Lecture 18 - Biochemical Tests

Question 1

Normal Na+ range

Answer 1

136-146 mmol/L

Question 2

Normal K+ Range

Answer 2

3.5-4.6 mmol/L

Question 3

Normal Cl- range

Answer 3

100-110 mmol. L

Question 4

Normal HCO3- range

Answer 4

24-30 mmol/ L

Question 5

Low Na+ risk

Answer 5

Confusion
Seizures,
Coma, death

Question 6

Syndrome of inappropriate ADH

Answer 6

• elevated serum levels of ADH
• plasma osmolality low
• water retention
• increased ECF volume without edema
• concentrated urine

Question 7

Origins of elevated ADH

Answer 7

• ectopic releae from lung

- enhance posterior pituitary release

Question 8

Other causes of low Na+

Answer 8

• diuretics
• MDMA
• Addison’s disease

Question 9

Treatment options for hyponatremia

Answer 9

• treat cause

- water restriction, urea, demeclocycline, vaptans

Question 10

Risk for high Na+

Answer 10

• confusion
• seizures
• coma
• death

Question 11

Diabetes insipidus: High Na+

Answer 11

1) cranial diabetes insipidus: serum ADH low, pituitary tumour, surgery, CNS infections
2) NEphrogenic diabetes insipidus: target organ resistance, Serum ADH high

Question 12

Low K+ risk

Answer 12

• arrythmias

- digoxin toxicity

Question 13

Clinical contexts of low K+

Answer 13

• diurectics
• GI K+ losses (diarrhea, vomiting)
• excessive mineralocorticoid effects

Question 14

High K+ risk

Answer 14

• arrythmias

- asystole due to depolarization

Question 15

Clinical contexts of high K+

Answer 15

• inadequate renal excretion
• addison’s disease (failure of adrenal cortex)
• Metabolic acidosis: K+ leaves cells
• Serious tissue injury

Question 16

PRimary defect in CO2 levels

Answer 16

• elevated CO2: Respiratory acidosis: H+ rises

- decrease CO2: respiratory alkalosis: H+ falls

Question 17

If primary defect is in H+

Answer 17

• high H+ : Metabolic acidosis: HCO3- falls

- low H+ : Metabolic alkalosis: HCO3- rises

Question 18

If primary defect is in HCO3-

Answer 18

• decrease HCO3-: Metabolic acidosis

- increased HCO3- : metabolic alkalosis

Question 19

High bicarbonate: metabolic alkalosis

Answer 19

• arterial pH >7.50

- causes; GI acid loss or high level of antacid intake

Question 20

High bicarbonate: chronic respiratoru acidosis: renal comepnsation

Answer 20

• arterial pH

Question 21

Low bicarbonate: metabolic acidosis

Answer 21

• primary abnormality and or excess tissue H+ production
  Causes: normal chloride (diabetic ketoacidosis or lactic acidosis) or high chloride (intestinal bicarbonate loss or chronic renal failure)

Question 22

Low bicarbonate: chronic respiratory alkalosis - renal compensation causes

Answer 22

• hyperventilation
• hypoxia
• fever
• salicylate toxicity

Question 23

Glucose nromal range

Answer 23

• 3.8 - 6.1 mM

Question 24

Low glucose dangers

Answer 24

• loss of consciousness, seizures, brain damage, death

Question 25

Low glucose causes

Answer 25

- drug induced (diabetics on insulin) - liver failure - insulinoma

Question 26

High glucose: chronically elevated in both type 1 and type 2 diabetics

Answer 26

- accelerated diabetic complications | - prolonged hyperglycemia

Question 27

High glucose in type 1 diabetic

Answer 27

- risk of diabetic ketoacidosis

Question 28

High gluose in type 2 diabetic

Answer 28

- risk of serious dehydration | - risk of hyperosmolar coma

Question 29

Creatinine normal range

Answer 29

- 60 - 120 um | - monitor kidney function

Question 30

High creatinine

Answer 30

Dehydration | - renal failure: acute or chronic

Question 31

Urea normal range

Answer 31

- 3-8mmol/L

Question 32

High urea causes

Answer 32

- enhanced protien breakdown | - renal failure

Question 33

Calcium normal range

Answer 33

2.2-2.6 mM

Question 34

Three main forms of calcium

Answer 34

- bound to albumin (45%) - complexed with organic anions (5%) - ionized (50%)

Question 35

Hyperventilation

Answer 35

- lowers CO2 and lowers H+ in blood - acute increase in plasma pH - negative charge on albumin increase - albumin binds more calcium - ionized calcium drops - dizziness, perioral numbness, paresthesia, tetanic contractions

Question 36

Liver failrue

Answer 36

- albumin synthesis drops - plasma albumin drops - total calcium drops - ionized calcium unchanged

Question 37

Hypocalcemia

Answer 37

- neuromuscular irritability - tetany - cardiac arrythmias - laryngospasm - convulsion - death

Question 38

Causes of hypocalcemia

Answer 38

- familial or sporadic hypocalcemia - hypoparathyroidism or resistance to PTH - chronic renal failure - impaired vit D metabolism - hungry bones

Question 39

Hypercalcemia

Answer 39

- primary hyperparathyoidiusm - malignancy - familial - Vit D intoxication - granulomatous disease

Question 40

Total protein normal range

Answer 40

60-80 g/l

Question 41

Albumin normal range

Answer 41

40-50 g/L

Question 42

Bilirubin normal range

Answer 42

0-18 um - derived from breakdown of heme - elevated bilirubin in enhanced hemolysis or impaired excretion

Question 43

Aminotransferases: AST and ALT

Answer 43

- role in detoxifying aa | - elevated in hepatitis

Question 44

Other enzymes for liver status: ALP, GGT

Answer 44

- ALP: metabolism of organic phosphates - GGT: role in aa transport - both are elevated in biliary stasis or bile duct obstruction - GGT elevated with chronic high ethanol intake