10/7- Drugs in Acid Peptic Disease and GERD Flashcards
T/F: Some degree of gastro esophageal reflux occurs normally in most individuals.
True
What is the basic underlying mechanism of GERD?
Some causes?
Factors potentially harmful to the esophagus overwhelm protective mechanisms
- Decreased salivation
- Impaired esophageal acid clearance
- Impaired tissue resistance
- Transient LES relaxation
- Decreased resting tone of LES
- Delayed gastric emptying
What are the symptoms of GERD? What is causing them?
Heartburn (and others) from mucosal damage
What are TLESRs? How long do they last?
Brief episodes of LES relaxation unrelated to swallowing or peristalsis
- Last ~10-35s
What is the most common cause of symptomatic GERD?
Excessive acid reflux due to TLESRs
Decreased ____ is more common among pts with GERD, especially those with ______ or ______
Decreased LES tone is more common among pts with GERD, especially those with esophageal strictures or Barrett’s esophagus
What are some substances that increase/decrease LESP: hormones?
Increase:
- Gastrin
- Motilin
- Substance P
Decrease:
- Secretin
- Cholecystokinin
- Glucagon
- Gastric inhibitory peptide (GIP)
- Vasoactive intestinal polypeptide
- Progesterone
What are some substances that increase/decrease LESP: Neural agents?
Increase:
- a-adrenergic agonists
- B-adrenergic antagonists
- Cholinergic agonists
Decrease:
- a-adrenergic antagonists
- B-adrenergic agonists
- Cholinergic antagonists
- Serotonin
What are some substances that increase/decrease LESP: medications?
Increase:
- Metoclopramide
- Domperidone
- Prostaglandin F2a
- CIsapride
Decrease:
- Nitrates
- CCBs
- Theophylline
- Morphine
- Meperidone
- Diazepam
- Barbiturates
What are some substances that increase/decrease LESP: foods?
Increase:
- Protein
Decrease:
- Fat
- Chocolate
- Ethanol
- Peppermint
What do you expect to hear in the history of someone with GERD (symptoms)?
Esophageal
- Heartburn
- Regurgitation
- Chest pain
Extra-esophageal
- Cough
- Laryngitis
- Asthma
- Dental erosions
What nerve is responsible for innervating sensation of the stomach? Other connections?
Vagal afferents provide the brain with feedback from the stomach (neural reflex mechanism)
- Vagal efferents drive the lungs
- GERD can cause direct mucosal injury of the lungs
Pros/Cons of Therapeutic trial?
When should an endoscopy be performed?
What can be diagnosed with it?
- Essential if there are alarm symptoms
- Will diagnose erosive esophagitis
- 2/3 of pts have normal endoscopy
- Enables ID of Barrett’s esophagus
What are some components of reflux monitoring?
Ambulatory pH
- Measure acid reflux
Ambulatory MII + pH
- Measure both acid and non-acid reflux
How does reflux testing via pH monitoring work?
Answers 2 questions:
- Is there an abnormal amount (pathological) of reflux?
- Is there an association between reflux episodes andsymptoms
Sensor lies 5 cm above LES
What is MII? How is it monitored?
Multichannel Intraluminal Impedance
- Multiple sensors along the catheter; internal reference with 1-2 pH channels and 7-8 rings
- Sense fluid (drop in impedance) pH sensed simultaneously
- pH under 4 is considered acidic and distinguishes between acid and non-acid reflux
What is impedance?
Electrical resistance measured with an alternating current
- Inverse of conductance
- Measured in Ohms Low impedance means many ions are moving (high impedance means only a few are moving)
Analyze this impedance graph- what is happening at each stage?
What conditions are seen here?
Left: swallow
Right: reflux
How does ambulatory pH testing work?
Tubeless method: Bravo system
- Radio telemetry capsule to be attached to the esophageal mucosa
- Minimizes discomfort of transnasal catheters
Benefit of joint impedance-pH monitoring?
Detects reflux regardless of acidity (can measure acid and non-acid reflux)
May increase sensitivity of study, especially when gastric acid secretion is suppressed
- Treatment with proton pump inhibitors
- Atrophic gastritis
What are the benefits of doing Barium swallow for diagnosis?
Sensitivity for esophagitis: 80% if severe, 25% if mild
Reflux of barium during exam:
- Positive in 25-75% of symptomatic patients
- Positive in 20% of normal controls
NOT useful for GERD diagnosis
- Only potential role = pre-op eval (hiatus hernia, foreshortening)
What are some pharmacological strategies for acid peptic disorders?
- Neutralize gastric acid
- Protect the mucosa from acid-peptic damage
- Control gastric acid secretion