Clinical trial NCT05073406: Cognition at Altitude in HEMS - Part II
Official title: Cognitive Performance After Acute Exposure to Altitude - Part II
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hypobaric Hypoxia
Hypobaric Normoxia
Cognitive Performance
Emergency Medicine
Stress Physiology
Lead sponsor: Institute of Mountain Emergency Medicine
Sponsor class: OTHER
Collaborators: name: University Grenoble Alps
name: Università degli Studi di Trento
name: Medical University Innsbruck
First posted: 2021-10-11
Enrollment: 36
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Interventional, non-pharmacological, randomized, controlled, double-blinded, cross-over
Primary purpose: BASIC_SCIENCE

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).

* 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.
* 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.


Eligibility 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;
* provided informed and written consent;
* 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.

Primary outcomes:
measure: Psychomotor Vigilance Test - PVT
timeFrame: Changes from baseline (T0) to altitude measurement (respectively after 5 min - T1 and after 30 min - T2)
measure: Digit-Symbol Substitution Task - DSST
timeFrame: Changes from baseline (TC0) to altitude measurement (respectively after 5 min - TC1 and after 30 min - TC2)
measure: 2-back Test
timeFrame: Changes from baseline (TC0) to altitude measurement (respectively after 5 min - TC1 and after 30 min - TC2)
Secondary outcomes:
Other outcomes:
Locations:
city: Bolzano
country: Italy
facility: Eurac Research, Institute of Mountain Emergency Medicine
state: BZ
Study officials:
affiliation: Eurac Research, Institute of Mountain Emergency Medicine
name: Giacomo Strapazzon, MD PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Trento, Center for Mind/Brain Sciences - CIMeC
name: Marika Falla, MD PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Eurac Research, Institute of Mountain Emergency Medicine
name: Michiel van Veelen, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Basner M, Moore TM, Nasrini J, Gur RC, Dinges DF. Standardization of psychomotor vigilance testing methods and reporting. Sleep. 2021 Jul 9;44(7):zsab114. doi: 10.1093/sleep/zsab114. No abstract available.
citation: Brodmann Maeder M, Brugger H, Pun M, Strapazzon G, Dal Cappello T, Maggiorini M, Hackett P, Bartsch 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.
citation: Cable GG. In-flight hypoxia incidents in military aircraft: causes and implications for training. Aviat Space Environ Med. 2003 Feb;74(2):169-72.
citation: EASA. https://www.easa.europa.eu/document-library/notices-of-proposed-amendment/npa-2018-04. (2018).
citation: Falla M, Papagno C, Dal Cappello T, Vogele A, Hufner 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.
citation: Falla M, Hufner K, Falk M, Weiss EM, Vogele 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. 2024 Feb;66(2):404-423. doi: 10.1177/00187208221086407. Epub 2022 May 31.
citation: 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.
citation: 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.
citation: 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. No abstract available.
citation: Nowacki J, Heekeren HR, Deuter CE, Joerissen JD, Schroder 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.
citation: 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.