General Surgery in the GI Tract Flashcards
What are the main blood investigations available?
VBG, FBC, CRP, urea and electrolytes, LFTs, amylase
What are the main imaging investigations available?
Erect CXR, AXR, CT angiogram, USS
How does bowel ischaemia present?
Sudden onset crampy abdominal pain
Severity of pain depends on the length and thickness of colon affected
Bloody, loose stool
Fever, signs of septic shock
What are some risk factors for bowel ischaemia?
Age >65 yr Cardiac arrythmias Atherosclerosis Hypercoagulation/thrombophilia Vasculitis Sickle cell disease Profound shock causing hypotension
What are the 2 main types of bowel ischaemia?
Acute mesenteric ischaemia
Ischaemic colitis
Describe acute mesenteric ischaemia in terms of area affected, onset and pain severity
It affects the small bowel
Sudden onset
Abdominal pain is out of proportion of clinical signs
Describe ischaemic colitis in terms of area affected, onset and pain severity
It affects the large bowel
Onset is usually more mild and gradual
Moderate pain and tenderness
Is acute mesenteric ischaemia occlusive or not?
Yes, due to thromboemboli
Is ischaemic colitis obstructive or not?
No, usually its due to low flow states or atherosclerosis
When CTAP or CT angiogram is done in bowel ischaemia what does one look for?
Disrupted flow
Vascular stenosis
Transmural ischaemia or infarction
Thumbprint sign
How is bowel ischaemia most often treated?
Usually surgical management is required
What does conservative management of bowel ischaemia involve?
IV fluids Bowel rest Brad spectrum ABx NG tube Anticoagulation Treat the cause
What are signs for surgical management in bowel ischaemia?
Small bowel ischaemia Signs of peritonitis or sepsis Haemodynamic instability Massive bleeding Fulminant colitis with toxic megacolon
What are the main surgical ways of managing bowel ischaemia?
Exploratory laparotomy (resect necrotic bowel etc) Endovascular revascularisation (in patients without signs of ischaemia)
How does acute appendicitis present?
Initially periumbilical pain that migrates to RLQ (within 24hours) Anorexia Nausea +/- vomiting Low grade fever Change in bowel habit
What is the main clinical sign for acute appendicitis?
McBurney’s point: tenderness in the RLQ
What will be seen when bloods are done on a patient with acute appendicits?
FBC shows high neutrophils
Raised CRP
Mild pyuria or haematuria
Electrolyte imbalance if vomiting a lot
How are patients with suspected acute appendicitis imaged?
CT: gold standard in adults esp. if age > 50
USS: children/pregnancy/breastfeeding
MRI: in pregnancy if USS inconclusive
What score chart is used when acute appendicitis is suspected?
Alvarado score
What are the indications for conservative management of acute appendicits?
If imaging is negative and appendicitis is clinically uncomplicated
In delayed presentation with abscess/phlegmon formation
How is acute appendicits managed surgically?
Laparoscopic appedicectomy is preferred over open
What are the advantages of a laparoscopic appendicectomy over an open one?
Less pain Lower incidence of surgical site infection Reduced length of hospital stay Earlier return to work Overall costs Better quality of life scores
Define an intestinal obstruction
Restriction of normal passage of intestinal contents
What are the 2 types of bowel obstruction?
Paralytic (adynamic) ileus
Mechanical
How are mechanical bowel obstructions classfied?
Speed of onset: acute, chronic, acute-on-chronic
Site: high or low
Nature: simple vs strangulating
Aetiology
What is meant by a simple mechanical bowel obstruction?
The bowel is occluded without damage to blood supply
What is meant by a strangulating mechanical bowel obstruction?
The blood supply of involved segment of intestine is cut off
What are some causes of mechanical bowel obstruction originating in the lumen?
Faecal impaction, gallstone ‘ileus’
What are some causes of mechanical bowel obstruction originating in the wall?
Crohn’s disease, tumours, diverticulitis of colon
What are some causes of mechanical bowel obstruction originating outside the wall?
Strangulated hernia (external or internal) Volvulus Obstruction due to adhesions or bands
How do small and large bowel obstruction differ in terms of abdominal pain?
