Using Simulation Models to Train Clinicians in the Use of Point-of-Care Ultrasound

Summary

The present protocol describes an ideal solution to train novices in the use of point-of-care ultrasound devices for the practical clinical skill of visually assessing distinct individual anatomical vascular conditions prior to and during an intended venous vascular cannulation using point-of-care ultrasound in a patient.

Abstract

The use of point-of-care ultrasound (POCUS) has shown to be a beneficial non-invasive vascular access assessment method by clinicians, which can provide critical elements of visual and measurable information that proves to be useful in the context of vascular access cannulation, in combination with the practical skill of the clinician performing the cannulation. However, the use of POCUS in this context is to practically train and enable individuals who are novices in using this technique to become proficient in performing this task subsequently on patients in a careful and successful way. The simulation of these vascular conditions may be useful to help healthcare professionals learn, understand, apply, and establish such practical skills for vascular cannulation safely to achieve the desired outcomes. This project intended, through the attendance of a half-day workshop, to establish skills to use POCUS in connection with simulation models and perform specific tasks to enable clinicians to use this method in their clinical practice for vascular access cannulation in patients. A mixed-methods longitudinal study design was used to evaluate the effect of a point-of-care ultrasound workshop for peripheral intravenous cannula insertion, including specific tasks for the participants to be performed on simulation models. A total of 81 individuals participated in 11 half-day workshops through 2021 and 2022. Offering a workshop that uses simulation models in combination with various POCUS devices is useful in establishing this newly learned skill in clinicians, such as measurements of depth, caliper, and direction of a vein with POCUS prior to cannulation providing essential anatomical facts to the operator, which increases the likelihood of first-time success in cannulation.

Introduction

Most patients being admitted to acute hospitals receive at least one peripheral intravenous catheter (PIVC), with the purpose of withdrawing blood, administration of fluids and/or medication, and for diagnostic purposes¹. It is common that first-attempt insertions fail, and it has been reported that up to 50% of hospitalized patients have difficult intravenous access (DIVA)². To alleviate this, the use of ultrasound-guided PIVC insertion (USGPIVC) has been demonstrated to improve insertion success rates, and training and practical education have been recommended for multiple healthcare professions^3,4,5. Point-of-care ultrasound (POCUS) at the bedside is nowadays more frequently used to gain vascular access. POCUS has also been described as a useful tool for augmenting the teaching and learning of physical examination⁶. While several studies have described that training in USGPIVC is likely to enhance the skills of clinicians^7,8,9,10, it has not yet been described in detail which specific elements of this training are the essential components to achieve the desired outcomes when applying POCUS for USGPIVC. To achieve this, a combined POCUS and USGPIVC training curriculum was developed covering the essential aspects of the training, which were considered as being the elemental aspects and learning objectives for USGPIVC workshops, including the theoretical background and practical hands-on aspects.

Training novices in the use of POCUS prior to and during vascular access cannulation requires an ideal simulation environment to enable effective learning success which replicates similar anatomical conditions as in a human anatomical environment¹¹. Therefore, simulation models created from chicken breast and fluid-filled modeling balloons were found to be ideal and can be used to generate such a simulation model¹². This approach teaches the learner the observational skill of assessing vascular conditions at an individual patient level first in a safe, simulated environment, which helps in the overall decision-making process of choosing the required cannula length, assessment of the vascular depth and width, and vessel direction for an individual patient. This allows for a critical assessment of any future patient's individual anatomical conditions, where a clinician may want to subsequently decide if the planned cannulation is likely to be successful or not. To obtain this information, POCUS-obtained images, when they are interpreted correctly, usually provide reliable and critical elements of information, which, in addition to the clinicians' experience and manual dexterity, are likely to lead to cannulation success.

In the second step, the learner is taught, in this simulative environment, the development of manual dexterity for using the ultrasound probe simultaneously with the manual skill of inserting a cannula, under vision, observing the POCUS screen and the insertion site, into the simulated blood vessel. This observational skill of constantly visualizing the simulated vessel and meticulously observing the needle tip during the insertion process is the most important aspect of the overall learning goal of this simulation activity until the needle tip is ultimately placed in the anatomical area of interest, in this case in the center of a simulated vessel. This process is crucial to avoid unintended and unnecessary vessel injury, tissue, bleeding, or extravasation, as this technique is intended to be subsequently used in a patient in clinical settings by the participant.

