APPENDICITIS, ACUTE

APPENDICITIS, ACUTE - Andrew H.Fenton, MD
BASICS
DESCRIPTION
Acute inflammation of the vermiform appendix
• 1st described by Fitz in 1886
• McBurney described point of maximal tenderness
EPIDEMIOLOGY
• Predominant age
- Ages 10-30: Male > Female (3:2)
- Over age 30: Male = Female
- Rare in infancy
• Predominant sex: Slight male predominance
Incidence
Lifetime incidence 1 in every 15 persons (7%)
Prevalence
• 10/100,000
• Most common acute surgical condition of abdomen
ALERT
Pregnancy Considerations
• Most common extrauterine surgical emergency
• 1 in 2,000 pregnancies
• Difficult diagnosis
• Appendix displaced superolaterally by gravid uterus
• Fetal mortality rate: 2-8.5%
RISK FACTORS
• Adolescent males
• Familial tendency
• Intra-abdominal tumors
Genetics
Unknown
PATHOPHYSIOLOGY
Obstruction of appendiceal lumen
• Fecaliths (most common)
• Lymphoid tissue hypertrophy
• Inspissated barium
• Vegetable, fruit seeds and other foreign bodies
• Intestinal worms (ascarids)
• Strictures


DIAGNOSIS
SIGNS AND SYMPTOMS
• Abdominal pain (100%): Periumbilical, then right lower quadrant; lessened with flexion of thigh
• Muscle guarding
• Anorexia (almost 100%)
• Nausea (90%)
• Vomiting (75%); mild
• Obstipation
• Diarrhea; mild
• Sequence of symptom appearance (95%): Anorexia, then abdominal pain, then vomiting
• Slight temperature elevation (1C)
• Slight tachycardia
• Patient frequently lies motionless with right thigh drawn up
• Maximal tenderness at McBurney point
• Direct and referred right-lower-quadrant tenderness
• Voluntary and involuntary guarding
• Cutaneous hyperesthesia at T10-12
• Rovsing sign: Right-lower-quadrant pain with palpatory pressure in left lower quadrant
• Psoas sign: Pain with right thigh extension
• Obturator sign: Pain with internal rotation of flexed right thigh
• Retrocecal appendix: Flank tenderness in right lower quadrant
• Pelvic appendix: Local and suprapubic pain on rectal exam
ALERT
Pediatric Considerations
• Decreased diagnostic accuracy
• Higher fever, more vomiting
Geriatric Considerations
Decreased diagnostic accuracy
History
Cornerstone of diagnosis, with clinical findings
Physical Exam
• Diagnostic laparoscopy: Consider in young adult females
• Rectal and pelvic examinations
• May need intensive in-hospital observation to allow serial examination
TESTS
Lab
• Moderate leukocytosis: 10,000-18,000/mm3 in 75%
• Moderate polymorphonuclear predominance
• hCG to rule out ectopic pregnancy
• Urinalysis
- Elevated specific gravity
- Hematuria (sometimes)
- Pyuria (sometimes)
- Albuminuria (sometimes)
• Drugs that may alter lab results
- Antibiotics
- Steroids
Imaging
• Used in differential diagnosis and to detect complications
• CT scan: Diagnostic test of choice; also for abscess (1)[B]
Diagnostic Procedures/Surgery
Diagnostic laparoscopy, especially in fertile women (1)[A]
Pathological Findings
• Acute appendix inflammation
• Local vascular congestion
• Obstruction
• Gangrene
• Perforation with abscess (15-30%)
DIFFERENTIAL DIAGNOSIS
• Any cause of acute abdomen
• 75% of erroneous diagnoses accounted for by
- Acute mesenteric lymphadenitis
- No organic pathologic condition
- Acute pelvic inflammatory disease
- Ovarian cyst torsion
- Ruptured graafian follicle
- Acute gastroenteritis
• Also consider
- Urologic causes
- Testicular torsion
- Inflammatory bowel disease
- Colonic disorders
- Other gynecologic diseases
TREATMENT
GENERAL MEASURES
• For nonsurgical patients, antibiotic coverage (e.g., quinolone and metronidazole)
• Recurrence rate too high in other patients to recommend antibiotics as a primary therapy
Diet
NPO
Nursing
Pre-op preparation
SPECIAL THERAPY
IV Fluids
• Fluid resuscitation with LR
• Correct fluid and electrolyte deficits.
MEDICATION (DRUGS)
First Line
• Uncomplicated acute appendicitis: 1 preoperative dose of broad-spectrum antibiotic (2)[A]
- Cefoxitin (Mefoxin)
- Cefotetan (Cefotan)
• Gangrenous or perforating appendicitis
- Broadened antibiotic coverage for aerobic and anaerobic enteric pathogens
- Adjust dosage and choice of antibiotic based on intraoperative cultures.
- Continue antibiotics for 7 days postoperatively or until patient becomes afebrile with normal white count.
- Pathogens usually sensitive to ampicillin, gentamicin, and clindamycin
• Contraindications: Documented allergy to specific antibiotic
• Precautions: Adjust antibiotic dosages for elderly and patients with renal failure.
• Significant possible interactions: Refer to manufacturer's literature for each drug.
Second Line
• Metronidazole (Flagyl): Anaerobic coverage only
• Ampicillin-sulbactam (Unasyn)
• Ticarcillin-clavulanate (Timentin)
• Piperacillin-tazobactam (Zosyn)
SURGERY
Inpatient surgery is appropriate measure
• Immediate appendectomy; laparoscopic favored unless perforation (3)[A]
• Drainage of abscess, if present
FOLLOW-UP
DISPOSITION
Admission Criteria
Complicated appendicitis
Discharge Criteria
Tolerating PO; return of bowel function; afebrile; normal WBC
Issues for Referral
Follow-up with surgeon 1-2 weeks
PROGNOSIS
• Generally uncomplicated course in young adults with nonruptured appendicitis
• Factors increasing morbidity and mortality
- Extremes of age
- Appendiceal rupture
• Morbidity rates
- Nonperforated appendicitis: 3%
- Perforated appendicitis: 47%
• Mortality rates
- Unruptured appendicitis: 0.1%
- Ruptured appendicitis: 3%
- Patients >60 years of age: 50% of deaths from appendicitis
- Elderly patient with ruptured appendix: 15%
ALERT
Pediatric Considerations
• Rupture earlier
• Rupture rate: 15-50%
Geriatric Considerations
Rupture rate: 67-90%
COMPLICATIONS
• Wound infection
• Intra-abdominal abscess; lower rate with antibiotic prohylaxis [2A]
• Fecal fistula
• Intestinal obstruction
• Incisional hernia
• Liver abscess (rare)
• Paralytic ileus
PATIENT MONITORING
Routine visits at 2 and 6 weeks after surgery
REFERENCES
1. Mun S, Ernst RD, Chen K, et al. Rapid CT diagnosis of acute appendicitis with IV contrast material. Emerg Radiol. 2005;17:1-4 [e-pub ahead of print]
2. Andersen BR, Kallehaue FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendectomy. The Cochrane Database of Systematic Reviews 2006 issue 1. John Wiley  Sons, Ltd.
3. Sauerland S, Lefering R, Neugebauer EAM. Laparoscopic versus open surgery for suspected appendicitis. The Cochrane Database of Systematic Reviews 2006 issue 1. John Wiley  Sons, Ltd