Appendicitis Flashcards
Clinical anatomy
- The appendix is an outpouching of the ________
- Is it intraperitoneal? If so, what is its peritoneum called?
- Does it contain immune tissue?
- Can the position of the appendix be variable? What is its usual location?
Caecum
Intraperitoneal - the mesoappendix
Yes - contains lymphoid follicles
Yes - usually retrocecal
Aetiology
- What is the precipitating event for appendicitis?
The lumen of the appendix is obstructed.
May be obstructed by
- Stool: normal or hardened (faecolith)
- Lymphoid hyperplasia: max size during adolescence, can grow in response to viral infection
Pathophysiology
- Next steps in appendicitis? (Not complications)
Resident flora of the appendix (E. coli, bacteroides fragilis) get trapped and multiply
Causes an inflammatory response
- WBCs recruited (neutrophils –> pus)
- Fever
Appendix continues to secrete mucus as normal –> increased pressure within the obstructed appendix
- Visceral pain at the umbilical region, N&V, anorexia
Appendix lumen pressure > venous pressure
- Engorgement of vessels –> oedema
Pathophysiology
- Why is there migratory pain during appendicitis?
Initially, visceral pain (umbilical region)
Eventually, peritonitic involvement/pain (RIF/McBurney’s point)
Complications of appendicitis
- Eventually, appendix can become ischemic/infarcted
- Infarcted appendix can perforate –> gangrenous necrosis
- Inflammation can leak into peritoneal cavity –> peritonitis
- Abscess or phlegmon can form
Complications of appendicitis
- Similarities between phlegmon and abscess?
- Differences?
Similarities: both involve neutral infiltration/pus
Difference: abscess has a boundary, phlegmon does not
Risk factors for appendicitis?
- Age: 10-30
- Smoking (weak)
History
- Murphy’s triad?
RIF pain
N&V
Fever
History: all symptoms?
- Migratory abdominal pain
- N&V
- Fever
- Diarrhoea and constipation
- Anorexia
Exam
- Vital signs?
- Abdomen?
Vital signs: may indicate shock/sepsis
Abdomen
- Tenderness
- Guarding, rigidity, rebound tenderness
- Cross tenderness (Rosving’s sign)
Exam
- Leg signs?
- Psoas sign + obturator sign
- Occur as inflamed appendix comes into contact with these muscles
Investigation
- Bedside tests?
Urinalysis: rule out UTI
Investigation
- Lab investigations?
- FBC: leukocytosis with left shift (ie. High neutrophil count)
- UEC: potentially raised lactate due to infarction, N&V may cause deranged renal function in severe cases
- CRP: predicts severity of inflammation
Group and save: in case blood transfusion is needed
Investigations: imaging
- First line?
- Second line?
First line: abdominal ultrasound
Second line: contrast enhanced CT abdomen, abdominal MRI
Investigations: imaging
- Positive finding on abdominal ultrasound?
> 6mm
Investigations: imaging
- Why would a CT be used over ultrasound?
- Why would an MRI be used over ultrasound and CT?
CT: if ultrasound is inconclusive, suspecting complications
MRI: as above, PLUS if pregnant
Investigations: imaging
- What findings would be found in CT abdo or MRI?
Diameter >6mm
Calcified appendicolith
Periappendiceal inflammation (eg. fat stranding)
Alvarado score (MANTRELS)
- What does it stand for?
- Results?
Management
- Initial management?
If in shock: fluid resuscitation
Analgesics: paracetamol or opiod
Prophylactic antibiotics: ceftriaxone and metronidazole
Nil by mouth if surgery is indicated
Management: uncomplicated appendicitis
- Surgery indicated?
- Are post op IV antibiotics indicated?
- Alternative?
Management of complicated appendicitis?
- Surgery indicated?
- Are post op IV antibiotics indicated?
- Alternative?
Patient explanation
- What is the appendix?
- What is appendicitis?
- Importance of treating appendicitis ASAP?
Appendix is an outpouching of your bowel.
Appendix gets blocked, bacteria within it multiply, leading to the appendix becoming infected and inflammed.
Important for appendicitis to be treated ASAP. May burst, causing a serious infection called peritonitis.
