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Prevention of Low Blood Pressure in Persons With Tetraplegia

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Department of Veterans Affairs
ClinicalTrials.gov Identifier:
NCT00237770
First received: October 7, 2005
Last updated: June 19, 2012
Last verified: June 2012
History of Changes
  Purpose

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.


Condition Intervention Phase
Hypotension
Spinal Cord Injury
 Drug: N-Nitro L-arginine-methylester (L-NAME)
Procedure: Head-up Tilt maneuver
 Phase 2
Phase 3

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Prevention of Low Blood Pressure in Persons With Tetraplegia

Resource links provided by NLM:

Drug Information available for: Arginine
U.S. FDA Resources

Further study details as provided by Department of Veterans Affairs:

Primary Outcome Measures:
  • Blood pressure during orthostatic challenges [ Time Frame: Blood pressure will be monitored before, during and after tilt table testing (progressively timed movement from 15-45 degrees) on active drug (1 mg/kg body weight of L-NAME) compared to placebo. ] [ Designated as safety issue: No ]

Enrollment: 60
Study Start Date: June 2003
Study Completion Date: June 2010
Primary Completion Date: June 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Arm 1
Placebo control (normal saline) is employed on a separate visit during procedure.
 Drug: N-Nitro L-arginine-methylester (L-NAME)
A non-specific inhibitor of the nitric oxide synthase enzyme.
Procedure: Head-up Tilt maneuver
Participant will be placed onto tilt table and brought to 15 degrees of head up tilt for 60 minutes (intravenous infusion time). After this time, a progressive increase to 45 degrees will be completed with a 10 degree increase every 5 minutes. Participant will remain at 45 degrees for 45 minutes or until symptom onset.

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.

  Eligibility

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

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

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.
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00237770

Locations
United States, New York
VA Medical Center, Bronx
Bronx, New York, United States, 10468
Sponsors and Collaborators
Department of Veterans Affairs
Investigators
Principal Investigator: William Bauman, MD VA Medical Center, Bronx
  More Information

Publications:

Responsible Party: Department of Veterans Affairs
ClinicalTrials.gov Identifier: NCT00237770     History of Changes
Other Study ID Numbers: B3600-R
Study First Received: October 7, 2005
Last Updated: June 19, 2012
Health Authority: United States: Federal Government
United States: Food and Drug Administration

Keywords provided by Department of Veterans Affairs:
Blood Pressure
Cardiovascular Autonomic Control
Nitric Oxide
NOS Inhibitor
 Orthostatic Hypotension
Spinal Cord Injury
Tetraplegia

Additional relevant MeSH terms:
Hypotension
Quadriplegia
Spinal Cord Injuries
Vascular Diseases
Cardiovascular Diseases
Paralysis
Neurologic Manifestations
 Nervous System Diseases
Signs and Symptoms
Spinal Cord Diseases
Central Nervous System Diseases
Trauma, Nervous System
Wounds and Injuries

ClinicalTrials.gov processed this record on May 21, 2013