Gastroesophageal reflux disease Flashcards
Define gastroesophageal reflux disease
When the reflux of gastric juices increases in frequency and volume to cause troublesome symptoms and/or damage to the oesophageal mucosa
What is the normal anti-reflux mechanism in humans?
- Mechanically effective LES
- Efficient esophageal clearance
- Adequately functioning gastric reservoir
What is the LES?
Specialized muscular thickening (collar sling musculature and clasp fibers) at the gastro-esophageal junction that acts as a one way valve to allow food into the stomach after swallowing while preventing backflow of gastric contents into the esophagus
Which mechanisms modulate the LES?
Neural mechanisms
Hormonal mechanisms
How does the LES maintain its barrier function?
- Resting pressure
- Overall length
- Intra-abdominal length
When does physiologic reflex occur more commonly?
During awake hours
Upright position
Why does physiological reflux occur more commonly during awake hours and upright position?
- Transient loss of the gastro-esophageal barrier
- relaxation of LES
- intragastric pressure > LES pressure - Increased pressure gradient between abdomen and thorax in upright position
- Apposition of hydrostatic abdominal pressure to the abdominal sphincter portion in supine
How is a permanently defective sphincter defined?
Mean resting pressure <6mmHg
Total sphincter length <2cm
Intra-abdominal sphincter length <1cm
How does the LES open?
Receptive relaxation during swallowing and with stomach/fundus distension
Name causes of stomach distension
Excessive eating
Excessive air swallowing
Delayed gastric emptying
What does repeated distension of the stomach lead to?
Permanent attenuation of the LES collar sling and clasp muscle fibres -> loss of acute Angle of His + stretching of phreno-esophageal ligament -> hiatal hernia
What usually clears gastric refluxate?
Peristalsis
Name typical symptoms of GERD
Heartburn
Regurgitation
Dysphagia
Name atypical symptoms of GERD
Cough Hoarseness Chest pain Asthma Bronchospasm Aspiration
What is the most specific symptom of foregut pathology?
Dysphagia