ABSTRACT
The pressure in the lumen at the gastrooesophageal junction (at the LOS) is a measure of the strength of the antireflux barrier. This is normally between 10 and 30mmHg at the end of expiration. Opposing this is the pressure within the stomach, which is normally above 7mmHg. These pressures can be measured by either static or ambulatory oesophageal manometry. The difference between the LOS tone pressure and the intragastric pressure is known as the barrier pressure. Thus, factors that increase intragastric pressure (e.g. a large meal, pregnancy, pyloric stenosis) or decrease LOS will predispose to reflux. In
Anticholinesterases Neostigmine Edrophonium
Antimuscarinics Atropine Glycopyrrolate
Cholinergics Volatile anaesthetic agents
Suxamethonium Sodium nitroprusside
Pancuronium Thiopentone (thiopental)
Histamine ß-Adrenoceptor agonists
a-Adrenoceptor agonists Dopamine
Metoclopramide Opioids
Domperidone Peppermint oil
Antacids
Ergometrine
Cisapride
a person who is supine, gastric contents may reflux into the pharynx. If the larynx is open there is a danger of aspiration of gastric contents into the trachea.
