Acute Appendicitis


About

  • Potential cause of abdominal sepsis and peritonitis.
  • Seen in all ages and can complicate pregnancy.
  • Complications highest in very young and elderly.
  • Different positions of appendix can vary mode of presentation.
 

Etiology

  • Obstruction of appendix lumen by a faecolith or edema.
  • Lumen fills with pus becoming increasingly infected.
  • Liquefaction and then perforation of the appendix.
  • Localized or generalized peritonitis.
 

Anatomy

  • Has its own mesentery : mesoappendix.
  • Appendicular artery lies in free edge of mesoappendix.
  • This is a branch of ileocolic artery.
  • Base of appendix told from convergence of three teniae coli of the caecum.

 

Position
  1. Retrocaecal 60%.
  2. Pelvic 30% (Dysuria).
  3. Paracaecal 2%.
  4. Pre-ileal 1%.
  5. Post ileal 1% (Diarrhoea).
 

Epidemiology

  • Affects 16% of the population but significant decline in past 20 years.
 

Clinical Presentation

  1. Dehydrated, Tachycardia.
  2. Fetor and Pyrexia > 37.5 C may be present.
  3. Central colicky abdominal pain moves to the right iliac fossa.
  4. Variable presentation necessitating a low threshold for diagnosis.
  5. Examination – varies from little to find to obvious peritonitis and sepsis.
  6. Rovsing’s sign – press LIF and RIF more tender.
 

Investigations

  • FBC – ↑ WCC ↑ CRP.
  • USS may show a swollen inflamed appendix and exclude an ovarian cyst or ectopic pregnancy.
  • CT abdomen can also help.
  • Diagnostic laparoscopy can be useful in young women and can proceed to open surgery if needed.
  • Beta-hCG ? ectopic pregnancy.
  • Urinalysis – ↑ WCC may be seen with appendicitis and UTI.

High Risk groups

  • Very young: misdiagnosed as gastroenteritis.
  • Elderly , Pregnancy.
  • Clinical Outcomes.
  • Treatment and resolution.
  • Perforation and diffuse peritonitis +/- appendix mass.
  • Forms an appendix mass.
 

Differential

  • UTI, Gastroenteritis, Mesenteric adenitis.
  • Tuberculosis, Yersinia infection,
  • Crohn’s disease, Ulcerative colitis, Diverticulitis.
  • Ectopic pregnancy, Acute Salpingitis, Ovarian torsion.
  • Meckel’s diverticulum.
 

Management

  • IV access and resuscitation IV fluids.
  • Adequate analgesia – IV Opiates.
  • Nil by mouth and surgical referral.
  • Appendicectomy by open or laparoscopic approach may be considered.
  • In a mild cases a conservative approach with antibiotic may be considered.
  • Laparoscopic Appendicectomy.
  • Has become more prevalent and is safer.
  • Complications such as perforation still possible.
  • Open Appendicectomy.
  • Preferred if there is generalized sepsis or complications.
  • McBurney’s or gridiron incision.
  • Split abdominal muscle fibers, enter peritoneum, locate caecum and deliver appendix.
  • Base is crushed and ligated and appendix removed. Invert stump using purse string suture.
  • If appendix normal then check for a Meckel’s diverticulum.
  • Wash out with warm saline if perforation or free pus.

General

  • IV Antibiotics (Cefuroxime + Metronidazole) or as per local protocol
  • Conservative management if there is an appendix mass and no peritonitis or if patient not suitable for surgery or very late presentation (controversial).
  • Interval appendicectomy can be done at a later stage.
  • Peritonitis needs urgent surgery.