S8) Abdominal Catastrophes Flashcards
1
Q
What is an abdominal catastrophe?
A
An abdominal catastrophe is an event within or behind the abdominal cavity that poses an imminent threat to life
2
Q
What is referred pain?
A
Referred pain is pain perceived at a site distant from the site causing the pain
3
Q
What is somatic referred pain?
A
Somatic referred pain is pain caused by a noxious stimulus to the proximal part of a somatic nerve that is perceived in the distal dermatome of the nerve
4
Q
How does visceral referred pain occur?
A
Visceral referred pain occurs when visceral afferent pain fibres (thorax and abdomen) follow sympathetic fibres back to the same spinal cord segments that gave rise to the preganglionic sympathetic fibres
5
Q
What causes visceral pain?
A
- Abnormally strong muscle contraction and stretch
- Inflammation
- Ischaemia
6
Q
Identify the three common regions where visceral pain is felt
A
7
Q
Where is gastric and duodenal pain felt?
A
8
Q
Where is gallbladder pain felt?
A
9
Q
Where is splenic pain felt?
A
10
Q
Where is pain due to acute appendicitis felt?
A
11
Q
Where is pancreatic and abdominal aorta pain felt?
A
12
Q
Where is small bowel colic felt?
A
13
Q
Where is large bowel colic felt?
A
14
Q
Where is renal/ureteric colic felt?
A
15
Q
Where is pain due to peritonitis felt?
A
as it is the inflammation of the serosal membrane that lines the abdominal cavity
16
Q
In terms of pain, how do patients with peritonitis present?
A
- Severe pain all over abdomen
- Pain may be referred to shoulder tips
- Shallow rapid breathing (diaphragmatic and abdominal wall movement)
- Very tender abdomen (on examination)
- ‘Rebound tenderness’ (early stages)
17
Q
Explain why an inflamed peritoneal cavity can exude litres of fluid
A
- Large surface area
- Fluid can collect in abdomen
- Perfusion rate can increase
18
Q
In a bowel obstruction, dehydration and increased haematocrit occur due to increased fluid loss.
Why is this?
A
- Accumulation of fluids
- Increased secretion
- Decreased reabsorption
19
Q
In four steps, explain why several patients with bowel obstructions are in hypovolaemic shock at the time of presentation
A
⇒ 3-4 L of isotonic fluid sequesters in gut
⇒ Vomiting begins & fluid is lost
⇒ More space for fluid to sequester
⇒ Hypovolaemic shock (±7 litres lost)
20
Q
Identify 2 useful indicators of dehydration in the context of bowel obstruction
A
- Raised haematocrit (>55%)
- Raised serum urea
21
Q
Identify 5 types of abdominal catastrophes
A
- Blood loss
- Perforation of a viscus (inflammation, hypovolaemia, sepsis)
- Acute pancreatitis
- Acute cholangitis
- Acute gut ischaemia
22
Q
Where is blood lost to in an abdominal catastrophe?
A
- Into the gut
- Into the retroperitoneum
- Into the peritoneal cavity
23
Q
Identify three common causes of bleeding into the gut and briefly describe how they present
A
- Bleeding oesophageal varices (haematemesis and melaena)
- Bleeding peptic ulcer (haematemesis and melaena)
- Bleeding diverticular disease (haematochezia)
24
Q
What is haematemesis?
A
Haematemesis is the vomiting of blood
25
What is haematochezia?
**Haematochezia** is bright red bleeding from the rectum, often seen with/in stools
26
What do haematemesis and haematochezia indicate?
Patient is bleeding massively from the upper GI tract
27
What is melaena?
**Melaena** is the passage of black tarry stools
28
What causes melaena and when does it occur?
- Caused by alteration of blood by **digestive enzymes** and **intestinal bacteria**
- Occurs with **bleeding** anywhere from the **mouth to caecum**
29
Patients taking oral iron have black stools.
What is the difference between this and melaena?
The **smell** will reveal the difference
30
How do bleeding duodenal ulcers present?
**Bleeding duodenal ulcers** nearly always present as a posterior duodenal ulcer that has eroded into the gastroduodenal artery
31
Why is serum urea a helpful indicator of upper GIT bleeding?
