Acute Abdomen Flashcards

Question

How does chronic mesenteric ischaemia present?

Answer 1

postprandial colicky pain due to claudication, this often leads to weight loss as eating is uncomfortable - Chronic mesenteric ischaemia is often called intestinal angina for this reason - Patients will also often have associated vascular disease e.g. TIA, angina On examination patients may have an upper abdominal bruit

Answer 2

Routine bloods and ECG should be carried out to assess CVD risk factors and exclude malnutrition Diagnostic investigation is imaging - Angiography is gold standard

Answer 3

MEdical: limited, only in pts not suitable for surgery and is usually with nitrates Surgical: Transaortic endarterectomy of coeliac os SMA, bypass grafting or angiography and stenting

Answer 4

Caused by compromise of the blood supply to the colon, commonly affecting the splenic flexure The most common cause is atheroma of the mesenteric arteries - Certain factors can predispose to ischaemic colitis, these factors are similar to mesenteric ischaemia

Answer 5

with acute onset abdominal pain, usually in the LIF | - There is often nausea, vomiting, and loose stools containing dark or fresh blood

Answer 6

loods should be the same as in mesenteric ischaemia. Following this there can be further imaging - Erect CXR and AXR - CT can indicate likely ischaemic colitis, further to this there can be either o Colonoscopy can show blue, swollen mucosa with contact bleeding o Barium enema shows thumb-printing with a similar appearance to UC and Crohn’s

Answer 7

Bowel ischaemia often resolves once the cause of hypoperfusion has been alleviated, therefore it is important to give IV fluids and rest the bowel - Surgery is rarely required, and used to correct perforation, necrosis and strictures

Answer 8

Static and dynamic causes. Dynamic is mechanical, static is a failure of peristalsis eg ileus

Answer 9

Small bowel obstruction can be identified by multiple dilated (>3cm) loops of central bowel, completely traversed by valvulae conniventis - Large bowel obstruction can be identified by dilated (>6cm or >9cm at the caecum) loops of peripheral bowel, incompletely traversed by haustra

Answer 10

Intraluminal Foreign body Faecal impaction Gallstone Transmural Neoplasm Stricture (e.g. Crohn’s disease, radiotherapy, diverticular disease, post-operative) Fistula Extraluminal ``` Adhesion (post-operative, infection, inflammation, congenital) Neoplasm Pregnancy Volvulus hernia ```

Answer 11

Adhesions - Hernias - Other causes e.g. foreign bodies, tumours (most commonly benign polyps), strictures, gallstone ileus

Answer 12

Neoplasm (usually primary malignancy) - Structures (usually diverticular) - Faecal impaction - Sigmoid or caecal volvulus o Volvulus is rotation of the gut on its mesenteric axis, more commonly sigmoid o This can produce a severe, rapid, strangulated obstruction

Answer 13

ileo-caecal valve remains competent, therefore there can be no decompression of bowel contents into the small bowel. This is much more dangerous, and likely to perforate Perforation occurs due to increasing pressure leading to decreased venous return, oedema, and decreased arterial supply. This causes necrosis of the bowel wall - Another effect of decreased venous return and oedema is bacterial translocation, risking peritonitis in the absence of perforation

Answer 14

Post-operative - Peritonitis or viscus perforation - Trauma - Metabolic and electrolyte disturbances e.g. uraemia, hypokalaemia - Other acute abnormalities e.g. chest infection, MI, stroke, AKI, DKA, hypothyroidism, pancreatitis

Answer 15

There are four cardinal features of intestinal obstruction. 1. Vomiting, which may be faeculant 2. Colicky pain, this is usually diffuse and central. In paralytic ileus, pain is absent 3. Complete constipation i.e. no flatus or faeces 4. Distension On examination there may be tenderness, highly active ‘tinkling’ bowel sounds on auscultation and hyper-resonant percussion. It is important to check for hernias Severe pain and tenderness suggests ischaemia or perforation

Answer 16

Therefore fluid charts are essential to monitor intake and output, and catheterisation may be needed for an accurate calculation of requirements (lots of third space losses) Routine bloods : clotting, group and save, and cross match as surgery may be required - AXR, looking for air-fluid levels and distention (>3cm in small bowel, >6cm in large bowel, and >9cm in the caecum) - Erect CXR where perforation is suspected - CT scanning can be used where there is diagnostic uncertainty

Answer 17

keep patients NBM and ensure they are catheterised Drip and suck NG tube -decompresses the bowel and reduces the risk of perforation, but also alleviates vomiting - After initial NG placement there should be aspiration of fluid, and then the tube should be left on free drainage

Answer 18

Conservative passage of a flatus tube

Answer 19

strangulation, perforation, or closed-loop large bowel obstruction. For other cases, usually conservative measures will be trialled for 24 – 48 hours before consideration of surgery to alleviate the obstruction

Answer 20

Endoscopic stenting