Arterial Blood Gas Analysis
OSCE IN PEDIATRICS
FOR PEDIATRICS PRACTICAL EXAMINATION
www.dnbpediatrics.com
SPOT 1
ABG report – Ph – 7.60 / PaCo2 – 30 / PaO2 – 54 mmHg / Bicarb 30.3
Na 120 , K 4 , Blood sugar 180 mg % , BUN 3 , Os...
SPOT 1 ANS
Ans 1 ) Metabolic alkalosis with metabolic alkalosis
Ans2 ) Increase in PaCo2 by 0.5-1 mm H
Ans 3 ) b
Ans 4 ) 3...
SPOT 2
• ABG report
• Ph – 7.343
• PaCo2 – 60
• PaO2 – 47.6 mmHg
• Bicarb 32
www.dnbpediatrics.com
Q
• Interpret this blood gas
www.dnbpediatrics.com
A
• Respiratory acidosis with metabolic
compensation
www.dnbpediatrics.com
Q
• What is normal PaO2 level expected if a
child is breathing at room air with normal
lungs?
www.dnbpediatrics.com
A
• 80-100 mmHg
www.dnbpediatrics.com
Q
• Above mentioned ABG was taken when
patient was inspiring 60% FiO2. Give the
correct option to describe oxygen status o...
A
•Under corrected Hypoxemia
www.dnbpediatrics.com
Q
• What is normal bicarbonate level in a
normal blood gas. Write unit also.
www.dnbpediatrics.com
A
• 24mmol/L
www.dnbpediatrics.com
Q
• What is normal PaCO2 in normal blood
gas – write unit also .
www.dnbpediatrics.com
A
• 40mmHg
www.dnbpediatrics.com
Which patient is more hypoxemic, and why?
• Patient A:
pH 7.48
PaCO2 34 mm Hg
PaO2 85 mm Hg
SaO2 95%
Hemoglobin 7 gm%
• Pa...
ANS
The body needs oxygen molecules, so oxygen content
takes precedence over partial pressure in determining
degree of hyp...
ANS CONT…..
• Patient A: Arterial oxygen content = .95 x
7 x 1.34 = 8.9 ml O2/dl
• Patient B: Arterial oxygen content = .8...
SPOT 4
Calculate Oxygen content in given blood gas
pH-7.465
PaCO2 40.5
PaO2120.3
Bicarb 28.5
SpO2 99%
Hb 8 gm%
www.dnbpedi...
ANS
• 11 ml O2/dl
• FORMULA
(1.34 X HB X SPO2/100)+.003 x PaO2
www.dnbpediatrics.com
True or False:
The pO2 in a cup of water open to the
atmosphere is always higher than the
arterial pO2 in a healthy person...
ANS
• The PO2 in the cup of water is always higher. This is for
several reasons. First, there is no barrier to oxygen
diff...
SPOT 6
State which of the following situations would
be expected to lower a patient's arterial pO2.
There may be none, one...
ANS
Only e) lung disease. . .
a) affects only content, not oxygen
saturation or PO2.
b) through d) affect only oxygen satu...
SPOT 7
What is the pH of a blood sample with
HCO3- 24 mEq/L and PaCO2 80 mm
Hg?
1. 7.10
2. 7.30
3. 7.40
4. 7.50
5. 7.60
ww...
ANS
This is a simple calculation from the
Henderson-Hasselbalch equation; the
answer is 7.1. Even without doing the
calcul...
• A patient is admitted to the ICU with the
following lab values:
• BLOOD GASES under room air
• pH: 7.199
PCO2: 32.2
HCO3...
Q
• Describe metabolic condition
www.dnbpediatrics.com
A
• Metabolic acidosis with partial
compensation
www.dnbpediatrics.com
Q
• Describe compensation (calculate
exact compensation)
www.dnbpediatrics.com
A
• 1 bicarb fall decreases CO2 1-1.5
www.dnbpediatrics.com
Q
• Calculate anion gap
www.dnbpediatrics.com
A
• Anion gap 12
www.dnbpediatrics.com
Q
• Name two conditions with normal anion
gap
www.dnbpediatrics.com
A
• Diarrhoea, RTA
www.dnbpediatrics.com
SPOT 9
• ABG report
• pH 7.343
• PaCO2 60
• PaO2 47.6 mmHg
• Bicarb 32
www.dnbpediatrics.com
Q
• Interpret this blood gas
www.dnbpediatrics.com
A
• Respiratory acidosis with metabolic
compensation
www.dnbpediatrics.com
Q
• What is normal PaCO2 level expected if a
child is breathing at room air with normal
lungs?
www.dnbpediatrics.com
A
• 40 mmHg
www.dnbpediatrics.com
SPOT 10
• 5 year male child recently diagnosed as a case of AML .
TLC 57000. Chest Xray normal. Hemodynamically stable
wit...
Q
Kindly explain blood gas.
www.dnbpediatrics.com
A
• Pseudo Hypoxemia due to oxygen
consumption by high TLC
www.dnbpediatrics.com
Q
• Suggest measure to improve PaO2 in
above patient ?
www.dnbpediatrics.com
A
• Send sample in ICE
www.dnbpediatrics.com
Spot 11
• pH 7.56
• PaCO2 23.7
• PaO2 157 mm Hg
• Actual HCO3 24 (UNDER 50% OXYGEN)
www.dnbpediatrics.com
Q
• DESCRIBE METABOLIC +
OXYGENATION STATUS OF THE
CHILD
www.dnbpediatrics.com
A
• Respiratory alkalosis with Hyperoxia
(overcorrected Hypoxemia)
www.dnbpediatrics.com
Q
• Calculate Aa DO2 , FiO2 50%
www.dnbpediatrics.com
A
• 175
www.dnbpediatrics.com
www.dnbpediatrics.com
https://www.facebook.com/groups/dnbpediatrics/
Upcoming SlideShare
Loading in …5
×

