GUIDELINES FOR THE MANAGEMENT OF DIABETIC FOOT INFECTIONS

Transcription

1 Index No: MMG51q GUIDELINES FOR THE MANAGEMENT OF DIABETIC FOOT INFECTIONS Version: 1.0 Date ratified: 13 May 2015 Ratified by: (Name of Committee) Name of originator/author, job title department: Director Lead (Trust-wide policies) Associate Medical Director (local Policies) Clinical Management Team / Directorate Applicable to Name of responsible committee for the policy: Medicines Management Committee Michael Pierides, Consultant in Diabetes Endocrinology Diabetes Foot Lead Naomi Fleming, Pharmacist Advanced Microbiology Infectious Disease Essam Rizkalla, Consultant Microbiologist Antibiotic Lead Medical Director Clinical Services Medicines Management Committee Date issued for publication: June 2015 Review date: February 2018 Expiry date: (Date 3 months following review date) Equality impact assessed by: (name, job title department) Date impact assessed: May 2018 N/A N/A Registration Requirements Outcome Number(s) (CQC) NHSLA stard CNST stard Page 1 of 13

2 CONTRIBUTION LIST Individuals involved in developing the document Name Michael Pierides Naomi Fleming Essam Rizkalla Dr Manjula Natarajan Designation Consultant in Diabetes Endocrinology Diabetes Foot Lead Pharmacist Advanced Microbiology Infectious Disease Consultant Microbiologist Antibiotic Lead Consultant Microbiologist DIPC Circulated to the following individuals for consultation Name Kishor Patel Lisa Owen Rob Hicks Vijay Bahal Rajan Natarajan Julian Northover Maria Mouseley Paula Granon Jo Patterson Jacqueline Mildred Lyndsey Burgess Kelly Brogan Mary Breslin Designation Consultant in Diabetes Endocrinology Consultant in Diabetes Endocrinology Consultant in Vascular surgery - NGH Consultant in Vascular surgery - NGH Consultant in Orthopaedics - NGH Consultant in Orthopaedics - NGH Consultant podiatrist Senior podiatrist Podiatrist Podiatrist Senior diabetes specialist nurse Diabetes specialist nurse Vascular specialist nurse Page 2 of 13

3 Index No. MMG51q Approval Authorisation Completion of the following signature blocks signifies the review approval of this process. Name Job Title Signature Date Naomi Fleming Antimicrobial Pharmacist 13/5/15 Local Committee approval (where applicable) Name of Committee Name of Chairperson Medicines Management Committee Dr R Lee 13/5/15 Change History Date of Approval Version Date Author Reason V1 May 2015 Naomi Fleming New guideline (previously incorporated within MMG00) Impact Assessment This clinical guideline does not involve direct engagement with staff, patients, carers, visitors, the public or others therefore does not require an Impact Assessment in line with Procedure D10a A translation service is available for this policy. for Staff (I55) is located on the library intranet under Trust wide policies. The Interpretation/Translation Policy, Guidance Page 3 of 13

4 CONTENTS PAGE 1 Introduction Page 5 2 Guidelines 2.1 Specimens for culture Page Diagnosing bone infection Page Classification of Infection Page Choice of Antibiotic Page Additional Considerations Page Empirical Treatment Page 10 3 Monitoring Arrangements for Compliance Page 11 Effectiveness 4 Plan for Dissemination Implementation Page 11 5 References Page 11 6 Appendix 1: Vancomycin dosing Page 12 Page 4 of 13

5 Introduction This guideline aims to promote the consistent care of patients with diabetic foot infections across the trust. When infection complicates a foot ulcer, it can be limb or life-threatening. Diabetic foot ulcers should be managed by a multidisciplinary footcare team, this is proven to reduce amputation rates. People with diabetes develop foot ulcers because of neuropathy, ischaemia, or both. The initiating injury may be from acute mechanical or thermal trauma or from repetitively or continuously applied mechanical stress. Patients with a neuropathic or neuroischaemic feet often have little or no pain leading to a delayed presentation diagnosis. It is therefore very important that patients with diabetes have their feet assessed on admission if evidence of an ulcer a referral is generated to the diabetes foot team as well as follow up reviews of the feet with dressings down. Patients may therefore present with an asymptomatic limb or life-threatening infection with the only clue being deterioration in glycaemic control. Inflammatory markers such as CRP WCC may not reflect the severity of the infection. Treatment of diabetic foot ulcers must include: 1. Off-loading to alleviate mechanical load on the ulcers eg: heel protectors, appropriate mattress, scotch cast boots potentially complete non-weight bearing status 2. Assessment for limb ischaemia. Patients with clinically significant limb ischaemia should be assessed by a vascular surgeon depending on severity: Dry gangrene no active foot infection: next day non urgent referral Wet gangrene: urgent immediate referral to Vascular consultant oncall at NGH Gas gangrene: urgent immediate referral to Vascular consultant oncall at NGH 3. Antibiotics will be required if there are symptoms of infection based on the IDSA grading system, they should be used to treat infection, not to heal the wound which usually takes longer. All patients admitted with a diabetic foot ulcer should be referred to the diabetic foot team for assessment whilst an inpatient for follow up care on discharge. 4. Optimisation of glycaemic control is crucial in the ulcer healing process. Ensure that the patient is not in DKA or Hyperosmolar Hyperglycamic State (HHS previously referred to as HONK). Consideration of changing oral treatment to SC or IV insulin if appropriate. Page 5 of 13