- Patients bleeding from the stomach/oesophagus present a large protein meal to the small bowel where it is **converted by the liver into urea**
- A **rise in serum urea** with a normal serum creatinine indicates: the **source & magnitude** of the bleeding
32
What are the two commonest causes of retroperitoneal bleeding?
- Ruptured **abdominal aortic aneurysm** (AAA)
- Patients on **anticoagulants** may bleed from torn retroperitoneal veins
33
Describe the typical presentation of a ruptured AAA (abdominal aortic anyerusm)
- Sudden death (50%)
- Sudden onset of severe abdominal, back or loin pain
- Sudden collapse
- Hypovolaemic shock
34
Briefly outline the outcome of a ruptured AAA
- Overall survival is about 17% (hospital, operation, recover)
- Overall mortality is 83% (sudden death/multi-organ failure in ITU)
35
How does ectopic pregnancy present in women of reproductive age?
- Lower abdominal pain
- Vaginal bleeding
- Collapse
- Left shoulder tip pain on lying down
36
What are the two commonest causes of perforation of the viscus?
- Perforated peptic ulcer
- Perforated diverticular disease
37
What are the two types of perforated peptic ulcers?
- Anterior perforated duodenal ulcer (more common)
- Posterior perforated gastric ulcer
38
What are the effects of the posterior perforation of a gastric ulcer?
- Initially allows gastric contents to enter the lesser sac
- Then fluid can track into the greater sac via the epiploic foramen
39
State the respective complications of perforated peptic ulcerations and perforated diverticular disease respectively as well as their associated mortality rates
- Perforated peptic ulceration leads to a **chemical peritonitis** (mortality 10%)
- Perforated diverticular disease leads to **peritoneal sepsis and septicemia** (mortality rate 50%)
40
What is a major clinical indicator of perforated viscus?
Pneumoperitoneum
41
Which two abnormalities must be corrected before the administration of anaesthesia?
- Potassium imbalances (hyperkalaemia & hypokalaemia)
- Fluid and electrolyte imbalances
42
Why must potassium imbalances be corrected before the administration of anaesthesia?
Many anaesthetic agents affect cardiac muscle/conduction function
43
Why must electrolyte and fluid imbalances be corrected before the administration of anaesthesia?
- Anaesthetic agents dramatically **reduce sympathetic tone** & have a **negative inotropic effect**
- In a patient who is dehydrated the **SNS is maximally activated** to maintain vital organ perfusion & hence could develop **hypotension** and possible **die**
44
Identify 4 causes of obstruction to the small bowel
- Adhesions due to previous surgery
- Femoral/inguinal hernia
- Volvulus
- Carcinoma of the caecum
45
Identify 3 causes of obstruction to the large bowel
- Carcinoma (particularly left-sided)
- Sigmoid volvulus
- Diverticular disease
46
What is the end result of a bowel obstruction?
- Isotonic hypovolaemia
- Hypochloremia
- Hypokalemia
- Metabolic alkalosis
47
In 4 steps, describe how bowel obstructions lead to metabolic alkalosis and hypokalaemia
⇒ Vomiting leads to loss of H+ and Cl-
⇒ Metabolic alkalosis
⇒ Renal compensation preserves H+ at the expense of K+
⇒ Hypokalemia ensues
48
What is acute pancreatitis?
**Acute pancreatitis** is a clinical condition involving the autodigestion by proteases of the retroperitoneum
49
Describe the aetiology of acute pancreatitis
- Alcohol
- Gallstones
50
Describe the management of acute pancreatitis
- No specific treatment
- Supportive management (fluid resuscitation & pain relief)
51
What can be used to diagnose acute pancreatitis?
Raised serum amylase
52
What is the commonest cause of acute gut ischaemia?
Embolism (atrial fibrillation)
53
How do patients with acute gut ischaemia present?
- Severe abdominal pain
- Tender over ischaemic gut (on examination)
- Patients rapidly become ‘toxic’ and hypotensive
54
How can acute gut ischaemia be diagnosed?
Very high white cell count \>20 x109/l (normal – 4-11/l)
55
What is the treatment for acute gut ischaemia?
Urgent laparotomy and resection of dead bowel
56
What is acute cholangitis?
**Acute cholangitis** is a clinical condition involving an infection in the bile ducts
57
What is the commonest cause of acute cholangitis?
