Response of the airways and autonomic nervous system to acid perfusion of the esophagus in patients with asthma: a laboratory studyReport as inadecuate




Response of the airways and autonomic nervous system to acid perfusion of the esophagus in patients with asthma: a laboratory study - Download this document for free, or read online. Document in PDF available to download.

BMC Pulmonary Medicine

, 13:33

First Online: 02 June 2013Received: 31 July 2012Accepted: 29 May 2013

Abstract

BackgroundGastro-esophageal reflux disease GERD predisposes to airway disease through a vagally-mediated esophago-bronchial reflex. This study investigates this vagal response to esophageal acid perfusion.

Methods40 asthmatics with mild stable asthma participated. Each subject underwent spirometry and autonomic function testing valsalva maneuver, heart rate response to deep breathing and to standing from supine position four times: a before intubation, b after intubation, and then immediately after perfusion with, in random order, c concentrated lime juice solution pH 2–3 and d 0.9% saline. Subjects were blinded to the solution perfused.

ResultsAsthmatics were of mean SD age 34.3 years 1.3, and 67.5% of them were females. pH monitoring demonstrated that 20 subjects had abnormal reflux and 20 did not. In each group 10 subjects had a positive GERD symptom score. Following perfusion with acid compared to saline, all subjects showed significant decreases in FEV1 and PEFR and significant increases in the mean valsalva ratio and heart rate difference on deep breathing from baseline values, but no changes in FVC or heart rate ratio on standing. There were no significant differences in any of the parameters between subjects with and without reflux.

ConclusionsAcid stimulation of the distal esophagus results in increased parasympathetic activity and concomitant broncho-constriction in asthmatics irrespective of their reflux state. This strengthens the hypothesis that GER triggers asthma-like symptoms through a vagally mediated esophago-bronchial reflex and encourages a possible role for anti-cholinergic drugs in the treatment of reflux-associated asthma.

KeywordsAsthma Gastro-esophageal reflux disease Vagal activity Spirometry Autonomic function testing AbbreviationsGERDGastro-esophageal reflux disease

FEV1Forced expired volume in the first second

GERGastro-esophageal reflux

PEFRPeak expiratory flow rate

HClHydrochloric acid

FVCForced vital capacity

LESLower esophageal sphincter

ECGElectrocardiography

SEStandard error

HR RatioHeart rate ratio of 30th beat- 15th beat on standing from supine position

HR DiffHeart rate difference between inspiration and expiration during deep breathing at 6 cycles per minute

VRratio of maximum heart rate during the valsalva maneuver to the maximum heart rate around the 20th beat after stopping the maneuver

Download fulltext PDF



Author: D Lakmali Amarasiri - Arunasalam Pathmeswaran - H Janaka de Silva - Channa D Ranasinha

Source: https://link.springer.com/







Related documents