Blood Gas Analysis Review Questions in Clinical Chemistry

I. MULTIPLE CHOICE (Select the BEST ANSWER)

1.    The ideal anticoagulant for arterial blood gas measurements is:
a.    EDTA
b.    Sodium citrate
c.    Lithium heparin
d.    Potassium oxalate
e.    All of the above
f.    None of the above

2.    The kidneys can compensate for nonmetabolic alkalosis by (excretion, retention) of bicarbonate and (increased, decreased) excretion of NaH2PO4.
a. excretion, increased            e.  None of the above
b. retention, increased
c. excretion, decreased
d. retention, decreased

3.    The normal ratio of carbonic acid to bicarbonate in arterial blood is:
a.     1:10                    d.  20:1
b.    7.4:6.1                    e.  None of the above
c.    1:20

4.    If the patient’s arterial  blood gas results are : pH = 7.15, PCO2= 85 mmHg
HCO3 = 35 mmol/L.  What would be your most likely concusion?
a.    partially compensated nonmetabolic acidosis
b.    partially compensated metabolic acidosis
c.    uncompensated nonmetabolic alkalosis
d.    uncompensated metabolic acidosis
e.    None of the above’

5.    If a patient’s arterial blood gas results are pH= 7.38, PCO2 = 35 mm Hg, HCO3 = 27 mmol/L.  What would be your most likely concusion?
a.    Partially compensated nonmetabolic alkalosis
b.    Partially compensated metabolic alkalosis
c.    Uncompensated respiratory alkalosis
d.    Uncompensated metabolic alkalosis
e.    None of the above

6.    The following are precautions for ABG analysis, except:
a.    The specimen should be collected anaerobically
b.    The best receptacle for collection is a glass syringe pre-treated with heparin
c.    If sample is not to be tested immediately, it should be refrigerated or kept in chilled ice.
d.    The temperature of the patient at the time of collection should be noted and recorded
e.    All of the above
f.    None of the above

II. IN THE TABLE BELOW, FILL IN THE CORRECT CHOICES BY USING THE LETTERS OF YOUR CHOICES.

pH

a.    acidic or decrease
b.    alkaline or increase

Concentrations of HCO3 and PCO2:

a.    HCO3 Normal
b.    HCO3 Increased
c.    HCO3 Decreased
d.    PCO2 Normal
e.    PCO2 Increased
f.    PCO2 Decreased

Resulting Condition

a.    Respiratory alkalosis
b.    Respiratory acidosis
c.    Metabolic alkalosis
d.    Metabolic acidosis

Compensatory Mechanism

a.    Increase retention and decrease excretion of HCO3 , H+ excretion by kidneys
b.    Increase excretion and decrease retention of HCO3, H+ retention by kidneys
c.    Increase retention and decrease excretion of CO2  by the lungs
d.    Increase excretion and decrease retention of CO2 by the lungs

Substance or Condition	pH	HCO3	PCO2	Resulting condition	Compensatory Mechanism
Hysteria
Morphine use
Alcohol intoxication
Hyperventilation
Hypoventilation

         


III. PROBLEM SOLVING:

1.    DETERMINE THE pH of the blood sample, if the TCO2 = 22 mmol/L, and the PCO2 is 20 mm Hg. ( 4 pts.)

2.    DETERMINE THE DCO2 IF the H2CO3 is 1.50 mmol/L. ( 2 pts.)

3.    DETERMINE THE pH if PCO2 = 20 mm Hg and HCO3 = 30 mmol/L. ( 4 pts.)

4.    DETERMINE THE pH if the TCO 2 = 28 mmol/L and the PCO2 = 15 mmHg. (5 pts.)

5.    DETERMINE THE ANION GAP If Chloride = 130 mmol/L,  Sodium = 150 mmol/L and HCO3 = 25 mmol/L ( 3 pts)


V. TRANSCRIPTION: ( 1 PT. EACH) Transcribe the acronyms.

1.    TLA______________________________________________
       
2.    NCCLS____________________________________________
           
3.    NIST______________________________________________
               
4.    POC_______________________________________________
           
5.    GGT_______________________________________________
           
6.    BGA_______________________________________________

7.    UDPGT_____________________________________________

8.    OCT________________________________________________

9.    H-H  Equation_________________________________________

10.    PCO2________________________________________________

11.    ALP_________________________________________________

12.      ACP_________________________________________________

13.    LDH_________________________________________________           

14.    CK___________________________________________________

15.    AST__________________________________________________



ANSWER THE QUESTIONS AND RECORD THEM. COME BACK NEXT WEEK TO CHECK YOUR ANSWERS AGAINST THE KEY ANSWERS.