Acute appendicitis is one of the most common causes of abdominal pain requiring emergency surgery. The appendix is located near the cecum but can be in retrocecal or pelvic positions, complicating diagnosis. Obstruction of the appendix is a key factor in pathogenesis as it leads to ischemia, necrosis, and inflammation. Classic symptoms include migrating pain starting around the umbilicus and later localized to the right lower quadrant, along with anorexia, fever, nausea, and vomiting. Physical exam may reveal tenderness at McBurney's point or other signs depending on appendix position. Laboratory tests typically show leukocytosis. Imaging like CT, ultrasound, or MRI can help in diagnosis by identifying an enlarged or fluid-

1. Acute apendicitis in adults

2. 03
02
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Contents
Introduction
Anatomy
Pathogenesis
Clinical features
Laboratory findings
Imaging exams

3. 01 Introduction
 Appendicitis, an inflammation of the vestigial
vermiform appendix.
 It is one of the most common causes of the
acute abdomen.
 It is one of the most frequent indications for
an emergent abdominal surgical procedure
worldwide.

4. 01 Anatomy
The vermiform appendix is located at the base
of the cecum, near the ileocecal valve where the
taenia coli converge on the cecum
 The appendicael orifice opens into the
cecum
 The layers of the appendicael wall: Mucosa,
submucosa, muscularis (longitudinal and
circular), and serosa.

5. 01 Anatomy
The attachment of the appendix to the base of
the cecum is constant.
 The tip may migrate to the retrocecal (64%),
subceal(32%), preileal(1%), postileal(0,5%),
and pelvic positions (2%).
Its blood supply, the appendiceal artery, is a
terminal branch of the ileocolic artery
traverses the length of the mesoappendix and
terminates at the tip of the organ.

6. 01 Anatomy

7. 02 Epidemiology
Appendicitis occurs most frequently in the
second and third decades of life.
The incidence is approximately 233/100,000
population and is highest in the 10 to 19 year-
old age group.
It is higher among men (male to female ratio of
1,4:1)

8. 02 Pathogenesis
Initial inflammation of the appendiceal wall is
followed by localized ischemia, perforation, and
the development of a contained abscess or
generalized peritonitis.
Appendiceal obstruction as the primary cause
of appendicitis.
The mechanism of luminal obstruction varies
depending upon the patient’s age.

9. 02 Pathogenesis
In the young, lymphoid follicular hyperplasia
due to infection  main cause.
In old patients, more likely to be caused by
fibrosis, fecaliths, or neoplasia (carcinoid,
adenocarcinoma, or mucocele).
In endemic areas, parasites can cause
obstruction in any age group.

10. 02 Pathogenesis
When obstruction of the appendix is the cause
of appendicitis:
The obstruction increase in luminal and
intramural pressure.
thrombosis and occlusion of the small vessels in
the appendiceal wall and stasis of lymphatic
Lymphatic and vascular compromise progress
The wall of the appendix becomes ischemic and
then necrotic.

11. 02 Pathogenesis
As the appendix becomes
engorged
 the visceral afferent
nerve fibers entering the
spinal cord at T8-T10 are
stimulated.
periumbilical abdominal pain.

12. 02 Pathogenesis
 Well-localized pain
occurs later when
inflammation
involves the
adjacent parietal
peritoneum.
RLQ pain.

13. 02 Pathogenesis
 When bacterial overgrowth cause appendicitis:
• Aerobic organisms predominate early in the
course, while mixed infection is more common in
late appendicitis.
• Intraluminal bacteria subsequently invade the
appendiceal wall further propagate a
neutrophilic exudate influx of neutrophils.
Fibropurulent reaction on the serosal surface

14. 02 Pathogenesis
 This results in stimulation of somatic nerves,
causing pain at the site of peritoneal irritation.

15. 02 Pathogenesis
• During the first 24 hours after symptoms
develop approximately 90 percent of patients
develop inflammation (perhaps necrosis, but not
perforation).
• Fecaliths /Calculi=6, but calculi were more often
associated with perforated appendicitis or
periappendiceal abscess.
• 20% patients develop perforation less than 24
hours after the onset of symptom, and 65%
patients longer than 48 hours.

