HEMS II: Cognition at Altitude in HEMS - Part II
Study Details
Study Description
Brief Summary
The aim of the current study is to evaluate under blinded conditions, both in a simulated environment and during helicopter flight, the effect of a rapid (within 20 minutes) exposure to altitude (4000 m asl) on physiological parameters and selected cognitive domains, in providers operating in helicopter emergency medical service (HEMS) exposed to hypobaric hypoxia or to hypobaric normoxia (H0: cognitive effects under hypobaric hypoxia = cognitive effects under hypobaric normoxia). Simulated environment will allow to control different factors. The parallelism between a study branch conducted in a simulated environment and another one conducted under a real-life condition will allow to evaluate the additive effects on additional stressor factors (processive and systemic ones).
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Simulation branch: each participant will take part in three research sessions: a familiarization session and two experimental sessions in simulation facility called terraXcube (test 1 and 2). On test 1 and test 2 each group will be exposed twice to the simulated altitude of 4000 m asl (under hypobaric hypoxia or hypobaric normoxia conditions) according to the randomization protocol. Participants will perform the neurocognitive tests three times on each of the two tests: before the ascent (TC0), after 5 min from the end of the ascent (TC1) and after around 30 min (TC2), to investigate European Union Aviation Safe Agency (EASA) proposed recommendations. After completing each neurocognitive test session, participants will be asked to rate their performance using a visual analogue scales (VAS). All participants will wear the vital parameters monitoring system during the entire duration of the tests inside the chamber, as well as the cerebral oxygen saturation (ScO2) sensor. Samples will be collected by saliva, urine and/or capillary blood. The same schedule is repeated in each test session.
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In-field branch: each participant will take part in three research sessions: a familiarization session and two experimental sessions during helicopter flights (test 1 and 2). On test 1 and test 2 each group will be exposed twice to the altitude of 4000 m (under hypobaric hypoxia or hypobaric normoxia conditions) according to the randomization protocol. Participants will perform the neurocognitive test two times on each test: before the ascent (TC0), after around 5 min from the end of the ascent (TC1). After completing each neurocognitive tests, participants will be asked to rate their performance using a visual analogue scales (VAS). All participants will wear the vital parameters monitoring system during the entire duration of the tests. Samples will be collected. The same schedule is planned in each test session.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Hypobaric normoxia Altitude exposure in hypobaric normoxic condition |
Other: Altitude exposure in hypobaric normoxic condition
Altitude exposure with oxygen supplementation to achieve normoxia at altitude
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| Sham Comparator: Hypobaric hypoxia Altitude exposure in hypobaric hypoxic condition |
Other: Altitude exposure in hypobaric hypoxic condition
Altitude exposure with air supplementation to obtain a sham comparator arm
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Outcome Measures
Primary Outcome Measures
- Psychomotor Vigilance Test - PVT [Changes from baseline (T0) to altitude measurement (respectively after 5 min - T1 and after 30 min - T2)]
Changes in reaction time using a computer-based test (PVT)
- Digit-Symbol Substitution Task - DSST [Changes from baseline (TC0) to altitude measurement (respectively after 5 min - TC1 and after 30 min - TC2)]
Changing in processing speed using a computer based test (DSST)
- 2-back Test [Changes from baseline (TC0) to altitude measurement (respectively after 5 min - TC1 and after 30 min - TC2)]
Changing in working memory using a computer based test (2-back test)
Eligibility Criteria
Criteria
Inclusion Criteria:
Members of emergency medical services (EMS) and search and rescue (SAR) services with an occupational licence, an age between 18 and 60 years, an American Society of Anaesthesiologists (ASA) physical status class I, providing informed and written consent with no current COVID 19 symptoms and temperature ≤ 37.5°on test days, not being tested positive for COVID-19, ideally COVID-19 vaccinated.