6 2.0 Guidelines 2.1 Specimens for culture: Clinically uninfected ulcers rarely need to be cultured. They will grow commensal flora, which is not an indication for antimicrobials. Other wounds should always be cultured. If a specimen is not taken at presentation of clinical signs, then cultures should be taken if there is clinical failure of empirical antibiotics. The best specimens for culture are taken ideally before initiating antibiotic therapy, although treatment should not be delayed in severe infection. The best correlation between isolate causative organism are from the following samples: Aspiration of purulent secretions Debrided tissue Curettage of the post-debridement wound base Punch biopsy Extruded or biopsied bone Deep wound swab Teams to ensure blood cultures taken if febrile or hypothermic as per sepsis bundle 2.2 Diagnosing bone infection: Probe to bone test (PTB): a positive PTB test is around 50% positive predictive value, whilst a negative PTB test has a negative predictive value of approximately 90%. (Jeffcoate Lipsky 2004) Plain X-ray: Although the initial investigation of choice, these can lag clinical signs by up to 4-6 weeks, therefore serial X-rays may be needed to rule out osteomyelitis. If there is clinical concern osteomyelitis cannot be diagnosed by the X-ray, secondary investigations can be carried out including: o Magnetic Resonance Imaging (MRI) o Isotope white cell scan o Triple phase bone scan Clinical signs indicative of osteomyelitis include: loose bone sausage shaped digit that is red swollen hammer head toe that is red swollen Page 6 of 13

7 Differentiating between osteomyelitis a Charcot foot is difficult is based on a good history physical examination. The presence of one condition does not rule out the presence of another. The diabetic foot team need to assess the patient for this condition. 2.3 Classification of infection: The presence severity of infection should be classified according to the IDSA system. (Lipsky et al 2012) Severity Grade Clinical Signs/Symptoms Grade 1- No infection No purulence or signs of infection Grade 2- No systemic illness, Mild infection infection is confined to the skin or subcutaneous tissues, any cellulitis is <2cm around the wound evidence of either: (a) Pus (purulent secretions) (b) Two or more signs or symptoms of inflammation from Erythema Warmth Pain Tenderness Induration Grade 3 No systemic illness Moderate infection Either: (a) Lymphatic streaking, deep tissue infection (involving subcutaneous tissue, facia, tendon, bone) or abscess (b) Cellulitis >2cm Grade 4 Severe infection Infection accompanied by systemic toxicity including Fever Chills Shock Vomiting Confusion Metabolic instability The presence of critical ischaemia of the involved limb may make the infection severe. Page 7 of 13

8 2.4 Choice of Antibiotic: The choice route of antibiotic should reflect the severity of infection, response to therapy, recent antimicrobial use results of relevant microbiology samples MRSA C difficile history of the patient (check MEDWAY) Mild infection in an antibiotic naïve person is likely to be caused by Staphylococcus aureus or beta-haemolytic streptococci can be treated empirically without the urgent need for culture. Specimens for culture should be taken if an unusual organism is suspected, if initial therapy fails or if previous ulceration. Moderate infections in antibiotic naïve patients are likely to be caused by Staphylococcus aureus or beta-haemolytic streptococci, obligate anerobes are often associated with limb ischaemia, gangrene, necrosis or wound odour. People with chronic infections, who are not antibiotic naïve may have polymicrobial infections including aerobic gram-negative bacilli, enterobacteriaceae. Organisms that are usually colonisers but may cause infection include coagulase negative Staphylococcus Pseudomonas aeruginosa, these may also need treatment if empirical therapy is failing following discussion with microbiology the diabetes foot team. Renal function, antibiotic allergies Clostridium difficile risk should be assessed when deciding on antibiotic choices for further treatment. Severe infections should always be treated in hospital. In antibiotic naïve patients they are likely to be caused by Staphylococcus aureus or beta-haemolytic streptococci, obligate anerobes are often associated with limb ischaemia, gangrene, necrosis or wound odour, enterobacteriaceae Pseudomonas aeruginosa may also need to be treated on discussion with diabetic foot team or microbiology as these organisms are usually a coloniser rather then being the infective organism. Start empirical therapy discuss management options with microbiology the diabetes foot team in the following patients: Those with a proven drug-resistant infection (eg MRSA, VRE) Those at risk of drug-resistant infection (eg previously colonised with MRSA) Those infected with an ESBL producing bacteria or Klebsiella spp Page 8 of 13