A1

7,092 views
7,110 views

Published on

Published in: Business, Technology
0 Comments
12 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
7,092
On SlideShare
0
From Embeds
0
Number of Embeds
5,497
Actions
Shares
0
Downloads
213
Comments
0
Likes
12
Embeds 0
No embeds

No notes for slide

A1

  1. 1. Arterial Blood Gas Analysis OSCE IN PEDIATRICS FOR PEDIATRICS PRACTICAL EXAMINATION www.dnbpediatrics.com
  2. 2. SPOT 1 ABG report – Ph – 7.60 / PaCo2 – 30 / PaO2 – 54 mmHg / Bicarb 30.3 Na 120 , K 4 , Blood sugar 180 mg % , BUN 3 , Osmolality - 300 Ques 1 - Interpret this blood gas Ques 2 – What change in Paco2 you expect if there is rise in bicarb by 1 mm ? Ques 3 - Above mentioned ABG was taken when patient was inspiring 60% Fio2 . Choose the correct option to describe oxygen status of the patient Corrected hypoxemia Under corrected Hypoxemia Normoxemia Over corrected hypoxemia Ques 4 What will be the PaCo2 level ( assuming normal PaCo2 level of 40 ) if Bicarb decreases by 10 in metabolic acidosis ( give maximum and minimum value ) Ques 5 What is osmolar gap in this patient www.dnbpediatrics.com
  3. 3. SPOT 1 ANS Ans 1 ) Metabolic alkalosis with metabolic alkalosis Ans2 ) Increase in PaCo2 by 0.5-1 mm H Ans 3 ) b Ans 4 ) 30-25 mmHg Ans 5 ) 49 www.dnbpediatrics.com
  4. 4. SPOT 2 • ABG report • Ph – 7.343 • PaCo2 – 60 • PaO2 – 47.6 mmHg • Bicarb 32 www.dnbpediatrics.com
  5. 5. Q • Interpret this blood gas www.dnbpediatrics.com
  6. 6. A • Respiratory acidosis with metabolic compensation www.dnbpediatrics.com
  7. 7. Q • What is normal PaO2 level expected if a child is breathing at room air with normal lungs? www.dnbpediatrics.com
  8. 8. A • 80-100 mmHg www.dnbpediatrics.com
  9. 9. Q • Above mentioned ABG was taken when patient was inspiring 60% FiO2. Give the correct option to describe oxygen status of the patient www.dnbpediatrics.com
  10. 10. A •Under corrected Hypoxemia www.dnbpediatrics.com
  11. 11. Q • What is normal bicarbonate level in a normal blood gas. Write unit also. www.dnbpediatrics.com
  12. 12. A • 24mmol/L www.dnbpediatrics.com
  13. 13. Q • What is normal PaCO2 in normal blood gas – write unit also . www.dnbpediatrics.com
  14. 14. A • 40mmHg www.dnbpediatrics.com
  15. 15. Which patient is more hypoxemic, and why? • Patient A: pH 7.48 PaCO2 34 mm Hg PaO2 85 mm Hg SaO2 95% Hemoglobin 7 gm% • Patient B: pH 7.32 PaCO2 74 mm Hg PaO255 mm Hg SaO2 85% Hemoglobin 15 gm% www.dnbpediatrics.com SPOT 3
  16. 16. ANS The body needs oxygen molecules, so oxygen content takes precedence over partial pressure in determining degree of hypoxemia. In this problem the amount of oxygen molecules contributed by the dissolved fraction is negligible and will not affect the answer. Also, the PaCO2 and pH are not needed to answer the question. www.dnbpediatrics.com
  17. 17. ANS CONT….. • Patient A: Arterial oxygen content = .95 x 7 x 1.34 = 8.9 ml O2/dl • Patient B: Arterial oxygen content = .85 x 15 x 1.34 = 17.1 ml O2/dl • Patient A, with the higher PaO2 but the lower hemoglobin content, is more hypoxemic www.dnbpediatrics.com
  18. 18. SPOT 4 Calculate Oxygen content in given blood gas pH-7.465 PaCO2 40.5 PaO2120.3 Bicarb 28.5 SpO2 99% Hb 8 gm% www.dnbpediatrics.com
  19. 19. ANS • 11 ml O2/dl • FORMULA (1.34 X HB X SPO2/100)+.003 x PaO2 www.dnbpediatrics.com
  20. 20. True or False: The pO2 in a cup of water open to the atmosphere is always higher than the arterial pO2 in a healthy person (breathing room air) who is holding the cup www.dnbpediatrics.com SPOT 5
