Acute Appendicitis Flashcards
What is acute appendicitis?
Appendicitis refers to inflammation of the appendix and is a common acute surgical presentation.
Briefly recap the 9 regions of the abdomen
How common is acute appendicitis?
It most commonly affects those in their second or third decade and there is an overall lifetime risk of 7-8%. It is one of the most common causes of abdominal pain in young people and children, with around 50,000 appendicectomies performed in both children and adults a year in the UK.
Briefly describe the pathophysiology of acute appendicitis
It is typically caused by direct luminal obstruction, usually secondary to a faecolith or lymphoid hyperplasia, impacted stool or, rarely, an appendiceal or caecal tumour.
When obstructed, commensal bacteria in the appendix can multiply, resulting in acute inflammation. Reduced venous drainage and localised inflammation can result in increased pressure within the appendix, in turn can result in ischaemia.
If left untreated, ischaemia within the appendiceal wall can result in necrosis, which in turn can cause the appendix to perforate.
What are the risk factors for acute appendicitis?
- Family history
- Twin studies suggest that genetics account for 30% of risk
- Ethnicity
- More common in Caucasians, yet ethnic minorities are at greater risk of perforation if they do get appendicitis
- Environmental
- Seasonal presentation during the summer
What are the clinical features of acute appendicitis?
Note: symptoms
The main symptom of appendicitis is abdominal pain. This is initially peri-umbilical, classically dull and poorly localised, but later migrates to the right iliac fossa, where it is well-localised and sharp.
Other symptoms can include vomiting (typically after the pain, not preceding it), anorexia, nausea, diarrhoea, or constipation.
What are the clinical features of acute appendicitis?
Note: on examination
On examination, there may be rebound tenderness and percussion pain over McBurney’s point, as well as guarding (especially if the appendix is perforated).
In severe cases, patients can show features of sepsis, being tachycardic and hypotensive, especially in untreated cases. An appendiceal abscess may also present with a RIF mass.
What are the specific signs on examination for acute appendicitis?
Specific signs that may be found on examination include:
- Rovsing’s sign: RIF fossa pain on palpation of the LIF
- Psoas sign: RIF pain with extension of the right hip
Specifically suggests an inflamed appendix abutting psoas major muscle in a retrocaecal position.
Why does the abdominal pain in acute appendicitis migrate from peri-umbilical to right iliac fossa?
Peri-umbilical: dull and poorly localised from visceral peritoneum inflammation.
Right iliac fossa:well-localised and sharp from parietal peritoneum inflammation.
Where is McBurney’s Point?
1: McBurney’s Point
Two thirds of the way between the umbilicus (2) and the anterior superior iliac spine (3).
How may acute appendicitis present in children?
Whilst some cases can present classically, a high proportion of acute appendicitis in children will present in an atypical manner. Such presentations may include diarrhoea, urinary symptoms, or even left sided pain.
When examining a child with suspected appendicitis, as well as examining the gastrointestinal system, it is therefore also essential to examine the cardiorespiratory and urinary systems.
What investigations should be ordered for acute appendicitis?
Note: laboratory
Urinalysis should be done for all patients with suspected appendicitis to help exclude any renal or urological cause. For any woman of reproductive age, a pregnancy test is also essential.
Routine bloods, importantly FBC and CRP, should be requested to assess for raised inflammatory markers, as well as baseline blood tests required for potential pre-operative assessment. A serum β-hCG may also be taken, if ectopic pregnancy still has not been excluded.
What investigations should be ordered for acute appendicitis?
Note: imaging
Imaging is not essential to diagnose an appendicitis, as cases can be a clinical diagnosis. Indeed, in certain cases (especially paediatrics), serial examinations may be the only method employed to make the diagnosis.
Ultrasound scan or CT imaging are often requested if the clinical features are inconclusive and an alternative diagnoses are equivocal.
Give examples of tools used to stratify risk of acute appendicitis
Men: Appendicitis Inflammatory Response Score
Women: Adult Appendicitis Score
Children: Shera score
What is the definitive treatment for acute appendicitits?
The current definitive treatment for appendicitis is laparoscopic appendicectomy.
