Appendix Flashcards
Pathophys and order of events in appendicitis
1) appendiceal lumen is occluded, usually by fecolith (possibly lymphoid hyperplasia 2/2 IBD or infections, parasites, foreign objects)
2) bacterial overgrowth
3) Reactive inflammation
4) Increased intraluminal pressure
5) venous outflow obstruction/ischemia
6) loss of epithelial integrity
7) Gengrene/perforation
Anatomy of the appendix
10cm true diverticulum of cecum with its own mesentery (mesoappendix)
Location (in order of decreasing freq):
1) Low cecal
2) Pelvic
3) Retrocecal
Usually at McBurney’s point = 2/3 of the distance from umbilicus to R ASIS
Incidence of appendicitis
Usually people in 2nd/3rd decade, previously healthy
Men:Women = 3:2
Presentation of appendicitis
Initial periumbilical pain that migrades to RLQ (correlates to vague abdominal pain of inflamed appendix coverting to irritation of parietal peritoneum)
But, appendix has variable location (ESP during pregnancy) so location of pain will change as such
N/V, anorexia, fever, increased leukocytes w/ L shift
Typical presentation seen in 50%
Other diagnoses to consider in appendicitis
Cholecystitis and biliary colic
Gastroenteritis
Enterocolitis
Diverticulitis
Pancreatitis
Perforated duodenal ulcer
Renal colic
UTI
In peds:
Lymphadenitis or intussusception
In women of childbearing age who are not pregnant: Ovarian cyst torsion Mittelschmerz Ectopic preg PID
What are some rarer mimics of appendicitis?
SBO
Crohn
Meckel
Tumors
Henoch-Schonlein purpura
Rectus sheath hematoma
Yrsenia enterolytica causing mesenteric adenitis***
What are some helpful physical exam signs that may correlate to appendicitis?
Obturator sign: internal rotation of thigh elicits pain (pelvic appendicitis)
Psoas sign: extension of R thigh elicits pain (retroperitoneal or retrocecal appendicitis)
Dunphy sign: increasing pain with cough
Blumberg sign: rebound tenderness from peritoneal irritation
Guarding
Surgical indications in appendicitis
Persistent abdominal pain, fever, and clinical signs of localized or diffuse peritonitis, esp if leukocytosis is present
If unclear, short period (4-6h) of watchful waiting and a CT scan
surgery is ALWAYS the treatment though for confirmed appendicitis (do NOT need CT to confirm)
Lab studies for appendicitis
CBC
UA (r/o UTI or pyelo)
CRP
Liver and pancreatic enzymes (r/o liver and panc diagnoses)
beta-hCG (r/o pregnancy)
Urinary 5-HIAA (serotonin metabolite that could be early marker of appendicitis)
Imaging for appendicitis
CT with oral contrast or rectal gastrograffin enema.
IV contrast is not usually need. May help differentiate btw appendicitis and other pelvic pathologies
Typical findings are a nonfilling appendix with distention and thickened walls of both the appendix and cecum. Enlarged mesenteric nodes. Periappendiceal inflammation or fluid
CT NOT NEEDED FOR DX
Medical management of appendicitis
no such thing
The only time to delay surgery is if appendix is contained in an abscess. Then give Abx and wait for infection to simmer down before operating
PostOp management for appendicitis
IV Abx
If non-complicated appendicitis, diet may be advanced quickly and the patient is D/C’d once diet is tolerated
In complicated appendicitis, Abx may be required for many days or weeks. Clear liquid started when bowel function returns
Advantages to lap appi
Less postop pain
Better cosmetic result
shorter time to return to usual activities
Lower incidence of wound infection or dehiscence
3 cannulae (umbilical 5mm, suprapublic 12mm, R periumbilical region)
Complications of appendectomy
Avg morbidity = 10%
Wound infection or dehiscence may occur, esp in patients with gangrenous or perf’d appendicitis, persistent ileus, cecal fistuals, and pelvic/abdom abscess
Postop infections usually present with mild fever, ab pain, disorders of bowel transit
Mortality rate is less than 1% if appediceal perf exists. An exception is elderly patients (5%)
Embryo of appendix
Buds off from cecum at week 6
Base is in fixed position…tips are variable.
How do you find it? Find cecum first…then trace the 3 taeniae coli down until they converge at the base
Blood supply of appendix
Appendicular artery
- branch of ileocolic which is branch of SMA
Lifetime incidence of acute appendicitis in USA
7%
Is a compressible appendix on U/S a good sign?
Usually
Good be false negative though. Appendix become compressible after perforation
Appendicitis in pregnant patients
Appendicitis is #1 surgical emergency in pregnant patients
Fetal mortality increases 3-8% with appendicitis and 30% with perforation
Surgery is standard tx, though 10-15% of women will experience premature labor
Pregnant patients may present with RUQ pain
Appendicitis in elderly
Presents atypically, leading to delays in dx
Present later in course and with less pain. May present as an SBO
Delayed leukocytosis
Higher risk of perf and higher mortality than in younger patients
Appendicitis in immunocomprosied
AIDS, high dose chemo
Although they may not have absolute leukocytosis, compared to baseline WBC they will demonstrate relative leukocytosis
Ddx should expand to include opportunistic infections like CMV-related bowel perf and neutropenic colitis
Carcinoid def
Relatively low grade neuroendocrine tumor (secretes enzymes aberrantly; enzymes typically cause nausea, diarrhea, flushing)
Appendix is #1 site of carcinoid tumors of GI tract
Carcinoid is #2 most common type of appendiceal tumor (#1 = mucinous adenocarcinoma)
Carcinoid dx and tx
Increased 5-HIAA in urine and increased serum serotonin
Tx: Size is the determinant of malignant potential and treatment
2cm = right hemicolectomy
Serotonin antagonists (cyproheptadine) or somatostatin analogues (octreotide) can be used for symptoms of carcinoid syndrome
***Carcinoid will not typically present unless tumor has metastasized to liver
Mucinous tumors
Can rupture, causing pseudomyxoma peritonei with mucin implants on peritoneal surfaces and omentum
Women:Men 3:2
Complications include bowel obstruction and perf
Have been associated with migratory thrombophlebitis
Adenocarcinoma
Colon cancer that arises from appendix
Very rare and almost never diagnosed preop
Rapid spread to regional LNs, ovaries, peritoneal surfaces
If confined to appendix and local LNs, R hemicolectomy is treatment of choice
Appendiceal abscess
Signs: similar to acute appendicitis
Increasing RLQ pain
Tender, fluctuant RLQ mass that is palpable on rectal exam
Anorexia
Think of this when you see appendicitis + RLQ mass
Fever
Localizing peritonitis
Leukocytosis
Dx = CT
Tx = percutaneous or operative drainage
