The Oesophagus and its Disorders II Flashcards
Types of oesophageal disorders
5 disorders
Achalasia: Disorders of motility or peristalsis of oesophagus (assess the motor function of the UOS, LOS and oesophageal body)
GORD: Reflux of stomach acids into oesophagus; regurgitation (weak LOS)
Aphagia: Swallowing difficulty; must determine the cause
Oesophageal spasm: Abnormal oesophageal contractions and food is not effectively reaching the stomach
Diffuse oesophageal spasm: Chest pain coming from oesophagus (~angina)
Achalasia – Pathophysiology
3 characteristics of achalasia?
what does this cause and lead to happening?
Hence what is the overall effect of having this? 3 things
Achalasia is characterised by:
• a loss of coordinated peristalsis
• spasms of the LOS
• a failure of the LOS to relax
This causes a hypertensive (high pressure) LOS. There is also a failure to develop the wave of peristaltic contractions at the distal oesophagus. Food and liquids hence tend to get stuck and fail to reach the stomach.
This leads to:
• long periods of sporadic dysphagia (difficulty swallowing)
• regurgitation of food and spasm disorders (chest pain not of cardiac cause, so could be misdiagnosed as angina)
• stacking of food within the oesophagus, this is a rare incidence but can present at any age
Aetiology (causes) of Achalasia
what are the 3 main causes?
what is tje initiating factor?
- Disorders of motility or peristalsis of oesophagus (assess the motor function of the UOS, LOS and oesophageal body)
- Damage to the innervation of oesophagus
- Degenerative lesions to the vagus nerve and loss of myenteric plexus ganglionic cells in the oesophagus
Initiating factor unknown, but thought to be autoimmune or triggered by infection
Symptoms of Achalasia
3 key symptoms?
what could causes heart burn? 4 reasons
- Dysphagia (Difficult or painful swallowing)
- Vomiting
• Heartburn due to:
o Retrosternal burning sensation due to oesophageal dysmotility
o Retention of ingested (acidic) food;
o Generation of lactic acid in the process of decomposition of retained food;
o Retention of small quantities of acid reflux in the oesophagus due to poor emptying and incomplete relaxation of LOS
Diagnosing Achalasia
WHat do you first do before any tests?
who are swallowing abnormalities common with?
what are the 2 ways to diagnose achalasia?
what can the popular method be used to find?
Patient’s description of the nature and history of symptoms; clinical examinations are first steps in the evaluation of any swallowing disorders
The patient’s self-report may suggest the type of disorder responsible for the complaints which may trigger tests required to determine, or verify, the specific cause of the complaint
Note that some abnormalities of swallowing may be frequent in the elderly
Achalasia can be diagnosed in 2 ways:
• Radiography, by doing a barium swallow, we would see dilation of the oesophagus with a “beak” deformity at the lower end
• Can use oesophageal manometry (quite popular)
o Can find disorders of motility or peristalsis of oesophagus (assess the motor function of the UOS, LOS and oesophageal body)
o Can assess cause of regurgitation, may be associated with achalasia (e.g. reflux of stomach acids into oesophagus) and could evaluate if you have weak LOS pressure (this is typically associated with GORD, as allows acidic chyme to go up) -> Having weak LOS pressure could cause this)
o Aphagia (can determine the cause of swallowing difficulty)
o Abnormal oesophageal contractions and food is not effectively reaching the stomach (oesophageal spasms)
o Diffuse oesophageal spasm, chest pain coming from oesophagus (angina)
Oesophageal manometry: why do it?
4 reasons
Oesophageal manometry is performed for the following reasons:
To determine the cause of non-cardiac chest pain
To evaluate the cause of reflux (regurgitation) of stomach acid and other contents back up into the oesophagus (GORD?)
To determine the cause of difficulty with swallowing food (does UOS/LOS contract and relax properly?)
Allows evaluation of strength of coordination of muscle contractions
Relaxation function of LOS
Overall, test evaluates if the oesophagus is contracting and relaxing properly
Oesophageal Manometry
what would we expect with normal person?
when will we expect GORD?
when will we expect achalasia?
Oesophageal manometry tests if the oesophagus is contracting and relaxing properly, it can be used to diagnose swallowing problems.
Also allows evaluation of strength of coordination of muscle contractions and also the relaxation functions of LOS.
This is important as assessing these can tell us if there is achalasia or GORD.
In a normal person we would find there to be a normal LOS pressure and normal muscle contractions upon swallowing.
Low LOS pressure suggests GORD, but GORD can also occur in individuals with normal LOS pressure because it is natural that LOS will open frequently when food goes through, so gastric chyme may flux up into oesophagus. The saliva we secrete should be able to clear this acidic material to be pushed into the gut.
