Acute Appendicitis Notes PDF

**[ACUTE APPENDICITIS]** Acute appendicitis is the most common cause of an acute abdomen in young adults. Appendicitis is sufficiently common that appendectomy is the most frequently performed urgent abdominal operation. **Anatomy of appendix** The vermiform appendix is a blind muscular tube with...

**[ACUTE APPENDICITIS]** Acute appendicitis is the most common cause of an acute abdomen in young adults. Appendicitis is sufficiently common that appendectomy is the most frequently performed urgent abdominal operation. **Anatomy of appendix** The vermiform appendix is a blind muscular tube with mucosal, submucosal, muscular and serosal layers. Morphologically, it is the undeveloped distal end of the large caecum. At birth, the appendix is short and broad at its junction with the caecum. During childhood, continued growth of the caecum commonly rotates the appendix into a retrocaecal but intraperitoneal position. In approximately one-quarter of cases, rotation of the appendix does not occur, resulting in a pelvic, subcaecal or paracaecal position. Occasionally, the tip of the appendix becomes extraperitoneal, lying behind the caecum or ascending colon. The position of the base of the appendix is constant, being found at the confluence of the three taeniae coli of the caecum, which fuse to form the outer longitudinal muscle coat of the appendix. During surgery, we can make use of this to find an elusive appendix, as gentle traction on the taeniae coli, particularly the anterior taenia, will lead the surgeon to the base of the appendix. The average length of the appendix is between 7.5 and 10 cm. **Etiology of appendicitis** Obstruction of the appendix lumen is an important cause of appendicitis, and some form of luminal obstruction, either by a faecolith or a stricture, is found in the majority of cases. Once obstruction occurs, continued mucus secretion and inflammatory exudation increase intraluminal pressure, obstructing lymphatic drainage. Edema and mucosal ulceration develop with bacterial translocation to the submucosa. **Clinical features of appendicitis** The classical features of acute appendicitis begin with poorly localised colicky abdominal pain. The pain is frequently first noticed in the periumbilical region and is similar to, but less intense than, the colic of small bowel obstruction. The central abdominal pain is associated with anorexia, nausea and usually one or two episodes of vomiting that follow the onset of pain (Murphy). Anorexia is a useful and constant clinical feature. With progressive inflammation of the appendix, the parietal peritoneum in the right iliac fossa becomes irritated, producing more intense, constant and localised somatic pain that begins to predominate (migratory right iliac fossa pain). The patient can also have fever. **Signs:** low-grade pyrexia, localised abdominal tenderness, muscle guarding and rebound tenderness. Another sign is the **Rovsing's sign** where deep palpation of the left iliac fossa may cause pain in the right iliac fossa. Occasionally, an inflamed appendix lies on the psoas muscle, and the patient, often a young adult, will lie with the right hip flexed for pain relief, this is the **psoas sign.** There's also the **obturator sign**, if an inflamed appendix is in contact with the obturator internus and the hip is flexed and internally rotated, this manoeuvre will cause pain in the hypogastrium. **Investigations** The diagnosis of acute appendicitis is essentially clinical; however, a decision to operate based on clinical suspicion alone can lead to the removal of a normal appendix in 15--30% of cases. A number of clinical and laboratory-based scoring systems have been devised to assist diagnosis. The most widely used is the **Alvarado score**. A score of 7 or more is strongly predictive of acute appendicitis. **Treatment** [Medical management:] Treatment is bowel rest and intravenous antibiotics, often metronidazole and 3rd generation cephalosporin. More recently, ertapenem has been used in this setting and has the benefit of broad antimicrobial cover administered as a single daily dose. However, approximately one-quarter of patients initially treated conservatively will require surgery within 1 year for recurrent appendicitis. The subsequent surgery, if needed, tends to be uncomplicated. [Surgical management:] The surgical treatment for acute appendicitis is appendectomy which can either be open or laparoscopic.