Oesophageal emergencies: caustic injuries

Question 1

What is the definition of caustic injury?

Answer 1

Ingestion of caustic substance causing injury to oesophagus

Caustic injuries can result from both accidental and intentional ingestion.

Question 2

What are the common aetiologies of caustic injury?

Answer 2

Accidental or intentional ingestions

Most children experience accidental ingestion, while adults tend to ingest intentionally.

Question 3

What is a common agent for alkali injury?

Answer 3

Ammonia or sodium hydroxide

These agents are often found in cleaners.

Question 4

What are common agents for acid oesophageal injury?

Answer 4

Toilet cleaners (hydrochloric acid), batteries (sulphuric acid), metal working (phosphoric and hydrofluoric acid)

These substances can cause significant damage to the oesophagus.

Question 5

What is the common pattern of injury caused by alkali agents?

Answer 5

Liquefactive necrosis, quickly causes perforation and extends towards mediastinum

Alkali injuries can be buffered by gastric acid, leading to more limited damage.

Question 6

What happens during the ingestion of acidic agents?

Answer 6

Cause pain on contact with oropharynx, ingestion tends to be limited

Acidic agents are less viscous than alkali agents, which allows them to pass rapidly to the stomach.

Question 7

True or False: Acidic agents cause more oesophageal injury than alkali agents.

Answer 7

False

Acidic agents tend to cause severe gastric injury rather than extensive oesophageal damage.

Question 8

Fill in the blank: A common agent for alkali injury is _______.

Answer 8

Ammonia or sodium hydroxide

Question 9

What type of necrosis is associated with alkali injury?

Answer 9

Liquefactive necrosis

This type of necrosis can lead to quick perforation.

Question 10

What is the effect of gastric acid on alkali injuries?

Answer 10

Can mean more limited injury

Neutralization by gastric acid may buffer the alkali effect.

Question 11

What is a significant consequence of acidic agent ingestion?

Answer 11

Severe gastric injury

Acidic agents cause more damage to the stomach than the oesophagus.

Question 12

What is liquifactive necrosis?

Answer 12

A process lasting 3-4 days resulting in extensive sloughing and ulceration.

Question 13

What happens to the oesophageal wall during liquifactive necrosis?

Answer 13

It becomes thinner due to sloughing and granulation tissue formation.

Question 14

How long does re-epithelisation take after liquifactive necrosis?

Answer 14

1-3 months.

Question 15

What does stricture formation depend on in liquifactive necrosis?

Answer 15

Depth of damage and degree of collagen deposition.

Question 16

What factors determine the severity of injury in liquifactive necrosis?

Answer 16

• Accidental vs intentional
• Concentration and volume of substance
• pH of substance
• Physical form (solid vs liquid)
• Duration of contact

Question 17

True or False: Solids tend to adhere more to mucosa than liquids.

Answer 17

True

Question 18

Fill in the blank: The process of liquifactive necrosis leads to extensive _______ and ulceration.

Answer 18

sloughing

Question 19

What characterizes a first degree oesophageal caustic injury?

Answer 19

Superficial mucosal damage causing oedema, erythema and possibly haemorrhage

First degree injuries primarily affect the mucosa.

Question 20

What are the effects of a second degree oesophageal caustic injury?

Answer 20

Transmucosal damage with ulceration, leading to granulation tissue and scar/stricture formation

Second degree injuries involve both the mucosa and submucosa.

Question 21

What defines a third degree oesophageal caustic injury?

Answer 21

Transmural damage with deep ulcers and perforation

Third degree injuries extend through all layers of the esophagus.

Question 22

What are the initial symptoms of caustic oesophageal injuries?

Answer 22

Symptoms include refusal to eat/drink, hypersalivation/drooling, stridor/hoarse voice, dyspnoea, pain, oropharyngeal pain, dysphagia/odynophagia, chest pain, nausea/vomiting, epigastric pain, and haematemesis.

Absence of oropharyngeal burns does not rule out more distal injury.

Question 23

What is the incidence of haematemesis in patients with caustic oesophageal injuries?

Answer 23

Haematemesis occurs in 3% of patients, usually 2-4 weeks post injury.

This is a potential complication of caustic injuries.

Question 24

What are the potential complications of caustic oesophageal injuries?

Answer 24

Complications include:
* Haematemesis
* Fistulisation
* Strictures
* Oesophageal SCC

Up to 30% of patients may develop oesophageal SCC.

Question 25

What factors influence the management of caustic oesophageal injury?

Answer 25

Management depends on: * Severity of burns * Associated upper airway and fascial burns * Patient's clinical state ## Footnote Management is divided into initial management and management of long-term complications.

Question 26

What is the gold standard for assessing injury severity in caustic oesophageal injuries?

Answer 26

OGD (oesophagogastroduodenoscopy) within the first 24 hours. ## Footnote Important for all symptomatic patients who do not require immediate surgery.

Question 27

What is the management protocol for minor caustic injuries?

Answer 27

Patients can be discharged or observed for 24 hours if they have: * Low volume, accidental ingestion of low concentration acid or alkali * No oral burns * Are otherwise asymptomatic. ## Footnote This approach minimizes unnecessary interventions.

Question 28

What should be done for patients with major caustic injuries?

Answer 28

Low grade injuries require supportive care and initiation of a liquid diet, progressing to a full diet in 24-48 hours. High grade injuries require surveillance for at least 1 week due to ongoing risk of perforation. ## Footnote A low threshold for repeat endoscopy is advised.

Question 29

What is the emergency surgical intervention for caustic oesophageal injuries?

Answer 29

Patients with signs of perforation may require oesophagogastrectomy with a combined cervical/abdominal approach and delayed reconstruction. ## Footnote Generally, primary repair is impossible in these cases.

Question 30

What is the timeline for endoscopic management of strictures following caustic injuries?

Answer 30

Endoscopic dilation should wait 3-6 weeks prior to attempting dilation. ## Footnote Rates of perforation are higher for dilations for corrosive strictures than for benign disease.

Question 31

What is the risk of malignancy associated with caustic injuries?

Answer 31

Approximately 16% risk of SCC transformation in caustic injuries, which is 1000 times higher than the general population. ## Footnote Surveillance OGD is recommended after 10-15 years of injury.

Question 32

What is the prognosis for patients with caustic oesophageal injuries?

Answer 32

Strictures occur in up to 50% of patients, with a higher risk for full thickness injury. High grade injuries have a mortality rate of 65% for full thickness injuries. ## Footnote Cancer risk is 16%, with surveillance every 2-3 years beginning 10-20 years post injury.