The acute abdomen Flashcards
What is the pathophysiology of appendicitis?
Appendiceal obstruction: Faecolith, Colorectal neoplasia or lymphoid tissue hyperplasia
Inflammation of wall: Then get ischemia from distention of wall causing mural vessel thrombosis -> can lead to perforation, abscess or peritonitis.
What are the common symptoms of appendicitis?
Central abdo pain that migrates to RIF pain
Anorexia
GI upset
Dysuria
Why is there central/non-specific pain in appendicitis?
Because there is involvement of the visceral peritoneum - autonomic innervation
When does RIF pain occur in appendicitis?
When the parietal peritoneum is involved - somatic nervous system
What clinical signs can be felt in appendicitis?
Tenderness at McBurney’s point
Rovsing’s sign
Mass in RIF
Where is McBurney’s point?
2/3 of distance from umbilicus to ASIS
What is Rovsing’s sign?
Pain in RIF when pressure applied to LIF
What are the differential diagnoses for appendicitis?
Mesenteric adenitis
Meckle’s diverticulum
IBD (Crohn’s)
Diverticulitis
What is Meckel’s diverticulum?
Congenital diverticulum - Vestigial remnant of the vitelline duct.
Which condition does the ‘rule of 2’s’ refer to? What are the rule of 2’s?
Meckel’s diverticulum
2% prevalence
2 inches long
Located 2 feet proximal to the ileocaecal junction
What are the symptoms of Meckle’s diverticulum?
Most are asymptomatic.
PR bleeding
Can cause volvulus or obstruction
Can be inflamed and mimic appendicitis
Can be lined with gastric mucosa causing ulceration
Which investigations are done for suspected appendicitis?
Bloods - High WCC and CRP. High Bilirubin
USS
CTAP
MRI abdo
What might a raised bilirubin in appendicitis indicated?
Complicated appendicitis
How is an appendix mass managed?
Appendix mass = delayed presentation - walled off mass +/- collection
Give antibiotics and percutaneous drainage of collection.
Delayed appendicectomy after acute event settles
What is the recurrence rate of appendicitis if only treated with abx?
40% within 5 years
What is diverticular disease?
Protrusion of mucosal pouches through bowel wall musculature
In which part of the bowel is diverticular disease likely to be seen?
Sigmoid colon
Highest intra-luminal pressure
Linked to constipation
What causes acute diverticulitis?
Micro-perforation of a diverticulum.
Erosion of diverticular wall by increased intraluminal pressure or inspissated food particles, resulting in inflammation.
Progression of inflammation leads to focal necrosis resulting in perforation.
What is the typical presentation of sigmoid diverticulitis?
Abdominal pain - LIF, but can be in RIF as sigmoid mobile.
N+V
Infection signs/sepsis
Change in bowel habits
Rarely PR bleeding
Urinary urgency/frequency/dysuria
Peritonitis
What are the differential diagnoses for sigmoid diverticulitis?
IBS
Colorectal cancer
Acute appendicitis
Epiploic appendagitis
Infectious or Ischaemic colitis
Which investigations are done for suspected sigmoid diverticulitis?
Bloods - Raised WCC + CRP
CTAB to rule out complications (Abscess, obstruction)
Which classification is used to describe perforation of the colon due to diverticulitis?
Hinchey classification
What are the four Hinchey classification stages?
I - Pericolic abscess
II - Remote abscess (pelvic, retroperitoneum)
III - Purulent peritonitis
IV - Faecal peritonitis
How is Hinchey I and II generally treated?
Abx (with abscess <4cm)
Larger abscess may need drainage (Percutaneous or surgical)
How is Hinchey III treated?
Often with surgery - laparoscopy and washout, or laparotomy and resection +/- anastomosis
How is Hinchey IV treated?
Laparotomy and resection +/- anastomosis
What are the main categories of GI perforation?
Ischaemia - obstruction, vascular
Infection - Appendicitis, diverticulitis, colitis
Erosion - Malignancy, ulcerative disease
Physical disruption - Trauma, iatrogenic
What causes oesophageal perforation?
Iatrogenic most common - dilatation at OGD
15% spontaneous - intense vomiting or retching causing increase in intra-oesophageal pressure (Boerhaave’s syndrome)
Foreign bodies
Caustic liquid ingestion (Especially alkalis)
What are the symptoms of oesophageal perforation?
