Acute Appendicitis Flashcards
What causes appendicitis?
Direct luminal obstruction usually secondary to faecolith (stone made of faeces) but may also be due to lymphoid hyperplasia, impacted stool or rarely an appendices or caecal tumour.
This lead to oedema, ischaemic necrosis and perforation.
What are the risk factors for appendicitis?
Family history
Caucasian ethnicity
Seasonal presentation during summer
What are clinical features of appendicitis?
Abdominal pain:
Initially peri-umbilical dull and poorly localised –> migrates to the right iliac fossa where it is well-localised and sharp
Vomiting, anorexia, constipation or diarrhoea
OE, tachycardia, fever, peritonism with guarding and rebound or percussion tenderness in RIF at Mc Burney’s point
What are important signs found on examination?
Rovsing’s sign - RIF fossa pain on palpation of the LIF
Psoas sign: RIF pain on hip extension of right hip - suggests inflamed appendix in retrocaecal position (hitting posts major muscle)
Where is McBurney’s point?
2/3 way from umbilicus to ASIS
What are differential diagnoses for lower abdominal pain?
Gynaecology: Pelvic inflammatory disease, ectopic pregnancy, ovarian cyst rupture
Renal: Ureteric stones, UTI, pyelonephritis
GI: Diverticulitis, IBD, Meckel’s diverticulum
Urological: Testicular torsion
What investigations for appendicitis?
Bedside:
Urinalysis - UTI, renal/urological cause
Pregnancy test
Bloods:
FBC, CRP (raised WCC and CRP)
Serum beta-hCG for ectopic pregnancy
Imaging:
CT
Transabdominal USS
How can you assess risk of appendicitis?
Alvarado Score
Appendicitis Inflammatory Response score
What is the management for appendicitis?
NBM
Definitive: Laparoscopic appendicectomy
Send appendicitis to histopathology to look for malignancy
Inspect for pathology and MEckel’s diverticulum
Antibiotics - piperacillin/tazobactam
What are complications of appendicitis?
Perforation - commoner if faecolith is present and in young children
Appendix mass - where momentum and small bowel adhere to the appendix. Conservative management - NBM and abx.
Wound infection
Appendix abscess:
Fever with palpable RIF mass -USS and CT to confirm
ABX and percutaneous drainage
What part of the gut refers pain to the epigastrium? What is the blood supply?
Foregut - proximal to 2nd part of duodenum
Coeliac axis
What part of the gut refers pain to the periumbilicus? What is the blood supply?
Midgut - 3rd part of duodenum to 2/3 along transverse colon
Superior mesenteric artery
What part of the gut refers pain to the suprapubic? What is the blood supply?
Hindgut
Distal to 2/3 along transverse colon
Inferior mesenteric artery
Describe the pattern of pain in appendicitis.
Internal organs and visceral peritoneum have no somatic innervation. Early inflammation irritates the structure and walls of the appendix.
The appendix is a midgut structure which corresponds to periumbilical somatic referral. - mid-abdomen.
As the inflammation progresses, the parietal peritoneum is irritated and pain localises to McBurney’s point, 2/3 away from umbilicus to ASIS.
Where does inflamed gallbladder refer pain?
Irritates underside of diaphragm - Phrenic nerve C3 C4 C5
–> Right shoulder dermatomes C3-C5