Small bowel= colicky and central
Large bowel= colicky or constant
How do small and large bowel obstruction differ in terms of vomitting?
Small bowel= early onset, large amounts and bilious
Large bowel= late onset, initially bilious and progresses to faecal vomitting
How do small and large bowel obstruction differ in terms of absolute constipation?
Small bowel= its a late sign
Large bowel= its an early sign
How do small and large bowel obstruction differ in terms of abdominal distention?
Small bowel= less significant
Large bowel= significant and an early sign
What happens to hydration levels in bowel obstruction?
Dehydration occours
What sounds will be heard in early or late bowel obstruction?
Early= increased high pitched tinkling sounds Late= bowel sounds absent
What are the 3 things to remember in intestinal obstruction?
It can be diagnosed by the presence of symptoms
Examination should include looking for hernias and abdominal scars
Always try to decide if its simple or strangulating
What features of bowel obstruction indicate that its strangulating?
Change in character of pain from colicky to continuous Tachycardia Pyrexia Peritonism (swelling of peritoneum) Bowel sounds absent or reduced Leucocytosis High C-reactive protein
What are common sites of hernias?
Epigastric Umbilical Incisional Inguinal Femoral
What are the 3 types of hernia?
Neck of sac
Strangulated
Richter’s
What is special about Richter’s hernia?
It isn’t associated with obstruction but neck of sac and strangulated are
In bowel obstruction what happens to WCC and CRP?
They are usually normal but may be raised if there is strangulation or perforation
In bowel obstruction what happens to urea and electrolytes?
There is an imbalance
In bowel obstruction what will VBG show if they are vomiting?
Low chloride
Low potassium
Metabolic alkalosis
In bowel obstruction what will VBG show if there is strangulation?
Metabolic acidosis
What will abdominal x ray show in small bowel obstruction?
Ladder pattern of dilated loops in a central position
What will abdominal x ray show in large bowel obstruction?
Distended bowel that lies peripherally
What are the indications for surgical management of bowel obstruction?
Haemodynamic instability or signs of sepsis
Complete bowel obstruction with signs of ischaemia
Closed loop obstruction
Persistent bowel obstruction >2 days despite conservative management
What surgery is performed for bowel obstruction?
Exploratory laparotomy/laparoscopy
Restoration of intestinal transit
Bowel resection with primary anastomosis or temporary/permanent stoma formation
How does GI perforation present?
Sudden onset severe abdominal pain associated with distention Diffuse abdominal guarding, rigidity, rebound tenderness Pain aggravated by movement Nausea Vomiting Absolute constipation Fever Tachycardia Tachypnoea Hypotension Decreased or absent bowel sounds
What will bloods show in GI perforation?
High neutrophils
Urea and creatinine may be elevated
VBG shows lactic acidosis
What are important differential diagnoses to consider when GI perforation is suspected?
Acute cholecystitis
Appendicitis
Myocardial infarction
Acute pancreatitis
What are indications for surgical management of GI perforation
In generalised peritonitis +/- signs of sepsis
What are the symptoms of biliary colic?
Postprandial RUQ pain that radiates to the shoulder
Nausea
What are the symptoms of acute cholecystitis?
Acute severe RUQ pain
Fever
Murphy’s sign
What is a positive murphy’s sign and when is it used?
A positive Murphy’s sign is seen in acute cholecystitis.
It is elicited by firmly placing a hand at the costal margin in the right upper abdominal quadrant and asking the patient to breathe deeply, if they have pain on inhalation and the gallbladder comes into contact with the hand its positive
What are the symptoms of acute cholangitis?
Charcot’s triad= jaundice, RUQ pain, fever
What are the symptoms of acute pancreatitis?
Severe epigastric pain that radiates to the back
Nausea with possible vomiting
Past history of gallstones
What is volvulus
When a loop of intestine twists around itself and the mesentery that supports it, resulting in a bowel obstruction
What shows up on x ray when someone has volvulus of the large bowel?
Coffee bean sign- its the loop of the large bowel thats been twisted on itself
