Lecture 18 - Biochemical Tests Flashcards Preview

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Flashcards in Lecture 18 - Biochemical Tests Deck (44):
1

Normal Na+ range

136-146 mmol/L

2

Normal K+ Range

3.5-4.6 mmol/L

3

Normal Cl- range

100-110 mmol. L

4

Normal HCO3- range

24-30 mmol/ L

5

Low Na+ risk

Confusion
Seizures,
Coma, death

6

Syndrome of inappropriate ADH

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

7

Origins of elevated ADH

- ectopic releae from lung
- enhance posterior pituitary release

8

Other causes of low Na+

- diuretics
- MDMA
- Addison's disease

9

Treatment options for hyponatremia

- treat cause
- water restriction, urea, demeclocycline, vaptans

10

Risk for high Na+

- confusion
- seizures
- coma
- death

11

Diabetes insipidus: High Na+

1) cranial diabetes insipidus: serum ADH low, pituitary tumour, surgery, CNS infections

2) NEphrogenic diabetes insipidus: target organ resistance, Serum ADH high

12

Low K+ risk

- arrythmias
- digoxin toxicity

13

Clinical contexts of low K+

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

14

High K+ risk

- arrythmias
- asystole due to depolarization

15

Clinical contexts of high K+

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

16

PRimary defect in CO2 levels

- elevated CO2: Respiratory acidosis: H+ rises
- decrease CO2: respiratory alkalosis: H+ falls

17

If primary defect is in H+

- high H+ : Metabolic acidosis: HCO3- falls
- low H+ : Metabolic alkalosis: HCO3- rises

18

If primary defect is in HCO3-

- decrease HCO3-: Metabolic acidosis
- increased HCO3- : metabolic alkalosis

19

High bicarbonate: metabolic alkalosis

- arterial pH >7.50
- causes; GI acid loss or high level of antacid intake

20

High bicarbonate: chronic respiratoru acidosis: renal comepnsation

- arterial pH

21

Low bicarbonate: metabolic acidosis

- 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)

22

Low bicarbonate: chronic respiratory alkalosis - renal compensation causes

- hyperventilation
- hypoxia
- fever
- salicylate toxicity

23

Glucose nromal range

- 3.8 - 6.1 mM

24

Low glucose dangers

- loss of consciousness, seizures, brain damage, death

25

Low glucose causes

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

26

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

- accelerated diabetic complications
- prolonged hyperglycemia

27

High glucose in type 1 diabetic

- risk of diabetic ketoacidosis

28

High gluose in type 2 diabetic

- risk of serious dehydration
- risk of hyperosmolar coma

29

Creatinine normal range

- 60 - 120 um

- monitor kidney function

30

High creatinine

Dehydration
- renal failure: acute or chronic

31

Urea normal range

- 3-8mmol/L

32

High urea causes

- enhanced protien breakdown
- renal failure

33

Calcium normal range

2.2-2.6 mM

34

Three main forms of calcium

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

35

Hyperventilation

- 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

36

Liver failrue

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

37

Hypocalcemia

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

38

Causes of hypocalcemia

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

39

Hypercalcemia

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

40

Total protein normal range

60-80 g/l

41

Albumin normal range

40-50 g/L

42

Bilirubin normal range

0-18 um

- derived from breakdown of heme

- elevated bilirubin in enhanced hemolysis or impaired excretion

43

Aminotransferases: AST and ALT

- role in detoxifying aa
- elevated in hepatitis

44

Other enzymes for liver status: ALP, GGT

- 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