Training Non-Anesthesia Personnel to Perform Nerve Blocks in Microgravity

NCT07849049 | Completed

• 1 other identifier: REB # 2024-7417
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Space exploration is rapidly progressing with multiple upcoming missions planned to the moon and International Space Station, and projected missions to Mars in the early 2030s. Multiple types of injuries and surgical emergencies are possible during space travel. With the rapidly increasing number of travelers, healthcare providers need to refine our plans for responding to surgical emergencies in space. It may not be possible to return injured crew members to earth for medical treatment depending on distance from earth and the severity of the injury. Furthermore, the casualty's physiologic changes in microgravity, and logistical limitations of repatriation make addressing medical emergencies challenging. Pain medications and general anesthesia have side effects that can impact safety in space and have worse side effect profiles when compared to on earth. Regional anesthesia, injecting local anesthetic near to a nerve(s) to create a large area of numbness on the body, has been used for many years for pain management and to allow for surgery in remote settings on earth. Military personnel have used these techniques to provide effective pain control for evacuating wounded soldiers, while maintaining their cognition. For these reasons, regional anesthesia (aka 'nerve block') has been promoted as a viable solution for injured astronauts. Our team has demonstrated that simple nerve blocks are possible in simulated microgravity among trained anesthesia providers. Recognizing that non-physician medical technicians may be integral to future space missions, this study aims to ascertain the feasibility of training such personnel to perform simple nerve blocks in microgravity.

Conditions

Nerve Block; Regional Anesthesia; Microgravity; Space Analogue

Outcome Measures

Primary Outcomes (1)

• Injection success

  Post-injection the models will be stored in a refrigerator for at least 24 hours to dry and allow the dye to settle. Two blinded investigators will dissect the models and score them. A successful nerve block will be defined as visible blue dye staining the outside of the beef tendon without evidence of injection inside of the tendon. The presence of primarily intraneural or intramuscular staining will be considered a failed block.

  3.5 minutes

Secondary Outcomes (5)

• Time to injection

  3.5 minutes

• Number of needle passes

  3.5 minutes

• Ease of ultrasound image acquisition

  5 minutes

• Ease of needle placement

  5 minutes

• Intraneural injection

  3.5 minutes

Study Arms (2)

Simulated Microgravity

EXPERIMENTAL

In the microgravity condition, the participants will be scuba diving in a pool. The mannikin will be secured to a table at the bottom of the pool and they will empty their buoyancy control device (causing them to sink), effectively removing the added complexity of buoyancy control. An investigator will assist each participant with the block by positioning the meat model in the mannikin, passing equipment, and injecting the dye through a syringe once they are signaled to do so. However, the investigator will not give the participant guidance on the accuracy of the needle position or the quality of their ultrasound image.

Other: Simulated microgravity

Normal gravity

ACTIVE COMPARATOR

In the normal gravity condition, participants will be in a seated position with the meat model positioned in the chest wall of a mannikin, supported on a table. Participants will use a high-frequency (4-13 MHz) linear transducer and a 22G 50 mm echogenic needle to inject the meat model with 1-2 ml of water mixed with blue food coloring. The ultrasound, phone, and dive case will be the same as in the microgravity condition. Participants will use hand signals to communicate with their block assistant since verbal communication will not be possible underwater.

Other: Normal earth gravity

Interventions

Simulated microgravity OTHER

Neutral buoyancy underwater

Simulated Microgravity

Normal earth gravity OTHER

Same procedure on land

Normal gravity

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• adult (age \>18 years)
• certified scuba divers
• no prior nerve block technique training.
• staff anesthesiologists or senior residents
• certified scuba divers

You may not qualify if:

• active ear nose and throat conditions that prevent ear equalization
• neuromotor conditions interfering with fine motor skills
• pregnancy
• inability to consent

Sponsors & Collaborators

• Nova Scotia Health Authority: lead

Study Sites (1)

Survival Systems Training Limited

Dartmouth, Nova Scotia, B2Y 4K9, Canada

Location

Related Publications (6)

• Kiberd MB, Brownbridge R, Mackin M, Werry D, Bird S, Barry G, Bailey JG. Feasibility of ultrasound-guided nerve blocks in simulated microgravity: a proof-of-concept study for regional anaesthesia during deep space missions. Br J Anaesth. 2024 Dec;133(6):1276-1283. doi: 10.1016/j.bja.2024.07.034. Epub 2024 Sep 25.

  PMID: 39327151 BACKGROUND

• Brownbridge RG, Kiberd MB, Werry D, Bailey JG. Discriminative Ability of Dye Injected Into a Meat Model to Determine Accuracy of Ultrasound-Guided Injection. Simul Healthc. 2025 Feb 1;20(1):54-60. doi: 10.1097/SIH.0000000000000799. Epub 2024 Jun 10.

  PMID: 38856652 BACKGROUND

• Komorowski M, Thierry S, Stark C, Sykes M, Hinkelbein J. On the Challenges of Anesthesia and Surgery during Interplanetary Spaceflight. Anesthesiology. 2021 Jul 1;135(1):155-163. doi: 10.1097/ALN.0000000000003789. No abstract available.

  PMID: 33940633 BACKGROUND

• Scarpa J, Wu CL. The role for regional anesthesia in medical emergencies during deep space flight. Reg Anesth Pain Med. 2021 Oct;46(10):919-922. doi: 10.1136/rapm-2021-102710. Epub 2021 May 21.

  PMID: 34021077 BACKGROUND

• Anderton R, Posselt B, Komorowski M, Hodkinson P. Medical considerations for a return to the Moon. Occup Med (Lond). 2019 Aug 22;69(5):311-313. doi: 10.1093/occmed/kqz099. No abstract available.

  PMID: 31436819 BACKGROUND

• Komorowski M, Fleming S, Mawkin M, Hinkelbein J. Anaesthesia in austere environments: literature review and considerations for future space exploration missions. NPJ Microgravity. 2018 Feb 23;4:5. doi: 10.1038/s41526-018-0039-y. eCollection 2018.

  PMID: 29507873 BACKGROUND

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Anesthesiologist

Model Details: This will be a prospective cohort study using within- and between-subjects comparisons. This study will assess the ease and success of ultrasound-guided injections ("nerve blocks") by non-anesthesia personnel comparing normal gravity to microgravity conditions using a meat model. Secondly, the ease and success rate of non-anesthesia participants will be compared to anesthesia participants.

Study Record Dates

• First Submitted: September 17, 2026
• First Posted: September 30, 2026
• Study Start: March 20, 2026
• Primary Completion: March 29, 2026
• Study Completion: March 29, 2026
• Last Updated: September 30, 2026

Record last verified: 2026-09

Locations

CA (1)