TissueDB/Simulators/Cricothyrotomy Simulator (Calvo)

The Cricothyrotomy Simulator (Calvo) is a modified version of the REAL CRIC Trainer originally described by Kei et al. in 2019.^[1] The inherited REAL CRIC base uses a 3D-printed airway covered with pork belly to reproduce palpable laryngeal landmarks, skin and subcutaneous tissue, bleeding, and escape of air when the cricothyroid membrane is entered.^[2] Calvo et al. modified this platform for a multidisciplinary "can't intubate, can't oxygenate" scenario by adding instructor-controlled foot-pump airflow, a pressurised simulated-blood circuit, a longer tunnel through the pork belly, integration with a high-fidelity patient simulator, and ultrasound landmark identification.

This simulator is a derivative build.

• Kei et al. 2019 is the construction authority for the underlying REAL CRIC Trainer, including its 3D-printed airway geometry and pork-belly tissue concept.
• Calvo et al. 2021 is the authority for the modified airflow system, pressurised simulated-blood circuit, longer pork-belly tunnel, high-fidelity-simulator integration, ultrasound use and observational evaluation.

Do not attribute the inherited REAL CRIC components to Calvo as if they originated in the 2021 study.

Step 1. Obtain the 3D-printable REAL CRIC airway geometry described by Kei et al.

The historical `airwaycollaboration.org` address printed in the Calvo paper no longer belongs to the Airway Collaboration and must not be used as evidence of current file provenance.

A surviving copy of the file has been identified at:

TheAirWayApp_Pro_Final.stl

Provenance note: the digital geometry is inherited from the REAL CRIC predecessor. Current file availability is separate from the historical source URL.

Step 2. 3D print the REAL CRIC airway component.

Source limitation: Calvo et al. do not state the print material, printer, slicing settings or total printing time. Do not infer these parameters.

Step 3. Seal the distal exit of the printed airway with paper tape.

Step 4. Secure the printed airway using foam adhesive tape.

Step 1. Place an endotracheal tube inside the 3D-printed airway.

Step 2. Connect the endotracheal tube to a foot-operated air pump.

The foot pump is a Calvo modification. It replaces the Ambu-bag airflow method of the predecessor trainer and permits the instructor to operate the airflow away from the participant while keeping both hands free.

Step 1. Prepare a 1 L saline bag stained red with food dye.

Step 2. Place the simulated-blood bag inside an IV pressuriser.

Step 3. Connect an IV infusion set to the bag.

The pressurised system is a Calvo modification. It replaces manual squeezing of the reservoir and is intended to provide a greater and more constant pressure.

Step 1. Obtain a pork-belly slab with intact skin that is large enough to cover the printed airway.

The pork-belly skin and subcutaneous-tissue concept is inherited from REAL CRIC. Calvo et al. do not state the slab dimensions.

Step 2. Infiltrate the pork-belly subcutaneous tissue with simulated blood.

Step 3. Tunnel the distal end of the IV infusion set through the subcutaneous tissue using the protective plastic sleeve of a spinal-block needle.

Step 4. Extend the tunnel beyond the planned incision line.

The longer tunnel is a Calvo modification. Calvo et al. explain that the shallower predecessor arrangement could produce sufficient tissue resistance to obstruct simulated-blood delivery. Extending the tunnel reduced that problem.

Step 1. Place the prepared pork belly over the 3D-printed airway with the skin facing outward.

Step 2. Centre the airway landmarks beneath the tissue layer.

Step 3. Connect the tunnelled IV line to the pressurised simulated-blood reservoir.

Step 4. Attach the assembled phantom to the neck of the high-fidelity simulator when it is being used in the complete multidisciplinary scenario.

Step 1. Palpate through the pork belly and confirm that the thyroid and cricoid cartilage landmarks can be located.

Step 2. Pressurise the simulated-blood reservoir.

Step 3. Operate the foot air pump.

Step 4. Confirm that the training setup can produce simulated bleeding at the planned incision region and escape of air when the cricothyroid-membrane region is entered.

Evidence label: these behaviours are part of the Calvo modified simulator configuration. They are not a separate TissueDB clinical-validation test.

Calvo et al. also evaluated ultrasound identification of the laryngeal landmarks using the simulator.

An ultrasound machine is therefore required for this optional use. The paper does not specify the ultrasound probe type.

Calvo et al. used SimMon vital-signs software displayed on an iPad and controlled from an iPhone during the multidisciplinary CICO scenario.

This software is part of the wider scenario environment and is not required to fabricate the physical cricothyrotomy trainer.

• Replace the pork-belly slab when previous incisions make it unsuitable for another attempt. Calvo et al. do not provide a reuse count.
• Replenish simulated blood as required.
• A fresh pork-belly slab requires reconstruction of the tunnelled blood-delivery path.
• Inspect the reusable printed airway and reseal the distal end if necessary.

Editorial note: Calvo et al. do not publish a formal between-learner reset protocol. These reset actions describe the practical dependencies of the documented configuration and must not be represented as an author-prescribed checklist.

The source reports €220 for the Calvo modified configuration.

Do not:

• convert that figure to a historical or current US-dollar estimate;
• substitute the cost of the original Kei REAL CRIC trainer;
• treat €220 as a generic price for every REAL CRIC implementation; or
• infer a total build time from individual preparation steps.

Calvo et al. completed an observational evaluation of the modified trainer, including expert/participant assessment and ultrasound landmark identification. The study did not establish transfer to patient care or clinical outcomes.

Figures 1A–1K in Calvo et al. (2021) document the modified assembly but are published under CC BY-NC-ND 4.0 and are therefore not reproduced on this page.

See the Calvo et al. article for the original figure plate.