9 2.5 Additional Considerations: Renal function Clostridium difficile risk should be assessed when deciding on antibiotic choices for further treatment. Refer to Antimicrobial page on KGH intranet, 0in%20Renal%20Failure%20%20Dialysis.pdf British National Formulary (BNF) or ward pharmacist for additional advice on dose of antibiotics in patients with poor renal function. Refer to ward pharmacist for advice on dose of antibiotics in patients with liver impairment. For information on contraindications, cautions, drug interactions adverse effects refer to the BNF or the medicines compendium Antibiotic therapy should be reviewed with the results of bone or deep tissue specimens therapy amended if required. Where a patient has been prescribed IV antibiotics for the purpose of enabling administration while the patient is unable to take medications orally, the antibitoics should be switched to oral as soon as possible. The diabetes foot team is contactable daily : Dr Mike Pierides: Ext 2656/through switchboard Diabetes SpR: bleep through switchboard Podiatry: Jo Moulton (secretary): ext 2187 All patients must have diabetic foot follow up arranged pre-discharge. Page 9 of 13

10 2.6 Empirical Treatment: Severity of First line Infection antibiotic (s) Mild Moderate Other antibiotics may be added depending on microbiology clinical signs. Good quality microbiological culture is helpful to guide additional therapy. Flucloxacillin 1g QDS Ist line: Flucloxacillin 1g QDS Metronidazole 400mg TDS 2 nd line: Co-amoxiclav 625mg TDS Amoxicillin 500mg TDS Penicillin Allergic Patients Doxycycline 100mg BD Doxycycline 100mg BD Metronidazole 400mg TDS Alternative agents Only if low risk of C difficile: Clindamycin 300mg QDSΔ Teicoplanin 400mg BD for 3 doses followed by 6mg/kg OD IV Metronidazole 400mg TDS PO Route Duration Likely Pathogen Oral 14 days Staphylococcu s aureus, betahaemolytic streptococci Oral & Home IV 14 days initially. Review in foot clinic weekly to check progress microbiology results. If patient needs home IV therapy please contact microbiology or diabetes foot team to discuss. Severe Discuss with Inpatient Variable Always initiate microbiologist or IV 14 days treatment in hospital. diabetes foot team initially Good quality microbiological culture should always be taken Critically unwell admission plus/minus referral to Vascular for debridement/ surgery Tazocin 4.5g TDS Vancomycin as per policy (see appendix 1) Aztreonam 1g TDS Vancomcyin as per policy (see appendix 1) Metronidazole 500mg TDS Regular ward review by diabetic foot team Staphylococcu s aureus, betahaemolytic streptococci. Obligate anerobes are often associated with limb ischaemia, gangrene, necrosis or wound odour Staphylococcu s aureus, betahaemolytic streptococci, anerobes, enterobacteria ceae, Pseudomonas aeruginosa If patient improves is well enough for home IV therapy please contact microbiology or diabetes foot team to discuss treatment options diabetes foot team to discuss patient follow up. Osteomyelitis needs at least 6 weeks of appropriate therapy orthopaedic review Calcaneal osteomyelitis needs at least 3 months of appropriate therapy orthopaedic review Doxycyline: Counsel patients about photosensitivity; patients should be advised to protect the skin from sunlight even on a cloudy day not to use sunbeds. Capsules should be swallowed whole with plenty of fluid during meals while sitting sting. Do not take milk, indigestion remedies, or medicines containing iron or zinc, less than 2 hours before or after you take this medicine. Δ Clindamycin: Counsel patients to stop taking Clindamycin immediately if they develop diarrhoea seek advice from microbiology or diabetes foot team. The patient may wish to buy probiotics for use whilst they are taking for two weeks after Clindamycin. Page 10 of 13

