2. Epidemiology
• The incidence of appendectomy appears
to be declining due to more accurate
preoperative diagnosis.
• Despite newer imaging techniques, acute
appendicitis can be very difficult to
diagnose.
3. Pathophysiology
• Acute appendicitis is thought to begin with
obstruction of the lumen
• Obstruction can result from food matter,
adhesions, or lymphoid hyperplasia
• Mucosal secretions continue to increase
intraluminal pressure
4. Pathophysiology
• Eventually the pressure exceeds capillary
perfusion pressure and venous and
lymphatic drainage are obstructed.
• With vascular compromise, epithelial
mucosa breaks down and bacterial
invasion by bowel flora occurs.
5. Pathophysiology
• Increased pressure also leads to arterial
stasis and tissue infarction
• End result is perforation and spillage of
infected appendiceal contents into the
peritoneum
6. Pathophysiology
• Initial luminal distention triggers visceral
afferent pain fibers, which enter at the 10th
thoracic vertebral level.
• This pain is generally vague and poorly
localized.
• Pain is typically felt in the periumbilical or
epigastric area.
7. Pathophysiology
• As inflammation continues, the serosa and
adjacent structures become inflamed
• This triggers somatic pain fibers,
innervating the peritoneal structures.
• Typically causing pain in the RLQ
8. Pathophysiology
• The change in stimulation form visceral to
somatic pain fibers explains the classic
migration of pain in the periumbilical area
to the RLQ seen with acute appendicitis.
9. Pathophysiology
• Exceptions exist in the classic presentation
due to anatomic variability of the appendix
• Appendix can be retrocecal causing the
pain to localize to the right flank
• In pregnancy, the appendix ca be shifted
and patients can present with RUQ pain
10. Pathophysiology
• In some males, retroileal appendicitis can
irritate the ureter and cause testicular pain.
• Pelvic appendix may irritate the bladder or
rectum causing suprapubic pain, pain with
urination, or feeling the need to defecate
• Multiple anatomic variations explain the
difficulty in diagnosing appendicitis
11. History
• Primary symptom: abdominal pain
• ½ to 2/3 of patients have the classical
presentation
• Pain beginning in epigastrium or
periumbilical area that is vague and hard
to localize
12. History
• Associated symptoms: indigestion,
discomfort, flatus, need to defecate,
anorexia, nausea, vomiting
• As the illness progresses RLQ localization
typically occurs
• RLQ pain was 81 % sensitive and 53%
specific for diagnosis
13. History
• Migration of pain from initial periumbilical
to RLQ was 64% sensitive and 82%
specific
• Anorexia is the most common of
associated symptoms
• Vomiting is more variable, occuring in
about ½ of patients
14. Physical Exam
• Findings depend on duration of illness
prior to exam.
• Early on patients may not have localized
tenderness
• With progression there is tenderness to
deep palpation over McBurney’s point
15. Physical Exam
• McBurney’s Point: just below the middle of
a line connecting the umbilicus and the
ASIS
• Rovsing’s: pain in RLQ with palpation to
LLQ
• Rectal exam: pain can be most
pronounced if the patient has pelvic
appendix
16. Physical Exam
• Additional components that may be helpful
in diagnosis: rebound tenderness,
voluntary guarding, muscular rigidity,
tenderness on rectal
17. Physical Exam
• Psoas sign: place patient in L lateral
decubitus and extend R leg at the hip. If
there is pain with this movement, then the
sign is positive.
• Obturator sign: passively flex the R hip
and knee and internally rotate the hip. If
there is increased pain then the sign is
positive
18. Physical Exam
• Fever: another late finding.
• At the onset of pain fever is usually not
found.
• Temperatures >39 C are uncommon in
first 24 h, but not uncommon after rupture
19. Diagnosis
• Acute appendicitis should be suspected in
anyone with epigastric, periumbilical, right
flank, or right sided abd pain who has not
had an appendectomy
20. Diagnosis
• Women of child bearing age need a pelvic
exam and a pregnancy test.
• Additional studies: CBC, UA, imaging
studies
21. Diagnosis
• CBC: the WBC is of limited value.
• Sensitivity of an elevated WBC is 70-90%,
but specificity is very low.
• But, +predictive value of high WBC is 92%
and –predictive value is 50%
• CRP and ESR have been studied with
mixed results
22. Diagnosis
• UA: abnormal UA results are found in
19-40%
• Abnormalities include: pyuria, hematuria,
bacteruria
• Presence of >20 wbc per field should
increase consideration of Urinary tract
pathology
23. Diagnosis
• Imaging studies: include X-rays, US, CT
• Xrays of abd are abnormal in 24-95%
• Abnormal findings include: fecalith,
appendiceal gas, localized paralytic ileus,
blurred right psoas, and free air
• Abdominal xrays have limited use b/c the
findings are seen in multiple other
processes
24. Diagnosis
• Graded Compression US: reported
sensitivity 94.7% and specificity 88.9%
• Basis of this technique is that normal
bowel and appendix can be compressed
whereas an inflamed appendix can not be
compressed
• DX: noncompressible >6mm appendix,
appendicolith, periappendiceal abscess
25. Diagnosis
• Limitations of US: retrocecal appendix may
not be visualized, perforations may be
missed due to return to normal diameter
26. Diagnosis
• CT: best choice based on availability and
alternative diagnoses.
• In one study, CT had greater sensitivity,
accuracy, -predictive value
• Even if appendix is not visualized,
diagnose can be made with localized fat
stranding in RLQ.
27. Diagnosis
• CT appears to change management
decisions and decreases unnecessary
appendectomies in women, but it is not as
useful for changing management in men.
28. Differential Diagnoses
• Mesenteric lymphadenitis (children,higher fever than in
appendicitis, + Hx of sore throat)
• Ectopic pregnancy!! (pregnancy test, anaemia, hypotesion)
• Torsion of ovarian cyst.(no fever, tender mobile mass in the
right suprapubic region or on vaginal examination)
• Ureteric colic (radiating to the glans penis or labia majora in
females)
• Testicular torsion
• Meckel’s diverticulitis
30. Special Populations
• Very young, very old, pregnant, and HIV
patients present atypically and often have
delayed diagnosis
• High index of suspicion is needed in the
these groups to get an accurate diagnosis
31. Treatment
• Appendectomy is the standard of care
• Patients should be NPO, given IVF, and
preoperative antibiotics
• Antibiotics are most effective when given
preoperatively and they decrease post-op
infections and abscess formation
32. Treatment
• There are multiple acceptable antibiotics to use as long
there is anaerobic flora, enterococci and gram(-) intestinal
flora coverage
• One sample monotherapy regimen is Zosyn (piperacillin+
tazobactam) 3.375g or Unasyn (ampicillin and Salbactam)
3g
• Also, short acting narcotics should be used for pain
management
33.
34. Disposition
• Abdominal pain patients can be put in 4
groups
• Group 1: classic presentation for Acute
appendicitis- prompt surgical intervention
• Group 2: suspicious, but not diagnosed
appendicitis- benefit from imaging and
4-6h observation with surgical consult if
serial exam changes or imaging studies
confirm
35. Disposition
• Group 3: remote possibility of appendicitis-
observe in ED for serial exams; if no
change and course remains benign patient
can D/C with dx of nonspecific abd pain
• Patients are given instructions to return if
worsening of symptoms, and they should
be seen by PCP in 12-24 h
• Also advised to avoid strong analgesia
36. Disposition
• Group 4: high risk population(including
elderly, pediatric, pregnant and
immunocomprimised)- require high index
of suspicion and low threshold for imaging
and surgical consultation
