Ep 129 – Acute appendicitis

Acute appendicitis is a medical emergency characterised by the sudden onset of inflammation in the appendix. As one of the leading causes of abdominal pain that necessitates surgical intervention, appendicitis can occur at any age, though it is most common in adolescents and young adults. The condition is primarily caused by a blockage in the appendix, which leads to bacterial infection, swelling and increased pressure. If left untreated, acute appendicitis can progress to life-threatening complications such as perforation, peritonitis and sepsis. Due to the non-specific symptoms, particularly in the early stages, diagnosing appendicitis can be challenging. Prompt recognition and treatment, typically through surgical removal of the appendix, are critical to preventing complications and ensuring a swift recovery. In this episode, Dr Roger Henderson looks at the clinical presentation, diagnosis and management of acute appendicitis, highlighting its significance as a common yet potentially dangerous medical condition.

Key references

1. Di Saverio S, et al. World J Emerg Surg. 2020; 15(27). doi:10.1186/s13017-020-00306-3.
2. Gorter RR, et al. Surg Endosc. 2016;30(11):4668-4690. doi: 10.1007/s00464-016-5245-7.
3. Royal College of Surgeons of England. 2014. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide/.
4. Moris D, et al. JAMA. 2021;326(22):2299-2311. doi: 10.1001/jama.2021.20502.
5. Fugazzola P, et al. World J Emerg Surg. 2020;15(19). doi: 10.1186/s13017-020-00298-0.
6. Bhangu A et al. Br J Surg. 2020;107(1):73-86. doi: 10.1002/bjs.11440.
7. Malik AK, et al. BMJ. 2023:382:e074652. doi: 10.1136/bmj-2022-074652.

Key take-home points

• Acute appendicitis is one of the most common causes of an acute abdomen in the Western world.
• In 90% of cases, it develops as a result of obstruction of the appendix.
• Approximately 10% of the population will develop acute appendicitis.
• Acute appendicitis can occur at any age but is most common between the ages of 10 and 20 years; it is more common in males.
• The classical clinical feature is abdominal pain that is often initially vague and central, developing into more severe pain in the right iliac fossa. Movement and coughing makes the pain worse.
• Associated symptoms include nausea and vomiting, occasionally diarrhoea and loss of appetite.
• There may be an associated low-grade pyrexia and raised pulse rate.
• Localised tenderness, guarding and rebound tenderness develop in the right iliac fossa. Rovsing’s sign may be positive.
• The Appendicitis Inflammatory Response (AIR) score may be helpful in determining the need for further investigations and treatment.
• Clinical assessment alone may be unreliable.
• Investigations may include urinalysis, pregnancy testing to rule out an ectopic pregnancy, full blood count and inflammatory markers.
• Imaging (ultrasound or computed tomography scanning) can be useful when there is diagnostic doubt.
• All suspected cases should be admitted to hospital.
• Appendicectomy is viewed as the "gold standard" treatment, often done laparoscopically.
• It is possible for early uncomplicated appendicitis to resolve spontaneously.
• Antibiotic treatment can be effective in patients with uncomplicated appendicitis, but up to 30% of patients treated with antibiotics will still require surgery and there is a substantial risk of recurrence.
• Delaying surgery increases the risk of more extensive investigations being required.
• A normal appendix is removed in approximately 20% of appendicectomies in patients aged 16–45 years in the UK.