GERD Flashcards
Postulated causes of increasing incidence of GERD
- H. Pylori Treatment
- Obesity
Four causative factors of GERD?
- Gastric Acid and Pepsin
- Duodenal contents
- High Gastric Volume
- High Abdominal Pressure
In what syndrome is GERD worse?
Zollinger Ellison Syndrome (hypergastrinemia)
Acid and Pepsin are synergistic in the pathophyiologi of gerd
ok…remember, pepsin = protein digestion
Duodenal reflux can be problematic in causing GERD. What are the Duodenal contents that we must worry most about?
Bile acids (act as a detergent to dissolve fats)
Amylase- dissolves polysaccharides
Trypsin (proteins)
lipase (lipids)
What are the three physiologic protective barriers against acid reflux
1) Diaphragm- forms a pinchcock around the the entrance of the esophagus into the stomach
2) Lower esophageal sphincter
3) Angulation created as the fundus of the stomach meets the esophagus. This is known as the angle of His. Forms a flap valve that prevents reflux.
Two components of the diaphragm?
Costal- ventilatory muscle
Crural- ventilatory muscle as well but also has a sphincter like action around the esophagus. The crural diaphragm increases lower esophageal pressure especially during instances when there is an increased pressure gradient between the stomach and the esophagus that favors reflux.
Healthy LES pressure
10-30mm Hg
Hypotensive LES that can lead to reflux occurs in two instances…they are
- Severe esophagitis (inflammation)
- Pregnancy ( related to hormonal change in estrogen and progesterone)
May also be related to systemic diseases such as scleroderma or surgical procedures such as Heller’s myotomy to fix achalasia
Fat, chocolate, peppermint
reduce LES
Transient LES relaxation accounts for
most epidsodes of GERD
transient LESr lasts about how long? Swallowing produces LESr that lasts how long?
30 seconds (longer than 10 at least) Just a few seconds (5)
Also note that tLESR leads to inhibition of the crural diaphragm which further decreases the functional pressure barrier to esophageal reflux.
Interesting, everytime you burp it is most likely a tLESR
Hiatal hernia occurs when?
When a widened diaphragmatic hiatus and relaxed phrenoesophageal ligament allows the proximal stomach to migrate into the thorax. In this condition, barrier functions are disrupted.
- The LES shortens
- Lose the angle of his
Some protective physiology when GERD is occuring:
- Peristalsis clears refluxate back into stomach
- Bicarbonate neutralizes acid
- squamous mucosa resistant to acid injury
Salivation is important
GERD is worse when
- Supine
- Delayed Gastric emptying
- Abdominal and Intrgastric pressure
GERD cardinal symptoms
- Heartburn: burning behind sternum readiating up to neck, worse after meals and when lying flat
- Regurgitation
- Dysphagia
Other symptoms
- Belchng and hiccups
- water brash: excess salivation due to high acid content
- Reflux laryngitis due to inflammation of vocal cords
- Cough and bronchospasm from aspiration
Clinical diagnosis procedure
- Symptom questionnaire: not very specific
- Two week therapeutic trial with anti-reflux lifestyle and high dose PPI
Regarding pH, acid reflux is defined as
pH less than 4 lasting more than 5 seconds.
Pathologic if this occurs more than 5% of teh time.
What is esophageal manometry
Measures esophageal motility in different sections of the esophagus over time.
Wht type of study allows you to evaluate for refluxed contents that are non-acidic?
Impedence
IMpedence studies are useful when evaluating duodenal content that has been refluxed because duodenal contents have been neutralized by pancreatic bi-carb and therefore are not acidic
ok
How to exploit gravity in treatment?
don’t lie down after a meal
elevate head
sleep on left side
What are the two classes of antacids?
Magnesium based agents (maalox or mylanta)
Aluminum based agents (amphogel)
Magnesium based antacids can cause what when overused?
diarrhea
Aluminum based antacids can cause what when overused?
constipation
H2 receptor blockers
block histamine receptors on parietal cells which release acid
PPIs block what pump
H/K ATPase. The acid is the H+.
This is the most effective antacid.
Best taken half an hour before meals.
Irreversible binders
Prokinetics
agents that effect GI motility. They ARE NOT effective as a single agent as mus tbe combined with acid suppression
Fundoplication
anti-reflux surgery which tacks down the stomach below the diaphragm, preventing the fomrmation of a hiatal hernia
- Strengthen the LES by wrapping the stomach around the esophagus
GERD complications
- Aspiration
- Vocal cord damage
- Inflammation and scarring- esophagiitis/ peptic strictures
- Intestinal metaplasia: Barrett Esophagus +/- dysplasia
- Cancer: adenocarcinoma
- Neoplastic transformation
Barrett Esophagus
Chronic GERD
- Damage to squamous epithelium
- heal through metaplastic process
- replaced by columnar epithelium
Significance of Barrett Esophagus?
Predisposition to esophageal adenocarcinoma
Z line
demarcation between end of squamous and beginning of columnar
