¹Parkview Health System, Advanced Medical Simulation Lab, Fort Wayne, IN
²Parkview Health System, Parkview Research Center, Fort Wayne, IN The authors listed declare no conflicts of interest.

Brief Description / Abstract:

Simulation-based central venous catheter insertion training has been well established in the literature. This training modality has been associated with reduction in overall central line associated blood stream infections (CLABSIs) and positive return on investment. Unfortunately, commercial central line trainers and consumable products require a significant capital investment and can be cost-prohibitive for organizations planning widespread implementation of simulation- based central venous catheter insertion training. A novel central venous catheter insertion task trainer was developed to address this barrier. Practicing physicians and advanced practice providers participated in simulation-based central venous catheter insertion training using both the commercial task trainer and the novel task trainer. Participants were surveyed regarding their confidence, skill, and knowledge of central venous catheter insertion pre- and post-training using both the commercial task trainer and the novel, more cost- effective task trainer created in house. Participants reported equivalent improvement in confidence, skill, and knowledge related to central venous catheter insertion using both the commercial and novel central venous catheter insertion simulation task trainers. The novel, central venous catheter insertion simulation task trainer is a replicable, more economically efficient alternative to a commercial task trainer for simulation-based clinician central venous catheter insertion training.

Introduction

The medical world is one of continuous progression, development, evolution, and transformation. Procedural training can be a costly investment for institutions.

Internal jugular (IJ) line is an important venous access that is placed to help manage many medical conditions. Traditionally this procedure is taught using anatomical landmarks for guiding the needle insertion. This technique has disadvantages because it relies on the assumption that the patient has ideal anatomy. Complications with the landmark approach are higher such as inadvertent arterial puncture, pneumothorax, and nerve injuries. Presently, the availability of ultrasound imaging equipment has made the use of this technology a standard when performing these procedures. It is essential that a physician develop the necessary skills to proficiently place the IJ line and observe methods which reduce serious complications. However, mastering this skill requires practice. This practice can be performed via simulation-based training and task trainers. Simulation-based training and task trainers are a means by which providers can perform certain tasks, for which high competence is critical, in a patient-free and repetitious environment. One of such tasks is the insertion of a central venous catheter.

Reproducing this clinical experience as cost-effectively as possible permits providers to gain invaluable repetitions in a patient-free environment while preserving budget integrity.

The availability of task trainers is expansive for the placement of central venous catheter (CVC) or central line catheter (CLC). These task trainers are highly available and have proven their value.¹ While highly available, accessibility may be low; these task trainers can be cost- prohibitive, and this cost-prohibitive concern raises the need for a novel central venous catheter insertion task trainer that is effectual and cost-effective.

Related literature explores the concept of novel task trainers and their effect on training programs in recent years. Nitsche et al. identified the opportunity for a more cost-effective ultrasoundable task trainer for ultrasound-guided invasive procedures.² Results favored the economical novel task trainer.² Several central venous catheter and arterial line insertion and management task trainers have been produced and tested for efficacy, also with favorable results.^3-5

A trend in the literature suggests a recurring need for “novel” and “low-cost” task trainers to get the job done. These motivators have driven other institutions to perform similar studies in hopes of achieving non-inferior outcomes.⁶ Unfortunately a gap in literature still exists with regard to a generalizable study evaluating novel, low-cost task trainers; some suggest the respective task trainer simply “shows promise” and will likely require further research.⁷ Chin et al. sought to validate the utility of their trainer with less emphasis on its novelty and financial partiality.⁸ Their study showed a statistically significant difference between pre-intervention and post- intervention confidence.⁸

Others, however, seek to achieve the novelty of the task trainer but have little to no interest, or at least secondary interest, in the cost of production or its subsequent savings. Lichtenberger et al. and Park et al. have developed novel task trainers without attention to cost-effectiveness.^9,10 As technology and medicine advance in unison, one method of production is described in today’s world as “additive manufacturing” or “3D-printing.” This innovative means of production is turning heads, and with the knowledge to utilize it, researchers can produce various tools for training that tailor to many different areas of medicine.⁹ While minimizing cost may not be the primary motivator for some researchers, it is certainly achievable with this modern method.⁹ In the realm of 3D-printing, some researchers have increased accessibility to these tools with “negligible costs.” ¹⁰

The goal of this study is to evaluate a low-cost central line trainer created in the Mirro Advanced Medical Simulation Lab as a cost-effective solution to implement widespread central line training within the health system. This will also serve to compare a novel simulation-based training to commercial training for central line insertion on participant confidence, skill, and knowledge.