Some authors have previously recommended implementing and integrating ultrasound into the medical school curriculum, using low-cost simulation models and small teaching groups¹³. Others have recommended developing structured training programs followed by a hands-on session in a simulated environment¹⁴. It has also been described that the use of ultrasound helps with procedural success and may reduce risks for patients¹⁵. Others have observed that using POCUS and USGPIVC to train clinicians in the emergency department (ED) has increased the use of this approach in the short term. Still, there may also exist a lack of consistency in formalized education programs for vascular access^7,16,17. In contrast, others have described that formalized vascular access training leads to improved adherence to best practices for PIVC insertion¹¹.

The aim of this educational approach was to simulate a comparable visual and dexterity experience for learners so that they could replicate and apply this skill in a clinical setting and on patients in the future. An observational longitudinal mixed methods study approach was chosen, and electronic surveys were used to assess the confidence level of workshop participants using ultrasound (POCUS) in connection with peripheral venous cannulation. The surveys were first used in simulation models and subsequently used in the clinical specialty of workshop participants in admitted patients.

The workshop was divided into three parts. First, participants were introduced to some basic principles and theories of using ultrasound in the space of vascular access cannulation in an interactive learning environment. In a second approach, the workshop facilitator demonstrated the vascular access assessment approach using a simulator with a simulated artificial vessel created, demonstrating the observation of vessel depth, size, and direction through transverse and longitudinal view and observation using POCUS. This was followed by a demonstrated cannulation using POCUS and the simulator through the workshop facilitator, as participants were then invited to practice this task themselves on their individual simulators. At the workshop conclusion, participants were individually assessed on their skill of identifying and measuring vessel size, depth, and direction using transverse and longitudinal views in the simulator, followed by ultrasound-guided cannulation of the simulated vessel. After the workshop attendance, participants were invited to rate their confidence skills in using USPIVC in an electronic survey. At 8 weeks after the workshop attendance, participants were again invited to respond in an electronic survey if they had applied this adopted skill in their individual clinical setting.

Protocol

This study was approved by the Human Research Ethics Committee of Edith Cowan University, Reference Number REMS 2021-02489-STEINWANDEL. Informed consent was obtained from workshop participants, and a copy of a participant information sheet was provided. Only workshop participants who participated in one of the ultrasound workshops during the delivery period between the years 2021 and 2022 were invited to participate and included in this study. All subsequent workshop participants in 2023 and 2024 were excluded from participation in this study.

1. Creation and preparation of the simulation model¹²

1. Cut a regular raw chicken breast with a sharp kitchen knife horizontally to allow for the insertion of three or more fluid-filled artificial blood vessels, which will simulate human blood vessels in this experiment.
2. Preparation of the artificial blood vessels
   1. Fill modeling balloons (size 260Q) with cold rosehip tea or water prepared with red food color using a 50 mL catheter-tipped syringe. Fill the modeling balloon with the prepared fluid and remove any surplus air from the balloon.
   2. Push the fluid in the balloon and remove any air bubbles at the same time by repeatedly pushing the syringe in and out of the modeling balloon. When this repetitive process is completed, the balloon must be free of air bubbles and slightly pressurized.
   3. Tighten the modeling balloon with a knot to avoid any fluid leaks.
3. Place the fluid-filled modeling balloon on the lower half of the chicken breast. Fold the other chicken breast half over (placed) on top. Wrap this chicken breast simulation model with a transparent film and place it on a tray (Figure 1).

Figure 1: Simulation model. The simulation model was created from raw chicken breast and fluid-filled modeling balloons (260Q). Please click here to view a larger version of this figure.

2. Simulated vascular access cannulation

1. Place a charged POCUS device (portable or stationary) with a linear probe and a probe cover onto this simulation model of patient tissue prepared in step 1.
2. Apply some ultrasound gel to the area of interest in the simulation model. Don a pair of non-sterile gloves.

3. Measurement of the depth and caliper of a vessel

1. In a transverse view of the simulated blood vessel in the simulation model, visualize a simulated vessel and achieve a good vision of the vessel of interest by placing the ultrasound probe on top of the simulation model and centering the view of the vessel in the middle of the screen of the ultrasound device, where it will appear as a black circular structure. Ensure a reasonable size of the vessel can be identified, taking up at least 1/3^rd of the screen.
2. Place this vessel in the center of the screen of the POCUS device by moving the ultrasound probe across the simulation model so that the whole vascular structure is visible. Adjust image size and contrast settings on the ultrasound device, if required, to obtain optimal vision of the vessel and surrounding tissue, to distinguish between vessel space and surrounding tissue. Freeze the image by pressing the Freeze function button on the ultrasound device.
3. On the frozen image, place digital markers, to indicate the depth of the center of the vessel. Place digital markers as well to measure the diameter (caliper) of the vessel (Figure 2).
   NOTE: This information helps the observer make critical decisions on the size and length of cannula needed, which may be suitable for potentially reaching this particular blood vessel and enabling successful cannulation.

