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Autonomic Control of the Circulation and VDR

NCT03513770 · Status: RECRUITING · Phase: EARLY_PHASE1 · Type: INTERVENTIONAL · Enrollment: 18

Last updated 2025-09-16

No results posted yet for this study

Summary

The study objective of this project is to examine the mechanisms of the venous distension reflex (VDR) in humans. We hypothesize that COX blockade with ketorolac tromethamine, an intravenous NSAID, will attenuate the muscle sympathetic nerve activity (MSNA) response to limb venous distension. To gain further insight into whether the COX byproducts directly stimulate chemically-sensitive afferents, or enable venodilation and indirectly evoke afferent stimulation, we will measure vein size using 3T MRI during venous distention with and without ketorolac infusions.

Conditions

  • Venous Distension Reflex
  • Blood Pressure

Interventions

OTHER

Wrist-to-elbow (W-E) occlusion

An IV will be inserted in the antecubital fossa of one arm. The arm will be fitted with occlusion cuffs arranged in a continuous fashion from the wrist to the elbow. A final cuff will be placed on the upper arm. The cuffs from the wrist to the elbow will be inflated to the same pressure of up to 300 mmHg using a pressurized air tank. First, the subject?s arm will be elevated and the subject will make a fist to squeeze blood from the hand. Then the wrist cuff will be inflated. Once that cuff is fully inflated, the next cuff in the sequence will be inflated. Cuffs are inflated in sequence until the elbow cuff is inflated. After a 10-15 second period to allow blood to drain, the upper arm cuff will inflate (up to 250 mmHg) to keep any additional blood from entering the forearm. Next, the cuffs on the forearm will be removed but the upper arm cuff will remain inflated.

DRUG

ketorolac tromethamine

In the COX blockade trial, just after the Wrist-to-elbow occlusion, 6 mg ketorolac tromethamine in 10 ml saline will be infused into the forearm over 1 minute. After 10 minutes, a second infusion of ketorolac tromethamine (up to 3 mg) in 5% of the forearm volume of saline,( \~40-60 ml) will be infused into the occluded forearm at a rate of \~ 30 ml/min. Five minutes of data will then be collected before releasing the upper arm cuff. Infusion 1 is to block the COX pathway, while infusion 2 is to induce venous distension.

DRUG

saline control

In the saline control trial performed on a separate day, saline (without ketorolac) in identical volumes as those in the COX blockade trial, will be infused.

Sponsors & Collaborators

  • Milton S. Hershey Medical Center

    lead OTHER

Study Design

Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Model
CROSSOVER

Eligibility

Min Age
21 Years
Max Age
35 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2019-08-14
Primary Completion
2026-05-01
Completion
2026-05-30
FDA Drug
Yes

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT03513770 on ClinicalTrials.gov