GERD Flashcards
True or false: gastric acid is the only troublesome contents that are regurgitated in GERD.
FALSE: while gastric acidity is an important factor in GERD pathophysiology, the activated digestive enzymes and the detergent bile acids contained in the duodenal contents will also be harmful.
True or false: the esophagus is not the only organ affected by GERD.
TRUE: while the main organ affected is the esophagus, extensive reflux can damage the vocal cords and respiratory airways
What is NERD?
Non Erosive Reflux Disease: which is GERD in the absence of pathologic evidence like esophagitis or inflammation
True or false: GERD is the most common outpatient GI diagnosis in the US
TRUE!
What are two factors in the US that are implicated for the rising incidence of GERD?
the extensive treatment of H. pylori and the current epidemic of obesit
True or false: if you have a smaller gastric volume, it is more likely that you will have GERD.
FALSE: the higher the gastric volume, the larger the refluxate
True or false: if you have higher pressure in the abdomen, it is more likely reflux will occur.
TRUE
What are the key agents in the stomach contents that lead to GERD?
Acid
Pepsin (proteolytic)
(synergistic)
Why is GERD worse in Zollinger-Ellison syndrome?
acid secretion is continuously stimulated by hypergastrinemia
Why does getting rid of H. pylori lead to an increased incidence of GERD?
because chronic H. pylori infection may ultimately result in gastric atrophy and decreased acid secretion
Which is more active in acid, conjugated or deconjugated bile salts?
conjugated
What duodenal contents can cause damage in GERD?
Bile salts (dissolve fats)
Amylase (polysaccharides)
Trypsin (proteins)
Lipase (lipids)
Why is it hard to detect duodenal reflux?
there is not good marker for it
Which part of the diaphragm forms a pinchcock around the entrance of the esophagus into the stomach?
crural diaphragm
What does the crural diaphragm do?
increases the lower esophageal pressure, especially during instances when an increased pressure gradient between the stomach and esophagus favors gastroesophageal reflux
What are two instances when the pressure gradient between the stomach and esophagus favors gastroesophageal reflux?
1) contraction of the inspiratory muscles of respiration produces negative intraesophageal pressure
2) contraction of the abdominal wall increases abdominal pressure
What is the name of the angulation where the fundus meets the esophagus that forms a flap valve that anatomically prevents reflux into the esophagus?
angle of His
What is the normal pressure gradient across the GE junction?
5-10 mm Hg
What is the resting pressure of the LES?
10-30 mm Hg
What happens when you swallow and propagation of an esophageal peristaltic wave occurs?
the LES relaxes to allow esophageal content and food to enter the stomach
What is it called when the ability of the LES to relax for food passage occurs?
achalasia (leads to dysphagia)
What are the two instances in which LES alterations lead to GERD?
hypotensive LES (uncommon) transient LES relaxation
What are some causes of hypotensive LES?
- Severe esophagitis
- Pregnancy
- Scleorderma
- Post ablative surgery (Heller myotomy)
- Fat, chocolate, peppermint and various medications
What is the cause of most reflux episodes in healthy patients?
transient LES relaxation (tLESR) which is accompanied by inhibition of the crural diaphragm
How long is the duration of tLESR?
greater than 10 seconds (longer than swallow-induced relaxation)
What stimulates tLESR?
- gastric distention (major, think of belching)
- stress, fat, and pharyngeal stimulation (minor)
Which is accompanied by a continuous repetitive “off contraction” throughout the esophageal body: tLESR or swallow-induced LESR?
tLESR
swallow-induced LESR is assoicated with a primary peristalsis
What is the condition where a widened diaphragmatic hiatus and a relaxed phreno-esophageal ligament allows the proximal stomach to migrate into the thorax?
hiatal hernia
List the three ways a hiatal hernia can lead to GERD.
- Loss of the diaphragmatic and abdominal pressure at the location of the hernia
- Loss of the angle of His and the accompanying flap valve
- Increased tLESR frequency
How do “sliding” and “rolling” hiatal hernias differ?
the “rolling” type of hiatal hernia is where the herniation is para-esophageal
What aids esophageal clearance of gastric acid?
esophageal peristalsis
What is the difference between primary and secondary peristalsis?
