Moninder Bhogal

Concordance in diabetic foot ulcer infection

Introduction Accurate identification of pathogens, rather than colonising bacteria, is a prerequisite for targeted antibiotic therapy to ensure optimal patient outcome in wounds, such as diabetic foot ulcers. Wound swabs are the easiest and most commonly used sampling technique but most published guidelines recommend instead removal of a tissue sample from the wound bed, which is a more complex process. The aim of this study was to assess the concordance between culture results from wound swabs and tissue samples in patients with suspected diabetic foot infection. Methods and analysis Patients with a diabetic foot ulcer that is thought to be infected are being recruited from 25 sites across England in a cross-sectional study. The coprimary endpoints for the study are agreement between the two sampling techniques for three microbiological parameters: reported presence of likely isolates identified by the UK Health Protection Agency; resistance of isolates to usual antibiotic agents; and, the number of isolates reported per specimen. Secondary endpoints include appropriateness of the empiric antibiotic therapy prescribed and adverse events. Enrolling 400 patients will provide 80% power to detect a difference of 3% in the reported presence of an organism, assuming organism prevalence of 10%, discordance of 5% and a two-sided test at the 5% level of significance. Assumed overall prevalence is based on relatively uncommon organisms such as Pseudomonas. We will define acceptable agreement as κ>0.6. Ethics and dissemination Concordance in diabetic foot ulcer infection (CODIFI) will produce robust data to evaluate the two most commonly used sampling techniques employed for patients with a diabetic foot infection. This will help determine whether or not it is important that clinicians take tissue samples rather than swabs in infected ulcers. This study has been approved by the Sheffield NRES Committee (Ref: 11/YH/0078) and all sites have obtained local approvals prior starting recruitment. Study registration NRES Ref: 11/YH/0078, UKCRN ID: 10440, ISRCTN: 52608451

Prognosis of the infected diabetic foot ulcer: a 12-month prospective observational study

To determine clinical outcomes and explore prognostic factors related to ulcer healing in people with a clinically infected diabetic foot ulcer.

Pressure RElieving Support SUrfaces: a Randomised Evaluation 2 (PRESSURE 2): study protocol for a randomised controlled trial

BackgroundPressure ulcers represent a major burden to patients, carers and the healthcare system, affecting approximately 1 in 17 hospital and 1 in 20 community patients. They impact greatly on an individual’s functional status and health-related quality of life. The mainstay of pressure ulcer prevention practice is the provision of pressure redistribution support surfaces and patient repositioning. The aim of the PRESSURE 2 study is to compare the two main mattress types utilised within the NHS: high-specification foam and alternating pressure mattresses, in the prevention of pressure ulcers.Methods/DesignPRESSURE 2 is a multicentre, open-label, randomised, double triangular, group sequential, parallel group trial. A maximum of 2954 ‘high-risk’ patients with evidence of acute illness will be randomised on a 1:1 basis to receive either a high-specification foam mattress or alternating-pressure mattress in conjunction with an electric profiling bed frame. The primary objective of the trial is to compare mattresses in terms of the time to developing a new Category 2 or above pressure ulcer by 30 days post end of treatment phase. Secondary endpoints include time to developing new Category 1 and 3 or above pressure ulcers, time to healing of pre-existing Category 2 pressure ulcers, health-related quality of life, cost-effectiveness, incidence of mattress change and safety. Validation objectives are to determine the responsiveness of the Pressure Ulcer Quality of Life-Prevention instrument and the feasibility of having a blinded endpoint assessment using photography. The trial will have a maximum of three planned analyses with unequally spaced reviews at event-driven coherent cut-points. The futility boundaries are constructed as non-binding to allow a decision for stopping early to be overruled by the Data Monitoring and Ethics Committee.DiscussionThe double triangular, group sequential design of the PRESSURE 2 trial will provide an efficient design through the possibility of early stopping for demonstrating either superiority, inferiority of mattresses or futility of the trial. The trial optimises the potential for producing robust clinical evidence on the effectiveness of two commonly used mattresses in clinical practice earlier than in a conventional design.Trial registrationISRCTN01151335. Registered on 14 May 2013. Protocol version: 5.0, dated 25 September 2015Trial sponsor: Clare Skinner, Faculty Head of Research Support, University of Leeds, Leeds, LS2 9JT; 0113 343 4897; C.E.Skinner@leeds.ac.uk.

CODIFI (Concordance in Diabetic Foot Ulcer Infection): a cross-sectional study of wound swab versus tissue sampling in infected diabetic foot ulcers in England

Objective To determine the extent of agreement and patterns of disagreement between wound swab and tissue samples in patients with an infected diabetic foot ulcer (DFU). Design Multicentre, prospective, cross-sectional study. Setting Primary and secondary care foot ulcer/diabetic outpatient clinics and hospital wards across England. Participants Inclusion criteria: consenting patients aged ≥18 years; diabetes mellitus; suspected infected DFU. Exclusion criteria: clinically inappropriate to take either sample. Interventions Wound swab obtained using Levine’s technique; tissue samples collected using a sterile dermal curette or scalpel. Outcome measures Coprimary: reported presence, and number, of pathogens per sample; prevalence of resistance to antimicrobials among likely pathogens. Secondary: recommended change in antibiotic therapy based on blinded clinical review; adverse events; sampling costs. Results 400 consenting patients (79% male) from 25 centres. Most prevalent reported pathogens were Staphylococcus aureus (43.8%), Streptococcus (16.7%) and other aerobic Gram-positive cocci (70.6%). At least one potential pathogen was reported from 70.1% of wound swab and 86.1% of tissue samples. Pathogen results differed between sampling methods in 58% of patients, with more pathogens and fewer contaminants reported from tissue specimens. The majority of pathogens were reported significantly more frequently in tissue than wound swab samples (P<0.01), with equal disagreement for S. aureus and Pseudomonas aeruginosa. Blinded clinicians more often recommended a change in antibiotic regimen based on tissue compared with wound swab results (increase of 8.9%, 95% CI 2.65% to 15.3%). Ulcer pain and bleeding occurred more often after tissue collection versus wound swabs (pain: 9.3%, 1.3%; bleeding: 6.8%, 1.5%, respectively). Conclusion Reports of tissue samples more frequently identified pathogens, and less frequently identified non-pathogens compared with wound swab samples. Blinded clinicians more often recommended changes in antibiotic therapy based on tissue compared with wound swab specimens. Further research is needed to determine the effect of the additional information provided by tissue samples. Trial registration number ISRCTN52608451.

CODIFI (Concordance in Diabetic Foot Infection): Agreement in reported presence of likely pathogens in swabs and tissue samples from infected diabetic foot ulcers

Aim Wound infection is common in diabetic foot ulcers with potentially life changing sequelae. Targeted treatment of infective organisms requires accurate identification of pathogens to enable refinement of antibiotic protocols to improve outcomes and reduce antibiotic resistance. Wound sampling is routinely conducted using swabs although some guidelines recommend use of tissue samples. To date there is a lack of robust evidence to inform clinical practice regarding sampling technique. This study aimed to evaluate the extent to which results from wound swab and tissue samples taken from the same patient agree with each other; one might report pathogens more than the other, they might both report the same pathogens consistently, or they might disagree with a more complex pattern of disagreement. Here we report agreement and disagreement between the techniques based upon reported presence of likely pathogens.