Presentation, diagnosis and management of bowel obstruction Flashcards
Describe roughly the pathophysiology of upper small bowel obstruction?
Acute presentation
Hours of onset
Large volumes vomited
Describe roughly the pathophysiology of distal small bowel/large bowel obstruction?
Colicky abdominal pain and distention
Vomiting (possibly faeculent)
When might vomiting develop earlier in obstruction?
The more proximal the obstruction is
Describe what semi-digested food eaten a day or two perviously (no bile) being vomited would suggest?
Suggests gastric outlet obstruction
Describe what copious bile -stained fluid being vomited suggests?
Upper small bowel obstruction
Describe what thicker brown, foul-smelling vomitus suggests?
A more distal obstruction
What is absolute constipation and what is it a major sign of?
It is neither faeces or flatus passed rectally
It is a sign of bowel obstruction
Describe how symptoms tend to develop in the large bowel obstruction?
More gradually due to the capacity of the colon and caecum and their absorptive activity
What might happen to the caecum in large bowel obstruction?
Due to its thin was the caecum might distend with swallowed air and eventually rupture - closed loop obstruction
What happens in large bowel obstruction if the ileo-caecal valve becomes incompetent?
The small bowel distends, delayed the onset of the symptoms
Describe what might happen in chronic incomplete obstruction?
Can lead to gradual hypertrophy of the muscle of the bowel wall proximally
Peristaltic activity in this hypertrophic muscle is responsible for bouts of colicky pain which can be more prominent than in complete obstruction
What might be some physical signs of intestinal obstruction?
Dehydration - dry mouth, loss of skin turgor and elasticity
Abdominal distention
Visible peristalsis
Relative lack of abdo tenderness
What can a bowel obstruction presenting with abdo tenderness indicate?
Bowel strangulation
What is the most useful investigation for suspected bowel obstruction?
Supine abdo Xray
- bowe proximal to the obstruction is distended with gas
What investigation might be done after the Xray to confirm diagnose and look for a cause?
CT scan
What is the initial management of intestinal obstruction?
Nil by mouth
IV cannula and send blood
Resuscitate with IV fluids, replacing electrolyte losses
Pass a NG tube to decompress stomach
How might adhesions or bands cause bowel obstruction?
Congenital or resulting from previous abdo surgery or peritonitis
What is a volvulus?
A mobile loop of bowel rotates causing obstruction at its neck - causing obstruction
Describe inflammatory strictures as a cause of bowel obstruction?
Crohns disease (inflammation, stricture, fistula...) Diverticular disease
- obstructions usually incomplete
What is intussusception?
A segment of bowel wall becomes telescoped into the segment distal to it
Usually initiated by a mass in the bowel wall
Common in kids
What is bowel strangulation?
A segment of bowel becomes trapped - lumen becomes obstructed
Venous return is obstructed
Rising local intravascular pressure - arterial inflow is compromised
IF strangulation is not relieved this will progress to infarction and perforation
When might bowel strangulation occur?
In external hernia or volvulus
What might pain over a hernia indicate?
Possible strangulation - and its a sign of requiring urgent surgical intervention
What is paralytic ileus?
Disruption of the normal propulsive activity of the GI tract- due to failure of peristalsis
