Appendicitis

From Anvita Health Wiki

Contents 1 Etiology 2 Clinical-manifestations 3 Pertinent-negatives 4 Laboratory 5 Radiology 6 Complications 7 Differential-diagnosis 8 Management 9 More General Terms 10 Additional Terms 11 Internet Database 12 References

Etiology

• appendiceal lumenal obstruction resulting in vascular congestion, edema & inflammation

• appendicolith

• consists of fecal material
• most common etiology

• calculi
• inspissated barium from previous contrast study
• Helminths

• pinworms, tapeworms, roundworms

• carcinoma
• carcinoid
• submucosal lymphoid hyperplasia secondary to viral infection

• immunocompromised patients

• tuberculosis
• cytomegalovirus
• Cryptosporidium
• Kaposi's sarcoma

Clinical-manifestations

• classic symptoms are infrequent
• abdominal pain

• initially, poorly localized periumbilical pain (4-6 hr)
• right lower quadrant pain with rebound tenderness

• McBurney's point is the point of maximal tenderness in the classic presentation
• if pain subsides temporarily, suspect perforation

• nausea/vomiting
• anorexia
• low-grade fever, consider perforation if T > 101 F
• hyperesthesia may be present
• a mass in the right lower quadrant suggests a periappendiceal abscess
• right-sided tenderness on rectal examination

Pertinent-negatives

• hunger

Laboratory

• complete blood count ( CBC)

• leukocytosis generally 10,00-20,000/ mm3 with band forms
• WBC > 20,000/ mm3 should raise suspicion of perforation
• WBC may be normal in immunocompromised hosts

• peripheral blood smear for toxic granulation
• urinalysis: microscopic hematuria or pyuria may occur if inflamed appendix abuts bladder
• urine pregnancy test in women of child-bearing age
• stool guaiac

Radiology

• multidetector computed tomography ( CT) [8]

• sensitivity, 98.5%
• specificity, 98.0%;
• negative predictive value, 99.5%
• positive predictive value, 93.9%.

• computed tomography ( CT) with rectal contrast

• presence of inflammatory mass
• abscess
• appendicolith
• thickened appendiceal wall may enhance with contrast
• sensitivity 99%, specificity 95%, positive-predictive value 93%, negative-predicitive value 99% [4]
• low-dose CT as good as standard CT [10]

• plain abdominal film

• appendicolith
• blurring of right psoas margin
• lumbar scoliosis with convexity to the right
• sentinel loop of bowel in right-lower quadrant
• gas-containing abscess or pneumoperitoneum with perforation

• graded-compression ultrasound

• appendix appears fluid-filled, non-compressible & > 6 mm in diameter
• radiographic exam of choice in women of child-bearing age

• barium enema: complete opacification of the appendix excludes the diagnosis

Complications

• perforation
• periappendiceal abscess

Differential-diagnosis

• cholecystitis
• diverticulitis - including Meckel's diverticulitis
• gastroenteritis
• ectopic pregnancy
• acute salpingitis
• tubo-ovarian abscess
• mittelschmerz
• ovarian torsion
• ruptured ovarian cyst
• ureteral calculus
• pyelonephritis
• perinephric abscess
• Crohn's disease
• Yersinia enterocolitis
• mesenteric adenitis
• psoas abscess
• torsion of an undescended testicle
• perforated duodenal ulcer
• omental torsion
• mucocele
• strangulated inguinal hernia
• Mycobacterium avium intracellulare in patients with AIDS

Management

• pelvic examination on all women
• hospitalization
• antibiotics coverage for gram-negative aerobic bacilli (E. coli), obligate anaerobes (Bacteroides sp.), & enteric Streptococci (S. milleri)

• amoxicillin-clavulanate alone may prevent need for surgery in 68% of patients [7,9]
• appendectomy remains standard of care [7,9]

• mild to moderate infections:

• cefoxitin, moxifloxacin, or ticarcillin- clavulanic acid, or
• metronidazole plus cefazolin, cefuroxime, ceftriaxone, cefotaxime, ciprofloxacin, or levofloxacin
• anti-pseudomonal or anti- enterococcal activity not needed

• high risk (elderly, immunocompromised) or severe infection:

