Acute Appendicitis Overview

Study Notes

Acute Appendicitis Overview

Acute appendicitis is the leading cause of acute abdomen in young adults and is the most common urgent abdominal surgery performed.

Anatomy of the Appendix

The appendix is a blind muscular tube with four layers: mucosal, submucosal, muscular, and serosal.
It is the undeveloped distal end of the large caecum, initially short and broad at birth.
Growth of the caecum during childhood commonly rotates the appendix into a retrocaecal position; in about 25% of cases, it remains in a pelvic, subcaecal, or paracaecal position.
The base of the appendix consistently located at the junction of the three taeniae coli of the caecum, helpful during surgery.
Average length of the appendix ranges from 7.5 to 10 cm.

Etiology of Appendicitis

Luminal obstruction of the appendix is a primary cause; faecoliths or strictures are frequently involved.
Obstruction leads to increased mucus secretion and inflammatory response, raising intraluminal pressure and obstructing lymphatic drainage.
Resulting edema and mucosal ulceration facilitate bacterial movement to the submucosa.

Clinical Features

Initial symptoms include vague, colicky abdominal pain, often starting in the periumbilical region, resembling small bowel obstruction pain.
Accompanied by anorexia, nausea, and typically one or two vomiting episodes following pain onset.
Anorexia is a consistent clinical indicator.
As inflammation progresses, pain localizes to the right iliac fossa, leading to more intense somatic pain.
Signs include low-grade fever, localized tenderness, muscle guarding, rebound tenderness, and specific signs such as:
- Rovsing's Sign: Pain in the right iliac fossa triggered by palpation of the left iliac fossa.
- Psoas Sign: Pain relief in the right hip when flexed indicates an inflamed appendix adjacent to the psoas muscle.
- Obturator Sign: Pain in the hypogastrium upon internal rotation and flexion of the hip suggests contact with the obturator internus.

Investigations

Diagnosis primarily clinical, with concern for false positives leading to unnecessary appendectomy (15-30% rate).
Clinical scoring systems assist, with the Alvarado Score being widely utilized; a score of 7 or above strongly indicates acute appendicitis.

Treatment

Medical Management: Involves bowel rest and IV antibiotics, commonly metronidazole alongside 3rd generation cephalosporins; ertapenem is increasingly used for broad coverage in single daily doses.
- Approximately 25% of conservatively treated patients might require surgery within a year due to recurrent appendicitis, often with uncomplicated outcomes.
Surgical Management: The definitive treatment is appendectomy, which can be performed via open or laparoscopic techniques.

Description

Explore the essentials of acute appendicitis, one of the leading causes of acute abdomen in young adults. This quiz covers the anatomy of the appendix and the rationale behind appendectomy as a common surgical procedure.