A skin abscess model for teaching incision and drainage procedures

Development of a Novel, Reusable Task Trainer for Foreign Body Removal and Abscess Incision and Drainage

INTRODUCTION

Cutaneous abscess incision and drainage and foreign body removal are 2 common procedures in a variety of outpatient settings. The goal of this project was to create a novel, clean, reusable task trainer that could more accurately reproduce all the steps necessary to perform cutaneous abscess drainage or foreign body removal including ultrasound to identify the abscess cavity or foreign body.

METHODS

The novel task trainer was constructed using silicone for both the base and the top skin. Toothpaste mixed with saline was used for the abscess material as this produced an ultrasound image that mimicked purulent material. A piece of a metal paper clip was imbedded in the top skin to mimic a cutaneous foreign body. Physician assistant (PA) students given a didactic lecture then used the novel task trainer as part of a clinical skills course.

RESULTS

After the activity, the PA students were asked to voluntarily complete a brief preretrospective/postretrospective survey comprised 8 questions that addressed their self-perceived knowledge and skills using a 5-point Likert scale. Survey data from an initial cohort of PA students at one university show effectiveness of the models when used with the associated curriculum.

DISCUSSION

This study demonstrates the feasibility of constructing a practical, low-cost, non-animal-based task trainer for the purpose of training incision and drainage of cutaneous abscesses and removal of cutaneous foreign bodies. This novel task trainer allows for ultrasound skill development and provides realistic imaging experience.

Which Way Would You Slice It? Evaluation of 3 Educational Models for the Loop Drainage Technique

INTRODUCTION

Emergency department visits for cutaneous abscesses are increasing. It is important for healthcare professionals to be proficient in identifying and treating abscesses. Loop drainage technique (LDT) is a newer technique which has been described in several articles but limited resources for teaching have been studied. The objective of this study was to compare 3 models for learning and teaching the LDT.

METHODS

This was a prospective survey study of a convenience sample of emergency medicine residents at a large urban academic center. Residents volunteered to participate during a scheduled cadaver and simulation session. After a self-directed review of the LDT, each participant performed ultrasound visualization and then the LDT on 3 simulated abscesses: a cadaveric model, a commercial abscess pad, and a homemade phantom. Participants completed pre- and post-simulation surveys.

RESULTS

Of 57 residents, 28 participated in the 1-day simulation. The majority (57.1%, p < 0.009) preferred the cadaver model for learning the LDT, and 78.6% reported it to have the most realistic physical examination for an abscess (p = 0.001). Prior to participation, 0% of residents felt proficient performing LDT. After participation, 46.4% of residents felt proficient and 78.6% reported intent to use in clinical practice (p < 0.001).

CONCLUSIONS

Simulation is an effective educational tool for both learning new skills and improving procedural competency. Residents found cadavers provided the most realistic physical examination, and the majority preferred it for learning the LDT. However, cadavers are not always accessible, an important factor when considering various educational settings.

A low-cost high-fidelity model for abscess simulation

BACKGROUND

Treatment of a subcutaneous abscess is a commonly encountered scenario across multiple specialties. Prior simulation models for abscess incision and drainage have been limited by their cost and reproducibility.

METHODS

We developed a realistic abscess model with commonly available materials that can be utilized in fresh cadaver labs at a cost of less than $1 USD per use. The model was evaluated for content validity with pre- and post-measures by 25 pre-clinical medical students.

RESULTS

The model described herein successfully simulates commonly encountered subcutaneous abscesses. Pre and post-training surveys demonstrated a significant increase in all outcomes measures.

CONCLUSIONS

The model presented in this manuscript can be easily incorporated into training programs that utilize a fresh cadaver lab for multi-procedural resident training. It provides a realistic abscess that can be placed in almost any anatomical location at a fraction of the cost, and significantly reduced preparation time compared to previously described models.

Solid, Cystic, and Tubular: Novice Ultrasound Skills Training Using a Versatile, Affordable Practice Model

OBJECTIVE

In spite of the recognized benefits of ultrasound, many physicians have little experience with using ultrasound to perform procedures. Many medical schools and residency programs lack a formal ultrasound training curriculum. We describe an affordable ultrasound training curriculum and versatile, inexpensive practice model.

DESIGN

Participants underwent a didactic session to teach the theory required to perform ultrasound-guided procedures. Motor skills were taught using a practice model incorporating analogs of common anatomic and pathologic structures into an opacified gelatin substrate.

SETTING

The Marcia and Eugene Applebaum Simulation Learning Institute, Beaumont Hospital, Royal Oak, MI; a private nonprofit tertiary care hospital associated with the OUWB School of Medicine, Rochester, MI.

PARTICIPANTS

The model was tested in a cohort of 50 medical students and general surgery residents.

RESULTS

The gelatin model can be constructed for $1.03 per learner. The solid, cystic, and vascular structural analogs were readily identifiable on ultrasound and easily differentiated based on their echotextures. Eighty-four percent of participants successfully aspirated the cystic structure, 88% successfully biopsied a portion of the solid structure, and 76% successfully cannulated the tubular structure. Overall, 82% of participants achieved a passing score for the exercise based on a validated Objective Structured Assessment of Technical Skill instrument. There were no significant differences between the medical students and residents.