Obstruction of the common bile duct by the gallstone, leading to jaundice and biliary stasis
58
What is the commonest causative organism in acute cholangitis?
E.Coli
59
what is peritonitis?
* inflammation of the serosal membrane that lines peritoneal cavity
* normally this is a sterile area
* breakdown of this membrane causes foreign substances entering
* this can be infectious or sterile
60
what is primary peritonitis → spontaneous bacterial peritonitis
* mainly seen in patients with end stage liver disease → cirrhosis
* infection of ascitic fluid build up
* symptoms are abdominal pain, fever and vomiting
* symptoms are normally mild
61
how is a build up of fluid caused in primary peritonitis
* due to liver cirrhosis
* portal hypertension → increase in hydrostatic pressure in veins and gut, reduced liver function means reduced albumin and reduced oncotic pressure
* all this fluid collects in the peritoneal cavity
62
what is secondary peritonitis?
* result of an inflammatory process, perforation or gangrene of an intra-abdominal pressure for retroperitoneal structure
* perforated: peptic ulcer disease, appendicitis, diverticulitis
* Non bacterial: Tubual pregnancy (ectopic) that bleeds, ovarian cyst
* small bowel is usually acidic and hypertonic so if it bursts it will disrupt the cavity
63
what is intussusception?
→ one part of the gut folds inside the another part of the gut, it can extend quite far
* if lymph and venous drainage is immured you can get oedema that could damage arterial supply
* abdominal pain, vomiting and haematochezia (blood in stool)
* can be due to an enlarged lymph node
* treat: air pushed inside the rectum to push it back
64
small bowel obstruction?
* abdominal distension
* caused by adhesions (fibrous bands between organs)
* cause: surgeries, damage to mesothelium, hernias, IBS
* vomiting seen earlier than large bowel as its closer to the mouth
* can get bilious vomiting
* painful during periods of peristalsis
65
large bowel obstruction?
→ typically found in older generation
* Causes: colon cancer, diverticular disease, Volvulus (twisting) in sigmoid colon (older) or caecal (younger)
* symptoms: gradual if by cancer, abrupt with Volvulus:
* cramps, nausea, vomiting, distension in abdomen
* blockage will; cause an overflow of diarrhoea
66
volvulus
* part of colon twists around the mesentery
* most common in Sigmoid
* can result from an overloaded sigmoid
* CT:
67
small vs large bowel obstruction
68
colicky
* abdominal pain
* cramping
* onset with palpitation
69
acute mesenteric ischaemia
* blockage (embolism) of blood flow to the gut
* more common in females
* usually effects the SMA (its acute angle)
* prone areas: splenic flexure, rectosigmoid flexure
* venous compromise: doesn't drain viscera → increased pressure
70
symptoms in acute mesenteric ischaemia
* can be hard to diagnose (can be fairly non specific)
* nausea and vomiting
* pain can be left sided due to splenic fixture
* TREAT: surgery
71
peptic ulceration
* must go through submucosa
* 20-50% of upper GI bleeding
* gastric ulcers → least common but found in either antrum or lesser curve
72
oesophageal varices - major upper GI bleed
* porto-systemic anastomosis areas with venous drainage
* portal oesophageal veins drain into left gastric vein and portal vein
* systemic oesophageal veins drain into azygous vein and superior vena cava
* TREAT:
* banding → bands around the anastomosis
* TIPS → metal bridges portal vein to hepatic and reduces vatical pressure and reduces ascites
* Terlipressin → reduces portal venous pressure
73
what is an abdominal aortic aneurysm (AAA)
* permanent pathological dilation of the aorta (1.5x)
* due to degeneration of the media layer of the arterial wall (smooth muscle and elastin)
* RISK FACTORS:
* male, smoking, age
* most are infrarenal
74
what are symptoms of an AAA
* normally asymptomatic until burst
* can compress nearby structures (stomach, bladder and vertebra )
* Abdominal and back pain, pulsatile abdominal mass and transient hypotension
* sudden CVS drop
75
how to diagnose an AAA
* pulsate abdominal mass
* ultrasound: detect free peritoneal blood
* CT
76
treating an AAA
* stop smoking and reduce hypertension
* Surgery
* endovascular repair
* clamp the aorta and open aneurism remove thrombus and then use a graft
