A Novel Low-Cost Phantom for Ultrasound-Guided Fascia Iliaca Nerve Blocks

This phantom is designed to instruct emergency medicine residents in ultrasound-guided fascia iliaca (FI) nerve blocks but could also be used for medical students and attending physicians.

Ultrasound-guided regional nerve blocks are increasingly used in the emergency department for pain management. The FI block, used for pain management in patients with hip fractures, have been shown to provide pain relief for up to eight hours with rare complications and to decrease need for parenteral pain medication.1,2 It is considered best practice to train physicians in ultrasound-guided procedures such as FI blocks by using phantoms, which are objects designed to mimic human tissue and anatomy relevant to the specific ultrasound-guided procedure. Commercial trainers are available but are quite expensive with those designed to mimic femoral anatomy priced at or over $5,000 USD, and they still lack some of the anatomical landmarks useful in FI blocks.3,4 Several lower cost FI models have been described made from a variety of perishable items including gelatin, tofu, chicken, konnyaku jelly, pork and meat glue.5-10 However, these models have the downside of limited uses due to the nature of perishable materials, and most are also lacking in block specific landmarks and durability.

By the end of the training session using the FI phantom and bedside ultrasound, learners should be able to: 1) discuss indications, contraindications, and complications of FI blocks; 2) identify anatomy relevant to performing an FI block on ultrasound; and 3) independently perform an FI block or demonstrate proper needle position for FI block on ultrasound of the phantom.

This low-cost FI block phantom was developed using ballistics gel to create the fascia layers and muscles, bungee cord for nerve, and latex balloons for vessels. Ballistics gel was also used as the base medium for the phantom.

Participants completed a short electronic survey following the educational session using five-point Likert scale questions to evaluate the phantom based on ultrasound image quality, anatomical accuracy, and perceived durability. An additional question asked participants if they felt more confident performing an FI block after practicing on the phantom.

Twenty-four emergency medicine residents completed the training session and the post-training survey. All learners were able to successfully demonstrate proper needle placement on ultrasound for the FI block. On a five-point Likert scale, ranging from 1 (very poor) to 5 (excellent), participants rated the phantom in durability, anatomical accuracy, and ultrasound image quality. Most participants agreed that the phantom was anatomically accurate (median 4) and durable (median 4). The phantom performed the best in the category of ultrasound image quality (median 5). Most participants agreed that practicing with the phantom increased their confidence in performing FI blocks (median 4). The phantom held up to 100 needle sticks with only mild degradation in image quality.

The phantom presented here effectively taught EM residents proper needle placement for an FI block since all participants were able to demonstrate appropriate needle placement. The phantom was low cost, particularly compared to commercial trainers, and held up to a large number of needle sticks.

Nerve blocks, ultrasound phantom, pain management, hip fractures, point of care ultrasound.