Petr Svoboda (28 years) worked as a librarian in the National Library of the Czech Republic. One morning his colleagues found him lying unconscious on the ground. Beside his body lay empty box of Paracetamol 500 mg (all together missing 20 tablets) and half-empty bottle of whiskey. Colleagues called an emergency that transported Mr. Svoboda immediately to the hospital where he was admitted to an intensive metabolic care unit.
The doctor performed physical examination (only pathological findings):
Patient was mildly icteric, in deep coma without reaction to painful stimuli. He breathed irregularly – rate about 18 per minute, heart rate fluctuated at about 120 per minute, blood pressure 105/70 mmHg and temperature 38,6 °C.
Initial laboratory values were:
RBC normal, WBC 28×109/l, Platelets 33×109/l
Glycemia 2,6 mmol/l, Na 138 mmol/l, K 3,9 mmol/l, Ca 2,5 mmol/l, Cl 106 mmol/l, ammonia 156 μmol/l, creatinine 120 μmol/l, total bilirubin 87 μmol/l, conjugated bilirubin 32 μmol/l, ALT 40 μkat/l, AST 27,6 μkat/l, ALP 5,8 μkat/l, GMT 4,9 ukat/l, paracetamol 200 μg/ml
HBsAg negative, anti-HCV negative
INR 2,4; D-dimer significantly increased
Urobilinogen +++, bilirubin +++, otherwise no pathological finding
Mr. Svoboda is in a very deep coma. Could some laboratory finding(s) explain this state? Explain.
How would you assess the function of hemostatic system in Mr. Svoboda?
Doctor took blood to investigate the state of acid-base balance (arterial Astrup). Here are the results:
Arterial blood pH 7,512
PaO2 10,6 kPa
PaCO2 4,84 kPa
HCO3– 27,5 mmol/l
Base excess 4,5 mmol/l
It was apparent that there is an excess of alkaline substances in the body. Can some laboratory result(s) explain this state? Explain.
Doctors performed immediately gastric lavage, gave charcoal and started treatment of liver failure. Level of paracetamol in the blood was so high that administration of N-acetylcysteine was indicated (it is used as an antidote of paracetamol poisoning).
What is the mechanism of paracetamol toxicity?
Why is liver more vulnerable to its effect than other organs?
Is the prognosis of poisoning influenced by some information in patient’s history? Explain.
N-acetylcysteine is used not only as an antidote of paracetamol poisoning, but also as a very effective mucolytic drug. Could you describe how this compound works?
One element of the therapy of acute liver failure is a correct nutrition, which primarily consists of:
1) continuous supply of glucose
2) restriction of aromatic amino acids
3) administration of branched-chain amino acids
Could you explain this?
Despite intensive care, the state of Mr. Svoboda progressively deteriorated. He was therefore indicated for a liver transplantation.