ACUTE appendicitis is inflammation of the appendix, a small pouch-like, blind-ending tubular structure located in the lower right side of the abdomen where the small intestine meets the large intestine – a worm-like extension of the caecum. It is a very common surgical abdominal emergency.

The lifetime risk is 8.6 per cent for males and 6.7 per cent for females. Even with investigations to assist with diagnostic accuracy, acute appendicitis still accounts for significant global morbidity and approximately 3 per cent mortality when it ruptures.

The appendix becomes inflamed after it is blocked, usually by faecalith — calcified faecal deposits — worms, inflamed lymph nodes or objects, and gets irritated then begins to swell, fill with bacteria and pus. This results in built-up pressure inside the lumen and walls of the appendix causing the area to become starved of oxygen, and eventually rupturing.

Symptoms

Early in the disease the patient typically experiences pain around the navel that settles in the right lower side of the abdomen or McBurney’s point. This pain gets progressively worse and may become associated with fever, lack of appetite, abdominal bloating, nausea, and vomiting. Some patients will present with atypical findings such as testicular pain, urinary or stool symptoms, pain over the bladder or pain in the right upper or middle part of the abdomen. These symptoms and signs will vary based on the location of the appendix.

The patient should not eat or drink once these symptoms and signs occur and must present to the Emergency Department where they will be assessed. Once the diagnosis is being considered based on history and examination, the patient is resuscitated through intravenous fluids and analgesia, basic blood investigations are done, and then referral is made to the surgical specialty.

If the diagnosis is doubtful or other conditions are being considered, other investigations such as an abdominal ultrasound may be warranted especially in children and women. However, the accuracy of diagnosing appendicitis has been improved in some centres by computed tomography scan of the abdomen — the test of choice in diagnoses of uncertainty.

Management

The management is usually immediate surgery which can either be open or done with laparoscopy — using scopes to make tiny incisions in the abdomen. The aim is to remove the appendix to prevent complications such as it rupturing, subsequent infection of the lining of the abdomen, overwhelming infection in the body, and death.

The overall recovery of patients with an unruptured appendix is good and so the aim is to seek early medical attention so the condition can be diagnosed and managed before rupture.