Figure 2: Vessel measurement. Measurement of the simulated vessel (transverse view) on the ultrasound screen. Please click here to view a larger version of this figure.

4. Observation of the direction of the vessel

1. Rotate the ultrasound probe by 90° to obtain a longitudinal view of the blood vessel. This view allows the observer to make a decision on the direction of the vessel and the intended cannulation, providing crucial information prior to the subsequent process of the actual cannulation.
2. Observe the direction of the vessel being aligned with the ultrasound probe. Once the vessel direction has been observed, use this to decide which direction of cannula placement might likely be useful and also successful for the insertion and placement of the cannula, even when the vessel might appear to be at a deeper level and may not be palpable or visible from the outside (Figure 3).

Figure 3: Longitudinal view of a simulated vessel. Please click here to view a larger version of this figure.

5. Cannulation of a deep vessel

NOTE: Combining all this information, a virtual picture of that vessel is created in the observer's mind; the process of vascular cannulation will follow.

1. Place the linear probe in a transverse view of the vessel. Remove the protective needle cover of the PIVC cannula to commence the cannulation procedure.
2. Place the transverse vision of the vessel centrally on the screen of the POCUS device. Slowly and carefully cannulate (perpendicular) in the middle of the linear probe the simulation model at an angle of around 40° and aim for the top (upper end) of the vessel.
3. Advance the needle tip into the tissue of the simulation model and aim for the vessel. Try to identify visually the needle tip on the screen of the POCUS device while it is advanced through the tissue by simultaneously advancing the needle but also following the needle tip with the ultrasound probe (Figure 4).
4. Final placement of the cannula with the use of POCUS
   1. Further advance the needle through the tissue towards the vessel and follow slowly with the ultrasound probe, the needle tip simultaneously in the same motion as the needle advancement.
      ​NOTE: Through this the clinician can ensure that the needle tip is always visible in the desired anatomical space within the simulation model tissue and then moving towards the intravascular space.
   2. Visualize the needle tip entering the intravascular space, then level the needle to a shallower angle and further advance the needle to finally rest it in the center of the vessel of the simulation model (final destination).
   3. Validate the position of the needle tip with the POCUS device by observing the needle tip on the screen by changing the angle of the ultrasound probe or moving the ultrasound in small (mm) increments back and forth until the needle tip visually disappears/reappears on the screen.
   4. Observe the opposite end of the PIVC for some evidence of red-colored fluid to confirm correct placement. Remove the stylet from the PIVC (Video 1).

Figure 4: Transverse view of a simulated vessel. Please click here to view a larger version of this figure.

Video 1: Cannula advancement into the center of the vessel. Please click here to download this Video.

Results

A total of 81 individuals participated in 11 half-day workshops between 2021 and 2022. Most participants were resident medical officers (n=43, 53%), followed by staff development/clinical nurses and clinical nurse consultants (n=19, 25.3%) with a mean of 8 years of clinical experience. Half of the participants (n=40, 49%) had only 2 years or less of clinical experience. There were also some other workshop participants, such as a nuclear medicine technologist, a dental sedationist, and a diagnostic radiologist. Almost a q...

Discussion

Vascular access cannulation of difficult venous conditions requires experience, manual dexterity, and continuous observation of the progress of the needle tip position while the cannula is advanced through human tissue into the intravascular space¹⁸. While the use of ultrasound has become more prevalent in the use in patients with difficult venous access², it is also necessary that junior clinicians and novices become familiar with the use of ultrasound in connection with i...

Materials

Name	Company	Catalog Number	Comments
BD Insyte Autogard BC Pro shielded IV catheter with blood control technology (PIVC)	BD	318054
Catheter tipped syringe 30 or 50 ml	BD Plastipak	301229, 300865
Celeste Nitrile Powder Free Examination gloves sizes S/M/L (non-sterile)	Celeste	CLS121
Goliath Cling wrap	Goliath
modelling balloons 260 Q	Qualatex	99321
Point-of care ultrasound device, eg. Philips Lumify or Vscan Air	Philips or GE Healthcare		https://www.usa.philips.com/healthcare/product/HC989605450382/lumify-c5-2-curved-array-transducer
probe cover for Philips lumify	Philips		https://www.usa.philips.com/healthcare/product/HC989605450382/lumify-c5-2-curved-array-transducer
raw chicken breast
Sunsonic Ultrasound Transmission Gel 250 ml	Sunsonic	LG250
Tasty Herbal Infusion Rosehip Tea	Tasty
Victorinox Fibrox Chef's Knife 20 cm	Victorinox	40520