Chest pain
Non specific: back pain, shoulder tip pain, vomiting, SOB, unwell
Mackler’s triad: Vomiting, chest pain, subcutaneous emphysema
Which condition does Mackler’s triad refer to?
Oesophageal perforation
Which investigations are done for oesophageal perforation?
CXR - pleural effusion, air in mediastinum or subcutaneous emphysema
Oral contrast (GOLD STANDARD) - water soluble (as free barium causes high mortality) via XR or CT
Endoscopy
How is oesophageal perforation treated?
NBM, IVI, abx, ITU involvement
Non operative management (If iatrogenic) if small defect, no systemic upset, and able to drain pleural/mediastinal collection.
Surgical repair, drain infection and control further effluence. High risk of mortality.
What is the most common cause of upper GI perforation?
Peptic ulceration
Which infection is linked to peptic ulceration?
H. pylori
90-95% duodenal ulcers
70-85% gastric ulcers
What are the risk factors for peptic ulceration?
H. pylori and NSAIDS biggest factor
Smoking
Steroids
More common in women.
What is the typical presentation of upper GI perforation?
Abdo pain - initially upper then generalised
Sometimes back pain (If retroperitoneal perforation)
Upper GI bleeding
May have history of UGI reflux
Systemically unwell (If free perforation or significant contamination)
How is a perforated ulcer managed?
Occasionally posterior (Retroperitoneal) DU can be managed without surgery
Surgery to close ulcer, omental patch placed over hole, high dose PPI.
H. pylori testing/eradication
Gastric ulcer biopsy for cancer
What are the causes of small bowel perforation?
Ischaemia - strangulated hernia, SMA/SMV thrombosis, SBO
Inflammatory - Crohns
Erosion - Small bowel tumours rare. Lymphoma most common.
Trauma - blunt or penetrating, foreign body, iatrogenic
What is the typical presentation of small bowel perforation?
Abdo pain
Systemically unwell
May have apparent cause - recent surgery, strangulated hernia, Crohns, evidence of bowel obstruction
Which investigations are done in suspected small bowel obstruction?
CT best to confirm perforation and identify site
Erect CXR may show free gas and preferred in unstable patient
How is small bowel obstruction managed?
Surgery most likely
Find perforation, repair, resect, +/- anastomosis (depends on stability and contamination. Stoma may be preferable).
Correct underlying cause
Washout contamination
What is the most common cause of large bowel perforation?
Diverticular disease
More common in men
NSAID use in 30% of cases
smoking increases risk
How does large bowel obstruction present?
History of causative event (recent colonoscopy)
Localised abdo pain (low left or low right)
Systemically unwell
Progressing to generalised peritonitis
Abdo distension (If cause is obstruction)
Closed loop large bowel obstruction and RIF pain 0 suggests impending caecal perforation. Relief of pain can occur initially when perforation occurs.
What does a closed loop large bowel obstruction and RIF pain suggest?
Impending caecal perforation.
Relief of pain can occur initially when perforation occurs.
How is colonic perforation diagnosed?
CT gold standard - establish anatomical site of perforation, identify additional pathology and assist pre-op planning.
How is colonic perforation managed?
Usually surgery - occasionally managed conservatively with percutaneous drainage.
Diseased bowel (cancer or Crohns) will never heal spontaneously
Segmental resection for localised problem
Subtotal colectomy may be needed if: Proctocolitis, Distal obstruction with proximal perforation, Rectal preservation usual in acute setting
Decide on anastomosis or stoma (depends on contamination and patient condition)
What are the symptoms of a rectal perforation?
Pelvic or back pain
PR bleeding
May not be systemically unwell due to containment in pelvis
How are rectal perforations diagnosed?
CT or XR with rectal contrast
MRI - high sensitivity and specificity for rectal pathology
How are rectal perforations managed?
Often conservatively
Complications need intervention - defunction with upstream colostomy, may heal spontaneously them stoma can be reversed
What are some extrinsic compression causes of bowel obstruction?
Abdominal masses
Adhesions/scar tissue (small bowel)
Hernias (mostly small bowel)
Volvulus
What are some bowel wall problems that can cause bowel obstruction?
Neoplasia
Inflammatory or fibrotic stricture/narrowing
Ischaemia
Paralytic ileus
What are some luminal causes of bowel obstruction?
Gallstones
Bezoar (Partially digested material that collects in body)/foreign body
Can bowels still be functional if they are obstructed?
Yes