Toxic megacolon

Disease class: Megacolon

Definition

 

Causes

• Inflammatory bowel disease
• Ulcerative colitis
• Clostridium difficile colitis

 

Complications

• Colonic rupture 
• Bacteraemia
• Sepsis
• Septic shock

 

Investigations

• Abdominal radiograph (AXR)
• CT scan of abdomen and pelvis with bowel contrast (if possible)

 

Diagnostic tips

• Faecal loading can cause small areas of dilatation.
• It is normal for some segments of bowel to have a relatively large diameter. The "369 rule" refers to the approximate normal diameters of small bowel (up to 3cm), large bowel (up to 6cm), caecum + sigmoid colon (up to 9cm). 
• If the clinical history and physical examination support a diagnosis of toxic megacolon and the AXR may show abnormal dilation, it is worth discussing the AXR with a specialist colleague.
• If there is a strong suspicion of toxic megacolon, inform senior colleagues, request an arterial blood gas analysis, request an urgent abdominal radiograph (if not done already) and seek specialist advice immediately.

 

Treatment

Depends on severity and underlying cause

Conservative

• Watchful waiting

Medical

• Antibiotic therapy
• Clostridium difficile eradication therapy (e.g. oral vancomycin)

Surgical

• Pancolectomy

Megacolon

Disease class: Colonic diseases

Types

• Hirschsprung disease 
• megacolon, Toxic

A megacolon is a colon with a significantly increased diameter, usually throughout a large continuous segment of bowel.

 

Investigations

• Abdominal radiograph (AXR)
• CT scan of abdomen and pelvis with bowel contrast (if possible)

 

Diagnostic tips

• Faecal loading can cause small areas of dilatation.
• It is normal for some segments of bowel to have a relatively large diameter. The "369 rule" refers to the approximate normal diameters of small bowel (up to 3cm), large bowel (up to 6cm), caecum + sigmoid colon (up to 9cm).

Retinal detachment

Disease class: Retinal diseases

Stevens-Johnson syndrome

Disease class: Erythema multiforme

Skin avulsion injuries

Disease class: Soft tissue injuries

Also known as

Degloving injuries 

 

Types

• Ring avulsion

Salter-Harris fractures

Disease class: Fracture dislocation

Femoral neck fractures

Disease class: Bone fractures

Disease class: Hip fractures

Management

• Replacement arthroplasty

Appendicitis

Disease class: Caecal diseases
Disease class: Gastroenteritis
Disease class: Intraabdominal Infections

This is an inflammatory condition of the appendix, and is a common surgical emergency,
affecting mainly adolescents and young adults.

It is usually due to a combination of obstruction and infection of the appendix, and has a variable clinical course ranging from episodes of mild self-limiting abdominal pain to life-threatening illness.

Abdominal pain, beginning in the centre of the abdomen but which later shifts position to the right iliac fossa, is the classic symptom. The patient usually has accompanying fever and sometimes nausea, vomiting, loss of appetite, diarrhoea, or even constipation. The precise symptoms vary with the exact location of the appendix within the abdomen. In some individuals the appendix may ‘grumble’ with repeated mild attacks which resolve spontaneously.

In an acute attack, the inflammatory process begins first in the wall of the appendix but, if the disease progresses, the appendix can become secondarily infected and pus may form within it. The blood supply may become compromised and the wall become gangrenous.

Eventually the appendix may rupture, giving rise to a localised abscess in the abdomen or, more rarely, free pus within the abdomen, which causes generalised peritonitis. Rupture of the appendix is a serious complication and the patient may be severely unwell.

Surgeons recognise that in order to make sure patients with appendicitis do not progress to peritonitis, a certain percentage of normal appendixes are removed when clinical signs are suspicious but not diagnostic of disease.

Subdural haematoma

Disease class: intracranial haemorrhage, Traumatic 

Types

Cranial epidural haematoma

Disease class: intracranial haemorrhage, Traumatic

Also known as

• Epidural Hemorrhage, Cranial 
• Extradural Hematoma, Cranial

Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of epidural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery.

Features

• features of raised intracranial pressure
• some patients may exhibit a lucid interval

Aortic rupture

Disease class: Ruptured aneurysm

Oesophageal perforation

Disease class: Oesophageal diseases

Types

• Mallory-Weiss syndrome

Flail chest

Thoracic injuries

 

Lemierre's syndrome

Disease class: Pharyngeal diseases

Also known as

• Septic phlebitis of the internal jugular vein
• Postanginal sepsis secondary to oropharyngeal infection
• Postanginal shock including sepsis
• Lemierre's disease
• Human necrobacillosis

 

Pathogens

• Fusobacterium necrophorum

 

Osteonecrosis

Disease class: Bone diseases

Also known as 

• Avascular necrosis 
• AVN

 

Pathophysiology

• Disruption of the normal vascular supply to bones can cause ischaemia and necrosis.