16. 02 Clinical Features
I. History
• RLQ (right anterior iliac fossa) abdominal pain
• Anorexia
• Nausea and vomiting
*Initial features are atypical or nonspecific:
• Indigestion
• Flatulence
• Bowel irregularity
• Dysuria
• Diarrhea
• Generalized
malaise
• Tenesmus

17. 02 Clinical Features
I. History
• The onset of abdominal
pain as the first symptom.
• Abdominal pain is the
most common symptom,
nearly all confirmed case
of appendicitis.
1. Abdominal pain

18. 02 Clinical Features
I. History
• The pain is typically epigastric or periumbilical
subsequent migration to the right lower
quadrant as the inflammation progresses (50-
60% patients).
• The symptoms of appendicitis vary depending
upon the location of the tip of the appendix.
1. Abdominal pain

19. 02 Clinical Features
I. History
• An inflamed anterior appendix
localized pain in RLQ.
• A retrocecal appendix
dull abdominal ache.
• The tip of the appendix located
in the pelvis Tenderness
below Mc Burney’s point
1. Abdominal pain
Variations in the position of
the appendix
The location of the pain may also be atypical.

20. 02 Clinical Features
I. History
2. Nausea and vomiting
• Vomiting is more variable,
61-92% of patients.
• Nausea and vomiting,
usually follow the onset of
pain.
• vomiting that precedes pain
suggests intestinal
obstruction

21. 02 Clinical Features
I. History
3. Anorexia
• Anorexia is the most
common of associated
symptoms (74-78% of
patients

22. 02 Clinical Features
I. Physical examination
• In early signs of appendicitis are often subtle:
 Low-grade fever reaching 38,3oC may be present.
 Physical examination may be unrevealing in very
early stages of appendicitis.
• The inflammation progresses:
 Localized tenderness in the right lower quadrant
and can be detected.
 High-grade fever (>38,3oC) occurs as
inflammation progress.

23. 02 Clinical Features
I. Physical examination
• Retrocecal appendix:
 May not exhibit marked localized tenderness in
RLQ the rectal and/or pelvic examination is
more likely to elicit positive signs
(may be mistake for adnexal tenderness)
 In women, right adnexal area tenderness may be
present on pelvic examination.

24. 02 Clinical Features
I. Physical examination
• Features of the abdominal
pain:
 Patients usually lie down,
flex their hips, and draw their
knees up to reduce
movements and to avoid
worsening their pain.

25. 02 Clinical Features
I. Physical examination
• Commonly described physical signs include:
 McBurney’s point tenderness.
 Rovsing’s sign.
 The psoas sign.
 The obturator sign.
 Dunphy sign.
 RLQ pain in response to percussion.
 Markle’s sign

26. 02 Clinical Features
I. Physical examination
 McBurney’s point tenderness.
• Deep tenderness located to
thirds of distance from
umbilicus to right anterior
iliac spine.
• Sensitivity 50-94%;
specificity 75-86%.

27. 02 Clinical Features
I. Physical examination
 Rovsing’s sign.
• Pain in the RLQ with
palpation of the LLQ.
• Sensitivity 22-68%;
Specificity 58-96%

28. 02 Clinical Features
I. Physical examination
 The psoas sign.
• Associated with a
retrocecal appendix.
• RLQ pain with passive
right hip extension.
• Sensitivity 13-42%,
specificity 79-97%.

29. 02 Clinical Features
I. Physical examination
 The obturator sign.
• Associated with a pelvic
appendix.
• Flex the right hip and knee
follow by internal rotation
of the right hip  RLQ
pain.
• Sensitivity 8%;
specificity 94%

30. 03 Laboratory findings
• A mild leukocytosis (WBC >10,000 cells/mcL) is
present in most patients with acute appendicitis.
• The sensitivity and specificity of an elevated
WBC count in acute appendicitis: 80% and 55%.
• Acute appendicitis is unlikely when the WBC
count is normal, except in the very early course.
• Mean WBC counts are higher:
 Acute: 14,500 ± 7300 cells/mcL.
 Gangrenous: 17,100 ± 3900 cells/mcL.
 Perforated: 17,900 ± 2100 cells/mcL.

