The validation of a guideline algorithm for the antibiotic treatment for infected lower limb wounds or ulcers

Abstract

Lower limb and foot ulcers are a common complication arising from multiple causative factors including peripheral vascular disease, excessive pressure and neuropathy. Pharmacological management is introduced if an infection is present. Infections are identified through clinical manifestations (signs and symptoms). These include erythema, pus, cellulitis and malodour amongst others. Moreover in order to appropriately treat a wound infection through the use of antibiotics, it is necessary to correctly identify the infecting organisms, through the use of culture testing. Antibiotic guidelines are used in order to aid practitioners administering the correct antibiotics to treat infections. In fact the Antibiotic Team at Mater Dei Hospital (MDH) the main teaching hospital in Malta have created an algorithm for lower limb wound infections and ulcers. The aim of this study was to assess and validate this algorithm. In addition, other secondary objectives were identified such as the importance of proper cleaning of a wound prior to taking a wound swab, identifying the importance of proper antibiotic treatment, exploring the relationship between the Ankle Brachial Pressure Index (ABPI) and wound improvement, and identifying any other parameters which might be implicated in wound improvement. To achieve these aims, 80 patients were identified who fulfilled the inclusion and exclusion criteria through non-probability sampling. Patients were selected from MDH Surgical Out- Patients, MDH Tissue Viability Clinic, and St Vincent De Paul Residence for the elderly (SVPR). The methodology used included, first and foremost, obtaining informed consent from the selected patient following patient selection. Demographic data of the patient was then was then performed using a specific form designed by the researcher. A wound swab for culture and sensitivity was taken from the wound pre-cleaning and post-cleaning twice with saline as advised by the antibiotic team. The Levine technique was the method employed to take the wound swab. The Bates Jensen Wound Assessment Tool (BJWAT) was then filled up by the researcher. The Ankle Brachial Pressure Index, (ABPI) was then calculated, and patients were administered antibiotics by the doctor according to the algorithm. Patients were then assessed during two more visits, where the BJW AT and the demographic data were filled on each occasion as required to monitor wound improvement. Following data collection, the patients were classified according to risk for antibiotic infection and for severity of wound infection. Analysis of the results indicate that the algorithm created by the MDH antibiotic team was validated, with a p-value of <0.001 in all the parameters of the BJW AT. Results indicate a p-value of 0.010 for wound improvement in those individuals who were compliant versus those non- compliant with the algorithm. Results also indicate that wound cleaning is imperative for proper identification of wound bacterial flora. In fact findings showed that the highly mixed cultures decreased from 38 to 4 individuals from pre-cleaning to post-cleaning. Moreover, the importance of wound cleaning was evident since, a statistically significant result with a p- value of < 0.001 was obtained for difference in number of organisms pre-cleaning and post-cleaning. ABPI was found to be important for wound improvement, as individuals who had a decreased ABPI and who have had a revascularization procedure, obtained better mean results, even though no significant p-value was obtained. Other parameters which were found to effect wound improvement were steroids, antiplatelet drugs, analgesics, and IDDM and NIDDM. Hence it can be concluded that the algorithm is validated. Moreover this study highlights also the importance of proper wound cleansing prior to taking a wound swab in order to identify the true infecting organisms. This study will be of benefit to patients and also to stakeholders, in reducing the unnecessary use of inappropriate antibiotics, which increase antibiotic resistance and also reduces medical costs of unnecessary antibiotic administration and hospital stays. Moreover this study highlights the importance for a protocol for proper wound swabbing technique, for the identification of infecting microorganisms, which will in turn, increase the reliability and validity of wound swabbing hence guiding appropriate antibiotic treatment.