Acute Appendicitis

Appendicitis is an inflammation of the inner lining of the vermiform appendix

Appendix is continuation of the caecum and is first delineated during 5th month of gestation Worm-like extension –> hence called Vermiform Average length is 8-10 cm ( range 2-20 cm ) Has no fixed position ( hence the variation in presentation and diagnostic difficulty )

No longer thought as vestigeal -repository for commensal bacteria that assist in normal digestive processes and may allow for recolonization of the intestinal flora in times of enteric bacterial destruction ( Rosen’s )

Faecolith Normal stool Lymphoid hyperplasia Indigestible food Mucus Parasites Tumours-Increased intraluminal pressure Bacterial overgrowth Ischaemia Necrosis-Perforation & other complications as
Appendix mass Adhesions
Appendix abscess Peritonitis Sepsis Death

No known genetic cause but increased risk has been observed in some studies in those with a positive family history

Most common acute surgical abdominal emergency Most common non-obstetric surgical emergency in pregnancy Most common between ages 10-20 yrs More common in males Lifetime risk is 8.6 % in males and 6.9 % in females Lifetime appendicectomy rate is 12 % in males and 23 % in females Perforation is found in 13-20 % Normal appendix is found in 15-40 % of patients who have an emergency appendectomy Misdiagnosed in 25-30 % children ( second most common cause of malpractice litigation against emergency physicians )
 Risk factors for appendicitis are
○ Age → most common 10-20 yrs
○ Male sex
○ frequent antibiotic use
○ Smoking ( incl exposure to passive smoking )
○ low fibre diet
○ less than 6 months of breast feeding

Diagnosis-Notoriously difficult to diagnose Classic clinical picture
○ anorexia
○ periumbilical pain followed by 
 RLQ pain
○ Vomiting
 Nausea and vomiting present in 75 %
Vomiting usually occurs once or twice Usually no significant changes in vital signs Fever – mild ( 1* or 1.8 *F rise ) Bowel sounds may be reduced on rt Duration of symptoms is less than 48 hrs in approximately 80 % of adults ( can be longer in elderly or in those with perforation )

Pain-Abdominal pain is the chief complain
○ tenderness on percussion at McBurneys pt ( 2/3rds of the way along a line drawn from umbilicus to the ASISpine )
○ guarding
○ rebound tenderness Migratory pain -> symptoms begin as peri-umbilical or epigastric pain migrating to the RLQ
Sensitivity and specificity of 80 %
Positive likelihood ratio of 3.18
Negative likelihood ratio of 0.5 Pain is worse with movement so patients
lie down
Flex their hips
draw their knees up
 Children – ask them to hop ( refusal indicates pain is worsened by hopping )
 Classical abdominal findings will be absent if appendix is in a atypical position
○ only 40 % of patients have the base of appendix within 3 cm of McBurney’s pt
○ 36 % have the base > 5 cm away – they can present with LLQ , Rt flank or back pain
 Peritoneal signs ( Rovsing’s , Psoas & Obturator ) are less commonly seen

Blood- elevated WCC , CRP , granulocyte count or proportion of polymorphonuclear leukocytes ( > 75 % ) Urine- pregnancy , infection , colic CT ( ideally with contrast ) is the most accurate examination for evaluating patients without a clear clinical diagnosis Scoring systems have been developed ( eg Alvarado score ) but in adults scoring systems have been inadequate as a single method Ultra-sound – limits radiation ( eg preferred in children ) MRI – in pregnancy results comparable following equivocal or inconclusive US

Medical emergency → needs immediate hospital admission Risk of complications increase with duration of symptoms Keep a very low threshold for admitting
○ Infants and young children
○ Elderly people
○ Pregnant women
○ If any signs of complications present It is unclear if antibiotics alone are a suitable treatment for non-complicated appendicitis ( in comparison to surgery )