Primary peristalsis, initiated by saliva/a swallow, will propagate and strip the entire esophagus, while secondary peristalsis will start at the point of esophageal irritation and will clear the esophagus from that point onwards.
What is responsible for the neutralization of any remaining small amount of esophageal acid left in the esophagus?
bicarbonate contained in saliva and in secretions from submucosal esophageal glands
What is an anatomical protective factor against gastric acid reflux in the esophagus?
many layers of keratinized cells in the squamous esophageal mucosa
Why is GERD worse during sleep, with smoking, or with anticholinergics?
these are times of xerostomia (inhibited salivation), so there is less saliva to protect from the gastric acid
How does esophageal dysmotility cause GERD?
preventing efficient clearance of the esophagus
True or false: GERD is worse in a prone position.
What is the implication for this?
FALSE: GERD is worse in a supine position– the basis for the recommendation that patient with GERD should not lie down for 2 hours after a meal and should sleep with the head of the bed elevated
Why is GERD worse in patients with delayed gastric emptying?
the fuller the stomach is, the more these contents will be prone to reflux
Why do physicians tell patients with GERD to lose weight and not to wear tight clothes?
increased abdominal and intragastric pressure (e.g with obesity) will also induce reflux
What are the cardinal symptoms of GERD?
heartburn
regurgitation
dysphagia
What are three potential causes of dysphagia in a GERD patient?
1) inflammation affecting esophageal motility
2) peptic strictures (obstructive scarring)
3) obstructive tumor
What is “waterbrash”?
salivary reflex reaction to acid reflux, causing sudden appearance of sour/ salty fluid in mouth
Why might a patient with GERD have cough and bronchospasm?
intermittent micro-aspiration into the airway
What is entailed in the two-week therapeutic trial for GERD diagnosis?
combining anti-reflux lifestyle modifications with acid suppression using high doses of a proton pump inhibitor
When can you make the diagnosis of gerd after the two-week therapeutic trial?
A symptomatic response and, in some instances, recurrence after cessation of treatment, will be sufficient to establish the diagnosis of GERD
True or false: barium contrast studies are sensitive and specific.
FALSE: specific but not sensitive (improve sensitivity with leg lifting, Valsalva, cauging and drinking water supine)
What is an added benefit of using barium studies?
they can detect factors that contribute to GERD (hiatal hernia, gastric obstruction)
Why is barium esophagram called a poor man’s manometry?
because it can detect dysmotility
True or false: Barrett’s Esophagus is difficult to detect with barium studies.
TRUE
When is an endoscopy warranted for a GERD patient?
should be performed for alarm symptoms suggestive of complications or alternate diagnoses of GERD
What are some “alarm” symptoms for GERD?
- dysphagia (difficulty with swallowing suggesting obstruction)
- odynophagia (pain upon swallowing usually suggesting severe esophagitis)
- weight loss (suggesting malignancy)
- bleeding (severe ulceration, need for therapy)
What are the 3 indications for pH monitoring for GERD?
1) Atypical symptoms
2) Rerfractory symptoms
3) Pre-op assessment (predict efficacy of surgery)
How does pH monitoring for GERD work currently?
wireless capsule can be stapled to the mucosa of the distal esophagus to transmit pH to an external receiver
What is the name for esophageal pH < 4.0 lasting more than 5 second?
acid reflux
What is it called when the percent of the time when the is pH is < 4.0 lasts over 5%?
pathologic reflux
What testing involves a transnasal catheter positioned with the tip at the LES to measure pressure and relaxation of the LES?
manometry
What are the GERD-related indications for manometry?
1) locate the LES (for pH monitor placement)
2) dysphagia without obstruction
3) Non-cardiac chest pain and normal pH (“nutcracker”)
4) Pre-op assessment
how do you assess if peristalsis is normal for a wet swallow?
