Clinical Trial: Exhaled Levels of Nitric Oxide

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: The Effect of Nitric Oxide on Pulmonary Resistances and Blood Pressure in Persons With Tetraplegia

Brief Summary:

Previously it was observed that individuals with tetraplegia have reduced baseline airway caliber and exhibit non-specific airway hyperresponsiveness (AHR). In persons with tetraplegia we have suggested that this is due to overriding cholinergic airway tone. In asthma, the mechanisms underlying bronchoconstriction and AHR are more closely tied to airway inflammation. Whether AHR in tetraplegia is also related to chronic airway inflammation is unknown.

Recently, a non-invasive technique for assessing airway inflammation has been established in asthma that involves measurement of nitric oxide (NO) concentrations (FeNO) in expired air. FeNO is elevated in asthma likely due to excess NO production by inflammatory cells within the airway Measurement of FeNO in persons with tetraplegia would help in assessing the role of airway inflammation in this population. This may have therapeutic significance in such individuals. NO in the lung is felt to be the principal inhibitory neurotransmitter of the non-adrenergic, non-cholinergic (NANC) system. It is thought that inhalation of NO has no effect on airway tone in healthy individuals but reduces methacholine responsiveness while having weak direct bronchodilatory effect in asthmatics.

The primary purpose of this study is to determine the levels of exhaled NO (FeNO) in individuals with chronic cervical spinal cord injury (SCI), and to compare them with those obtained in age and sex matched able-bodied individuals and subjects with stable mild to moderate asthma. If the FeNO levels are high and comparable to those found in asthmatic subjects, this will imply the role of chronic inflammation in reduced baseline airway caliber and non-specific airway hyper-responsiveness (AHR) exhibited by individuals with chronic cervical SCI. If the FeNO levels are comparable with those found in able-bo

Detailed Summary: The study requires a maximum of five study visits in the following order: 1. nebulized normal saline, 2. nebulized 1mg/kg of L-NAME (see below), 3. intravenous normal saline, 4. intravenous 1 mg/kg L-NAME, 5. intravenous 2 mg/kg L-Name.
Sponsor: VA Office of Research and Development

Current Primary Outcome: Exhaled Levels of Nitric Oxide [ Time Frame: Exhaled NO was reported as the mean of three values within 10% of each other. ]

Nitric Oxide was measured applying a real time technique for measurement of Nitric Oxide in Exhaled Breath Condensate. Elevated Nitric Oxide in exhalate is a measure of elevated production of NO in conditions such as underlying inflammation and/or oxidative stress


Original Primary Outcome: Exhaled Levels of Nitric Oxide [ Time Frame: During study visits, measures are obtained prior to intervention (intravenous or nebulized) and 60, 120 minutes post intervention. ]

Current Secondary Outcome:

  • Lung Function as Measured by Plethysmography [ Time Frame: During study visits, measures are obtained prior to intervention (intravenous or nebulized) and 60, 120 minutes post intervention. ]
  • Methacholine Challenge [ Time Frame: During study visits, methacholine challenge will be performed 120 minutes post intervention. ]


Original Secondary Outcome: Same as current

Information By: VA Office of Research and Development

Dates:
Date Received: September 15, 2008
Date Started: December 2006
Date Completion:
Last Updated: July 2, 2014
Last Verified: May 2014