Appendix Flashcards
What vessel provides blood supply to the appendix?
Appendiceal artery (branch of the ileocolic artery)
Name the mesentery of the appendix. What does it contain?
Mesoappendex (contains the appendiceal artery)
How can the appendix be located if the cecum has been identified?
Follow the teniae coli down to the appendix; the teniae converge on the appendix
What is appendicitis?
Inflammation of the appendix caused by obstruction of the appendiceal lumen, producing a closed loop with resultant inflammation that can lead to necrosis and perforation
Causes of appendicitis?
Lymphoid hyperplasia
Fecalith (aka appendicolith)
Lifetime incidence of acute appendicitis in the US?
~7%
Most common cause of emergent abdominal surgery in the US?
Acute appendicitis
Classical presentation of appendicitis?
Periumbilical pain (intermittent and crampy) -> N/V -> anorexia -> pain migrates to RLQ (constant and intense), usually in <24 hours
Why does periumbilical pain occur?
Referred pain
Why does RLQ pain occur?
Peritoneal irritation
What are the signs/symptoms of appendicitis?
Signs of peritoneal irritation may be present (guarding, muscle spasm, rebound tenderness, obturator, psoas signs), low-grade fever (high grade if perf occurs), RLQ hyperesthesia
Define - obturator sign.
Pain upon internal rotation of the leg with the hip and knee flexed; seen in patients with pelvic appendicitis
Define - psoas sign.
Pain elicited by extending the hip with the knee in full extension or by flexing the hip against resistance; classically seen in retrocecal appendicitis
Define - Rovsing’s sign.
Palpation or rebound pressure of the LLQ results in pain in the RLQ; seen in appendicitis
Define - McBurney’s point.
Point 1/3 from the ASIS to the umbilicus (often the point of max tenderness)
DDx for appendicitis? (everyone)
Everyone: Meckel’s, Crohn’s disease, perforated ulcer, pancreatitis, mesenteric lymphadenitis, constipation, gastroenteritis intusussception, volvulus, tumors, UTI (eg., cystitis), pyelonephritis, torsed epiplociae, cholecystitis, cecal tumor, diverticulitis (floppy sigmoid)
DDx for appendicitis? (females)
Ovarian cyst, ovarian torsion, tuboovarian abscess, mittelschmerz, PID, ectopic pregnancy, rupture pregnancy
What labs should be performed in suspected appendicitis?
CBC: increased WBC (>10000 in >90% of cases), most often with a “left shift”
UA to evaluate for pyelo or renal calculus
Can you have an abnormal UA in appendicitis?
Yes; mild hematuria and pyuria are common in appendicitis with pelvic inflammation, resulting in inflammation of the ureter
What additional tests can be performed if the dx of appendicitis is not clear?
Spiral CT, U/S (may see a large, non-compressible appendix or fecalith)
In acute appendicitis, what classically precedes vomiting?
Pain (in gastroenteritis, the pain classically follows vomiting)
What radiographic studies are often performed?
CXR to rule out RML or RLL pneumonia, free air
AXR: abdominal films are usually non-specific, but calcified fecalith present in ~5% of cases
What are the CT scan findings with acute appendicitis?
Periappendiceal fat stranding, appendiceal diameter >6 mm, periappendiceal fluid, fecalith
Preoperative prep for appendicitis?
Rehydration with IV fluids (LR)
Preoperative ABX with antibiotic coverage (appendix is considered part of the colon)
