resistant Staphylococcus aureus differ from those with other pathogens?

Medical and surgical management of the diabetic foot and ankle.

Literature review on the management of diabetic foot ulcer.