Methods

Practicing physicians and advanced practice providers participated in simulation-based central venous catheter insertion training using both the commercial task trainer and the novel task trainer. Participants were surveyed regarding their confidence, skill, and knowledge of central venous catheter insertion pre- and post-training using both the commercial task trainer and the novel, more cost- effective task trainer created in house.

A non-inferiority analysis was undertaken to demonstrate that the new Advanced Medical Simulation Lab (AMSL) training was no worse than the commercial training. Thus, this analysis uses a one-sided test with a pre-specified minimum value, above which the AMSL training was considered not inferior to the commercial training. This minimum value of score improvement for AMSL training from pre- to post-assessment was expected to be within 0.5 points (within 10% on a 5-point scale) compared to the commercial training improvement. Paired t-tests were conducted between pre- and post-assessments scores to test that both training programs were effective.

Additionally, a mixed effects generalized linear model estimated the effect of the training program on scores, adjusted for patient baseline score, time and training condition.

Surveys

A within-subjects design was employed: each participant received both types of training. Items assessing confidence, skill, and knowledge were averaged for the pre-assessment and post- assessment administrations. Descriptive statistics were calculated for all measures.

Participants were asked to complete pre- and post-assessments to evaluate their level of comfort in the procedure and overall satisfaction whilst using these task trainers. The questionnaire (Figure 4) contains these two sections, each built to assess one or the other.

The first section asks participants to disclose their level of agreeance/agreement with the following statements: I feel confident in performing the procedure in my practice; My skill in performing the procedure is adequate; My knowledge of the procedure is adequate. The section asks participants to disclose their level of agreeance/agreement with the following statements: The instructor was knowledgeable about the procedure; The task trainer was realistic; The task trainer was easy to use; I had sufficient time to practice with the task trainer; The necessary equipment and tools for the indicated procedure were provided; I would recommend using this task trainer to a colleague or coworker.

Finally, participants are provided the opportunity to offer comments, feedback, and thoughts of prospective trainers that they would like to see offered.

Production Components

The Mirro Internal Jugular Line Trainer (Figure 3) provides an alternative option to live model practice by providing a system which replicates all the characteristics of a live model. Real tissue characteristics, laminar venous, and pulsatile carotid flow are recreated thus providing a realistic training environment. This novel task trainer was produced using the resources itemized in “Bill of Material” (Table 1).

The neck is the main component of the IJ trainer. It is composed of 10% ballistic gel that has carbon powder incorporated to provide opacity and realistic ultrasound granularity. There are two pairs of silicon tubing. One pair representing the right internal jugular vein and right carotid artery is located on the right half of the trainer. Water, used to represent blood, is pumped through the tubing via two separate miniature pumps. A dedicated electronic control system activates one pump to recreate a pulsatile blood flow to the carotid artery. Another pump, directly connected to a USB power bank or equivalent power supply, creates a laminar flow to the internal jugular vein. The other pair of silicone tubing is located on the left half of the neck and provides a cost effect option for prolonging the useful life of the gel neck. When the right pairs of tubing have been damaged due to the multiple needle puncture, the gel neck can be turned 180 degrees and reconnected to provide more practice. The compliance of the gel neck closely approximates human tissue. Similarly, puncturing the “blood vessels” will cause the neck to “bleed” just as it would in a live model.