A high LOS pressure suggests there is achalasia (greater than 100mmHg), if it is greater than 200mmHg called nutcracker achalasia.
Oesophageal Manometry: Procedure
The procedure of oesophageal manometry is as follows:
• Spray local anaesthetic/apply a numbing gel (no sedation)
- Lubricated pressure-sensitive tube (catheter) is inserted into nostril→ throat → oesophagus → stomach
- Take deep breath and swallow water
- Measurement of the strength and coordination of muscle contractions
- Strength and relaxation function of the LOS also evaluated
- Slowly remove the catheter at the end
- Data acquired may help determine where in the oesophagus to place the pH probe
Treatment of achalasia
Why must we treat it?
2 things we can do if low risk to surgery
what to do if at risk of surgery
Achalasia is a risk factor for squamous carcinoma of the oesophagus, so it is important we treat it.
We can do an endoscopic balloon dilation of the LOS or perform surgery to weaken the sphincter. Subsequently if reflux occurs, we may want to perform a fundoplication, this is where we get some fundal tissue and wrap it around the oesophagus.
We may wish to inhibit the release of acetylcholine, because the contractile effects of the LOS are mediated by Ach, this can be done by injecting botulinum toxin into the LOS.
Botulinum toxin injections are well tolerated, safe and efficacious (successful in producing the desired consequences). It blocks cholinergic nerve endings in the ANS.
Reflux in normal individuals
how does it occur? when does it occur? how long is it? how is it resolved?
Is the retro-grade movement of gastric content into oesophagus, due to relaxation of the LOS?
Reflux is often brief, relatively infrequent;
Often occurs after meals in normal individuals (- transient spontaneous LOS relaxation, tsr);
Reflux usually stimulates salivation
Saliva is an effective natural antacid - dilutes and neutralises refluxed gastric contents
Gastro-Oesophageal Reflux Disease (GORD)
How frequent is it?
2 reasons the reflux may not be resolved?
what does this lead to?
main symptom
GORD is when reflux is more frequent and troublesome.
A low rate of salivation and lack of ability to swallow own saliva leads to prolongation of contact of refluxed material with oesophagus, causing oesophageal irritation and oesophageal damage.
Causes a burning sensation in chest after meals – angina-like pain?
Causes of reflux in those with GORD
what is the main reason for GORD in normal individuals? how is this resolved?
2 reasosn why you may get reflux in GORD?
what is the pathway from tsr to los? what may lower the threshold for triggering TSR?
But, 98% of reflux events in normal individuals is associated with transient spontaneous relaxation (TSR) of LOS. This is sorted by saliva, so GORD doesn’t happen.
- It may be in GORD that the resting LOS pressure is too weak to resist the pressure within the stomach
- Or that sudden relaxation of the LOS is not induced by swallowing (i.e. at times the LOS relaxes in the absence of swallowing, causing acid to move up and reach the oesophagus)
TSR only accounts for about 60% of reflux events in patients with reflux
Recap = A malfunction of extrinsic and intrinsic components of LOS = GORD
Intrinsic component: thick circular muscle layers of oesophagus; clasp-like semicircular smooth muscles (↑myogenic activity, but less ACh responsive), sling-like oblique fibres (little resting tone, but ACh-responsive)
The pathway for TSR of LOS is a vagal reflex pathway triggered by gastric distention or pharyngeal stimulus and integration that occurs in the brainstem. The threshold for triggering TSR may be lowered by concurrent stimulation of the pharynx (and possibly larynx) and increased potentially by the supine posture (lying on the back with face up) , sleep, and anaesthesia.
Factors that contribute to the severity of GORD
time?
pressure?
stasis?
o Weak or uncoordinated oesophageal contractions (may be a result of oesophageal irritation from reflux disease itself -> prolonged duration of contact of refluxed digestive contents with oesophagus)
o Length of time oesophagus is bathed in refluxed acid (if swallowing of one’s saliva is not occurring properly/not enough saliva)
o Increased gastric acid secretion coupled with the presence of bile in gastric contents = Severe damage
o The amount of pressure placed on the anti-reflux barrier (if a lot of pressure placed on it, a lot of chyme will go into oesophagus)
Overall, reflux occurs after eating, lying down and when there is delayed gastric emptying.
This occurs especially when there is high fat food.
Gastro-oesophageal reflux disease (GORD)
A recap: Overall, GORD is caused by following
Factors associated with GORD:
A recap: Overall, GORD is caused by following:
Reflux of gastric contents through the LOS (acid or bile)
- Chronic oesophagitis (erosive or non-erosive)
- Prevalence: 30%
Factors associated with GORD:
- Pregnancy or obesity
- Fat, chocolate, coffee or alcohol ingestion
- Large meals, tomatoes, orange juice, onions, etc
- Cigarette
- Drugs (e.g. Anticholinergic agents, calcium channel blockers and nitrate drugs)
Complications of GORD
4 reasons
Oesophagus has squamous mucosa; acid reflux can cause desquamation of oesophageal cells (injury of squamous mucosa).
