The Detection of Wound Infection by Ion Mobility Chemical Analysis
Emma Daulton1, Alfian Wicaksono1, Janak Bechar2
1School of Engineering, University of Warwick, Coventry CV4 7AL, UK.
Abstract:
Surgical site infection represents a large burden of care in the National Health Service. Current methods for diagnosis include a subjective clinical assessment and wound swab culture that may take several days to return a result. Both techniques are potentially unreliable and result in delays in using targeted antibiotics. Volatile organic compounds (VOCs) are produced by micro-organisms such as those present in an infected wound. This study describes the use of a device to differentiate VOCs produced by an infected wound vs. colonised wound. Malodourous wound dressings were collected from patients, these were a mix of post-operative wounds and vascular leg ulcers. Wound microbiology swabs were taken and antibiotics commenced as clinically appropriate. A control group of soiled, but not malodorous wound dressings were collected from patients who had a split skin graft (SSG) donor site. The analyser used was a G.A.S. GC-IMS. The results from the samples had a sensitivity of 100% and a specificity of 88%, with a positive predictive value of 90%. An area under the curve (AUC) of 91% demonstrates an excellent ability to discriminate those with an infected wound from those without. VOC detection using GC-IMS has the potential to serve as a diagnostic tool for the differentiation of infected and non-infected wounds and facilitate the treatment of wound infections that is cost effective, non-invasive, acceptable to patients, portable, and reliable.
Insights
Diagnosing wound infections can be slow. This study shows volatile organic compound (VOC) detection using gas chromatography-ion mobility spectrometry (GC-IMS) accurately differentiates infected from non-infected wounds, enabling faster treatment.
Area of Science:
- Medical Diagnostics
- Microbiology
- Analytical Chemistry
Background:
- Surgical site infections (SSIs) pose a significant healthcare burden.
- Current diagnostic methods (clinical assessment, wound swabs) are slow and unreliable.
- Delays in diagnosis hinder timely, targeted antibiotic use.
Purpose of the Study:
- To evaluate volatile organic compound (VOC) detection for differentiating infected from colonized wounds.
- To assess the utility of gas chromatography-ion mobility spectrometry (GC-IMS) as a diagnostic tool.
Main Methods:
- Collected malodorous wound dressings from patients with post-operative wounds and vascular leg ulcers.
- Used GC-IMS to analyze VOCs produced by microorganisms.
- Compared GC-IMS results with wound microbiology swabs and clinical assessments.
Main Results:
- Achieved 100% sensitivity and 88% specificity in differentiating infected from non-infected wounds.
- Demonstrated a 90% positive predictive value and an Area Under the Curve (AUC) of 91%.
- GC-IMS effectively discriminated between infected and non-infected wounds.
Conclusions:
- VOC detection via GC-IMS shows high accuracy in wound infection diagnosis.
- This method offers a potential cost-effective, non-invasive, and reliable diagnostic tool.
- GC-IMS can facilitate prompt and appropriate treatment for wound infections.
Related Concept Videos
01:09Ion-Exchange Chromatography
01:21Chemical Ionization (CI) Mass Spectrometry
01:20Inductively Coupled Plasma-Mass Spectrometry (ICP-MS): Interferences
01:21Gas Chromatography: Types of Detectors-I
TCD is the earliest and most widely used detector that operates by measuring the changes in the thermal conductivity of the carrier gas. When a sample compound enters the detector,...
01:08Matrix-Assisted Laser Desorption Ionization (MALDI)