Related Experiment Video
Updated: Aug 14, 2026

A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects
Published on: May 4, 2021
The effects of hyperpnea on exhaled nitric oxide synthesis in normal subjects
Erin West1, Mary Skowronski, Albert Coreno Ms
1Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, MetroHealth Medical Center, Cleveland, OH 44109, USA.
Study Objectives:
To determine if the concentration of nitric oxide (NO) in the lungs increases with hyperpnea by contrasting calculated production (ie, the product of the fractional expired NO concentration [FeNO] and minute ventilation [Ve]) [Vno] with the amount of NO in equilibrium with the conducting airways (eNOair) and the amount of NO diffusing from the alveoli (eNOalv).
Design:
Observational study.
Setting:
University teaching hospital.
Participants:
Normal subjects.
Interventions:
Measurements were made in 16 healthy people during and after 4 min of tidal breathing (10 L/min) and isocapnic hyperventilation of 60 L/min.
Measurements And Results:
FeNO was measured by collecting the exhaled air during the last minute of each trial and passing it through a chemiluminescence analyzer. The expired NO levels in the plateau phases of slow (30 mL/s) and fast (200 mL/s) single-breath exhalations were also obtained before and after hyperventilation. The Vno (mean +/- SEM) increased from 89.8 +/- 12.3 to 329.1 +/- 36.2 nL/min as Ve rose (p < 0.001). However, neither the quantities of eNOair nor eNOalv changed with hyperventilation (eNOair range before to after, 34.9 +/- 7.7 to 30.9 +/- 6.4 parts per billion [ppb], p = 0.96; eNOalv range before to after, 7.3 +/- 1.5 to 6.5 +/- 1.1 ppb, p = 0.97).
Conclusions:
These data demonstrate that the amount of NO in equilibrium with the airway walls and alveoli are not altered by hyperpnea. Rather, the apparent augmentation in Vno in such circumstances appears to be an arithmetic artifact.
Related Concept Videos
Hyperpnea and Hyperventilation
Nitric Oxide Signaling Pathway
Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Factors Affecting Respiration
Other Factors Affecting Respiration Centers
However, the ability to hold one's breath voluntarily is not limitless. When the CO2 concentration in the blood reaches a critical level,...
