Overview
This four-group prospective study will enroll travelers who have independently booked economy or premium business/first-class flights to Bogota. Within each cabin stratum, participants will be randomized to moderate graduated compression stockings or no stockings. Bilateral popliteal vein ultrasound will be performed before flight, within 2 hours after arrival, and at 24 and 48 hours. The primary outcome is the interaction between cabin class and compression assignment for change in mean bilateral popliteal vein diameter.
Description
Participants will enter the study according to their prebooked cabin class and then be randomized within that stratum to wear properly fitted knee-high graduated compression stockings or no compression during the flight. The design creates four groups. Standardized bilateral ultrasound will quantify venous diameter and cross-sectional area before departure and through 48 hours after arrival, before surgery. Mixed-effects models will estimate the randomized stocking effect, the adjusted cabin-class association, and their interaction. The protocol will record seat characteristics, ambulation, hydration, adherence, symptoms, and safety events.
Eligibility
Inclusion Criteria:
- Age 18 to 65 years.
- Commercial itinerary to Bogota with at least 4 hours of total airborne time.
- Prebooked premium business/first-class or economy-class cabin documented before randomization.
- No medical requirement for or contraindication to graduated compression stockings.
- Ability to complete standardized ultrasound before flight and through 48 hours after arrival before surgery.
- Written informed consent.
Exclusion Criteria:
- Current deep venous thrombosis, therapeutic anticoagulation, or severe peripheral arterial disease.
- Pregnancy.
- Lower-extremity skin, neurologic, or anatomic condition preventing safe stocking use or ultrasound.
- Cabin upgrade or downgrade after randomization that changes the prespecified stratum.
- Surgery or major intravenous fluid therapy before the 48-hour examination.
- Inability to follow the randomized stocking assignment.