 

Causes

• Trauma (particularly bone fracture)
• Cancer
• Lupus
• Sickle cell disease
• HIV infection
• Gaucher’s disease
• Decompression sickness
• Heavy metal poisoning (e.g. lead and cadmium)
• Adverse drug reactions (e.g. corticosteroids, bevacizumab)

Types

• Osteonecrosis of the Jaw (associated with bisphosphonate treatment)
• Avascular necrosis of the femoral head
• Avascular necrosis of the knee
• Avascular necrosis of the ankle
• Avascular necrosis of the humeral head
• Avascular necrosis of the shoulder
• Avascular necrosis of the scaphoid
• Preiser's Disease: Avascular necrosis of the scaphoid without fracture
• Avascular necrosis of the spine 

Management 

• Arthroplasty
• Arthrodesis
• Revascularisation procedures (emerging field)

Surgical emergencies

Surgery homepage

These are situations which require immediate management by a surgeon.

 

Always a surgical emergency

When these situations are significantly probable, urgent surgical review is indicated.
Immediate surgical intervention may prevent disability or death.

1. Acute angle-closure glaucoma
2. Acute pancreatitis
3. Anterior ischaemic optic neuropathy
4. Ruptured aortic aneurysm
5. Aortic dissection
6. Aortic transection
7. Appendicitis
8. Avascular necrosis
9. Cardiac tamponade
10. Cardiac trauma
11. Cauda equina syndrome
12. Central retinal artery occlusion
13. Clostridial myonecrosis
14. Compartment syndrome
15. Critical limb ischaemia 
16. Eclampsia
17. Ruptured ectopic pregnancy
18. Endophthalmitis
19. Fournier gangrene
20. Intestinal obstruction
21. Intracranial aneurysm
22. Ischaemic colitis
23. Ludwig’s angina
24. Major trauma
25. Mesenteric ischaemia
26. Microbial keratitis  
27. Necrotising fasciitis
28. Ocular burn 
29. Open-globe injury
30. Orbital cellulitis
31. Ovarian torsion
32. Paraphimosis
33. Penile fracture
34. Pericardial effusion
35. Peritonsillar abscess
36. Priapism
37. Pyogenic flexor tenosynovitis
38. Rhegmatogenous retinal detachment 
39. Skin avulsion injuries
40. Strangulated hernia
41. Subarachnoid haemorrhage 
42. Testicular torsion
43. Traumatic amputation
44. Ventricular septal rupture

 

Always an emergency, could be medical or surgical

These are emergencies which may be resolved by urgent surgical, medical or anaesthetic intervention. There may be resolution without any surgical involvement.

• Amoebic liver abscess
• Brain herniation
• Giant-cell arteritis 
• Infective endocarditis
• Necrotising enterocolitis 
• Septic arthritis

 

Potentially an emergency

These situations are variable: they range from mild to severe.
There are specific indications for urgent surgical involvement (e.g. magnitude of fluid loss, age of patient, signs of neurovascular dysfunction).

• Acute mastoiditis 
• Burns
• Epistaxis 
• Extravasation injury
• Flail chest 
• Haemorrhage
• Ruptured ovarian cyst 
• Polytrauma
• Supracondylar fracture of humerus
• Traumatic brain injury
• Acute urinary retention
• Urolithiasis

Traumatic brain injury

Disease class: Brain injuries

Also known as TBI.

 

Types

• Diffuse axonal injury

Infected aneurysm

Disease class: Aneurysm

Disease class: Infection

Commonly known as mycotic aneurysm.
This refers to an infection of an arterial wall.

 

Causes

• Infective endocarditis
• Post-operative (cardiothoracic) infections 

 

Pathophysiology

Infectious agents penetrate the innermost layer of an artery and grow, forming an aneurysm.

When this is secondary to IE, there are likely to be many aneurysms around the circulatory system. As many as 15% to 29% of patients with IE have neurologic symptoms. IE may be responsible 2.6% of aortic aneurysms.

 

Causative organisms

• Commonly bacteria
• Rarely fungal

Investigations

On imaging, the aneurysm may appear 'mushroom-shaped' (this is the only reason why it is known as 'mycotic' aneurysm).

Complications

• Haemorrhage
• Sepsis

 

Management 

• Antibiotic therapy
• Surgical resection
• Surgical removal of infectious source

Traumatic amputation

Disease class: Wounds and Injuries

This term refers to traumatic removal of an external body feature (often digits or limbs). This is a surgical emergency.

 

Complications

• Haemorrhage
• Hypovolaemic shock
• Fat embolism
• Necrosis of removed tissue
• Infection of remaining tissue
• Sepsis
• Post-traumatic stress disorder
• Disfigurement
• Permanent disability

Ludwig’s angina

Disease class: Infection

Disease class: Mouth diseases

This refers to a type of cellulitis affecting the floor of the mouth.
This is a surgical emergency.

 

Etymology

From the Greek word ankhone = choke
From the Latin word angere = strangle

Angina refers to a feeling of strangling and choking.
In severe Ludwig's angina there is signficiant airway obstruction.

 

Causes

• Dental infections (75% to 90%)