GI - Large and small intestine Flashcards
what is intestinal failure
when the gut can no longer supply hydration and nutritional needs of body - failure of ability to absorb food via intestines
what is type 1 intestinal failure associated with
short term - post op, chemo
what qualifies as acute intestinal failure
lasting 2 weeks
type 1 and type 2
what is type 2 intestinal failure associated with
sepsis abdo fistula /Crohns metabolic comp ischaemia prolonged surgery comps
what is the treatment of acute intestinal failure
parenteral nutrition if unable to tolerate food/fluid - 7 days post op but allow as much enteral feeding as possible
PPI
Octreotide (reduced bowel movements)
alpha-hydroxycholecalciferol (preserves Mg)
what is type 3 intestinal failure
chronic - SBS
what length of bowel qualifies as SBS
< 200cm functioning small bowel
what is the treatment of chronic SBS
home parenteral nutrition
PPI
if venous access lost or liver disease - transplant
what are some complications of parenteral nutrition
pneumothorax arterial puncture misplacement endocarditis (venous lines) hepatitis (venous lines)
where is access for parenteral nutrition gained
via subclavian/internal jugular vein - US guided
what nutrient deficiencies is referring syndrome associated with
hypokalaemia
hypophosphataemia
hypomagnesaemia
what is referring syndrome
imbalances in fluid and electrolytes leading to cell/organ damage
what can refeeding syndrome result in
arrhythmia
CF
death
what are some s/s of small bowel obstruction
intermittent episodes of colicky pain absolute constipation - no flatus/burping abdominal distension faeculent vomiting high pitched/tinkling bowel sounds (like water against a boat) obstruction may be palpable lack of abdo tenderness visible peristalsis
if copious volumes of bile stained fluid was vomited where would you suspect the obstruction was
upper small bowel
if semi-digested food eaten half a day ago was vomited where would you suspect the obstruction was
gastric outlet
how does bowel obstruction look on an investigation
dilation of bowel proximal to the obstruction and collapsed bowel distal
what are the investigations for bowel obstruction
supine AXR - looks for distension
CT - confirm and look for cause
what is the treatment of bowel obstruction
NBM cannula - take blood and IV fluids NG tube to decompress stomach (drip and suck) anti embolism measures
what are some causes of bowel obstruction
congenital tumour hernia - abode wall/internal volvulus post op comp strictures - Crohn's, Diverticular (usually incomplete) intususceptioin GS ileus adhesions
what is strangulation of the bowel
twisting of bowel in loops around itself cutting off blood supply
what does strangulation of the bowel lead to
progresses to infarction and perforation due to arterial inflow compromise
what are some s/s of strangulation
constant pain "pain over hernia" - can occur in external hernia or volvulus sepsis/shock MSO failure death
what is the treatment of strangulation
urgent surgery
how is perforation of bowel diagnosed
erect CXR - free subphrenic gas
CT may help find source
what is paralytic ileus
Obstruction of the intestine due to paralysis of the intestinal muscles
what are the s/s of paralytic ileus
similar to obstruction but tinkling bowel sounds and pain less common
what is the treatment of paralytic ileus
drip and suck while awaiting restoration of peristalsis
what is pseudo-obstruction (ogilvie’s syndrome)
acute dilation of colon in absence of colonic obstruction in acutely unwell patients
what bowel obstruction is associated with hip replacement CABG spinal anaesthesia pneumonia frail/eldering
pseudo-obstruction
ogilvie’s syndrome
how is pseudo-obstruction diagnosed
AXR +/- CT
confirms gaseous distension proximal to distal rectum
what may be required in pseudo-obstruction
colon may require colonscopic decompression
when is surgery done early in SBO
strangulation
ischaemia
perforation
to prevent dead guts
what does acute mesenteric ischaemia usually affect
small bowel
why is the large bowel less commonly affected by acute mesenteric ischaemia
marginal artery of drummond
what are some s/s of acute mesenteric ischaemia
elderly acute severe abdominal pain poorly localised cramping rapid hypovolaemia --> shock reduced bowel sounds
true/false
acute mesenteric ischaemia is associated with AF
true
what are some causes of acute mesenteric ischaemia
volvulus
SMA thrombosis/embolism
mesenteric vein thrombus - affects smaller lengths of bowel
low flow states - poor CO, post cardiac surgery, renal failure
what are some complications of acute mesenteric ischaemia
gangrene
translocated bacteria across dying gut wall
septic peritonitis
MODS
what is the treatment of sepsis caused by acute mesenteric ischaemia