Under ultrasound imaging, the artificial blood vessels are clearly defined. The carbon powder added to the ballistic gel provides granularity. Without this addition, an unrealistic image with large hypoechoic areas is interrupted only by the pairs of silicone tubing. Turning on the doppler mode, the practitioner is able to observe pulsatile flow in the carotid vessel and laminar flow in the internal jugular vein.

The pump base is a box with raised edges containing a pair of pumps, water reservoir, and tubing. The raised edge of the base allows for water to be recirculated when the gel neck is punctured and “bleeds”. Fluid drains back into the reservoir through two drain holes. One pump located inside the base provides a connection to the carotid tubing and the other pump provides a connection to the internal jugular tubing.

A compact circuit board regulates power to the carotid pump so that an intermittent activation of the pump can simulate carotid blood flow. USB connector designed into the circuit board allows any USB power bank to be used as a power source. Alternatively, a higher-powered power supply such as 6V is used to provide greater flow if one desires.

Production Process

Neck molds are made using aluminum to ensure the durability. Other materials such as silicone can be used which would be capable of withstanding prolonged temperatures of 250 degrees Fahrenheit. However, silicone or high temperature plastics would ultimately degrade under prolonged heat exposure. The mold consists of a semicircular main body and two end plate. The endplates have four holes grouped in two pairs. One pair is positioned at the lower right half and represents the carotid and internal jugular vessels. The other pair is located at the lower left half. The end plates can be replaced with different configurations. A normal anatomy would present the IJ superior and lateral to the carotid artery. Since there are variations to this, the end plate could configure multiple alignments of the vessels for increased challenge.

Molds – necessary materials include: Aluminum Mold
10% Ballistic Gel manufactured by Clear Ballistics 6mm Silicone Tubing
10” Stainless Steel rod 1/8” diameter Oven & Vacuum Chamber

1500g of 10% ballistic Gel is heated in an oven at 250 degrees Fahrenheit until completely melted. 7 grams of carbon powder is added to the gel and thoroughly mixed. 10 inches of silicone tubing is threaded through the corresponding hole in the end plates. Stainless steel rods are inserted through the tube to provide support. Without these rods, the tubing would assume unpredictable positions within the mold. The gel mixture is poured into the mold and placed into the vacuum chamber at -25in H20. After two hours or when the gel has cooled, the mold is reheated until the gel is in liquid state to release any remaining air bubbles. Once the gel has cooled, it is removed from the mold and stored in a container to keep dust from collecting on the surface.

Pump Base – necessary materials include: 2x Aluminum bar 4”x5”x0.125” Aluminum channel
2x Aluminum bar 4”x4”x0.25” Aluminum plate 4”x6”x0.08” 2x 5V Water pump model
4 Right angle brass connection ¼” NTP 4 Right angle plastic connectors
6mm Silicone tubing

The aluminum base supporting the gel is a water reservoir which also houses two internal water pumps. These pumps deliver pulsatile and steady flow through two tubing that connect to the neck gel. As the gel is punctured during the procedure, water will inevitably leak. Since there is a raised barrier around the gel, water will not flow onto the table. Instead, water will drain back into the pump base via holes drilled at one end (Figures 1 & 2).

The electronic pump control is designed to control the water pump located within the base. There are two settings: pulsatile and non-pulsatile.

Table 1: Itemized, tabulated list of materials necessary for production.

Neck Gel

Pump Base

Pump Control Circuit

Total production cost of novel trainer consisting of neck gel, pump base, pump control circuit:

$65.17 USD (single unit) or $62.41 USD (100 units)
*Production cost is slightly decreased when produced in large volumes due to bulk material purchase.

Total purchase cost of commercial trainer [CAE Blue Phantom Ultrasound Central Line Trainer]:

$2,915.00 USD (single unit)

Figure 1: Front-side, transparent graphic of novel task trainer displaying internal components and respective measurements.

Figure 2: Left-side, transparent graphic of novel task trainer displaying internal components and respective measurements.

Figure 3: Finalized concept model of novel task trainer.¹

Figure 4: Pre- and post-assessment.