Acute appendicitis is inflammation of the appendix that is most common in people aged 5-35. It occurs when the appendix becomes blocked, usually by a fecalith, causing bacterial infection and tissue damage. Common symptoms include abdominal pain localized to the lower right side, nausea, vomiting, and fever. A physical exam may reveal tenderness at McBurney's point. Imaging tests and bloodwork can help diagnose appendicitis, and it is scored using the Alvarado scale. Treatment involves antibiotics, IV fluids, and an appendectomy to remove the inflamed appendix. Complications can include perforation, abscess formation, and infection spread.

1. ACUTE
APPENDICITIS
MWALIMU SIMFUKWE
5TH YEAR MEDICAL STUDENT
LUSAKA APEX MEDICAL UNIVERSITY
13/12/2022

2. Anatomy of the Appendix
• The appendix buds off from the caecum after 6 weeks of embryological development.
• The vermiform appendix is narrow, has a variable length of 2-20cm, with its base attached to
the terminal end (posteromedial surface) of the caecum, where the 3 taeniae join and about
2cm below the ileo-cecal orifice (junction of the ileum and cecum).
• The taeniae are Omental, Mesocolic and Free taeniae.
• The diameter of the appendix is 3-8cm, lumen size and luminal capacity is 1-3mm and <1ml
respectively.
• The mesoappendix is an extension extension of the mesentery and contains the appendicular
artery, which is an end artery thus, thrombosis of this artery will cause gangrenous
appendicitis.
• The base of the appendix is fixed in its position but the tip can move and end up in various
positions such as Pre-ileal appendix, Post-ileal appendix, Retro-cecal appendix, Pelvic
appendix, Sub-cecal appendix and Para-cecal appendix.

4. Appendicular Layers and Function
• The appendix, like any other organ of the Gastrointestinal Tract (GIT), is composed of
the Mucosa (Epithelium, Lamina Propria and Mascularis Mucosa), Submucosa, Inner
Circular and Outer Longitudinal Muscle, and Serosa or Adventitia.
• The submucosa contains lymph follicles, which when enlarged due to infection, makes
the submucosal layer swollen, resulting in the blockage of the appendicular lumen.
• The appendix is an immunological organ that secretes IgA. However, it is said to be a
vestigial organ and so it is not an essential organ therefore, can be removed without
immunological compromise.

5. Definition of Acute Appendicitis
• Acute Appendicitis is the inflammation of the appendix. It is most common in young
people aged 5-35 years but can also occur in the elderly.
• Males are often affected slightly more than females.
• The condition may be confused with mesenteric lymphadenitis (often secondary to
unrecognized Yersinia infection or viral enterocolitis), acute salpingitis, ectopic
pregnancy, mittelschmerz (pain associated with ovulation), and Meckel diverticulitis.
Etiology
• Diet (Reduced Fiber Content)
• Obstruction of the lumen (obstructive appendicitis) - Fecalith, Strictures, Foreign body
or tumors.
• Infection - associated with mucosal edema and inflammation lymphoid hyperplasia)
with bacterial infections such as E. coli (80%) and Enterococci (30%).

6. Pathogenesis
• Acute appendicitis can either arise from Obstructive or Non-obstructive (catarrhal) causes.
• Acute inflammation of the mucous membrane (catarrhal) with secondary infection without
lumen obstruction causes Non-obstructive appendicitis. It may lead to resolution, fibrosis,
recurrent appendicitis or eventual obstructive appendicitis.
• Luminal obstruction, which is caused by Fecalith, lymphoid hyperplasia, mass of worms or
tumors results in mucus and inflammatory fluid collection in the lumen, which leads to the
increase of intraluminal pressure. The pressure increase exceeds the capillary and venous
pressure leading to the blockage of lymphatic and venous drainage causing ischemia and
mucosal ulceration, which in turn favors bacterial proliferation, triggering an inflammatory
response - tissue edema and neutrophilic infiltration of the lumen. Bacteria translocation
occurs through the mucosa, submucosa, muscular wall and peri-appendiceal soft tissues
causing Acute Obstructive appendicitis.

