GI Emergencies Flashcards
What is peritonitis?
Inflammation of the serosal membrane that lines the abdominal cavity
What are the 2 categories of peritonitis?
Primary peritonitis
Secondary peritonitis
What is the difference between primary and secondary peritonitis?
Primary = spontaneous and not caused by pathology of an other
Secondary = breakdown of the peritoneal membrane leading to foreign substances entering the cavity
What is the peritoneal cavity?
The space between the visceral and parietal layers of the peritoneum
What are the 2 sections of the peritoneal cavity and what joins them?
Greater sac
Lesser sac
Foreman of Winslow
Go to the last slide and label the diagram
1 = parietal peritoneum
2 = visceral peritoneum
3 = peritoneal cavity
4 = greater sac
5 = lesser sac
What usually the cause for primary peritonitis?
Spontaneous bacterial peritonitis (SBP)
What is the pathophysiology of spontaneous bacterial peritonitis? (SBP/primary peritonitis)
An infection of ascitic fluid that cant be attributed to any intr-abdominal, ongoing inflammatory or surgically correctable condition
What condition do patients who have primary/spontaneous bacterial peritonitis have?
End stage liver disease/cirrhosis
How do patients with primary/sponteous bacterial peritonitis present?
Abdominal pain
Fever
Vomiting
How do you diagnose primary/sponetous bacterial peritonitis?
Aspirate the ascitic fluid
If neutrophil count>250cells/mm^3 then it’s Spontaneous Bacterial Peritonitis
What is secondary peritonitis?
The result of an inflammatory process in the peritoneal cavity secondary to inflammation, perofration or gangrene of an Intraabdominal or Retroperitoneal strucutre
What are the 2 types of secondary peritonitis?
Bacterial
Non bacterial
What are some bacterial causes of secondary peritonitis?
Perforated peptic ulcer disease
Perforated appendicitis
Perforated diverticulitis
Post surgery
What are some non bacterial causes of secondary peritonitis?
Tubal pregnancy that bleeds
Ovarian cysts
Blood irritates the peritoneal cavity
How can secondary peritonitis present?
Abdominal pain
Can have gradual or acute onset
Diffuse abdominal pain in perforated viscera
Patients often lie very as movement makes pain worse
Guarding on exam and rebound tenderness
How do you treat secondary peritonitis?
Control infectious source (surgery)
Eliminate bacteria and toxin (abx)
Maintain organ system function
What is bowel obstruction?
A mechanical or functional problem that inhibits the normal movement of gut contents
What are the 2 main causes of bowel obstruction in kids?
Intussusception
Intestinal atresia (congenital defect)
What is intestinal atresia?
When the lumen of intestine fails to recanalise
(Normally the duodenum most commonly affected)
What are the most common causes of bowel obstruction sin adults?
Adhesions
Incarcerated hernias
What is intussusception?
When one part of the gut tube inverts/telescopes into an adjacent section of gut (small intestine inverts into the large intestine)
What is the cause of intussusception?
Motility issues
A mass like a Meckels diverticulum
What is the cause of intussusception?
Motility issues
A mass like a Meckels diverticulum
What is the concern with intussusception?
Can lead to infarction of gut
How can intussusception cause infarction?
The inversion of the part of the gut compresses another part of the gut
This impairs lymphatic and venous drainage leading to oedema
If the oedema is large enough arterial supply is impaired
How does intussusception present?
Abdominal pain
Vomiting
Haematochezia
What is Haematochezia?
Fresh red blood in stool
How is intussusception treated?
Air enema (reverses the inversion)
Surgery
What are some causes of small bowel obstruction?
Adhesions
Hernias (incarcerated groin hernias)
IBD (crohns repeat episodes of transmural inflammation and healing
How does small bowel obstruction resent?
Nausea and vomiting EARLY ON
Abdominal pain (colicky pain) and distension
Absolute constipation (late)
What is meant by colicky abdominal pain?
Comes in waves due to the peristalsis
What point of the small bowel being obstructed would lead to the vomiting being bilious in a small bowel obstruction?
Distal to D2 since this is where bile drains into small intestine/duodenum
How is small bowel obstruction diagnosed?
Hx
Physcial exam (abdominal distension, inc/absent bowel sounds, hernia)
Imaging
What can cause large bowel obstruction?
Colon cancer (most common)
Diverticular disease
Volvulus (sigmoid or caecal)
What is the function of the iliocecal valve and why is it important?
It prevents the backflow of large intestine contents into the small intestine
What is a closed loop obstruction?
Where there are 2 points of obstruction
For example distal to the ileocecal valve
Inc risk of ischaemia and perofration in closed loop obstruction
How does large bowel obstruction present?
Symptoms are gradual if cancer but abrupt with Volvulus
Change in bowel habit
Abdominal distension
Crampy abdominal pain
Nausea and vomiting (late)
How does the nausea and vomiting differ in large and small bowel obstruction?
Small bowel is nausea and vomiting early on
Large bowel is nausea and vomiting late
This is since it takes longer for the gut contents to build up to stimulate vomiting in large bowel obstruction
How is large bowel obstruction diagnosed?
Hx
Physical exam
Imaging
What is a Volvulus?
When the large colon twists around its mesentry
What part of the large intestine is Volvulus most common in ?
Sigmoid colon since faeces are solid, heav and high pressure
What can lead to sigmoi overload?
Constipation
High fibre diets
Which bowel can have an obstruction with a caecal Volvulus?
Small and large since it can back up into the small bowel
What age group do large bowel obstructions typically occur in?