CONCLUSION

This model can be used to teach basic ultrasound skills such as aspiration, biopsy, and vessel cannulation, providing a foundation for the use of ultrasound in a broad range of clinical procedures, as well as providing practice opportunities for medical students and residents to gain increased ultrasound competency and confidence.

Teaching Incision and Drainage: Perceived Educational Value of Abscess Models

OBJECTIVES

Incision and drainage (I&D) of skin abscesses is an important procedural skill for pediatric emergency medicine providers. Practical skills training using simulation provides an opportunity to learn and gain confidence with this invasive procedure. Our objective was to assess the perceived educational value of 2 versions of an abscess model as part of an educational workshop for teaching I&D.

METHODS

A combined didactic and practical skills workshop was developed for use at 2 national conferences. The didactic content was created through an iterative process. To facilitate hands-on training, 2 versions of an abscess model were created: 1 constructed from a negative mold and the other using a 3-dimensional printer. Participants were surveyed regarding prior experience with I&D, procedural confidence, and perceptions of the educational utility of the models.

RESULTS

Seventy physicians and 75 nurse practitioners participated in the study. Procedural confidence improved after training using each version of the model, with the greatest improvements noted among novice learners. Ninety-four percent of physicians, and 99% of nurse practitioners rated the respective models as either "educational" or "very educational," and 97% and 100%, respectively, would recommend the abscess models to others.

CONCLUSIONS

A combined didactic and practical skills educational workshop using novel abscess models was effective at improving learners' confidence. Our novel models provide an effective strategy for teaching procedural skills such as I&D and demonstrate a novel use of 3-dimensional printers in medical education. Further study is needed to determine if these educational gains translate into improvement in clinical performance or patient outcomes.

Cadaver-based abscess model for medical training

Ultrasound imaging is a rapid and noninvasive tool ideal for the imaging of soft tissue infections and is associated with a change of clinician management plans in 50% of cases. We developed a realistic skin abscess diagnostic and therapeutic training model using fresh frozen cadavers and common, affordable materials. Details for construction of the model and suggested variations are presented. This cadaver-based abscess model produces high-quality sonographic images with internal echogenicity similar to a true clinical abscess, and is ideal for teaching sonographic diagnostic skills in addition to the technical skills of incision and drainage or needle aspiration.

Interexaminer agreement in physical examination for children with suspected soft tissue abscesses

OBJECTIVE

This study aimed to measure interexaminer agreement for physical examination (PE) findings in children with a suspected soft tissue abscess.

METHODS

A prospective study was conducted from March 1 to July 31, 2007, at an urban, tertiary care children's hospital emergency department. Children presenting to the emergency department with a suspected local skin abscess were independently examined by 2 physicians. Interrater agreement of 7 PE findings for children with a suspected soft tissue abscess was assessed. Interrater agreement was calculated for the diagnosis of the lesion and decision to incise and drain.

RESULTS

A total of 105 paired observations were completed by a total of 27 physicians. The patients examined were aged 2 weeks to 18 years, with a mean age of 80 months. Lesions were most frequently encountered on the buttocks (38%). Incision and drainage was attempted in 75% of cases, with purulent material obtained in 92% of all attempts. Interrater agreement was substantial for erythema (κ = 0.66) and size of the lesion (intraclass correlation coefficient = 0.78), moderate for drainage (κ = 0.57) and tenderness (κ = 0.40), fair for fluctuance (κ = 0.35), and poor for warmth (κ = 0.15) and showed no agreement for induration (κ = -0.08). There was moderate agreement on diagnosing the lesion as an abscess (κ = 0.48) and determination if the lesion required incision and drainage (κ = 0.44).

CONCLUSIONS

Interexaminer agreement of examination findings and diagnosis of an abscess was fair to moderate, implying a lack of precision of PE as the primary means for diagnosis. Future studies of diagnostic adjuncts, such as bedside ultrasonography, may lead to improved management of soft tissue infections in children.

Thread-dragging therapy in treatment of a rat model of infected subcutaneous fistula

OBJECTIVE

This study was to develop an experimental rat model of subcutaneous fistula induced by bacteria infection and treat it with thread-dragging therapy.

METHODS

A spring-gauze was surgically implanted into 24 male Sprague-Dawley rats' dorsal muscles, respectively, then mixed Staphylococcus aureus and Escherichia coli were injected into the spring-gauze. After 45 d, all the spring-gauzes were removed from the rats under anesthesia. X-ray and ultrasound were performed to assess the fistula tract. Each rat was examined by a fistula probe and four rats were randomly selected for histological assessment. The residual rats were randomly divided into two groups. Group A was treated with thread-dragging therapy, and group B was treated with fistulotomy. The healing time and body weight of the two groups were compared.

RESULTS

On the 45th day of the spring-gauze implantation, imaging assessment proved a tract with two openings in all rats and histological results proved that lumen and surrounding granulation tissue with epithelium were similar to the features of fistula in human beings. The mean healing time of rats in group A was shorter than that of the rats in group B (P<0.01). The body weight of rats in group A was heavier than that of the rats in group B on the 7th and 14th day after surgery, respectively (P<0.05).

CONCLUSION

A rat model of subcutaneous fistula induced by mixed Staphylococcus aureus and Escherichia coli infection was successfully established. Traditional Chinese medicine thread-dragging therapy is less invasive and safer than fistulotomy.