17 GI Emergencies Flashcards
What is peritonitis?
Inflammation of serosal membrane that lines abdominal cavity
Peritoneal cavity usually= sterile
=infectious or sterile
- Can be:*
- Primary- spontaneously (eg bacterial- see later)*
- Secondary- breakdown of peritoneal membranes- foreign substance enters cavity*
What structure divides the supracolic and infracolic compartments?
What structure connects the greater and lesser sacs? (abdomen)
Foramen of winslow
Epiploic foramen
How is primary peritonitis usually caused? (SBP) (what is the patient likely to have)?
SBP= spontaneous bacterial peritonitis
Infection of ascitic fluid - CANNOT BE ATTRIBUTED to any intra-abdominal, ongoing inflammatory or surgically correctable condition
Patient likely to have: end stage liver disease (liver cirrhosis)
How is secondary peritonitis caused? (process)
Inflammatory process in peritoneal cavity
…secondary to pathology relating to intrabdominal or retroperitoneal structure:
- Inflammation
- Perforation
- Gangrene
Give some specific causes of secondary bacterial peritonitis (bacterial and non bacterial). (6)
Bacterial:
- Peptic ulcer disease (perforated)
- Appendicits (perforated)
- Diverticulitis (perforated)
- Post surgery
Non-bacterial:
- Ectopic pregnancy (tubule) that bleeds
- Ovarian cyst
Blood= highly irritant to peritoneal cavity
What are the symptoms of peritonitis?
- Abdominal pain (may be diffuse from viscera)
- Fever
- Vomiting
More mild with primary peritonitis, more severe with secondary
Patient may lie very still, knees flexed, shallow breathing
How are primary and secondary peritonitis diagnosed and treated?
Diagnosed: aspirating ascitic fluid- neutrophil count > 250 cells/mm3
- Control infectious source
- Surgery may be required
- Antibiotics
- Maintain organ system function
- Intensive care
Give some common causes of bowel obstruction in a) children (2) and b) adults (2)
Children:
- Intussusception
- Intestinal atresia
Adults:
- Adhesions
- Incarcerated hernias
What is intussusception? How is it caused?
One part of gut tube telescopes into adjacent section
Causes (not well known):
- motility issues
- mass causing telescoping action= lead point
- Meckel’s diverticulum
- Enlarged lymph node
What are the consequences of intussusception? (include symptoms) (5)
Oedema-as lymphatic and venous drainage impaired
Infarction- arterial supply impeded
Abdominal pain
Vomiting
Haematochezia (red currant jelly stools- mucus and blood- in children)
How is intussusception treated?
Air enema
(A therapeutic enema using air or a contrast material solution may be performed to create pressure within the intestine and “un-telescope” the intussusception while relieving the obstruction)
Surgery
Give some causes of a small bowel obstruction:
- Intra-abdominal adhesions
- arise after > 50% surgeries
- direct trauma/post operative infection
- capillary bleeding–> exudation of fibrinogen
- Hernias
- Narrow lumen
- incarcerated groin hernias= most common
- Narrow lumen
- IBD
- Crohn’s
- repeated inflammation- healing causes narrowing
- Crohn’s
Apart from small bowel obstruction, give 2 other consequences of adhesions:
- Abdominal pain
- Secondary infertility
How is the diagnosis of a small bowel obstruction made?
History= intermittent- crampy abdominal pain
Physical examination= abdominal distension, increased/absent bowel sounds, presence of hernia
Imaging eg AXR
What are the symptoms of a small bowel obstruction? (4)
- Nausea and vomiting (early)
- Abdominal pain (3-4mins)
- Abdominal distension
- Absolute constipation (late)
Give some causes of large bowel obstruction (typically affects older generation).
Colon cancer (60%)
Diverticular disease
Volvulus- sigmoid, caecal
What are the symptoms for a large bowel obstruction? How do they differ if they are caused by a volvulus/cancer?
Symptoms:
- Abdominal distension
- Crampy abdominal pain
- Nausea/ vomiting (later)
Cancer: gradual; Volvulus: sudden
Change in bowel habit seen with cancer
Where is a volvulus most likely to occur? What are some of the risk factors for a volvulus?
Where?
- Sigmoid colon- 60%
- Caecum - will cause small and large bowel obstruction
Risk factors?
- Extra mass ie constipation- elongates sigmoid mesenteric attachment
- High fibre diet- sigmoid overloading
- Cancer
AXR- coffee bean sign
What are the risk factors for acute mesenteric ischaemia (3) and what are some of the specific causes (3)?
How does acute mesenteric ischaemia present?
(can be difficult to diagnose as symptoms can be non specific)
- Abdominal pain= disproportionate to clinical findings
- Pain=
- classically 30mins after meal and lasts 4hrs
- Often on left side because blood supply to splenic flexure= most fragile
- Pain=
- Nausea and vomiting
What investigations can be done into suspected acute mesenteric ischaemia?
- Blood tests
- metabolic acidosis/increases lactate levels
- Erect chest x-ray (check for perforation)
- CT angiography- intravenous contrast
What are some of the causes of acute upper GI bleeding?
- Peptic ulceration
- Oesophageal varices
- normal pressure in portal vein= around 5-10mm Hg, problems happen around 10+ mm Hg
Where do the oesophageal veins drain into (portal drainage and systemic drainage)?
How is a major upper GI bleed due to oesophageal varices treated?
- Band ligation
-
TIPS
- Transjugular intrahepatic portosystemic shunt
- bridge portal vein and hepatic vein
- reduce variceal pressure and ascites
- Drug treatment: Terlipressin
- reduce portal venous pressure
Define an abdominal aortic aneurysm. (AAA) Below which areteries do most aneurysms occur?
- Permanent pathological dilation of aorta
- Diameter >1.5x expected anteroposterior diameter of that segment (given patient’s sex and body size)
- usually 3cm
>90% of aneurysm= below RENAL ARTERIES
How is an abdominal aortic aneurysm usually caused? What are the risk factors?
(most AAAs= asymptomatic)
Cause?
- Degeneration of media layer of arterial wall
- Degradation of elastin and collagen - lumen gradually dilates
Risk factors?
- Male
- Inherited risk
- Increasing age
- Smoking
Abdominal aortic aneurysms are usually asymptomatic until acute expansion or rupture. How is it going to present if there is acute exapansion or rupture?
Compressing nearby structures: stomach, bladder, vertebrae
- Nausea
- Pain
- abdominal, back, flank, groin
- Pulsatile abdominal mass
- Transient hypotension
- syncope- retroperitoneum can temporarily tamponade bleed
- Sudden CVS collapse (65% ruptured AAAs die before hospital)
How is an abdominal aortic aneurysm diagnosed?
How is an aortic aneurysm treated? (not ruptured)
Non surgical
- Smoking cessation
- Hypertension control
- Surveillance of AAA
- less than 5.5 cm- conservative management
- more than 5.5cm- refer to vascular surgeons
Surgical
- Endovascular repair - reline aorta with endograft inserted through femoral artery
How do you treat an abdominal aortic aneurysm that has acutely expanded or ruptured?
