Acute Appendicitis

1. Acute Appendicitis

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. 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

29. 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

30. 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 3.375g or Unasyn 3g • Also, short acting narcotics should be used for pain management

31. 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

32. 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

33. 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

34. Ileitis, Colitis, and Diverticulitis

35. Crohn Disease • Chronic granulomatous inflammatory disease of the GI tract. • Can involve any part of GI tract from mouth to anus • Ileum is involved in majority of cases • Confined to colon in 20% • Terms:regional enteritis, terminal ileitis, granulomatous ileocolitis

36. Crohn Disease • Etiology and pathogenesis are unknown. • Infectious, genetic, environmental factors have been implicated. • Autoimmune destruction of mucosal cells as a result of cross-reactivity to antigens from enteric bacteria.

37. Crohn Disease • Cytokines,including IL and TNF have been implicated in perpetuating the inflammatory response. • Anti-TNF(remicade) drugs have shown efficacy in treating Crohn disease

38. Crohn Disease • Epidemiology: peak incidence is 15-22 years old with a second peak 55-66years • 20-30% increase in women • More common in European • 4 times more common in Jews than non-Jews • More common in whites vs blacks • 10-15% have family hx

39. Crohn Disease • Pathology: most important is the involvement of all layers of the bowel and extension into mesenteric lymph nodes • Disease has skip areas between involved areas • Longitudinal deep ulcers and cobblestoning of mucosa are characteristic • These result in fissures, fistulas, and abscesses

40. Crohn Disease • Clinical features: variable and unpredictable • Abd pain, anorexia, diarrhea, and weight loss are present in most cases • 1/3 of patients develop perianal fissures or fistulas, abscesses, or rectal prolapse

41. Crohn Disease • Patients may present with lat complications including: • Obstruction, crampy abd pain, obstipation, intraabdominal abscess with fever • 10-20% have extraabdominal features such as: arthritis, uveitis, or liver disease • Crohn’s should also be considered when evaluating FUO

42. Crohn Disease • Clinical course and manifestation depends of anatomic distribution. • 30% involves only small bowel, 30% only colon, and 50% involves both

43. Crohn Disease • Recurrence rate is as high as 50% for those responding to medical management • Rate is even higher for those requiring surgery • Incidence of hematochezia and perianal disease is higher when the colon is involved

44. Crohn Disease • Dermatologic complications: erythema nodosum and pyoderma gangrenosum • Ocular: episcleritis and uveitis • Hepatobiliary: pericholangitis, chronic hepatitis, primary sclerosing cholangitis, cholangiocarcinoma, pancreatitis, gallstones

45. Crohn Disease • Vascular: thromboembolic disease, vasculitis, arteritis • Other: anemia, malnutrition, hyperoxaluria leading to nephrolithiasis, myeloplastic disease, osteomyelitis, osteonecrosis

46. Crohn Disease • Complications: >75% of patients will require surgery within the first 20 years • Abscesses present with pain and tenderness, but may also have palpable masses or fever spikes • Most common fistula sites are between ileum and sigmoid colon, cecum, another ileal segment, or the skin

47. Crohn Disease • Fistulas should be suspected when there is a change in bowel movement frequency, amount of pain or weight loss • GI bleed is common, but only 1% develop life threatening hemorrhage. • Toxic megacolon occurs in 6% of patients and results massive GI bleed 50% of the time

48. Crohn Disease • Complications can also arise from the treatment of the disease • Sulfasalazine, steroids, immunosuppressive agents, and antibiotics can cause leukopenia, thrombocytopenia, fever, infection, diarrhea, pancreatitis, renal insufficiency, liver failure.

49. Crohn Disease • Incidence of malignancy is 3 times higher in Crohn disease than in general population

50. Crohn Disease • Diagnosis: history, Upper GI, air-contrast barium enema and colonoscopy • Characteristic radiologic findings in small intestine include: segmental narrowing, destruction of normal mucosal pattern, and fistulas.