NCT06636825

Influence of Caffeine on Psychomotor Vigilance and Carbon Dioxide Tolerance During Graded Hypercapnia

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 29 (actual)
• Sponsor: United States Army Research Institute of Environmental Medicine · Federal
• Sex: All
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

Summary

The aim of this randomized, double-blind, placebo-controlled crossover trial is to determine the effects of caffeine vs. placebo on psychomotor vigilance and carbon dioxide tolerance during graded hypercapnia.

Detailed description

Healthy and fit young adults (men and women) will participate in this study. Participants will perform two primary experimental trials on separate days, one after consuming 400 mg caffeine, and the other after consuming a non-caffeinated placebo. During each trial, participants will breathe increasing levels of inspired CO2 in a stepwise manner (0%, 2%, 4%, 6%, 8% CO2; all with 21% oxygen) during successive 12-minute stages. The endpoints of the graded hypercapnia protocol will be completion of the 8% CO2 stage, voluntary subject termination due to discomfort, or end-tidal CO2 greater than 70 mmHg. The investigators hypothesize that, compared to placebo, caffeine will lower end tidal and arterialized PCO2 and mitigate CO2-mediated decrements in psychomotor vigilance.

Conditions

• Hypercapnia

Interventions

Type	Name	Description
OTHER	Graded hypercapnia	Volunteers breathe 0%, 2%, 4%, 6%, and 8% CO2 (with 21% O2, balance nitrogen) for 12 minutes each
DRUG	Caffeine	400 mg caffeine capsule taken in a single dose 1 hour prior to graded hypercapnia
DRUG	Placebo	Placebo (microcrystalline cellulose) capsule taken in a single dose 1 hour prior to graded hypercapnia

Timeline

• Start date: 2023-11-09
• Primary completion: 2024-09-17
• Completion: 2024-09-17
• First posted: 2024-10-15
• Last updated: 2024-10-15

Locations

1 site across 1 country: United States