Inhaled lidocaine aerosol changes resting human breathing pattern

Area of Science:

• Respiratory Physiology
• Neuroscience

Background:

• Vagal airway receptors play a role in regulating breathing patterns.
• Understanding the precise function of these receptors is essential for respiratory control research.

Purpose of the Study:

• To investigate the effects of lidocaine aerosols on resting breathing patterns in normal humans.
• To determine the role of vagal airway receptors in breathing regulation.

Main Methods:

• Twelve healthy subjects inhaled normal saline or 4% lidocaine aerosols in a single-blind, randomized order.
• Breathing patterns, including ventilation (VI), breathing frequency (f), and tidal volume (VT), were measured.
• Pulmonary function tests (FEV1.0) and airway resistance were also assessed.

Main Results:

• Lidocaine aerosols significantly decreased breathing frequency (f) and ventilation (VI).
• Lidocaine aerosols increased tidal volume (VT) and inspiratory duration (Ti).
• Neither saline nor lidocaine aerosols affected FEV1.0, end-tidal PCO2, functional residual capacity, or airway resistance.

Conclusions:

• Lidocaine aerosols alter breathing patterns in resting humans, likely by affecting vagal airway receptors.
• These findings highlight the importance of vagal airway receptors in the regulation of normal breathing.
• The observed changes suggest a role for decreased stretch receptor activity, though further investigation is needed.