Simulating contamination of the operator and surrounding environment during wound debridement through fluorescent labelling
BACKGROUND The work clothes of medical staff are potential sources of contamination contributing to healthcare‐associated infections (HAIs) that may jeopardize infection prevention control, which is an important facet of medical institutions. , Specifically, when treating infected wounds, both the wound and the surrounding environment may contaminate the hands or work clothes of the medical staff, thereby spreading infection. In daily clinical practice, hand hygiene holds paramount significance in hospital infection prevention and control. However, contamination of work clothes is often disregarded. , Given the increasing number of wounded patients in China, frontline medical staff from primary medical institutions to tertiary hospitals are tasked daily with wound operations, ranging from simple dressing changes to more complex debridement procedures. Here, fluorescent labelling was employed to standardize operating procedures and reduce the occurrence of HAIs. Specifically, we analysed operator and surrounding environment contamination during simulated wound debridement operations, to provide evidence‐based recommendations for clinical practice improvement. 

MATERIALS AND METHODS 2.1 Study participants This was a prospective cohort study, involving 29 female trainees who participated in the wound management course in 2022. The trainees were all hospital nurses engaged in ostomy or wound care from across China, and their working experiences ranged from 5 to 21 years (mean 11.55 ± 4.837 years). The training included theoretical knowledge and clinical practice related to wounds and ostomy. On‐site simulated operation assessments were conducted on the trainees before and after the training. Due to the COVID‐19 pandemic, 14 trainees were unable to participate in the post‐training assessment. 2.2 Simulated operation Oranges and square towels were used to simulate wounds and inpatient units, respectively. The orange peel represented the skin and soft tissue, and the orange flap represented the muscle layer. Black areas were marked on the orange surface to indicate the area of debridement. The surfaces of both the orange and square towels were coated with fluorescent powder. Operations on oranges were performed to simulate bedside debridement, and the distribution of the fluorescent powder after the operation reflected the contamination. Specifically, a 40 × 50 cm towel was placed on the operating table inside an operating room. Fluorescent powder was spread across the square towel, and an orange was placed on top of it. The surface of the orange was marked with a black spot with a diameter of 2 cm. Fluorescent powder was spread to the surface orange, with the oranges fixed with pins (Figure ). A treatment cart loaded with the instruments and sterile dressings was placed on the left side of the operating table, and a clinical waste bin was placed on the right. The participants wore clean hats, masks, work clothes, and gloves that were uniformly distributed. Additionally, they were tasked to perform sharp debridement of the skin and soft tissues within the marked range using tools, including scalpels and forceps. Prior to each assessment, an ultraviolet (UV) flashlight was used to examine and ensure that there was no fluorescent powder in areas outside the square towel. After the assessment, the participants removed the gloves and entered the darkroom, and a UV flashlight was used to examine the fluorescent powder on various parts of their body. Concomitantly, the distribution of fluorescent powder in the environment surrounding the operating area was determined. A 1 cm unit scale was placed in the area with fluorescent powder to capture images and record the information. Afterward, the setting was rearranged. 2.3 Study indicators 2.3.1 Contamination of the operator The contamination of the operator included adhesion of the fluorescent powder on exposed parts such as the operator's hands, work clothes, face, and neck. 2.3.2 Contamination of the environment surrounding the operating area During the pre‐training assessment, only the farthest distance of the fluorescent powder to the right side of the treatment towel was observed, mainly due to the placement of the medical waste bin on the right side of the operator. However, the assessment revealed that the contamination level of the fluorescent powder was significantly higher than anticipated. Therefore, in the post‐training assessment, the observations of the fluorescent powder were expanded to include the front, back, and left sides of the treatment towel and the treatment cart. The farthest distance was calculated as the vertical distance from the farthest point of the area with the fluorescent powder to the edge of the square towel in that corresponding direction, as determined by a ruler. 2.4 Statistical analysis All data were entered into an Excel 2021 spreadsheet. The count data were expressed as the number of cases or percentages. 

Study participants This was a prospective cohort study, involving 29 female trainees who participated in the wound management course in 2022. The trainees were all hospital nurses engaged in ostomy or wound care from across China, and their working experiences ranged from 5 to 21 years (mean 11.55 ± 4.837 years). The training included theoretical knowledge and clinical practice related to wounds and ostomy. On‐site simulated operation assessments were conducted on the trainees before and after the training. Due to the COVID‐19 pandemic, 14 trainees were unable to participate in the post‐training assessment. 

