Am. J. Respir. Crit. Care Med., Vol 153, No. 2, 02 1996, 747-751.
The effect of inhaled nitric oxide in pediatric asthma
KD Pfeffer, G Ellison, D Robertson and RW Day
Department of Pediatrics, University of Utah Medical Center, Salt Lake City 84132, USA.
Nitric oxide (NO) appears to play an important role in regulating several
biologic functions in the lung, including modulation of pulmonary arterial
and bronchial smooth muscle tone. Recent studies have shown that relatively
high concentrations of inhaled NO reduce the bronchoconstrictor effect of
methacholine in animal models. This raises the possibility that NO
inhalation might have therapeutic potential as an alternative
bronchodilator. Although investigation of this potential in adults with
airway reactivity or bronchial asthma has been reported, data are lacking
on the role of NO in the pediatric asthma population. We therefore
performed spirometry on 12 children with asthma (mean age 11.1 yrs) at
baseline (B), immediately after inhaling 40 ppm NO (NO-1), 10 min after
inhaling NO (NO-10), and after inhalation of a standard beta 2-agonist,
albuterol (A). Baseline pulmonary functions (% predicted +/- SEM) were FVC
of 103.2 +/- 5.6, FEV1 of 82.2 +/- 3.3, FEF- max of 97.0 +/- 3.6, and
FEF25-75% of 53.5 +/- 3.3. There were no statistically significant
differences between baseline and NO-1 or NO- 10 between any of the four
pulmonary function parameters measured. Inhaled albuterol, however,
resulted in significant improvement (% predicted +/- SEM) in FVC to 109.8
+/- 3.5, FEV1 to 99.7 +/- 2.9, FEFmax to 106.5 +/- 5.1, and FEF25-75% to
84.4 +/- 6.4 compared with the baseline and NO inhalation groups. We
conclude that NO inhaled at 40 ppm has no apparent bronchodilatory effect
in pediatric subjects with asthma and mild airways disease. The clinical
application of this gas as a therapeutic modality under these conditions is
questionable.