Exclusion Criteria:
Members under the age of 18 years, an ASA physical status class II or more, a medical history of psychiatric disorders and neurological diseases, previous high altitude pulmonary oedema (HAPE) or high altitude cerebral oedema (HACE) or severe acute mountain sickness (AMS) (defined as a Lake Louise Score (LLS) > 9) occurred at altitudes similar to the ones tested in the study, no informed consent, current COVID 19 symptoms, being tested positive for COVID-19 or symptoms and body temperature ≥ 37.5°on test days.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Eurac Research, Institute of Mountain Emergency Medicine | Bolzano | BZ | Italy | 39100 |
Sponsors and Collaborators
- Institute of Mountain Emergency Medicine
- University Grenoble Alps
- Università degli Studi di Trento
- Medical University Innsbruck
Investigators
- Principal Investigator: Giacomo Strapazzon, MD PhD, Eurac Research, Institute of Mountain Emergency Medicine
- Principal Investigator: Marika Falla, MD PhD, University of Trento, Center for Mind/Brain Sciences - CIMeC
- Principal Investigator: Michiel van Veelen, MD, Eurac Research, Institute of Mountain Emergency Medicine
Study Documents (Full-Text)
None provided.More Information
Publications
- Basner M, Moore TM, Nasrini J, Gur RC, Dinges DF. Standardization of psychomotor vigilance testing methods and reporting. Sleep. 2021 Jul 9;44(7). pii: zsab114. doi: 10.1093/sleep/zsab114.
- Brodmann Maeder M, Brugger H, Pun M, Strapazzon G, Dal Cappello T, Maggiorini M, Hackett P, Bärtsch P, Swenson ER, Zafren K. The STAR Data Reporting Guidelines for Clinical High Altitude Research. High Alt Med Biol. 2018 Mar;19(1):7-14. doi: 10.1089/ham.2017.0160. Epub 2018 Feb 9.
- Cable GG. In-flight hypoxia incidents in military aircraft: causes and implications for training. Aviat Space Environ Med. 2003 Feb;74(2):169-72.
- EASA. https://www.easa.europa.eu/document-library/notices-of-proposed-amendment/npa-2018-04. (2018).
- Falla M, Hüfner K, Falk M, Weiss EM, Vögele A, Jan van Veelen M, Weber B, Brandner J, Palma M, Dejaco A, Brugger H, Strapazzon G. Simulated Acute Hypobaric Hypoxia Effects on Cognition in Helicopter Emergency Medical Service Personnel - A Randomized, Controlled, Single-Blind, Crossover Trial. Hum Factors. 2022 May 31:187208221086407. doi: 10.1177/00187208221086407. [Epub ahead of print]
- Falla M, Papagno C, Dal Cappello T, Vögele A, Hüfner K, Kim J, Weiss EM, Weber B, Palma M, Mrakic-Sposta S, Brugger H, Strapazzon G. A Prospective Evaluation of the Acute Effects of High Altitude on Cognitive and Physiological Functions in Lowlanders. Front Physiol. 2021 Apr 28;12:670278. doi: 10.3389/fphys.2021.670278. eCollection 2021.
- Hart, S., and Staveland, L. (1988). "Development of NASA-TLX (task load index) - results ofempirical and theoretical research," in HumanMental Workload, eds P. Hancock and N. Meshkati (Amsterdam: Springer), 139-183. doi: 10.1016/ s0166- 4115(08)62386- 9.
- Hinkelbein J, Glaser E. Evaluation of two oxygen face masks with special regard to inspiratory oxygen fraction (FiO2) for emergency use in rescue helicopters. Air Med J. 2008 Mar-Apr;27(2):86-90. doi: 10.1016/j.amj.2007.07.005.
- Mrakic-Sposta S, Vezzoli A, Malacrida S, Falla M, Strapazzon G. "Direct" and "Indirect" Methods to Detect Oxidative Stress During Acute or Chronic High-Altitude Exposure. High Alt Med Biol. 2017 Sep;18(3):303-304. doi: 10.1089/ham.2017.0067. Epub 2017 Jul 28.
- Nowacki J, Heekeren HR, Deuter CE, Joerißen JD, Schröder A, Otte C, Wingenfeld K. Decision making in response to physiological and combined physiological and psychosocial stress. Behav Neurosci. 2019 Feb;133(1):59-67. doi: 10.1037/bne0000288. Epub 2018 Dec 17.
- Wilson MH, Newman S, Imray CH. The cerebral effects of ascent to high altitudes. Lancet Neurol. 2009 Feb;8(2):175-91. doi: 10.1016/S1474-4422(09)70014-6. Review.
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