Acute Abdomen Flashcards
Different characteristics of abdominal pain and what they indicate…
Colicky pain = gall stones, bowel obstruction
Constant, sharp pain worse on movement/ coughing = peritonitis
Constant dull ache = inflammation
Specific signs on examination which reveal pathology…
- Board like rigidity with positive cough test = peritonitis
- Restless patient in pain = colic
- Cullen’s and Grey Turner’s sign = pancreatitis
- Involuntary guarding = peritonitis
- Rebound tenderness= peritonitis
- Loss of hepatic dullness on percussion = pneumoperitoneum
- Tinkling/ high-pitched bowel sounds = bowel obstruction
Where is abdominal pain referred from and to?
Foregut structures (oesophagus to 2nd duodenum, liver, pancreas) = EPIGASTRIC
Midgut structures (2nd duodenum to 2/3 of transverse colon) = UMBILICAL
Hindgut structures =(distal 1/3 of transverse colon to rectum) = SUPRAPUBIC
Initial management of acute abdo pain…
- Analgesia for the pain
- IV fluids
- Keep NBM (in case need for surgery)
Differential diagnosis dependent on location…
Epigastrium:
- MI
- Oesophagitis/ GORD
- Oesophageal rupture
- Peptic ulcer
RUQ:
- Acute cholecystitis
- Ascending cholangitis
- Hepatitis
- Pyelonephritis
- Basal pneumonia
RLQ:
- Appendicitis
- Salpinigits
- Tubo-ovarian abscess
- Ectopic
- Hernial obstruction
- Meckel’s diverticulum
- Crohn’s
- Psoas abscess
LUQ:
- Ruptured spleen
- Gastric ulcer
- AAA
- Pyelonephritis
- Basal pneumonia
- Perforated colon
LLQ:
- Diverticular disease
- Tubo-ovarian abscess
- Salpingitis
- Ectopic
- UC
- Crohn’s
What key diagnoses need to be ruled out?
- Ruptured AAA
- Peritonitis
- Volvulus
- Appendicitis
- Mesenteric ischaemia
- Torsion of structures
What is Meckel’s diverticulum, and what is the rule of 2s?
Congential diverticulum (outpouching) found at the terminal ilieum. Can cause appendicitis-like pain.
Rule of 2s: 2 % of population affected 2 feet from ileocoecal valve 2 inches long 2 year-olds
Pathophysiology of appendicitis…
Appendical lumen is obstructed by lymphoid hyperplasia, faecolith or foreign body.
This obstruction leads to stasis and bacterial overgrowth causing inflammation and distension of the appendix.
How does appendicitis present?
- Initial peri-umbilical pain which migrates to the RIF as the inflamed appendix irritates the peritoneum causing localisation of pain
- Pyrexia
- Vomiting - but not marked
- Loose stools
- Anorexia - loss of appetite
Examination findings in appendicitis…
- Guarding
- Rebound tenderness in RIF
- Rovsing’s sign= tenderness in RIF when pressing on LIF
- Psoas sign = pain on hip extension = retrocaecal appendix (irritating posterior parietal peritoneum)
Investigations for appendicitis…
Bloods:
- FBC - raised WCC in infection
- CRP
- U&E
- LFTs
- Serum B-hCG in young woman
Imaging:
- USS can show inflammation
- CT - rarely used
Management of appendicitis…
- Prompt referral for surgery: laparoscopic/ open appendicectomy
- Broad spec triple antibiotic therapy to be given before surgery:
- Amoxicillin
- Gentamicin
- Metronidazole
Complications of appendicitis…
- Perforation of appendix
- Appendix mass - covered in omentum
- Appendix abscess - requires drainage and appendicectomy
What are the main types of bowel ischaemia?
- Acute mesenteric ischaemia
- Chronic mesenteric ischaemia
- Ischameic colitis
What are the main causes of acute mesenteric ischaemia ?
- Thrombosis or embolus (60-70%) - mainly after vascular event e.g. MI/ stroke, AF
- Non-occlusive (20%) - low flow to the bowel in low output states e.g. cardiac failure or vasopressors e.g. cocaine
- Venous thrombosis (5%) - coagulation disorders, infection
Clinical triad of acute mesenteric ischaemia…
- Severe, acute abdominal pain - disproportionate to clinical signs
- NO clinical signs of peritonitis/ other pathology
- Hypovolaemia/ shock
Investigations for acute mesenteric ischaemia…
Bloods:
- FBC, U&E, CRP, LFT, amylase, clotting
- ABG - metabolic acidosis due to ischaemia
Imaging:
- Plain AXR = gasless abdomen
- Angiography = gold standard
Other:
- ECG - identify precipitating cardiac cause e.g. MI,AF
Management of acute mesenteric ischaemia…
- Fluid resuscitation is important to prevent shock
- Broad spec antibiotics to prevent SBP
- Viable bowel needs thrombolytic infused via catheter
- Emergency surgery - embolectomy/ angioplasty
- All dead bowel must be removed
What are the causes of chronic mesenteric ischaemia?