11 3.0 Monitoring Arrangements for Compliance Effectiveness This policy will be monitored via antibiotic diabetic foot ward rounds. Deviation in practice will be constructively discussed with the clinicians on the wards. An audit will be carried out annually to measure compliance results shared with the diabetes foot team, microbiology team clinical teams. 4.0 Plan for Dissemination Implementation This guideline will be disseminated via the Antibiotic Steering Group, the Medicines Management Committee to the endocrinology admission wards. It will be available as part of the diabetic foot antibiotic guidelines on KGH intranet. 5.0 References 1/ Graham Leese, Dilip Nathwani et al: Use of antibitoics in people with diabetic foot disease: A consensus statement. The Diabetic Foot Journal Vol. 12, No / Peter Cavanagh et al: Treatment for diabetic foot ulcers. The Lancet Nov , Vol. 336, No9498, p / WJ Jeffcoate BA Lipsky Controversies in diagnosing managing osteomyelitis in diabetes. CID 2004:39 (suppl 2): S115-S22 4/ Benjamin Lipsky, Anthony Berendt et al: Diagnosis treatment of diabetic foot infections. IDSA guidelines. CID 2004:39 5/ University Hospitals of Leicester NHS Trust: Antimicrobial Guidelines for the Empirical Management of Diabetic Foot Infections (D. Modha, S. Bukhari, A.Swann, Marie-France Kong, K. Dawson) May 2007 Page 11 of 13

12 Appendix 1: Vancomycin dosing schedule: This is a two stage process of loading dose depending on body weight followed by maintenance doses based on Creatinine Clearance calculated using the Cockroft Gault equation. Weight Loading Dose (g) <60kg kg 1.5 >90kg 2.0 Creatinine Clearance (ml/min) Maintenance dose prescribed mg every 48 hours mg od mg od mg bd mg bd g bd g bd > g bd If creatinine clearance changes, doses will change to reflect the new clearance. Calculate the creatinine clearance using the following Cockroft Gault equation [140 - Age(years)] x Weight (Kg) Serum creatinine(micromol/l) X Factor Factor = 1.23 for males OR 1.04 for females Monitoring Request an initial pre-dose vancomycin level prior to the FOURTH dose. Try to time doses so they are convenient for taking pre-dose levels. Doses should not be significantly delayed whilst awaiting the blood sample to be taken. This extends the dosing interval renders assay results meaningless. Measuring plasma peak levels is not required. The target pre-dose (trough) level is 10-20mg/l Levels should be rechecked: Following a change in dose or frequency (prior to 4 th dose after the change) At least weekly (preferably twice weekly) for patients with normal stable renal function Consider more frequent monitoring in patients with renal impairment or deteriorating renal function Daily monitoring of the patient s renal function is recommended whilst on IV vancomycin. To give the dose or not? Doses should not normally be withheld whilst awaiting the result of a vancomycin assay. The prescriber may request doses are withheld depending on the clinical situation. Consider: Implications of withholding treatment (treatment failure, risk of resistance developing) Does the patient have significant or deteriorating renal impairment or poor urine output? If so, withhold await the result. After taking a level, do NOT give more than a further 24 hours of treatment to any patient without knowing the assay result. Page 12 of 13

13 Administration Check Injectable Medicines Administration Guide on medicines management page of KGH intranet for full details. Reconstitute each 500mg with 10ml water for injections, then dilute with at least 100ml sodium chloride 0.9% or glucose 5%. Infuse over at least 1 hour. Give doses above 1g at 10mg per minute. i.e. a 1g dose should be infused over 100minutes. Infusion rates exceeding the above may cause tingling flushing of the face, neck upper torso (Red man syndrome). Requesting vancomycin levels Take a pre-dose sample (red or yellow top). Post dose samples are NOT required. The sample should be labelled as a "pre-dose" The request form must include the following information to allow accurate interpretation of the assay result: o Patient details o Name o Hospital number o Date of birth o Antibiotic name o Date time sample taken o Type of sample (pre-dose or rom sample?) o Date time of last dose of vancomycin (note the time the infusion started) Interpretation of assay results Results should be interpreted in conjunction with the patient s clinical condition prescription chart. Ensure that you know: When the blood sample was taken relative to doses of vancomycin (is it a pre-dose level?) Was the patient at steady state (i.e. has had 3-4 doses at the current dosing regimen)? What is the current renal function Level <10 (Sub-therapeutic) Action Consider dose/frequency increase Recheck pre-dose levels prior to 4 th dose Continue current dose. Recheck pre-dose levels twice weekly >20 Omit a dose. Consider dose/frequency reduction. Recheck predose levels prior to 4 th dose References i) Martin J, Norris R, Barras m, Roberts J, Morris et al. Therapeutic monitoring of vancomycin in adult patients: a consensus review of the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, the Society of Infectious Diseases Pharmacists. Clin Biochem Rev 2010; 31: ii) Joint Formulary Committee. British National Formulary. 68 th ed. London: British Medical Association Royal Pharmaceutical Society of Great Britain; iii) Ashley C, Currie A, editors. The Renal Drug Hbook. 3rd ed. Radcliffe Publishing, London; 2009 iv) Thomson AH, Staatz CE, Tobin CM, Gall M, Lovering AM. Development evaluation of vancomycin dosage guidelines designed to achieve new target concemtrations. JAC 2009; 63: Page 13 of 13