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Prevention of Low Blood Pressure in Persons With Tetraplegia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00237770
Recruitment Status : Completed
First Posted : October 12, 2005
Results First Posted : May 19, 2014
Last Update Posted : May 19, 2014
Information provided by (Responsible Party):
VA Office of Research and Development ( 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.

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

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 16 participants
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Prevention of Low Blood Pressure in Persons With Tetraplegia
Study Start Date : June 2003
Actual Primary Completion Date : June 2010
Actual Study Completion Date : June 2010

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
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.

Primary Outcome Measures :
  1. Systolic Blood Pressure During Head-up Tilt [ Time Frame: 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.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00237770

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

Publications of Results:
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: US Department of Veterans Affairs Identifier: NCT00237770     History of Changes
Other Study ID Numbers: B3600-R
First Posted: October 12, 2005    Key Record Dates
Results First Posted: May 19, 2014
Last Update Posted: May 19, 2014
Last Verified: April 2014
Keywords provided by VA Office of Research and Development ( US Department of Veterans Affairs ):
Blood Pressure
Cardiovascular Autonomic Control
Nitric Oxide
NOS Inhibitor
Orthostatic Hypotension
Spinal Cord Injury
Additional relevant MeSH terms:
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Spinal Cord Injuries
Spinal Cord Diseases
Central Nervous System Diseases
Nervous System Diseases
Trauma, Nervous System
Wounds and Injuries
Vascular Diseases
Cardiovascular Diseases
Neurologic Manifestations
Signs and Symptoms
Molecular Mechanisms of Pharmacological Action
Enzyme Inhibitors