appendicitis

see also:

• the patient with acute abdominal pain in the ED
• appendiceal faecoliths
• general surgery

• 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
• clinical diagnosis can be very difficult in young children, the elderly, the pregnant patient or those with atypical presentations
• Alvarado appendicitis probability scoring tool

• nil orally
• iv fluids - 0.9% saline
• baseline FBE, U&E plus HCG if female
• consider blood culture if temp > 38.5deg C
• urinalysis
• commence fluid balance chart
• analgesia as needed
• consider PR exam if atypical history or findings as it maybe helpful in diagnosing a pelvic appendicitis which tends to present with minimal abdominal findings and often some diarrhoa
  • PR exam is generally NOT indicated in children
• ensure pregnancy and gynaecologic causes of the pain have been reasonably excluded

• surgical team to obtain consent, book theatre
• pre-op CXR, ECG if comorbidities or elderly
• fast for minimum 6 hours if clinically possible
• maintain iv therapy
• surgical shave in theatre
• DVT prophylaxis as per surgical protocol
• if signs of peritonitis, commence antibiotics as below ASAP rather than just at induction of anaesthesia

• Aust. Therapeutic Guidelines recommend prophylactic dual Rx for appendicitis with metronidazole AND either cephazolin or gentamicin
• however, many surgeons will prefer triple Rx (as per peritonitis) with:
  • amoxycillin/ampicillin 2g (child: 50mg/kg up to 2g) 6h iv, PLUS,
  • gentamicin 4mg/kg (usually 320mg in an adult for 1st dose and 6mg/kg for children > 10yrs) iv daily and adjust for renal function, PLUS
  • metronidazole 500mg (child: 12.5mg/kg up to 500mg) iv 12h
• NB: patients with hypersensitivity (HS):
  • immediate HS to penicillins:
    • use vancomycin instead of amoxycillin
  • non-immediate HS to penicillin &/or HS to gentamicin:
    • use ceftriaxone instead of both amoxycillin and gentamicin

• ongoing antibiotics post-op:
  • not needed if normal appendic or only mildly inflamed appendix
  • if necrotic/purulent appendix or signs of peritonitis then:
    • iv ampicillin 1g qid plus iv gentamicin 4-6mg/kg daily (subsequent doses according to age, CRN levels, gentamicin levels) plus iv metronidazole 500mg tds
    • if gentamicin C/I, then use iv timentin 3.1g 6hrly
    • complete 5-7 day course depending on clinical response - cease when afebrile > 24hrs and normalising WCC
    • if responding well, consider changing to oral augmentin duo forte i bd after 48 hours
• routine post-op obs
• diet when tolerated, iv fluids until then
• encourage mobilisation
• encourage regular analgesia to allow mobilisation

• written and verbal discharge instructions:
  • no vigorous exercise or lifting > 10kg for 4 weeks, then increase exercise slowly
  • can shower
  • can drive a motor vehicle when able to move comfortably (eg. 2-3 weeks)
  • normal diet as tolerated
  • contact LMO or hospital if fevers, wound inflammation or excessive nausea occurs
• sick certificate
• surgical team to check histopathology within 2 weeks
• outpatient follow up appt within 2 weeks if complicated case, otherwise at 6 weeks

• patients with atypical history and examination findings may be considered for admission under the general surgical unit and monitored rather than going to theatre initially
• continue initial Mx as above but no antibiotics
• at least bd reassessment by surgical team
• iv fluids
• fluid balance chart
• 4/24 obs
• record bowel movements / passage of flatus
• repeat WCC
• mobilise as tolerated
• educate why patient needs to rest gut - ice chips only or fast until decision regarding surgery has been made
• if pain settles and not for surgery, diet as tolerated
• if pain does not settle within 24 hours, consider CT abdomen with contrast (after excluding pregnancy and gynaecologic conditions)
• discharge when:
  • tolerating diet
  • haemodynamically stable
  • bowel function returning to normal
• discharge planning:
  • advise patient to see GP within 7 days
  • provide written and verbal discharge instructions to patient
  • check if outpatient appointment is required
  • check if sick certificate is required

• currently this is NOT practiced in most Western centres but an Italian study in 2010 suggests it may be practical¹⁾:
  • patients with severe illness or complications ⇒ surgery
  • other patients admitted for short term observation and Rx with amoxycillin/clavulanic acid:
    • if worse or no improvement ⇒ surgery
    • otherwise home on antis:
      • within 7 days 12% had failed Rx and required surgery
      • of the remainder over 2 years, 14% had recurrence of appendicitis (none after the initial 15 days?):
        • 2/3rds settled with antibiotics
        • 1/3rd went to surgery
        • did not appear to increase mortality or morbidity

• derived from South Australia's Flinders Medical Centre surgical guidelines 2007 for Mx of appendicitis