Aerosolized spread of bacteria and reduction of bacterial wound contamination with three different methods of surgical wound debridement: a pilot study

Coblation Versus Surgical Debridement Against MRSA Infection in Wounds With Shrapnel: A Preliminary Study

INTRODUCTION

Debridement plays a critical role in wound management. In addition to removing necrotic tissue, debridement can eliminate bacteria frequently harbored within the tissue. This study evaluated a novel debridement method that uses plasma-based radiofrequency technology to remove tissue and bacteria. Coblation is a technology that uses radiofrequency energy to excite the electrolytes in a conductive medium, such as saline, to create a precisely focused plasma. This plasma field contains highly energized particles that possess sufficient energy to break tissue molecular bonds, causing the tissue to dissolve at relatively low temperatures (typically 40 °C to 70 °C).

MATERIALS AND METHODS

Eighteen deep dermal wounds measuring 22 mm × 22 mm × 3 mm deep were created on pigs. Wounds were inoculated with methicillin-resistant Staphylococcus aureus USA300 (MRSA USA300) in combination with shrapnel and then covered with a polyurethane dressing for 24 hours. Wounds were then randomly assigned to one of the 3 treatment groups: (1) Coblation, (2) surgical debridement, and (3) no debridement. Wounds were biopsied on days 0, 5, 9, and 12, and specimens were processed for MRSA counts using selective media. Statistical analysis was performed using IBM SPSS statistics 27 using one-way ANOVA.

RESULTS

Comparison between coblation and surgical debridement showed a decrease in bacterial count in all assessment times. The lowest bacterial count in all assessment times was observed in wounds debrided with coblation showing a statistically significant (P ≤ .05) decrease in more than 2 Log CFU/g on days 0, 5, and 9 compared to no debridement. On day 12, coblation-debrided wounds exhibited 6.10 ± 0.22 Log CFU/g, and this value represents 99.99% of reduction compared with non-debrided wounds (P ≤ .05). More than 96% of reduction (P ≤ .05) resulted in wounds treated with coblation compared with surgically debrided.

CONCLUSIONS

Reducing MRSA bacterial infection counts, especially of biofilm-associated organisms, in combination with shrapnel may have important clinical implications, especially for the military personnel. Further research into the use of this technology in wound management is warranted.

Novel Diagnostic Technologies and Therapeutic Approaches Targeting Chronic Wound Biofilms and Microbiota

Purpose of Review

To provide an up-to-date overview of recent developments in diagnostic methods and therapeutic approaches for chronic wound biofilms and pathogenic microbiota.

Recent Findings

Biofilm infections are one of the major contributors to impaired wound healing in chronic wounds, including diabetic foot ulcers, venous leg ulcers, pressure ulcers, and nonhealing surgical wounds. As an organized microenvironment commonly including multiple microbial species, biofilms develop and persist through methods that allow evasion from host immune response and antimicrobial treatments. Suppression and reduction of biofilm infection have been demonstrated to improve wound healing outcomes. However, chronic wound biofilms are a challenge to treat due to limited methods for accurate, accessible clinical identification and the biofilm's protective properties against therapeutic agents. Here we review recent approaches towards visual markers for less invasive, enhanced biofilm detection in the clinical setting. We outline progress in wound care treatments including investigation of their antibiofilm effects, such as with hydrosurgical and ultrasound debridement, negative pressure wound therapy with instillation, antimicrobial peptides, nanoparticles and nanocarriers, electroceutical dressings, and phage therapy.

Summary

Current evidence for biofilm-targeted treatments has been primarily conducted in preclinical studies, with limited clinical investigation for many therapies. Improved identification, monitoring, and treatment of biofilms require expansion of point-of-care visualization methods and increased evaluation of antibiofilm therapies in robust clinical trials.

New techniques for wound management: A systematic review of their role in the management of chronic wounds

Debridement is a crucial component of wound management. Recent technologies such as hydrosurgery (Versajet), ultrasound therapy (the MIST therapy device), or plasma-mediated bipolar radio-frequency ablation therapy (Coblation) seem to represent interesting alternatives for wound debridement. The purpose of this systematic review was to describe, evaluate, and compare these three recently developed methods for the management of chronic wounds. In January 2016, an electronic database search was conducted of MEDLINE, PubMed Central, and Embase for articles concerning these three innovative methods for the management of chronic wounds. A total of 389 references were identified by our search strategy, and 15 articles were included. We extracted data regarding the number and age of patients, indications, operating time, number of procedures, costs, wound healing time, decrease in exudation, perioperative blood loss, bacterial load, and the occurrence of complications. The 15 articles included studies that involved 563 patients who underwent hydrosurgery (7 studies), ultrasound therapy (6 studies), or Coblation (2 studies). Six randomized controlled trials were included that compared the use of a scalpel or curette to hydrosurgery (2 studies) or ultrasound therapy (6 studies). Hydrosurgery, in addition to being a very precise and selective tool, allows significantly faster debridement. Ultrasound therapy provides a significant reduction of exudation, and improves the wound healing time. No comparative study dedicated to Coblation was identified. Despite the obvious clinical interest of the topic, our review of the current literature revealed a lack of prospective randomized studies comparing these devices with each other or with standard techniques, particularly for Coblation and hydrosurgery.

Does the new low-frequency ultrasonic debridement technology pose an infection control risk for clinicians, patients, and the clinic environment?

BACKGROUND

Low-frequency ultrasonic debridement (LFUD) is a technology that uses sound waves conducted through saline mist to debride wound tissue. Whilst this technology purportedly reduces wound-healing times, the airborne mist generated is potentially problematic. Theoretically, the saline mist could carry an increased number of microbes into the surrounding environment, posing an infection control risk to the patient, clinician, and clinical environment. This research aimed to establish the degree and extent to which there is microbial spread during the use of, and following the use of, LFUD. The total number of colony forming units was identified for use of LFUD without the suction attachment (control) and with the suction attachment (intervention).

METHODS

This was a prospective, observational study with repeated measures across each treatment (before, during, and after). Quota sampling in a 2 × 2 × 2 factorial design was undertaken so that half of the 24 treatments were conducted at each health service (Monash Health vs Peninsula Health), in different treatment environments (inpatient vs outpatient), and half were conducted with and without suction. The use of suction was not randomized but was determined at the treating clinician's discretion. Patients treated in the inpatient environment lay on their beds, whereas patients in the outpatient environment sat in a treatment chair.

RESULTS

There was higher microbial count during treatment (P < .001) with a higher microbial count associated with lower ultrasound amplitude (P = .028), lower saline flow rate (P = .010), no suction attachment (P = > .001), and a larger wound area (P = .002). All were independently associated with greater microorganism aerosolization. There was no correlation between the type of handpiece selected, the presence of wound infection, and the treatment time or treatment environment.

CONCLUSIONS

This research has assisted in developing guidelines for cleaning of equipment and environments following treatment, as well as around the use of personal protective equipment required to protect the staff member and the patient during the use of LFUD. Additionally, recommendations have been made regarding the specific LFUD settings to reduce the risk of cross-infection to the clinic environment. These include selecting a higher ultrasound amplitude and saline flow rate as well as the use of suction where clinically possible.