Intestinal Obstruction Flashcards
symptoms
vomiting: undigested food suggests gastric outlet obstruction, bilous vomiting suggests SBO, faceculent vomiting suggests more distal SBO
pain: colicky abdo pain in early obstruction, pain can be absent in chronic
constipation: may not be absolute in proximal obstruction
distension
signs
distension tinkling, hyperactive bowel sounds dehydration central resonance to percussion, dull flanks scars (adhesions) palpable mass no abdo tenderness unless strangulation rectum will be devoid of faecal matter
intraluminal causes
gallstone ileus
faecal impaction
FB
intramural causes
IBD malignancy strictures (Crohns) NM ileus intussusception diverticular disease
extramural causes
adhesions
volvulus
malignancy
herniae
small bowel obstruction causes
adhesions
hernias
Crohns
intussusception
large bowel obstruction causes
colon cancer
diverticular disease
sigmoid volvulus
constipation
acute obstruction pathology
good peristalsis immobility and distension secretions increase absorption decreases (bacteria flourish) stagnation of bowel distal to obstruction means bacteria multiply
subacute obstruction pathology
time for proximal SM to hypertrophy and overcome blockage
eventually muscle hypertrophy cannot compensate
dilation of bowel
accumulation of swallowed gas and secretions
complications of small bowel obstruction
retroperistalsis
pressure
bacterial proliferation
oedematous and distends (fluid and electrolyte shifts)
retroperistalsis
fluid passes to stomach and faecal vomiting, vomitus is alkaline leading to acidosis
pressure
blood supply impaired due to vessel stretch and ischaemia and necrosis occur leading to diffusion of toxic material into peritoneal cavity and toxaemia –> perforation
bacterial proliferation
proximal and distal to obstruction
inflammation and ulceration
perforation and peritonitis
