Arterial Blood Gas

Question 1

What does ABG test

Answer 1

PaO2 - oxygen tension
PaCO2 - carbon dioxide tension 
pH - acidity 
SaO2 - oxyhemoglobin saturation 
HCO3 - bicarbonate

Question 2

Indications of ABG

Answer 2

monitoring or identifying acid-base disturbances
assessing response to treatments
evaluation of severity of illness

Question 3

Contraindication of ABG

Answer 3

lack of collateral circulation - Allen’s test
Local infection, clot, abnormal anatomy at puncture site
Severe PVD
Active Raynaud’s syndrome (can decrease collateral circulation)
Relative contraindication: coagulopathy or use of thrombolytic

Question 4

What is the primary regulator of bicarbonate in the body

Answer 4

the kidneys

Question 5

Loss of HCO3- can be seen with

Answer 5

diarrhea causing acidosis

Question 6

loss of H+ can be seen with

Answer 6

vomiting causing alkalosis

Question 7

Respiratory mechanisms

Answer 7

occur very quickly (within minutes) but can not be maintained long-term

Question 8

Metabolic mechanisms

Answer 8

much slower than respiratory (days) but can be maintained indefinitely

Question 9

Hyperventilation

Answer 9

alkalosis

Question 10

hypoventilation

Answer 10

acidosis

Question 11

vomiting

Answer 11

alkalosis

Question 12

diarrhea

Answer 12

acidosis

Question 13

nasogastric tube

Answer 13

alkalosis

Question 14

aldosterone antagonist

Answer 14

acidosis

Question 15

normal value pH

Answer 15

7.35-7.45

Question 16

PCO2 normal value

Answer 16

35-45mmHg

Question 17

HCO3- normal values

Answer 17

22-26 mEq/L

Question 18

anion gap represents

Answer 18

unmeasured anions which are not part of the usual laboratory tests

Question 19

when should you calculate the anion gap

Answer 19

when a patient has metabolic acidosis; will guide differential diagnoses

Question 20

in normal anion gap acidosis

Answer 20

the kidney is attempting to preserve volume by retaining NaCl; therefore, the loss of HCO3- is replaced by Cl- (hyperchloremic metabolic acidosis)