Simulated operation Oranges and square towels were used to simulate wounds and inpatient units, respectively. The orange peel represented the skin and soft tissue, and the orange flap represented the muscle layer. Black areas were marked on the orange surface to indicate the area of debridement. The surfaces of both the orange and square towels were coated with fluorescent powder. Operations on oranges were performed to simulate bedside debridement, and the distribution of the fluorescent powder after the operation reflected the contamination. Specifically, a 40 × 50 cm towel was placed on the operating table inside an operating room. Fluorescent powder was spread across the square towel, and an orange was placed on top of it. The surface of the orange was marked with a black spot with a diameter of 2 cm. Fluorescent powder was spread to the surface orange, with the oranges fixed with pins (Figure ). A treatment cart loaded with the instruments and sterile dressings was placed on the left side of the operating table, and a clinical waste bin was placed on the right. The participants wore clean hats, masks, work clothes, and gloves that were uniformly distributed. Additionally, they were tasked to perform sharp debridement of the skin and soft tissues within the marked range using tools, including scalpels and forceps. Prior to each assessment, an ultraviolet (UV) flashlight was used to examine and ensure that there was no fluorescent powder in areas outside the square towel. After the assessment, the participants removed the gloves and entered the darkroom, and a UV flashlight was used to examine the fluorescent powder on various parts of their body. Concomitantly, the distribution of fluorescent powder in the environment surrounding the operating area was determined. A 1 cm unit scale was placed in the area with fluorescent powder to capture images and record the information. Afterward, the setting was rearranged. 

Study indicators 2.3.1 Contamination of the operator The contamination of the operator included adhesion of the fluorescent powder on exposed parts such as the operator's hands, work clothes, face, and neck. 2.3.2 Contamination of the environment surrounding the operating area During the pre‐training assessment, only the farthest distance of the fluorescent powder to the right side of the treatment towel was observed, mainly due to the placement of the medical waste bin on the right side of the operator. However, the assessment revealed that the contamination level of the fluorescent powder was significantly higher than anticipated. Therefore, in the post‐training assessment, the observations of the fluorescent powder were expanded to include the front, back, and left sides of the treatment towel and the treatment cart. The farthest distance was calculated as the vertical distance from the farthest point of the area with the fluorescent powder to the edge of the square towel in that corresponding direction, as determined by a ruler. 

Contamination of the operator The contamination of the operator included adhesion of the fluorescent powder on exposed parts such as the operator's hands, work clothes, face, and neck. 

Contamination of the environment surrounding the operating area During the pre‐training assessment, only the farthest distance of the fluorescent powder to the right side of the treatment towel was observed, mainly due to the placement of the medical waste bin on the right side of the operator. However, the assessment revealed that the contamination level of the fluorescent powder was significantly higher than anticipated. Therefore, in the post‐training assessment, the observations of the fluorescent powder were expanded to include the front, back, and left sides of the treatment towel and the treatment cart. The farthest distance was calculated as the vertical distance from the farthest point of the area with the fluorescent powder to the edge of the square towel in that corresponding direction, as determined by a ruler. 

Statistical analysis All data were entered into an Excel 2021 spreadsheet. The count data were expressed as the number of cases or percentages. 

RESULTS 3.1 Contamination of the operator During the pre‐training assessment, fluorescent powder was observed in 28 of the 29 trainees. As shown in Figure , each black dot indicated one trainee who had fluorescent powder in the area. The commonly contaminated parts were the extensor side of the forearm, middle abdomen, upper abdomen, and hands, which accounted for 79.3%, 51.7%, 48.3%, and 48.3%, respectively (Figure ). In the post‐training assessment, fluorescent powder was seen in 13 of the 15 trainees (Figure ). The commonly contaminated parts in descending order were the hands, the extensor sides of the forearms, and the lower abdomen, which accounted for 53.3%, 26.7%, and 26.7%, respectively. 3.2 Contamination of the environment surrounding the operating area In the pre‐training assessment, the fluorescent powder was observed on the right side of the operating area of 24 of the 29 trainees, with the farthest distance ranging from 3 to 55 cm. In the post‐training assessment, the fluorescent powder was seen at the front, back, left, and right side of the operating area in 12, 9, 11, and 14 of the 15 trainees, respectively. The farthest distances were 3–15 cm, 4–9 cm, 3–16 cm, and 2–18 cm, respectively. Meanwhile, fluorescent powder was observed in the treatment cart of five trainees. 

Contamination of the operator During the pre‐training assessment, fluorescent powder was observed in 28 of the 29 trainees. As shown in Figure , each black dot indicated one trainee who had fluorescent powder in the area. The commonly contaminated parts were the extensor side of the forearm, middle abdomen, upper abdomen, and hands, which accounted for 79.3%, 51.7%, 48.3%, and 48.3%, respectively (Figure ). In the post‐training assessment, fluorescent powder was seen in 13 of the 15 trainees (Figure ). The commonly contaminated parts in descending order were the hands, the extensor sides of the forearms, and the lower abdomen, which accounted for 53.3%, 26.7%, and 26.7%, respectively. 

