Appendicitis

Background

• Most common nonobstetric surgical emergency in pregnancy
• Most commonly caused by luminal obstruction by a fecalith
• There are no historical or physical exam findings that can definitively rule out appy

Clinical Features

• Early on primarily malaise, indigestion, anorexia
  • Later pt develops abdominal pain
    • Initially vague, periumbilical (visceral innervation)
    • Later migrates to McBurney point (parietal innervation)
• Nausea, w/ or w/o emesis, typically follows onset of pain
• Fever may or not occur
• Urinary symptoms common given proximity of appendix to urinary tract (sterile pyuria)
• Sudden improvement suggests perforation
• 33% of pts have atypical presentation
  • Retrocecal appendix can cause flank or pelvic pain
  • Gravid uterus sometimes displaces appendix superiorly -> RUQ pain

Physical Exam

• Rovsing sign (palpation of LLQ worsens RLQ pain)
• Psoas sign (extension of R leg at hip while pt lies on L side elicits abd pain)
• Obturator sign (internal and external rotation of thigh at hip elicits pain
• Peritonitis suggested by:
  • Right heel strike elicits pain
  • Guarding

Clinical Examination Operating Characteristics

Procedure	LR+	LR-
RLQ pain	7.3-8.4	0-0.28
Rigidity	3.76	0.82
Migration	3.18	0.50
Pain before vomiting	2.76	NA
Psoas sign	2.38	0.90
Fever	1.94	0.58
Rebound	1.1-6.3	0-0.86
Guarding	1.65-1.78	0-0.54
No similar pain previously	1.5	0.32
Anorexia	1.27	0.64
Nausea	0.69-1.2	0.70-0.84
Vomiting	0.92	1.12

Work-Up

1. Labs
   1. CBC
      1. Normal WBC does not rule-out appy
   2. UA
      1. Sterile pyuria or hematuria c/w appy
   3. Urine pregnancy
   4. CRP
      1. Normal CRP AND WBC makes appy very unlikely
2. Imaging
   1. Early sx consultation should be obtained before imaging in straightforward cases
   2. Not universally necessary; consider in:
      1. Women of reproductive age
      2. Men w/ equivocal presentation
   3. Modality
      1. US
         1. First choice for pregnant women and children
         2. Findings: noncompressible appendix >6mm in diameter
      2. CT
         1. First choice for adult males and nonpregnant women

DDx

Abdominal Pain#RLQ