Bowel obstruction Flashcards
Causes of gastrointestinal perforation
Diverticulitis(most common in higher-income countries) Peptic ulcer disease GI malignancy(mainly gastric or colorectal) Iatrogenic Foreign body Appendicitis Mesenteric ischaemia Excessive vomiting
Clinical features of GI perforation
Abdo pain(rapid onset and sharp) Systemically unwell(malaise, vomiting and lethargy) Features of peritonism
Which blood test parameters are raised in bowel perforation
Raised WCC and CRP
Amylase is often mildly elevated
Gold standard for diagnosis of bowel perforation
CT scan confirming the presence of free air and suggesting a location of the perforation
CXR and AXR features of bowel perforation
eCXR may show air under the diaphragm in cases of pneumoperitoneum, whilst an AXR may show either rigler’s sign or psoas sign
Management of bowel perforation
NBM with consideration of nasogastric tube
Broad spectrum antibiotics
Adequate IV fluid resus and appropriate analgesia
Surgical intervention
Surgical intervention for GI perforation
Identification of underlying cause
Thorough washout
Which patients with GI perforation may be managed conservatively
Localised diverticular perforation with only peritonitis and tenderness, and no evidence of generalised contamination on imaging
Patients with a sealed upper GI perforation on CT imaging without generalised peritonism
Elderly frail patients with extensive co-morbidities who would be very unlikely to survive surgery
Early complications of bowel perforation
Haemodynamic instability leading to hypoperfusion, shock, and multi-organ system failure, infection
Late complications of bowel perforation
Delayed wound healing, postop adhesion leading to bowel obstruction, fistula formation and hernias
Risk factors for small intestinal obstruction
May be due to adhesions, strangulated hernia, malignancy or volvulus(majority are due to intra-abdominal adhesions from prior operations)
Risk factors for large intestinal obstruction
Most often the result of colorectal malignancies
Risk of obstruction increases the further down the bowel the lesion is sited, as the contents become more solid
Tumours are often advances and there may be distant mets
Perforation can occur at the site of the tumour or in a dilated caecum
Risk factors for sigmoid and caecal volvulus
Describes rotation of the gut on its mesenteric acis
Usually seen in the elderly or those with psychiatric illness
What is the most common site of volvulus
Sigmoid volvulus
What is paralytic ileus
Bowel ceases to function and there is no peristalsis
Which conditions are associated with paralytic ileus
Chest infection Acute MI Stroke AKI Puerperium Trauma Severe hypothyroidism DKA
Symptoms associated with bowel obstruction
Nausea Vomiting Dysphagia Abdo pain Failure to pass bowel movements Abdo distension Tympany due to an air-filled stomach High-pitched bowel sounds
Examination findings in bowel obstruction
Signs of dehydration Abdo distension Resonant distended bowel Palpable abdo masses Features of peritonism Potential hernias Active and tinkling bowel sounds
IX for bowel obstruction
Fluid charts Plain AXR CT abdomen(Non-contrast CT recommended) Patients with peritoneal fluid evident on CT scan are 3x more likely to require surgical intervention MRI and ultrasound (diagnosis of small bowel obstruction)
Management of uncomplicated bowel obstruction
Fluid resus
Electrolye replacement
Intestinal decompression
Bowel rest
Purpose of endoscopy in bowel obstruction management
Bowel decompression
Dilation of strictures or placement of self-expandable metal stents to restore the luminal flow either as a final treatment or to allow for a delay until elective surgical therapy
Surgical management of intestinal obstruction
Laparotomy(resection of bowel may be required)
Early surgery is required if there is local or generalised peritonitis
Prophylactic antibiotics for gut surgery are advised
Non-surgical treatment for intestinal obstruction
Endoscopic stenting
What is sigmoid volvulus
A large sigmoid loop full of faeces and distended with gas twists on its mesenteric pedicle to create a closed-loop obstruction
If uncorrected, venous infarction leads to perforation and faecal peritonitis
Risk factors for sigmoid volvulus
Elderly Chronic constipation Megacolon, large redundant sigmoid colon and excessively mobile colon More common in men Pregnancy
Presentation of sigmoid volvulus
Sudden-onset colicky lower abdominal pain associated with gross abdo distension and failure to pass either flatus or stool
Vomiting
History of recurrent mild attacks relieved by passage of stool
Shock and an elevation of temp if colonic perforation
What might a delay in diagnosis and treatment of sigmoid volvulus result in
Colonic ischaemia with features of perforation and peritonitis
IX for sigmoid volvulus
Plain AXR
Limited barium enema without bowel prep
CT scan
Results of plain AXR in sigmoid volvulus
Single grossly dilated sigmoid loop commonly reaching the xiphisternum
Management of acute sigmoid volvulus
Majority treated with non-operative decompression(with sigmoidoscope and flatus tube alongside allowing for rapid decompression)
Resection of the redundant sigmoid colon is gold-standard operation(indicated in failure of tube decompression or signs of bowel ischaemia)
Complications of sigmoid volvulus
Recurrence
Bowel obstruction
Perforation and faecal peritonitis
Complications of bowel obstruction
Perforation and ischaemia of the bowel may cause peritonitis and septicaemia
Fluid and electrolyte imbalance –> AKI
Death
What is a sigmoid volvulus associated with
High fibre diet
Excessive use of laxatives
What is gallstone ileus
Occurs when a gallstone passes through a fistula between gallbladder and small bowel before becoming impacted at the ileocaecal valve
Uncommon cause of small bowel obstruction
Typical presentation of gallstone ileus
Recurrent right RUQ pain history
Chronic cholecystitis with repeated inflammatory events
Colicky abdominal pain and distension
Management of gallstone ileus
Surgery is definitive with removal of stone and repair of fistulae accompanied by a cholecystectomy
