CH 20 Right Lower Quadrant Abdominal Pain

Signs of appendicitis

Anorexia (hamburger sign), nausea, vomiting Vague periumbilical pain that shifts to the RLQ Rovsing's: RLQ pain with palpation of LLQ Psoas: RLQ pain on passive extension of the right hip or active flexion of the right hip Obturator: RLQ pain on internal rotation of the hip, typical of a pelvic appendix McBurney's: Tenderness to palpation at McBurney's point

DDX appendicitis

IBD, pancreatitis, cholecystitis, gastroenteritis, nephrolithiasis, perforated duodenal ulcer, pyelonephritis, sigmoid diverticulitis, meckel's diverticulitis In women: PID, ovarian torsion, Mittelschmurz, ruptured ectopic In child: mesenteric lymphadenitis, yersinia enterocolitica (pseudoappy), pneumococcal, gastro, intuss

App special considerations

• Abnormal urinalysis does not rule out an appendicitis • CT is the most sensitive test for appendicitis and may show fecalith, periappendiceal fat stranding, free fluid, or phlegmon • Perforated appendicitis is a result of a closed-loop obstruction creating an ischemic mucosal wall and not a direct result of increased intraluminal pressure • Most common cause of appendicitis is fecalith in adults, and lifetime incidence of acute appendicitis is 6-7 % • Consider pseudoappendicitis in a patient with history suggestive of appendicitis + extensive diarrhea

Pathophys appendicitis

• Closed-loop obstruction • Fecalith in adults, lymphoid hyperplasia in children

Appendicitis labs and imaging

• Elevated WBC with left shift • C-reactive protein • Pregnancy test • Urinalysis: sterile pyuria Imaging • None needed with classic H&P and leukocytosis • US: women and children • Avoid CT in children (increased risk of malignancy) and pregnancy (risk to fetus) • CT: if diagnosis is equivocal in men and nonpregnant women • MRI: pregnant women