DRY GAUZE AND IODINE TULLE DRESSINGS FOR THE PREVENTION OF INFECTION IN PATIENTS WITH A LOWER LIMB EXTERNAL FIXATOR: A RETROSPECTIVE OBSERVATIONAL STUDY
Authors: North Arlene , Stratton Jean , Moore David , McCann Margaret 
Published: July 2023

Introduction

External fixators are attached to bones with percutaneous pins and wires inserted through soft tissues and bone increasing the risk of infections. Such infections compromise patient outcomes e.g., through pin loosening or loss, failure of fixator to stabilise the fracture, additional surgery, increased pain, and delayed mobilisation. These infections also impact the healthcare system for example, increased OPD visits, hospitalisations, treatments, surgeries and costs. Nurses have a responsibility in the care and management of patients with external fixators and ultimately in the prevention of pin-site infection. Yet, evidence on best practices in the prevention of pin-site infection is limited and variation in pin-site management practices is evident. Various strategies are used for the prevention of pin-site infection including the use of different types of non-medicated and medicated wound dressings. The aim of this retrospective study was to investigate the use of dry gauze or iodine tulle dressings for the prevention of pin-site infections in patients with lower limb external fixators.

Methodology

A retrospective study of patients with lower limb external fixators who attended the research site between 2015–2022. Setting & Sample: The setting was the outpatient's (OPD) orthopaedic clinic in a University Teaching Hospital in Dublin, Ireland. Eligibility Criteria:

Over the age of 16, treated with an Ilizarov, Taylor Spatial frame (TSF) or Limb Reconstruction System (LRS) external fixators on lower limbs,

Pin-sites dressed with dry gauze or iodine tulle,

Those with pre-existing infected wounds close to the pin site and/or were on long term antibiotics were excluded.

Follow Up Period: From time of external fixator application to first pin-site infection or removal of external fixator. Outcome Assessment: The primary outcome was pin-site infection, secondary outcomes included but were not limited to frequency of pin-site infection according to types of bone fixation, frequency of pin/wire removal and hospitalisation due to infection. Data analysis: IBM SPSS Version 25 was used for statistical analysis. Descriptive and inferential statistics were conducted as appropriate. Categorical data were analysed by counting the frequencies (number and percentages) of participants with an event as opposed to counting the number of episodes for each event. Differences between groups were analysed using Chi-square test or Fisher's exact test, where appropriate. Continuous variables were reported using mean and standard deviations and difference analysed using a two-sample independent t-test or non-parametric test (Mann-Whitney), where appropriate. Using Kaplan-Meier, survival analysis explored time to development of infection. Ethical approval: granted by local institute Research Ethics Committee on 12th March 2018.

Results

During the study period, 97 lower limb external fixators were applied with 43 patients meeting the study eligibility criteria. The mean age was 38 (SD 14.1; median 37) and the majority male (n=32, 74%). At least 50% (n=25) of participants had an IIizarov fixator, with 56% (n=24) of all fixators applied to the tibia and fibula. Pin/wire sites were dressed using iodine (n=26, 61%) or dry gauze dressings (n=15, 35%). The mean age of participants in the iodine group was significantly higher than the dry gauze group (p=.012). The only significant difference between the iodine and dry gauze dressing groups at baseline was age. A total of 30 (70%) participants developed a pin-site infection with 26% (n=11) classified as grade 2 infection. Clinical presentation included redness (n=18, 42%), discharge (n=16, 37%) and pain (n=15, 35%). Over half of participants were prescribed oral antibiotics (n=28, 65%); one required intravenous antibiotics and hospitalization due to pin-site infection. Ten (23%) participants required removal of pin/wires; two due to pin-site infection. There was no association between baseline data and pin-site infection. The median time to developing an infection was 7 weeks (95%, CI 2.7 to 11.29). Overall, there were 21 (81%, n=26) pin-site infections in the iodine group and nine (60%, n=15) in the dry gauze group, difference in proportion and relative risk between the dressing groups were not statistically significant (RR 1.35, 95% CI 0.86–2.12; p= .272). There was no association between baseline data, pin-site infection, and type of dressing

Conclusions

At the research site, patients are referred to the OPD orthopaedic clinic from internal and external clinical sites e.g., from Hospital Consultants, General Practitioners and occasionally from multidisciplinary teams, throughout Ireland. Our retrospective observation study found that 97 lower limb external fixators were applied over a seven-year period which is lower than that reported in the literature. However, the study period included the COVID pandemic years (2020 and 2021) which saw a lower number of external fixators applied due to lack of theatre availability, cancelled admissions and social/travel restrictions that resulted in fewer accidents and lower limb trauma cases requiring external fixator application. The study highlighted a high infection rate with 70% of participants developing pin-site infection which is in keeping with findings reporting in other studies. Our study showed that neither an iodine nor dry gauze dressing was successful in preventing pin-site infection. In the iodine group 81% of participants developed infection compared to 60% in the dry gauze group. Given the lack of difference between the two groups consideration needs to be given to the continued use of iodine dressings in the prevention of pin-site infection. Pin-site infections result in a high portion of participants being prescribed antibiotics and, in an era, that stresses the importance of antimicrobial stewardship there is a need to implement effective infection prevention and control strategies that minimise infection. Further research is therefore needed to investigate more innovative medicated dressings such as those that contain anti-microbial or anti-bacterial agents.