Can Ammonium Inhalants Maintain Performance in Sleep Deprived Soldiers?
Condition: Sleep Deprivation; Military Activity; Sleep; Cognitive Change; Military Combat Stress Reaction
MeSH terms: Sleep Deprivation; Fractures, Stress
Study type: Interventional
Phase: Phase 1

Summary: 
      This study aims to examine the effectiveness of ammonia inhalants in countering the effects
      of total sleep deprivation on cognitive and physical performance tests relevant to military
      personnel.
    

Detailed description: 
      Data from this study are part of a broader research project aimed at investigating the
      effects of different light conditions on cognitive and physiological performance during
      periods of total sleep deprivation. We used a crossover randomized controlled trial design
      with within-subject repeated-measures to assess the effects of ~36 hours of total sleep
      deprivation and acute ammonia inhalation on occupationally relevant military tasks in
      military personnel.

      Participants reported to the Sleep and Chronobiology laboratory (National Institute of Mental
      Health) on Thursday evening after a standardized dinner at ~1800 h. They then completed a
      series of questionnaires addressing psychological and physiological health, which were
      followed by a general familiarization of the layout of the facility (i.e., location of the
      bathrooms, testing stations, etc.). During this familiarization, the participants were also
      familiarized with the specific testing procedures and practiced each of the required tasks.

      The actual testing protocol began with a night of uninterrupted sleep from ~2200 h to ~0630
      h. Participants then underwent 5 identical testing sessions from every ~0730-0930 h in the
      morning and ~1900-2100 h in the evening. The first test occurred in the morning after the
      full night of baseline sleep (0 h) and again after 12 hours (-12 h), 24 hours (-24 h), and 36
      hours of total sleep deprivation (-36 h) followed by additional testing session after 8 hours
      (from 2230-0630 h) of recovery sleep (+8 h). During total sleep deprivation, participants
      were not allowed to sleep and were kept awake in a common room by passive means, such as
      playing board games, watching television and reading books while under constant supervision
      of the research team. Furthermore, the participants were subjected to a constant ambient room
      light for the entire duration of total sleep deprivation period.

      Participants were administered a standardized sleepiness scale and underwent simple reaction
      time testing, handgun shooting accuracy protocol, a rifle disassembly and reassembly
      protocol, and countermovement jump testing at each testing session. Participants performed
      each individual test twice at each testing period, either with AI (AI) or without AI (CON),
      in randomized order and separated by 2 minutes of rest (in order to minimize any potential
      carryover effects of the AI)

      For all AI trials, a capsule containing 0.3 mL of AI (composed of 15% of ammonia and 35% of
      alcohol) (31) was used according to the manufacturer's instructions (Dynarex Corporation,
      Orangeburg, NY). When the ammonia fumes were released, researcher immediately held the
      capsule under the participant's nose to inhale until a voluntary withdrawal reflex was
      observed.

      During the entire study protocol, participants received personalized daily food rations
      consisting of standard 'ready to eat' meals commonly used in the Czech military. One week
      before the experiment, participants' body composition was measured (using air displacement
      plethysmography; Bod Pod Body Composition System; Life Measurement Instruments, Concord, CA),
      and the total daily energy expenditure was derived from the estimated resting metabolic rate
      and application of an "active" physical activity factor of 1.6 to the individual caloric
      requirements. In addition, each participant was allowed ad libitum water consumption.
      Breakfast was consumed at ~0930 h, lunch at ~1230 h, and dinner at ~1730 h, each day.
      Additionally, all forms of stimulants were prohibited 72 hours before and during the testing
      protocol.
    

Intervention name(s): Ammonia Inhalant
Intervention type(s): Drug
Intervention description(s): For all AI trials, a capsule containing 0.3 mL of AI (composed of 15% of ammonia and 35% of alcohol) was used according to the manufacturer's instructions (Dynarex Corporation, Orangeburg, NY). When the ammonia fumes were released, researcher immediately held the capsule under the participant's nose to inhale until a voluntary withdrawal reflex was observed.
Other intervention name(s): smelling salt
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: cognition; military; sleep deprivation; performance; ammonia