fluids
gentamicin + metronidazole + heparin
what is the treatment of acute mesenteric ischaemia
surgery to remove dead bowel
revascularisation - arteriography + thrombolysis
what are some tests for acute mesenteric ischaemia
increased Hb increased WCC increased plasma amylase AXR - gasless abdomen CT/MRI angiography
what gut layer is most sensitive to ischaemia
mucosa - most metabolically active
what is chronic mesenteric ischaemia also known as
intestinal angina
what are some s/s of chronic mesenteric ischaemia
severe, colicky post prandial abdominal pain weight loss upper abdominal bruit \+/- PR bleeding malabsorption N+V
often Hx vascular disease
how is chronic mesenteric ischaemia diagnosed
CT/MR angiography
Doppler US
what is the treatment of chronic mesenteric ischaemia
surgery
percutaneous transluminal angioplasty
stent (palliative)
what are some complications of chronic mesenteric ischaemia
scarring and fibrosis –> stricture
gangrene
perforation
what is ischaemic colitis
chronic colonic ischaemia
where does ischaemic colitis most commonly affect
sigmoid colon
who does ischaemic colitis affect
elderly
those at risk of atherosclerosis
what are some s/s of ischaemic colitis
lower left sided abdominal pain
+/- bloody diarrhoea
what does ischaemic colitis look like on a barium enema
THUMB PRINTING OF SUBMUCOSAL SWELLING AT SPLENIC FLEXURE
what are some investigations for ischaemic colitis
colonoscopy + biopsy - gold standard
CT
barium enema
what is the histological appearance of ischaemic colitis
withering of crypts
pink smudgy lamina propria
fewer chronic inflammatory cells
how is ischaemic colitis caused and what can is progress to
low flow in IMA
mild ischaemia
gangrenous colitis
peritonitis/hypovolaemia shock
what is the treatment for ischaemic colitis
fluids and antibiotics
resection of affected bowel (gangrenous colitis) + stoma
true/false
strictures are common in ischaemic colitis
true
what is volvulus and what does it cause
twisting of bowel along mesentery - cause of acute mesenteric ischaemia
obstruction and disruption of blood flow –> infarction –> gangrene
where does volvulus affect elderly
sigmoid
where does volvulus affect young adults
caecum
how is volvulus diagnosed
AXR
what is the treatment of volvulus
flatus tube + sigmoidoscope (removes flatus and fixes volvulus)
surgical resection
what is intussusception
part of intestine invaginate into another section of intestine
often causing obstruction
what is the most common cause of intussusception in children (emergency)
lymphoid hyperplasia due to rotavirus in terminal ileum
leads to intussusception in caecum (ileocaecal junction)
what are the s/s of intussusception
current jelly stool/red currant stool
bullseye appearance on US
what is the most common cause of intussusception in adults
tumour
what is a diverticulum
mucosal herniation through muscle coat usually at sites of arterial perforation - out pouching of gut wall
what is a true diverticulum
involves all layers of the gut wall
what is a false diverticulum
just mucosa and serosa
where are diverticula most commonly found
sigmoid colon
how is diverticulosis diagnosed
incidental finding on endoscopy
what is diverticulitis
inflammation of diverticulum e.g. from blockage - food, seeds
what is the cause of diverticulum
low fibre diet - high intraluminal pressures and stool more liquid so higher pressure contractions needed
what classification is used for acute diverticulitis
hichney
what are some s/s of diverticular disease
LIF pain/tenderness relieved by defecation nausea flatulence if diverticulitis - pyrexia, increased WCC CRP and ESR
what are some investigations for diverticular disease
sigmoidoscopy
Ba enema
CT - first line for diverticulitis
what are some complications of diverticular disease
fistula stricture pericolic abscess haemorrhage - rectal bleeding perforation - shock sepsis
what is the most common fistula associated with diverticular disease
colovesical - bladder
what is the treatment of diverticular disease
fluids/rest/oral ABs
if complicated:
Percutaneous drainage
Hartmann’s procedure
what is Hartmann’s procedure
remove sigmoid colon and attach colostomy bag to descending colon
is meckel diverticulum true or false
true
what is meckel diverticulum
distal ileum contains embryonic remnants of gastric and pancreatic tissue due to the incomplete regression of the vitello-intestinal duct - gastric acid secretion
where does meckel diverticulum occur
60cm from ileocaecal valve
what are some s/s meckel diverticulum
pain
rectal/faecal bleeding
can mimic appendicitis
when does meckel diverticulum usually present
1st 2 years of life
how is meckel diverticulum diagnosed
Technicium Tc 99M scan
what kind of inflammation if crohn’s
transmural