ASSCC 5 Flashcards
Which enzyme would you expect to raise MOST in obstructive jaundice?
Alkaline phosphatase
How do bile salts cause the emulsification of fat?
- Bile salts have a hydrophobic and hydrophilic side
- Hydrophobic side aggregates around fat droplet
- Forms micelle
- Hydrophilic side faces outwards, preventing fat droplets from re-aggregating into larger fat particles
Which enzyme conjugates bilirubin?
Glucuronyl transferase
Explain the enterohepatic circulation:
Bile salts are reabsorbed in the terminal ileum and return them back to the liver
= high rate of production, low rate of secretion
How much bile is secreted in 24hrs?
500-1000ml
4 Causes of pre-hepatic jaundice:
1) Autoimmune haemolytic anaemia
2) Congenital: SCA / hereditary spherocytosis
3) Transfusion reactions
4) Drug toxicity
4 Causes hepatic jaundice:
1) Viral hepatitis
2) Alcohol-related liver disease
3) Fatty liver disease
4) Metastatic disease
5) Congenital unconjugated hyperbilirubinaemia
= Crigler-Najjar, Gilbert’s
3 causes post-hepatic jaundice:
1) Intraluminal - CBD stone
2) Mural abnormalities - Biliary stricture / PSC
3) External compression - Mirizzi’s syndrome, cancer of head of pancreas
5 Physical findings of pt with pulmonary oedema:
1) Extended neck veins
2) Puffiness of face
3) Anxiety, confusion
4) Widespread crepitations
5) Tachycardia, tachypnoea
Initial mx of pt with pulmonary oedema:
1) ABCDE
2) Sit pt up
3) Stop IV infusions
4) Commence high flow O2 aiming sats >94%
5) Consider:
- Morphine for anxiolytic
- IV GTN if sBP >100
- IV Furosemide
- Higher level of support if signs of fatigue/acidosis/resp failure
6) Re-review
CXR findings pulmonary oedema:
1) Alveolar oedema - bat wing
2) Kerley B lines
3) Cardiomegaly
4) Dilated prominent upper lobe vessels
Why is pt with pulmonary oedema at high risk of MI?
- Tachycardia
- Reduced time for filling of coronary vessels during diastole
- Increased oxygen demand to myocardium
Sodium content in 0.9% saline:
154 mmol/L
Sodium content in Hartmann’s:
131 mmol/L
Define enterocutaneous fistula:
Abnormal tract lined by granulation tissue between gastrointestinal tract and the skin
7 causes of enterocutaneous fistula:
FRIENDS:
1) Foreign body
2) Radiation enteritis
3) Inflammatory bowel disease
4) Epithelialized fistula tract
5) Neoplasm
6) Distal obstruction
7) Sepsis
3 complications of enterocutaneous fistula:
1) Sepsis
2) Malnutrition
3) Fluid and electrolyte imbalance
Mx of enterocutaneous fistula:
1) ABCDE
2) Sepsis control
3) Nutritional support - TPN + dietician
4) Adequate fluid and electrolyte replacement
5) Anatomical assessment - MRI/CT/USS exclude abscess/collection
6) Protect skin from excoriation
7) MDT approach
What percentage of fistula will close spontaneously with conservative management?
60%
How would you perform an anatomical assessment of an enterocutaneous fistula?
USS/CT AP to exclude underlying collection/abscess/distal obstruction
MRI fistulogram - locate fistula, delineate length, distal obstruction
7 factors which will prevent spontaneous healing of enterocutaneous fistula:
1) Malnutrition
2) Distal obstruction
3) High output
4) Infection
5) Malignancy
6) Radiation
7) Crohn’s disease
5 causes of confusion, hypoxia and hypotension post TURP:
1) TURP syndrome
2) Effect of sedation + analgesia
3) Hyponatraemia
4) Blood loss
5) Cerebrovascular disease
Define TURP syndrome:
Dilutional hypotonic hyponatraemia
Due to Glycine rich hypotonic irrigation solution absorbed
Why is Glycine used as irrigation fluid in TURP?
As saline fluid limits diathermy use due to electrical conduction properties
6 signs/symptoms of TURP syndrome:
1) Restlessness
2) Confusion
3) Initial HTN followed by hypotension
4) Blurred vision
5) Heart failure
6) Pulmonary oedema
2 causes of confusion in TURP syndrome:
1) Hyponatraemia due to glycine irrigation fluid being absorbed
2) High ammonia - glycine is broken down to ammonia in the liver
What causes hypoxia in TURP syndrome?
Pulmonary oedema
If hyponatraemic, aim to increase by how much per day?
9-10mmol/day
If hyponatraemia corrected too fast, what complication?
Central pontine demyelination
When would you consider hypertonic saline to treat hyponatraemia? How would you give?
If Na+ < 110,
Give 250-500ml 3% saline via central line
Name an osmotic diuretic + MoA:
Mannitol
Acts at PCT, LoH, CD
Inhibits water and sodium reabsorption
Name a Loop diuretic + MoA:
Furosemide
Thick asc LoH
Inhibits Na+/K+/Cl- cotransporter
MoA of thiazide diuretic:
DCT
Inhibits Na+/Cl- cotransport
Name a K+ sparing diuretic + MoA:
Spironolactone
Aldosterone antagonist
DCT, CD
Inhibits sodium reabsorption + potassium secretion
Blood changes in rhabdomyolysis:
- CK 5 times higher than normal
- high lactate
- high creatinine
- hyperkalaemia
- hypocalcaemia
- hyperphoshataemia
- hyperuricaemia
Normal pressure of muscle compartments:
0-15mmHg
At which compartment pressure is fasciotomy indicated?
> 30mmHg
Why does rhabdomyolysis cause acute renal injury?
Myoglobin is oxygen binding protein found in muscle
Rhabdomyolysis = Muscle cell destruction
Release of myoglobin
Myoglobin is nephrotoxic causing acute tubular necrosis