Increased cell loss can result in basal cell hyperplasia.
Excessive desquamation can result in ulceration, ulcers may haemorrhage, perforate or heal by fibrosis with strictures.
Barrett’s oesophagus may form also and oesophageal cancer
Pathophysiology of GORD
give the reasons for gord
symtoms too
o As stated before, the resting LOS tone is low or absent
o LOS tone fails to increase when lying flat or during pregnancy
o Importantly, poor oesophageal peristalsis leads to a decrease in clearance of acid
o A hiatus hernia impairs the functioning of LOS and the diaphragm closing mechanisms which can lead to acid reflux
o Delayed gastric emptying may also cause GORD
Symptoms include heart burn and acid regurgitation. They may also wake up at night, due to reflux irritating the larynx.
There is also commonly dysphagia.
Investigating GORD
4 things you can do
what will the 24 hour study show you?
- Low dose proton pump inhibitor (PPI) challenge is 1st line
- Upper GI endoscopy
- Manometry
- 24-hr ambulatory pH monitoring
Findings from continuous pH monitoring:
24 hr hour pH monitoring shows that most normal
individuals (non-refluxers) reflux on a daily basis
Therefore, GORD implies not just the presence of reflux, but reflux in excess of that experienced by non-refluxers
Pregnancy and GORD
what will the foetus do? why does it get worse with time and what can it lead to?
when does heartburn subside and why?
When pregnant, the foetus increases pressure on abdominal contents, this pushes terminal segments of oesophagus into the thoracic cavity.
The last part of pregnancy is associated with increased abdominal pressure and this forces gastric contents into the oesophagus.
HCl from the stomach irritates the oesophageal walls, leading to pain (heartburn).
• Heartburn subsides in the last months of pregnancy as the uterus descends into the pelvis.
Heartburn in the absence of pregnancy
when does it occur? 2 reasons
what can it lead to?
- Often occurs after large meals
- A less efficient LOS
Gastric contents get episodically refluxed into the oesophagus and thus you get heartburn.
This can lead to ulceration, scarring and then obstruction or perforation of the lower oesophagus.
Potential Long-Term Effects of GORD
4 long term effects
what two symptoms are needed when ordering a manometry?
There are various long-term effects of GORD, these include
- Oesophagitis and oesophageal strictures
- Squamous cell carcinoma
- Barrett’s syndrome -> this may predispose someone to oesophageal adenocarcinoma
- Ulcer
Because of these possible effects, it is important to diagnose symptoms of GORD
Manometry will be ordered if you have symptoms of:
• Heartburn or nausea after eating (GORD)
• Problems swallowing (feeling that food is stuck behind breastbone, this would be achalasia)
Management and drug of GORD
3 things you can do not drug related
what 3 drugs can you take?
- Life – style changes. For example, raising head of bed at end of night, so any chyme in oesophagus can drain into stomach
- Decreasing intake of food and drink which precipitate attacks
- Anti-reflux surgery (such as a fundoplication, where we wrap the fundus around the LOS)
From a drug perspective
o Take antacids
o Use H2 (histamine) receptor antagonists and proton pump inhibitors
o Metoclopramide may enhance peristalsis and help aid clearance (of acid, in GORD)
More lifestyle changes that can help alleviate the symptoms of GORD include:
o Avoiding large meals
o Losing weight (if overweight)
o Avoid foods that lower oesophageal sphincter pressure
o Avoid foods that slow gastric emptying
o Avoid foods that increase gastric acidity e.g. onions
o Avoid some drugs and smoking
o Decrease total fat intake
Use of antacids in the treatment of GORD
what do they do?
what is the issue with the 2 salts?
how to work around this?
what else will you give? why?
how do you stop ulcer returning?
Antacids neutralise gastric acid and increase pH of the gastric lumen. They inhibit peptic activity and stop acid secretion.
BUT
Magnesium salts -> diarrhoea
Aluminium salts -> constipation
Therefore, use a mixture of the two to ensure bowel function is kept relatively normal.
Combine alginates (e.g. Gaviscon) with antacids for oesophageal reflux.
Alginic acid and saliva form a raft which floats on the contents of the gastric lumen and protects the oesophageal mucosa from reflux.
All of the above agents decrease acid secretion and help heal any ulcers that may have occurred. But removal of H. Pylori is essential to stop the ulcer returning.
