Acute Appendicitis

Related Subjects: Acute Cholecystitis |Acute Appendicitis |Chronic Peritonitis |Abdominal Aortic Aneurysm |Ectopic Pregnancy |Acute Cholangitis |Acute Abdominal Pain/Peritonitis |Assessing Abdominal Pain |Penetrating Abdominal Trauma |Acute Pancreatitis |Acute Diverticulitis

If tests are negative but concern that appendicitis then consider diagnostic laparoscopy. Even in the best hands, 15-20% of the appendices removed are normal

About

• Affects 6-9% of population more common in females
• 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 the appendix can vary the mode of presentation

Anatomy

• Appendix is a vestigial blind-ended tube originating from the apex of the caecum
• Attached by a fold of peritoneum about 8 cm in length and can lie in several positions
• Supplied by the appendicular artery from the ileocolic artery in the mesoappendix

Aetiology

• Obstruction of appendix lumen by a faecolith or oedema
• Lumen fills with pus becoming increasingly infected
• Liquefaction and then perforation of the appendix
• Localised or generalised peritonitis

Causes

• Lymphoid hyperplasia
• Viral infections
• Faecal stasis
• Inflammatory disease
• Parasites Foreign bodies and neoplasms

Epidemiology

• Affects 16% of the population but significant decline in past 20 years
• Peak age is 10-20 years old

Position

• Retrocaecal 60%
• Pelvic 30% (Dysuria)
• Paracaecal 2%
• Pre-ileal 1%
• Post ileal 1% (Diarrhoea)

Clinical

• Dehydrated, Tachycardia, Fetor, Pyrexia > 37.5°C may be present
• Central/periumbilical colicky abdominal pain moves to the right iliac fossa
• Variable presentation necessitating a low threshold for diagnosis
• Examination - varies from little to find to obvious peritonitis and sepsis
• Rovsing's sign - press LIF and RIF more tender
• Digital rectal exam

Investigations

• FBC - High WCC High 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 - High 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: seen in children
• Tuberculosis, Yersinia infection,
• Crohn's disease, Ulcerative colitis, Diverticulitis
• Ectopic pregnancy: check Beta HCG if fertile female
• Acute Salpingitis, Ovarian torsion
• Meckel's diverticulum

Complications

• Rupture with peritonitis
• Appendix mass: omentum envelops appendix
• Complications of surgery - bleeding, infections, scars, damage to bowel bladder
• Post op DVT/PE, post op abscess formation, Sepsis, ARDS

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 mild cases a conservative approach with antibiotics may be considered
• Laparoscopic Appendicectomy
  • Has become more prevalent and is safer
  • Complications such as perforation still possible
• Open Appendicectomy
  • Preferred if there is generalised sepsis or complications
  • McBurney's or gridiron incision.
  • Split abdominal muscle fibres, 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 is not suitable for surgery or very late presentation (controversial).
  • Interval appendicectomy can be done at a later stage. Peritonitis needs urgent surgery
  • The risks from appendicitis to mother and baby are greater than the risk of appendicectomy; therefore, pregnancy should not influence the decision to operate