Old
Go to the last slide and fill out the table labelled 2 for small bowel:
1 = colicky/in waves (3-4mins)
2 = relatively early
3 = relatively late
4 = younger
Go to the last slide and fill out the table labelled 2 for large bowel:
1 = colicky/in waves (10-15mins)
2 = relatively late
3 = relatively early
4 = older
Label image 3 saying which bowel is obstructed in each xray:
1 = small
2 = large
How can you tell the difference between a a small bowel and large bowel obstruction on an x-ray?
Small bowel is more central and can see white lines going the full thickness = Plica circularis
Large bowel is more peripheral and are white lines called Haustra which dont span the full thickness
What is Acute Mesenteric Ischaemia?
An MI of the gut
Symptomatic reduction in blood supply to the GI tract
What is a risk factor of acute mesenteric ischaemia?
Female
Hx of peripheral vascular disease
What is more common in acute mesenteric Ischaemia, arterial compromise or venous compromise?
Arterial
What are the main causes of arterial problems leading to acute mesenteric ischaemia?
Acute occlusion:
Arterial embolism in Superior Mesenteric Artery (SMA)
Non occlusive mesenteric ischamiae (hypoperfusion due to low cardiac output like Conjestive Heart Failure)
What is a venous issue that can cause acute mesenteric ischameia?
Mesenteric venous thrombosis
(Systemic coagulopathy and malignancy)
How does mesenteric venous thrombosis cause acute mesenteric ischamia?
Venous blood backs up leading to arterial pressure increasing which decreases perfusion
How does Acute Mesenteric Ischameia present?
Most are elderly patients with CVS risk factors
Excruciating abdominal pain
Pain 30mins after eating since GI demand goes up
Nashua and vomiting
Often pain left sided
Why is pain of Acute Mesenteric Ischamia often left sided?
Splenic flexure has a very poor blood supply (water shed area) only has marginal artery supplying
What investigations are done for Acute Mesenteric Ischaemia?
Blood tests (metabolic acidosis or inc lactate levels indicate ischamia)
CXR for perforation
CT angiography
How is acute mesenteric ischamia treated?
Surgery-resection of ischaemic bowel
Thrombolysis/angioplasty
What are the 2 main causes of Upper GI bleeds?
Peptic ulceration
Oesophageal Varices
What is a peptic ulcer?
When an ulcer forms in the oesophagus, stomach or small intestine
What layers are affected in peptic ulceration?
Mucosa to submucosa through the Muscularis mucosa
What are the 2 main types of peptic ulcers?
Which ones most commmon?
Gastric ulcer
Duodenal ulcer
Duodenal ulcer most common
What artery is at risk if a duodenal ulcer ulcerated posteriorly?
Gastroduodenal artery (behind D1)
What are the most common sites for gastric ulcers?
Lesser curve
Antrum
What artery can a gastric body ulcer ulcerate into?
Splenic artery
What are oesophageal Varices?
Portosystemic anastomoses that become distended due to portal hypertension
What are some pre-hepatic, hepatic and post-hepatic causes of portal hypertension?
Pre-hepatic = portal venous thrombosis
Hepatic = cirrhosis
Post hepatic = hepatic vein thrombosis , right sided heart failure
What veins are involved in the portosystemic anastomoses in oesophageal Varices?
Oesophageal branch of left gastric vein (from portal circ)
To the azygous drainage of the oesophagus (systemic circ)
How is a major upper GI bleed , oesophageal Varices treated?
Endoscopy and band ligation
Blood transfusion (activate Major Haemorrhaging Protocol, blood bank keeps giving blood)
If bleeding not controll3d by banding do TIPS
What is TIPS?
Trans jugular intrahepatic portosystemic shunt
How does a Transjugukar intrahepatic portosystemic shunt (TIPS) help treat a haemorrhaging oesophageal Varices?
Where the portal vein is joined to another hepatic vein to help decrease portal vein pressure
What is an abdominal aortic aneurysm?
The permanent pathological dilation of the aorta with a diameter more than 1.5 times the. Expected Anteroposterior diameter of that segment
Where do the majority of abdominal aortic aneurysms occur?
Below the renal arteries
What layer of the artery wall is normally affected in an abdominal aortic aneurysm?
Tunica media
What is affected in the tunica media of the abdominal aorta in an aneurysm?
Elastin and collagen broken down (smooth muscle fine)
Lumen dilates
What are the risks factors for an Abdominal Aortic Aneurysm?
Male
Family Hx
Old
Smoking
How does an AAA present?
Asymptomatic until acute expansion or rupture
Can compress structures like stomach (vomit), bladder (urine freq) and vertebra (back pain)
Once an AAA has ruptured how does it present?
Abdominal pain raidating to the back
Back
Pain
Pulsatilla abdominal mass
Hypotension leading to syncope
Most die before the hospital
Why do some patients with ruptured AAA survive for longer than others?
Retroperitonuem is small so blood builds up and temporaliy compresses/tamponades the bleed
What is done to investigate/diagnose an AAA?
Physical exam (pulsation abdominal mass)
Ultrasonography
CT
X-rays (if the aneurysm has calcified outside is visible)
What are the non surgical treatments for an AAA?
Smoking cessation
Hypertension control
Surveillance with ultrasounds
What point does an AAA need treatment?
When > 5.5cm (diameter)
What are the 2 types of surgical repair for AAA?
Endovascular repair
Open surgical repair
What is Endovascular repair for an AAA?
Aorta relined using an endograft which is inserted via femoral artery
What is an open surgical repair for an AAA?
Clamp aorta
Open the aneurysm (remove thrombus and debris)
Then suture in a synthetic graft to replace the diseased segment
What drug reduces portal venous pressure?
Terlipressin
