Respiratory expulsive efforts evoked by maximal lung emptying

Area of Science:

• Pulmonology
• Gastroenterology
• Respiratory Physiology

Background:

• Some patients exhibit unusual cough-like expiratory efforts during pulmonary function tests.
• The origins and motor characteristics of these

Purpose of the Study:

• To investigate the cause and motor features of deflation cough.
• To assess the role of gastroesophageal reflux in deflation cough.
• To evaluate the efficacy of antacid treatment for deflation cough.

Main Methods:

• Studied 43 patients with deflation cough during slow vital capacity (SVC) or forced vital capacity (FVC) maneuvers.
• Recorded cough motor patterns, intensity, frequency, and integrated surface abdominal electromyographic activity (IEMG).
• Administered antacid, salbutamol, or placebo and analyzed changes in cough variables.

Main Results:

• All patients with deflation cough had symptoms of gastroesophageal reflux.
• Deflation cough correlated with peak expiratory flow rates.
• Antacid abolished or reduced deflation cough in 15 of 18 patients; placebo was less effective.

Conclusions:

• Gastroesophageal reflux, potentially triggered by lung emptying efforts, is the likely cause of deflation cough.
• Acidic reflux may be the primary causative factor.
• Lung collapse receptors might also contribute when antacids are ineffective.