Prevention of Low Blood Pressure in Persons With Tetraplegia

Phase 2

Completed

• Conditions: Spinal Cord Injury; Hypotension
• Interventions: Drug: N-Nitro L-arginine-methylester (L-NAME); Procedure: Head-up Tilt maneuver

• Registration Number: NCT00237770
• Lead Sponsor: US Department of Veterans Affairs

Brief Summary

The aim of this investigation is to determine the blood pressure response to NOS inhibition, with L-NAME, in persons with tetraplegia compared to non-SCI control subjects and to establish if blood pressure can be increased while upright in those with tetraplegia. If blood pressure is increased with NOS inhibition in persons with tetraplegia, this would improve our treatment of the condition of low blood pressure during seated postures in individuals with tetraplegia.

Detailed Description

Despite disruption of central command of the vasculature during orthostatic maneuvers, individuals with tetraplegia are generally able to be seated in an upright position for long periods of time without developing symptoms of orthostatic intolerance. It must be appreciated however, that orthostatic hypotension may occur unpredictably in persons with chronic tetraplegia. This may result in a range of symptoms due to cerebral hypoperfusion from mild reduction in mental acuity to loss of consciousness. Nitric oxide (NO) is the most potent endogenous vasodilator which is synthesized by the enzyme NO synthase (NOS) and may be largely responsible for orthostatic hypotension in individuals with immobilizing conditions. Recent evidence suggests an up-regulation of inducible nitric oxide synthases (NOS) activity with prolonged exposure to hind limb suspension. The effects of NOS inhibition during orthostasis on blood pressure regulation in those with chronic tetraplegia may provide insight into effective pharmacological therapy to reduce or prevent pathologic orthostatic changes. Treatment with a NOS inhibitor may facilitate the process of mobilization in those with acute higher cord lesions.

Basic Information
|
Recruitment & Eligibility
|
Study & Design
|
Trial Locations

Study Timeline

• Study Start: 2003-06
• Study First Submitted: 2005-10-07
• Study First Submitted QC: 2005-10-11
• Study First Posted: 2005-10-12
• Primary Completion: 2010-06
• Study Completion: 2010-06
• Results First Submitted: 2013-09-24
• Status Verified: 2014-04
• Results First Submitted QC: 2014-04-23
• Last Update Submitted: 2014-04-23
• Results First Posted: 2014-05-19
• Last Update Posted: 2014-05-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 16

Inclusion Criteria

• 18 to 65 year olds.
• Non-ambulatory Chronic tetraplegia (1 year after acute SCI).

Read More

Exclusion Criteria

• central nervous system disease (other than SCI) e.g., multiple sclerosis, amyotrophic lateral sclerosis, syringomyelia, tabes dorsalis;
• peripheral neuropathies;
• surgical sympathectomy;
• coronary heart and/or artery disease;
• anemia;
• hypertension;
• renal function abnormalities;
• diabetes mellitus;
• pituitary insufficiency;
• adrenal insufficiency;
• hypothyroidism; and
• medications known to affect the cardiovascular system.

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Arm 1	N-Nitro L-arginine-methylester (L-NAME)	Placebo control (normal saline) is employed on a separate visit during procedure.
Arm 1	Head-up Tilt maneuver	Placebo control (normal saline) is employed on a separate visit during procedure.

Primary Outcome Measures

Name	Time	Method
Systolic Blood Pressure During Head-up Tilt	Average systolic blood pressure during head-up tilt (45 degrees) comparing active drug (L-NAME: 1.0 and 2.0 mg/kg) to placebo.	Average systolic blood pressure over 45 minutes at 45 degrees of head-up tilt.

Trial Locations

Locations (1)

VA Medical Center, Bronx; 🇺🇸 Bronx, New York, United States