General Flashcards
Who is an autopsy done by?
Pathologist
What are the 2 types of autopsy?
Coronial & conserted
What is a coronial autopsy?
To examine the cause of death
- eg. violent death, suicide, unexplained
What is a conserted autopsy?
To gain insight into pathological processes/hospital care
When does a coroner hold an inquest?
If the death is violent/unexplained/in prison
What is a coroner?
Doctor/lawyer who enquire into deaths
What is the commonest acute admission in under 40s?
Paracetamol overdose
What does paracetamol overdose cause?
Death (necrosis) of liver cells
What are the main functions of the liver?
- glucose/lipid/AA/bilirubin metabolism
- vitamin storage
- sepsis barrier (removes toxins)
What is an idiosyncratic reaction?
Unusual reaction to medication in a person
What are intrinsic hepatotoxins?
Some drugs (eg. paracetamol) cause liver damage in higher doses
What are the 3 pathways for paracetamol metabolism?
SMALL DOSE - glucuronyl transferase
HIGHER DOSE - sulfotransferase
DANGEROUS DOSE - rapqi formation (binds to cell membranes»_space; severe damage)
What can prevent rapqi formation in paracetamol overdose?
Acetylcysteine (» glutathionine)
What is the difference between apoptosis and necrosis?
APOPTOSIS = programmed cell death NECROSIS = rapid death of cells/tissues
What problems does liver cell death cause?
- Enzyme release (AST, ALT)
- Jaundice (no bilirubin metabolism)
- Confusion/coma (failure to detoxify)
- Bleeding (failure to make proteins; FII, FVII, FIX, FX)
- Renal failure (decreased glomerular filatration)
What are the criteria for an emergency liver transplant?
- Prothrombin time >100 seconds (normal: 14)
- Creatinine >300 (normal: 100)
What is the leading cause of death?
Ischaemic heart disease
How is ischaemic heart disease treated?
No cure - just improve symptoms (e.g. medication, exercise)
What is sudden cardiac death?
Umbrella term - unexpected death from loss of heart function
What is hypertrophic cardiomyopathy?
Autosomal dominant disorder
Abnormasl structural proteins»_space; increased LVH»_space; arrythmia/SCD
What is arrythmogenic RV dysplasia?
Abnormal cell-to-cell adhesion»_space; fibrosis of RV muscle
What is the total acid production in the body each day?
TOTAL CO2 - 25 mol/day
UNMETABOLISED ACIDS - 50 mmolday
PLASMA [H+] - 40nmol/day
What are the main buffering systems in the body?
Haemoglobin
Bicarbonate
Phosphate
Proteins
What causes a right-shift on an o2-Hb dissociation curve?
^ 2,3diPG
^ [H+] acidosis
^ Temperature
Where is the dominant site of lactate metabolism?
The liver
What is a co-oximeter used for?
Looks at types of Hb (detects damage)
What are the main compensatory mechanisms in acid-base disorders?
RESPIRATORY (seconds) BICARBONATE REGENERATION (1-2 days) HEPATIC SHIFT(~1 week. Urea synthesis/ammonia excretion)
What is a normal [H+] range?
36-44 nmol/L
What happens during metabolic acidosis?
Increased H+ formation
Increased acid ingestion
Decreased renal H+ excretion
Decreased bicarbonate
Increased H+ and pO2
Decreased pCO2
What happens during metabolic alkalosis?
Increased bicarbonate generation (gastric)
Increased HCO3- generation (renal)
Increased bicarbonate ingestion
Increased H+ excretion (vomit)
Increased pCO2
Decreased H+ and pO2
What happens during respiratory acidosis?
CO2 retention (inadequate ventilation, decreased perfusion, parenchymal lung disease)
Increased H+ and pCO2
Decreased pO2
What happens during respiratory alkalosis?
Increased CO2 excretion (^ventilation)
Increased pO2
Decreased H+ and pO2
What are the consequences of metabolic alkalosis?
K+»_space; cells & urine
PO4»_space; cells
Respiratory supression
What are the 2 types of lactic acidosis?
Type a - shock
Type b - metabolic & toxic causes
What causes increased H+ formation? (4)
Ketoacidosis
Diabetes
Poisoning
Alcohol
What causes acidosis in alcoholics?
NAD+ depletion
»thiamine deficiency
»enhanced glycolysis for ATP
» keto-acids
How does renal failure cause reduced H+ excretion?
Reduced volume of nephrons
» increased bicarbonate loss
» reduced NH4+ excretion
