large bowel obstruction Flashcards
volvulus
- when a loop of intestine twists around itself and the mesentery which supplies it
- causing bowel obstruction
definition
a medical emergency where the intestines’ normal passage of food, fluids, and gas is impeded, requiring immediate medical intervention
epidemiology
- more prevalent in elderly due to inc risk of risk factors
- colorectal cancer most common globally
- diverticular disease leading in western
aetiology
- colonic tumours - most common
- strictures (narrowing) secondary to diverticular disease, inflammatory disease or post-surgical anastomosis
- volvulus - sigmoid/caecal - most common benign
- hernias
- adhesions
signs and symptoms
- cramping abdominal pain
- bloating
- absolute constipation + inability to pass wind or faeces
- potential nausea and vomiting - late signs + more common in SBO
- faeculent vomitting suggests lower level of obstruction
investigations
FBC:
- anaemia + low iron - malignancy
- electrolyte imbalance - fluid shift
- lactate - ischaemia
CEA - colorectal cancer
abdominal Xray
CT abdomen - identify cause + differenciate between caecal and sigmoid volvulus
bowel wall thickness
thickened
valvulae conniventes
not seen in large intenstine
haustra instead
gas pattern
peripheral or haustral pattern
luminal air fluid levels
less frequently seen
stool in colon
often present
birds beak sign
may be seen in LBO
peritoneal fluid
less common unless perforation occurs
management
- drip and suck
- Decompression of sigmoid volvulus - using flexible sigmoidoscope
- surgical intervention - laparoscopic/open colonic resection - may involve primary anastomosis or stoma formation
Palliative stenting - those with malignancies that aren’t fit for surgery - relieved symtpoms
lacroscopic
keyhole surgery
primary anastomosis surgery
The surgeon closes two open ends of the colon - can cut out the part with the obstruction
stoma formation surgery
cut out entire large colon and leave ileum to come out the skin for a bag
most common cause of large bowel obstruction
malignancy - colorectal cancer
embryo sign
- distended loop of large bowel which looks like an upside down human ambryo
- found in caecal volvulus - LRQ
- can be seen in sigmoid volvulus - not in LRQ tho
harttmans procedure
sigmoid colectomy with formation of an end colostomy
coffee bean shape on Xray
sigmoid volvulus
antiemetic of choice for vomitting
IM cyclizine
signs which are in contrast to sbo
late vomiting early constipation
