Other Tests

Question 1

What is the lights criteria for transudate pleural fluid?

Answer 1

• Pleural : serum protein <0.5
• Pleural : serum LDH <0.6
• Pleural fluid LDH <2/3 upper limit of normal

Question 2

What’s the lights criteria for exudate pleural fluid?

Answer 2

• Pleural : serum protein >0.5
• Pleural : serum LDH >0.6
• Pleural fluid LDH >2/3 upper limit of normal

Question 3

What would be the results for acute HepB?

Answer 3

• HBSAg +
• HBEAg +
• HBV DNA +
• Anti-HBS -ve
• Anti-HBC IgM +

Question 4

Which serology markers are +ve in increased replication and infectivity?

Answer 4

• HBEAg

- HBV DNA

Question 5

What is the anti-HBE marker?

Answer 5

Appears in 6 months in chronic infection when there is decreased replication and infectivity.

Question 6

What are the serology markers for hepatitis A?

Answer 6

Acute:
- HAV RNA +
- IgM +
Past exposure or immunised:
- HAV RNA -
- IgG +

Question 7

What does high specific gravity in a urine dip mean?

Answer 7

Increased i.e. concentrated urine

• Dehydration
• SIADH
• HF/renal artery stenosis (decreased renal perfusion)
• Proteinuria

Question 8

What does low specific gravity on a urine dip mean?

Answer 8

Decreased i.e. dilute urine

• Inability to concentrate urine e.g. diabetes insipidus, renal failure
• Excess hydration e.g. psychogenic polydipsia

Question 9

What does bilirubin in the urine indicate?

Answer 9

Conjugated hyperbilirubinaemia

• Bile duct obstruction
• Liver disease

Question 10

What does urobilinogen in the urine indicate?

Answer 10

(Bilirubin conjugated in liver, enter bowel in bile and is converted to urobilinogen)

• Increased: increased bilirubin turnover (haemolytic anaemia), liver disease
• Decreased: bile duct obstruction

Question 11

What are the results from a low dose (1mg) dexamethasone suppression test?

Answer 11

Low cortisol > normal

High/normal cortisol > Cushing’s syndrome

Question 12

What are the results from a high dose (8mg) dexamethasone suppression test?

Answer 12

Low cortisol > Cushing’s disease
High/normal > ACTH low > adrenal Cushing’s
High/normal > ACTH high > ectopic ACTH

Question 13

What are the most common causes of metabolic acidosis?

Answer 13

• DKA
• Lactic acidosis
• Renal failure
• Chronic diarrhoea

Question 14

What causes respiratory acidosis?

Answer 14

• Pneumonia
• COPD exacerbation
• life-threatening asthma (decompensated)
• opiate overdose
• neuromuscular disease
• benzodiazepines overdose
• obesity hypoventilation syndrome

Question 15

What are the causes of respiratory alkalosis?

Answer 15

• Hyperventilation
• PE
• Pneumothorax
• CNS disorders: stroke, haemorrhage, encephalitis
• altitude
• pregnancy

Question 16

What does a normal LP show?

Answer 16

• 0.5/mm3 lymphocytes
• Protein 0.15-0.45g/l
• Glucose 2.8-4.2 mmol/l (>50% blood)
• Other: opening pressure 7-18cm/CSF

Question 17

What does a bacterial LP show?

Answer 17

• Neutrophils + lymphocytes (listeria) - cloudy and turbid
• Protein >0.45g/l
• Glucose: reduced <50%
• Opening pressure: elevated >25cm
• Culture, PCR, blood culture

Question 18

What does a viral LP show?

Answer 18

• Lymphocytes (neutrophils early) - clear
• Protein: raised >0.45g/l
• Glucose: normal 2.8-4.2 mmol/l (>50% blood)
• Opening pressure: normal or elevated
• PCR

Question 19

What does an LP for SAH show?

Answer 19

• Blood-stained initially, then xanthachromia (yellow) >12 hours later
• Opening pressure elevated
• WBC + RBC elevated
• Glucose normal
• Protein elevated

Question 20

What are the causes of transudate pleural fluid?

Answer 20

• HF
• Constrictive pericarditis
• Cirrhosis
• Nephrotic syndrome
• Hypothyroidism

Question 21

What are the causes of exudate pleural fluid?

Answer 21

• Infection - pneumonia, TB
• Inflammation - SLE, rheumatoid arthritis
• Malignancy - lymphoma, mesothelioma