Contamination of the environment surrounding the operating area In the pre‐training assessment, the fluorescent powder was observed on the right side of the operating area of 24 of the 29 trainees, with the farthest distance ranging from 3 to 55 cm. In the post‐training assessment, the fluorescent powder was seen at the front, back, left, and right side of the operating area in 12, 9, 11, and 14 of the 15 trainees, respectively. The farthest distances were 3–15 cm, 4–9 cm, 3–16 cm, and 2–18 cm, respectively. Meanwhile, fluorescent powder was observed in the treatment cart of five trainees. 

DISCUSSION In hospital infection prevention and control, the spread of pathogens, especially multidrug‐resistant (MDR) bacteria, has received the most attention. MDR bacteria are typically spread through the hands of the medical staff, contaminated medical equipment, and the medical environment , after coming into contact with the patients. When treating wounded patients, medical staff are often required to perform invasive operations such as debridement and dressing change at the bedside. These procedures inherently require contact with the patient and the surrounding environment, making them the ideal target of hospital infection prevention and control. In this study, serious contamination of the work clothes of the participants was observed, with contamination rates before and after training reaching 96.6% (28/29) and 86.7% (13/15), respectively. Meanwhile, contamination was observed across all body parts above the thighs on both sides, mainly concentrating on areas such as the hands, forearms, and lower abdomen that were directly in contact with or adjacent to the operating area. The proportion of contamination in the upper and middle abdomen of the trainees was high before the training, while that above the chest was low. After removing the gloves, contamination of the hands can still be observed. Therefore, we recommend that when performing debridement on infected wounds, especially for patients with MDR bacterial infections, medical staff should routinely wear gloves and isolation gowns, change them in a timely manner postoperatively, as well as perform hand hygiene. However, given health economics, gloves, surgical aprons, and oversleeves may be an option. In this study, fluorescent powder was found around the operating area for some trainees, indicating that debridement may have contaminated the surrounding environment. Meanwhile, there were cases where the participant contaminated the operation cart by touching it with contaminated hands. This suggests that if debridement and dressing change were performed in a public area (e.g., bedside or dressing room), cleaning and disinfecting of the environment are recommended. For patients with infected wounds caused by MDR bacteria, the surrounding environment should be monitored regularly to improve hygiene, which may reduce environmental contamination. When using a treatment cart, the operator should follow standardized operating procedures to ensure its cleanliness. When touching the clean area of the treatment cart, the hands of the operator must be kept clean. Once contaminated, the treatment cart must be cleaned and disinfected promptly after the operation. Both the aseptic operation concepts and operation proficiency of the participants have improved following their enrolment at the school. This improvement is substantiated by the reduced proportion of body contamination and contaminated distance of the surrounding environment after the training. Therefore, regular and continuous training as well as visualizing contamination that was otherwise invisible through detection tools may help improve the effectiveness of infection prevention and control. However, regardless of whether the nurses have received training, contamination of the hands, work clothes, and the surrounding environment remained visible. Necessary measures for in‐hospital prevention and control such as hand hygiene, wearing work clothes, and environmental disinfection should not be overlooked. In summary, fluorescent labelling was performed to simulate the contamination of the operator and the surrounding environment during wound debridement. We found that debridement contaminates the operator and the surrounding environment. In hospital infection prevention and control, attention should be paid to hand hygiene and wearing and changing of work clothes, as well as disinfection of the surrounding environment. Moreover, training should be provided regularly. This study had some limitations. First, this was a simulation study, which was relatively different from the actual debridement. However, currently, it is not feasible to perform clinical research on these topics in addition to ethical risks. Nevertheless, simulation training and teaching remain of great significance to the vast number of grassroots frontline medical workers in China. Second, due to the COVID‐19 pandemic, 14 trainees failed to participate in the post‐training assessment, resulting in inconsistent numbers of trainees before and after the training. Last, this study failed to investigate whether secondary contamination occurs when taking off isolation gowns. Thus, attention should be paid to self‐contamination when taking off isolation gowns. , Guidelines should be consulted for properly wearing and taking off personal protective equipment. Operators are prone to self‐contamination if they fail to follow the standardized operation procedures. Moreover, different protective equipment can be contaminated to varying degrees during removal. , Data regarding this subject will be supplemented in future investigations. 

This work was supported by National High Level Hospital Clinical Research Funding (Interdisciplinary Clinical Research Project of Peking University First Hospital) (2023IR08 and 2023IR32). 

The authors declare that they have no competing interests. 

The need for informed consent and the provision of an information sheet were waived because the test was conducted on a model, not on the patients. The Clinical Research Ethics Committee of Peking University First Hospital approved the study. 