• imipenem-cilastatin, meropenem, doripenem, or piperacillin-tazobactam, or
• combination of metronidazole plus cefepime, ceftazidime, ciprofloxacin, or levofloxacin
• Enterococcal coverage recommended

• pediatrics:

• ertapenem, meropenem, imipenem-cilastatin, ticarcillin-clavulanate, or piperacillin-tazobactam, or
• combination of metronidazole plus ceftriaxone, cefotaxime, cefepime, or ceftazidime, or
• combination of gentamicin or tobramycin plus metronidazole or clindamycin, with or without ampicillin

• surgical consultation:

• immediate surgery ( appendectomy) unless patient is poor surgical risk or diagnosis is uncertain [3]
• if patient is poor surgical risk

• treat with intravenous ( IV) antibiotics as long as symptoms are subsiding
• percutaneous drainage for perforation with peri- appendiceal abscess

• surgery should not be delayed because of pregnancy
• delay of surgery for 12-24 hours in clinically stable patients does not affect outcomes [5]

• prognosis

• 0.7% mortality in young healthy adults
• 31% mortality in the elderly with abscess or perforation

More General Terms

• gastrointestinal disease
• acute inflammation

Additional Terms

• appendectomy
• appendix; vermiform appendix

Internet Database

OMIM: 107700

References

1. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 330-31
2. Journal Watch 23(3):26, 2003 Garcia Pena BM et al, Pediatrics 110:1088, 2002
3. Journal Watch 24(4):34, 2004 Kosloske AM et al, Pediatrics 113:29, 2004 PMID: [1] Ziegler MM, Pediatrics 113:130, 2004 PMID: [2]
4. Journal Watch 25(14):111, 2005
   - Rhea JT, Halpern EF, Ptak T, Lawrason JN, Sacknoff R, Novelline RA. The status of appendiceal CT in an urban medical center 5 years after its introduction: experience with 753 patients. AJR Am J Roentgenol. 2005 Jun;184(6):1802-8. PMID: [3]
   - Daly CP, Cohan RH, Francis IR, Caoili EM, Ellis JH, Nan B. Incidence of acute appendicitis in patients with equivocal CT findings. AJR Am J Roentgenol. 2005 Jun;184(6):1813-20. PMID: [4]
   - Chan I, Bicknell SG, Graham M. Utility and diagnostic accuracy of sonography in detecting appendicitis in a community hospital. AJR Am J Roentgenol. 2005 Jun;184(6):1809-12. PMID: [5]
5. Abou-Nukta F et al, Effects of delaying appendectomy for acute appendicitis for 12-24 hours Arch Surg 2006; 141:504 PMID: [6]
6. Prescriber's Letter 17(3): 2010 CHART: Antibiotics for Complicated Intra-Abdominal Infections GUIDELINES: Diagnosis and Management of Complicated Intra- abdominal Infections Detail-Document#: [7] (subscription needed) [8]
7. Vons C et al. Amoxicillin plus clavulanic acid versus appendicectomy for treatment of acute uncomplicated appendicitis: An open-label, non-inferiority, randomised controlled trial. Lancet 2011 May 7; 377:1573 PMID: [9]
8. Pickhardt PJ et al Diagnostic Performance of Multidetector Computed Tomography for Suspected Acute Appendicitis Annals of Internal Medicine June 20, 2011 154(12):789-796 <PubMed> PMID: [10] <Internet> [11]
9. Varadhan KK et al Safety and efficacy of antibiotics compared with appendicectomy for treatment of uncomplicated acute appendicitis: meta-analysis of randomised controlled trials BMJ 2012;344:e2156 <PubMed> PMID: [12] <Internet> [13]
   - Bakker OJ Should conservative treatment of appendicitis be first line? BMJ 2012;344:e2546 <PubMed> PMID: [14] <Internet> [15]
10. Kim K et al. Low-dose abdominal computed tomography for evaluating suspected appendicitis. N Engl J Med 2012 Apr 26; 366:1596. <PubMed> PMID: [16] <Internet> [17]
11. Appendicitis: NIH Institute and Center Resources [18]
12. National Guideline Clearinghouse
    - Clinical policy: critical issues in the evaluation and management of emergency department patients with suspected appendicitis. American College of Emergency Physicians ngc-guideline: [19]

appendicitis