Normally, more than 80% of these peristalsis should sweep through the whole esophagus and less than 60% is considered abnormal
What are tertiary contractions?
uncoordinated contractions that do not follow a peristaltic pattern and are not propulsive
What are the most common symptoms of non-acid reflux?
regurgitation and cough
What do you use to evaluate for non-acid reflux?
impedance (evaluates for refluxed contents that are not acid)
What does impedance detect?
ion rich fluid (conductivity of liquid contents refluxed into the esophagus)
Why does lying on the left side to sleep help GERD patients?
also allow gastric contents to pool in the fundus, lessening reflux
Why should patietns with GERD stop smoking, coffee, and alcohol?
these things increase acid secretion
Why should GERD patients avoid anticholinergics?
these decrease saliva (and prevvent primary peristalsis that clears the esophagus)
What type of meals should GERD patients eat?
small, frequent meals
What are the 3 major behavioral changes that have been shown to help with GERD?
- Elevation of head of bed at night
- Sleep on left side
- Weight loss
What are the two classes of antacids?
Mg based
Al based
Which type of antacid causes diarrhea? Which type causes constipation?
Mg- diarrhea
Al- constipation
Which type of antacids are contraindicated in patients with renal insufficiency?
Al based
What is the indication for antacids?
mild/infrequent GERD symptoms (NOT for healing esophagitis)
What is the antacid that contains alginic acid, which mixes with saliva to form a highly viscous solution that floats over of the gastric pool to acts as a mechanical barrier?
Gaviscon
What 3 agents stimulate the gastric parietal cells?
Ach
Gastrin
Histamine
Where does the Ach that stimulates gastric parietal cells come from?
secreted by vagal cholinergic nerves and acting through the muscarinic M2 receptor
Where does the gastrin that stimulates gastric parietal cells come from?
secreted by G cells and acting through the gastrin or CCK-2 receptor
Where does the histamine that stimulates gastric parietal cells come from?
secreted by enterochrmaffin cells and acting through specific H2 receptors
Which of the 3 agents that stimulate gastric parietal cells is a popular drug target?
histamine (via H2 receptor blockers)
What do H2 blockers end with?
“tidine”- ex. ranitidine
Why do H2 blockers have slow and limited use in treating GERD?
they only block one of the three pathways whereby the parietal cell is stimulated
What is the exchanger that mediates the secretion from the parietal cell of acid, in the form of proton, in exchange for a potassium ion?
H+/K+ ATPase
What drug class targets parietal cell H+/K+ ATPase
Proton Pump inhibitors
What do PPIs typically end with?
“prazole”- ex. omeprazole
True or false: the action of PPIs is irreversible.
TRUE: it is based on their covalent binding to the proton pump
When should you give PPIs?
these agents are best given half an hour before meals, to allow their concentrations to peak at the time of the meal, when the proton pumps are themselves most highly expressed
What is the name for agents that affect GI motility?
prokinetics
What is the name of the dopamine antagonist that increases the LES pressure and enhances gastric emptying and acid clearance?
metoclopramide
What drug is an inhibitor of vagal neurotransmission in the CNS, which can be used to decrease transient LES relaxation?
Baclofen
Which prokinetic drug is a cholinergic agonist that is not often used due to its severe side effects?
bethanecol
GERD surgery consists of what major processes?
1) tack stomach below diaphragm
2) different types of gastric fundoplication that wrap the stomach around the esophagus
What are the indications for surgical treatment for GERD?
1) medical failure
2) patient preference
3) volume reflux
4) peptic stricture
What are the most common complications of GERD surgery?
- dysphagia
- gas-bloat (can’t burp or vomit)
- vagus nerve injury that leads to impaired gastric emptying
What is a smooth circumferential ring of scarred tissue that will partially obstruct the flow of esophageal contents into the esophagus?
esophageal stricture
What is the “z-line”?
when the squamous epithelium, usually glossy pale white, meets the velvety salmon pink columnar epithelium
What structure usually coincides with the “z-line”?
the GE junction
What do you suspect if the Z line is proximal to the GE junction?
Barrett’s esophagus
What are the treatment options for high grade dysplasia or esophageal cancer?
Esophagectomy Endoscopic treatment (ablation, resection of mucosa)
What is the goal of endoscopic treatment of dysplasia?
eliminate high risk cell and replace them with squamous cells
GERD increases risk of what type of esophageal cancer?
Esophageal adenocarcinoma arising from segment of Barrett’s
