1996 OPEN FORUM Abstracts
Nitric Oxide is Only a Research Tool
Dean R. Hess, PhD, RRT Wednesday, November 6, 1996
Inhaled nitric oxide is one of the most exciting new therapies for the treatment of patients with ARDS, PPHN, and other diseases characterized by hypoxemia and pulmonary hypertension. However, applications of nitric oxide are in their infancy and should only be used in approved research protocols. Until multicentered prospective clinical trials are completed, the appropriate role of nitric oxide in the care of patients is unknown.
Use of inhaled nitric oxide is not approved by the FDA. Therefore, it can only be used if the FDA approves an IND application. Provided the FDA grants approval, the use of nitric oxide is supervised by the Institutional Review Board of the hospital and can only be used as part of approved protocols.
The correct dose of inhaled nitric oxide is unknown. This is important because doses too low may be ineffective and doses too high may be toxic. Nitric oxide should only be used as part of an approved protocol until the correct dose is known.
Commercially available nitric oxide delivery systems are not available in the United States. Therefore, many homemade systems to delivery nitric oxide have been described. Some of these do not deliver a constant and precise nitric oxide concentration. The result can be inaccurate dosing and the potential for toxicity. If assembled incorrectly, nitric oxide delivery systems can result in the delivery of toxic doses of nitrogen dioxide. Nitric oxide should not be administered unless the inspired dose is monitored and nitric oxide and analyzers are not commonly available.
Inhaled nitric oxide is not benign. Potential complications and toxicity include nitrogen dioxide production, methemoglobinemia, decreased platelet function, increased left heart filling pressure, intracellular production of peroxynitrite, and rebound hypoxemia and pulmonary hypertension when nitric oxide is discontinued.
At this point in our knowledge of the use of inhaled nitric oxide, its use should be restricted to approved research protocols.