Atherosclerotic disease of the mesenteric vessels leading to low flow state which causes ‘intestinal angina’.
Vascular risk factors can all contribute to this condition
Clinical triad of chronic mesenteric ischaemia …
- Severe, colicky post-prandial abdominal pain
- Weight loss
- Upper abdominal bruit
Management of chronic mesenteric ischaemia…
*Diagnosed via CT/ MR angiography
Surgery = percutaneous transluminal angioplasty/ stent insertion, bypass
Long term anticoagulation & nitrates given to those not suitable for surgery.
Causes of ischaemic colitis…
Low flow from IMA leads to poor perfusion- mainly affecting splenic flexure
Presentation of ischaemic colitis…
- Large bowel only
- Lower left abdominal pain
- Bloody diarrhoea
- N+V
Investigations for ischaemic colitis…
- Abdominal x-ray: thumb-printing sign due to mucosal oedema
- Lower GI endoscopy = gold standard: Blue, swollen mucosa with contact bleeding
Management of ischaemeic colitis:
- Conservative management for most patients - regaining perfusion with IV fluids
- Surgical management for more severe cases (peritonitis, hypovolaemic shock) - removal of necrotic bowel and stoma formation
What are the two types of bowel obstruction?
Mechanical = bowel has a physical obstruction, peristalsis is still present
Funtional = lack of peristalsis in specific region of the bowel leading to obstruction
Differentiating features of small and large bowel obstruction on imaging…
Small bowel:
- > 3cm dilatation
- Central loops
- Completely traversed by valvulae conniventes
Large bowel:
- > 6m dilatation in bowel, >9 cm dilatation in caecum
- Peripheral loops
- Incompletely traversed by haustra
Differentiating features between small bowel and large bowel obstruction…
Small bowel:
- Pain higher in the abdomen
- Vomiting
- Less distension
Large bowel:
- More constant pain
- Increased distension
What are the main causes of mechanical bowel obstruction?
Intraluminal:
- Foreign body
- Faecal impaction
- Gallstone ileus
Transmural:
- Neoplasm
- Stricture e.g. IBD, diverticular disease
- Fistula
Extramural:
- Neoplasm
- Adhesions e.g. post-op, infection
- Pregnancy
- Hernia
What are the main causes of SBO and LBO?
Small bowel:
- Adhesions
- Hernias
Large bowel:
- Neoplasms
- Strictures
- Faecal impaction
- Sigmoid volvulus
Why are closed loop large bowel obstructions at more risk of perforation?
- Ileocoecal valve remains competent therefore does not allow bowel contents to move back into small bowel
- This causes increasing distension and so greater risk of perforation
What is sigmoid volvulus?
Large bowel obstruction where the sigmoid bowel twists on its mesentery causing rapid, severe, strangulated obstruction.
Risk factors for sigmoid volvulus…
- Elderly
- Chronic constipation
- Parkinson’s disease
Clinical features of sigmoid volvulus…
- Distended abdominal pain
- Absolute constipation
- Vomiting = late sign
Management of sigmoid volvulus …
Rectal tube insertion with rigid sigmoidoscopy to decompress the obstruction
What is paralytic ileus, and what are the causes?
Functional bowel obstruction where there is loss of normal peristalsis in the bowel Causes include: - Abdominal surgery - Peritonitis - Electrolyte abnormalities (K,P, Mg)
Presentation of bowel obstruction…
Symptoms:
- Vomiting
- Colicky abdominal pain - diffuse and central
- Constipation - absolute in large bowel obstruction
Signs:
- Abdominal distension
- PR= faecal impaction
- High pitched tinkling bowel sounds (absent in ileus)
Management of bowel obstruction…
Strangulated and large bowel obstruction = surgery
Small bowel obstruction = drip and suck:
- NG tube to decompress obstruction, then allow drainage
- IV fluids to make up for third space losses of fluid
What is diverticulosis?
Very common disorder where increased intraluminal pressure in the sigmoid colon forces mucosa to herniate through muscle layers outwards - normally between taenia coli.
What is the difference between diverticulosis, diverticular disease and diverticulitis?
Diverticulosis = the umbrella term for the presence of diverticulum:
- Diverticular disease = pathological and symptomatic diverticulum
- Diverticulitis = infection of the diverticulum
Presentation of diverticular disease…
- Altered bowel habits
- L sided colicky abdominal pain - relieved by defecation
- Rectal bleeding
- Constipation
Investigations for diverticular disease…
Bloods: FBC, U&E, LFT, clotting, VBG (lactate for ?infection)
Imaging: colonoscopy, CT, barium enema - all will identify diverticular disease
Management of diverticular disease…
- High fibre diet can help with sx
- Mebeverine can help with pain
- Mild attacks of diverticulitis can be managed with abx