31. 03 Laboratory findings
• Mild elevations in serum bilirubin (total bilirubin
>1 mg/dL) marker for appendiceal perforation
with a sensitivity (70%) and specificity (86).
• Leukocytosis and a left shift (increase in total
WBC count, bands-immature neutrophils, and
neutrophils.

32. 03 Laboratory findings
• Patient History, physical examination and
investigation
 Alvarado Score (MANTRELS score)
Clinical appendicitis (probable) a score: 7-10

33. 03 Laboratory findings

34. 03 Imaging exams
I. Computed tomography findings:
Normal appendix
• Images of the pelvis from
CT with intravenous and
oral contrast shows an
appendix (arrow)
air-filled with double-
layer wall thickness <6cm.

35. Acute appendicitis
Image of the pelvis (A and B) from a CT with
intravenous and oral contrast shows a thickened
appendix (arrow) containing an appendicolith and
surrounding fluid indicating inflammation.

36. 03 Imaging exams
I. Computed tomography findings:
Standard abdominal computed tomography (CT)
scanning with contrast including:
 Enlarged appendiceal diameter >6mm with an
occluded lumen.
 Appendiceal wall thickening >2mm.
 Periappendiceal fat stranding.
 Appendicolith (25% of patients)

37. 03 Imaging exams
II. Ultrasound findings:
The most accurate ultrasound finding for acute
appendicitis is an appendiceal diameter of>6mm.

38. Normal appendix by ultrasound imaging

39. 03 Imaging exams
• The gray scale ultrasound (A, and magnified in
B) and Doppler image (C) of the appendix are
projected in the transverse plane.
• Images A and B show a normal appendix
measuring almost 6mm in maximum transverse
dimension (arrow).
• The appendix was compressible and no
hyperemia was demonstrated (arrow) on the
Doppler image (C)
Consistent with a normal appendix by
ultrasound.

40. A 19-year-old female who admitted to the
emergency department with RLQ pain.

41. 03 Imaging exams
• The gray scale ultrasound of the appendix is
projected in the longitudinal (A) and transverse
planes (B).
• A noncompressible appendix measures almost 20
mm in diameter.
consistent with a diagnosis of acute appendicitis.
• The echogenic mucosal and submucosal portion
of the wall discontinuous (arrow) suggesting
disruption sloughing.
• Luminal air (arrowheads)posterior shadowing.

42. 03 Imaging exams
II. Magnetic resonance imaging:
• Magnetic resonance imaging (MRI) can assist
with the evaluation of acute abdominal and
pelvic pain during pregnancy.
• A normal appendix: tubular structure ≤ 6mm in
diameter and filled with air
• An enlarged fluid-filled appendix (>7mm
d)an abdominal finding.
• An appendix with a diameter 6 to 7 mm
 an inconclusive finding.

43. • T2 weigh magnetic resonance image of a woman
with appendicitis at 9 weeks of gestation.
• The appendix was fluid-filled and measured
7mm (arrow)

44. Summary and recommendations
• Appendicitis is one of the most common causes
of the acute abdomen and one of the most
frequent indications for an emergent abdominal
surgical procedure worldwide.
• The tip of the appendix can be found in a
retrocecal or pelvic location. Anatomic
variability can complicate the diagnosis.
• Appendiceal obstruction plays a role in the
pathogenesis of appendicitis.
• The classic symptom of appendicitis include
RLQ pain

45. Summary and recommendations
• The classic symptom of appendicitis include RLQ
pain, anorexia, fever, nausea, and vomiting.
• The abdominal pain is initially periumbilical in
nature with subsequent migration to the RLQ as the
inflammation progresses.
• The differential diagnosis of RLQ abdominal pain
includes inflammatory disease process (Crohn’s
disease, ruptured cyst), infectious disease (acute
ileitis, tubo-ovarian abscess), and obstetrical
condition( ectopic pregnancy).

46. References
• Uptodate.com.
• Emedicine.medscape.com
• Guideline.
Hoang Cuong,Yen Y3C