7. • Acute Obstructive appendicitis leads to thrombosis of the appendicular artery
resulting in ischemic necrosis of the full thickness of the appendicular wall causing
gangrene of the appendix, which leads to perforation of the tip or base of the
appendix leading to peritonitis.
• After perforation, there is localization by the greater omentum and dilated ileum. This
can suppurate forming an appendicular abscess or if pus is not present inside, it is
referred to as an appendicular mass.
• Acute appendicitis, with blockage at the opening of the lumen of the appendix
resulting in its enlargement is referred to as Mucocele of the Appendix.

8. Clinical Features and Signs
Clinical Features
• Murphy’s Triad - Pain, Temperature (Fever),
Vomiting
• Constipation
• Tachycardia
• Increased urinary frequency
• Tenderness and Rebound tenderness at
McBurney’s point are typical
Clinical Signs
• Rovsing’s sign
• Pointing sign (McBurney’s point)
• Blumberg’s sign (Releasing sign)
• Psoas (Cope’s) test
• Obturator test
• Baldwing test
• Bastede test
• Sherren’s triangle

9. Differential Diagnosis for Acute Appendicitis
• Crohn’s Disease
• Merkel’s Diverticulum
• CA caecum
• Intestinal Obstruction
• Perforated duodenal ulcer
• Ectopic Pregnancy
• Pyelonephritis
• PID

10. Investigations
• Blood - FBC/DC
• Urinalysis
• Imaging - X-Ray, Ultrasound, Abdominal CT with contrast
• Laparoscopy
• Aspiration Cytology
• Gravindex

11. Diagnosis - Alvarado Score,1986
• This scoring system is out of 10
• MANTRELS (Mnemonic)
• Migrating pain - 1
• Anorexia - 1
• Nausea/Vomiting - 1
• Tenderness in RIF - 2
• Rebound tenderness - 1
• Elevated Temperature - 1
• Leukocytosis (>10,000/µl) - 2
• Shift towards Neutrophils (Neutrophilia) – 1
• Score is <5 = Not Sure
• Score is 5-6 = Compatible
• Score is 6-9 = Probable
• Score is >9 = Confirmed

12. •Resuscitation
•Pre-operative Management
•Antibiotics
•IV fluids
•Appendicectomy
•Gridiron incision
•Lanz crease
•Rutherford Morison’s muscle
•Right Lower Paramedian incision/ Lower midline
incision
•Laparoscopic approach
•Foweler – Weir approach
Treatment (Management)
• Post-operative Management - Antibiotics
are given for 5 days as well as IV fluids.
Once bowel sounds are heard, oral diet is
started.
• Analgesics
• Appendiceal abscesses can be managed
non-operatively with antibiotics and
percutaneous abscess drainage.
• For Perforation, peritoneal washout and
Parenteral antibiotics.

13. Complications
Acute Appendicitis
• Perforation
• Appendicular Mass
• Appendicular Abscess
• Relapse/Recurrent Appendicitis
• Intestinal Obstruction
• Intraperitoneal Abscess formation
• Portal pyemia (Pylephlebitis)
• Generalized Peritonitis
• Septicemia
• Overwhelming sepsis
• Death
After Appendicectomy
• Paralytic ileus
• Portal pyaemia
• Residual Abscess
• Right Inguinal Hernia
• Wound Infection and Sepsis
• Faecal Fistula
• DVT
• Respiratory problems
• Recurrent Intestinal Obstruction
• Reactionary Haemorrhage

14. REFERENCES
• Bhat, S.M. (2013). SRB’s Manual of Surgery. 4th edition. New Delhi: Jaypee
Brothers Medical Publishers (P) Ltd.
• Kumar, V., Abbas, A.K. and Aster J.C. (2013). Robbins Basic Pathology. 9th
edition. Philadelphia: Elsevier Saunders Inc.