RIF pain in the ED

read this first: abdominal pain in ED

• appendicitis
• mesenteric adenitis
• terminal ileitis (eg. Yersinia, Crohn's disease)
• gynaecology causes:
  • ectopic pregnancy
  • pelvic inflammatory disease (PID)
  • the patient with an adnexal mass
  • ovarian cyst
  • endometriosis
  • chronic pelvic pain in women
  • rarely, pelvic vein (ovarian vein) thrombophlebitis:
    • usually post-partum or assoc. with gynae. surgery, malignancy or PID
    • fever, RIF pain & R pelvic inflammatory mass
    • +/- retrograde extension into ileo-femoral vessels causing lower leg swelling
    • +/- extension into IVF & risk of PE
• renal colic
• acute pyelonephritis
• testicular torsion
• inflammatory bowel disease (eg. Crohn's disease, ulcerative colitis)
• groin herniae - these are usually occult in women and may cause neuropathic type pains
• uncommonly diverticulitis may cause RIF pain due to either:
  • redundant sigmoid colon lying on the right but usually in those > 50yrs
  • caecal diverticulitis - rare, probably congenital diverticula, usually in the 30's or 40's in Asian men, 80% are within 2cm of ileocaecal valve and nearly all are solitary; 60% are anterior and cause peritonitis; posterior ones may present as a mass simulating carcinoma or present in a more chronic form as a “grumbling appendicitis”
• Low-grade appendiceal mucinous neoplasm (LAMN)
• other causes of chronic RIF pain
  • tuberculosis (TB)
  • chronic caecal amoebiasis due to E.histolytica - may also cause oral ulcers, chronic diarrhoea, and perianal absess/fistulae
  • caecal carcinoma
  • adhesions
  • caecal distension - faeces or flatus
  • abdominal wall nerve entrapment pain - usually discrete area of abdo wall is very sensitive to light touch

• urgent pregnancy test if not already known to be pregnant
  • if pregnant & significant iliac fossa tenderness, Mx as per suspected ectopic pregnancy:
    • ie. FBE, HCG, Gp & Hold, IV access (16G if severe pain), urgent US, senior consult
• examine inguino-scrotal region to exclude hernia/testicular torsion
  • if child with very tender testes, contact paed. surgeon ASAP (within minutes)
  • if adult with tender testes, consider US & epididymo-orchitis vs testes torsion (young adults mainly)
    • if epididymo-orchitis then decide whether most likely UTI-based or STD-based as this will decide choice of anti's (see antibiotic guidelines online).
• FWT urine:
  • if microhaematuria only (BUT absence of microhaematuria does not exclude renal colic), suspect renal colic if Hx fits
    • don't do a KUB Xray (these are only really useful for ongoing monitoring of radio-opaque calculi)
    • consider CT-KUB that day or next day IF pain not settling - avoid unnecessary CT scans, particularly if clinical picture is clear and pain settling
    • consider admission to SSU for pain control
• see WA imaging pathway for RIF pain
  • US is usually preferred imaging modality unless elderly or obese and not pregnant and not a child, in which case contrast CT scan may be considered.
• if paediatric, blood tests not usually needed, consider US if female over age 8-10yrs
• if adult then:
  • FBE + HCG if female aged 13-50yrs.
  • if PH inflammatory bowel disease (IBD) then add erythrocyte sedimentation rate (ESR), C reactive protein (CRP) to assess activity
  • if possible pelvic inflammatory disease (PID) (usually gradual onset pain) then Cx swabs for Chlamydia PCR & m/c/s
  • if possible ovarian cyst or torsion of ovary (usually sudden onset pain) then pelvic US
  • if it seems more likely to be appendicitis, contact surg. reg
    • pain initially epigastric and migrated to RIF with anorexia, nausea +/- low grade fever
    • max. tenderness over McBurney's point
    • +/- Rovsing's sign - rebound tenderness LIF
    • +/- psoas sign (pain on passive extension of the right hip) - esp. likely in retrocaecal appendicitis
    • +/- obturator sign (pain on passive internal rotation of the flexed right thigh) - esp. pelvic appendicitis
    • remember, pelvic appendicitis may have few abdo signs and present with diarrhoea
  • if more likely to by gynae and pain not settling then contact O&G reg.
• if age > 50yrs, consider diverticulitis:
  • suspect if change in bowel habit, tenesmus, esp. if fever but remember WCC only raised in 36%
  • consider CT abdomen with contrast but check renal function first and ensure not on metformin before using iv contrast
• if sudden severe lower abdo. pain, becoming generalised with toxicity/peritonitis consider erect CXR to exclude perforated bowel secondary to diverticulitis
• if working Dx is diverticulitis, then Amoxyl + Flagyl, liquid diet for 48hrs, if more than mild, will need admission.
• if female and post-partum or post gynae surgery then consider pelvic vein thrombosis:
  • pelvic color doppler US +/- CT abdomen