  21. 21. ANS • The PO2 in the cup of water is always higher. This is for several reasons. First, there is no barrier to oxygen diffusing into the water; thus the PO2 in the cup will be the same as the atmosphere, at sea level approximately 160 mm Hg. • Second, there is no CO2 coming from the cup to dilute the oxygen, as there is in people. • Third, there is no V-Q inequality or shunt; even healthy people have a difference between alveolar PO2 and arterial PO2 for this reason. Thus a healthy person and a cup of water exposed to the atmosphere at sea level would have PO2 values of about 100 mm Hg and 160 mm Hg, respectively. www.dnbpediatrics.com
  22. 22. SPOT 6 State which of the following situations would be expected to lower a patient's arterial pO2. There may be none, one, or more than one correct answer. a) Anemia b) Carbon monoxide poisoning c) An abnormal hemoglobin that holds oxygen with half the affinity of normal hemoglobin d) An abnormal hemoglobin that holds oxygen with twice the affinity of normal hemoglobin e) Lung disease with intra-pulmonary shunting. www.dnbpediatrics.com
  23. 23. ANS Only e) lung disease. . . a) affects only content, not oxygen saturation or PO2. b) through d) affect only oxygen saturation and content, not PO2. www.dnbpediatrics.com
  24. 24. SPOT 7 What is the pH of a blood sample with HCO3- 24 mEq/L and PaCO2 80 mm Hg? 1. 7.10 2. 7.30 3. 7.40 4. 7.50 5. 7.60 www.dnbpediatrics.com
  25. 25. ANS This is a simple calculation from the Henderson-Hasselbalch equation; the answer is 7.1. Even without doing the calculation, it should be apparent that a very high PaCO2 and normal bicarbonate will give a very acidic pH, and that 7.10 is the closest fit. www.dnbpediatrics.com
  26. 26. • A patient is admitted to the ICU with the following lab values: • BLOOD GASES under room air • pH: 7.199 PCO2: 32.2 HCO3: 12.3 PO2: 86.6 • ELECTROLYTES, BUN & CREATININE • Na: 131 K: 4 Cl: 100 www.dnbpediatrics.com SPOT 8
  27. 27. Q • Describe metabolic condition www.dnbpediatrics.com
  28. 28. A • Metabolic acidosis with partial compensation www.dnbpediatrics.com
  29. 29. Q • Describe compensation (calculate exact compensation) www.dnbpediatrics.com
  30. 30. A • 1 bicarb fall decreases CO2 1-1.5 www.dnbpediatrics.com
  31. 31. Q • Calculate anion gap www.dnbpediatrics.com
  32. 32. A • Anion gap 12 www.dnbpediatrics.com
  33. 33. Q • Name two conditions with normal anion gap www.dnbpediatrics.com
  34. 34. A • Diarrhoea, RTA www.dnbpediatrics.com
  35. 35. SPOT 9 • ABG report • pH 7.343 • PaCO2 60 • PaO2 47.6 mmHg • Bicarb 32 www.dnbpediatrics.com
  36. 36. Q • Interpret this blood gas www.dnbpediatrics.com
  37. 37. A • Respiratory acidosis with metabolic compensation www.dnbpediatrics.com
  38. 38. Q • What is normal PaCO2 level expected if a child is breathing at room air with normal lungs? www.dnbpediatrics.com
  39. 39. A • 40 mmHg www.dnbpediatrics.com
  40. 40. SPOT 10 • 5 year male child recently diagnosed as a case of AML . TLC 57000. Chest Xray normal. Hemodynamically stable with RR of 23/min. Normotensive Pulse oximetry showed SpO2 of 98%. ABG report • pH – 7.43 • PaCO2 – 34 • PaO2 – 47.6 mmHg • Bicarb 24 . • Above mentioned ABG was taken when patient was inspiring at room air. www.dnbpediatrics.com
  41. 41. Q Kindly explain blood gas. www.dnbpediatrics.com
  42. 42. A • Pseudo Hypoxemia due to oxygen consumption by high TLC www.dnbpediatrics.com
  43. 43. Q • Suggest measure to improve PaO2 in above patient ? www.dnbpediatrics.com
  44. 44. A • Send sample in ICE www.dnbpediatrics.com
  45. 45. Spot 11 • pH 7.56 • PaCO2 23.7 • PaO2 157 mm Hg • Actual HCO3 24 (UNDER 50% OXYGEN) www.dnbpediatrics.com
  46. 46. Q • DESCRIBE METABOLIC + OXYGENATION STATUS OF THE CHILD www.dnbpediatrics.com
  47. 47. A • Respiratory alkalosis with Hyperoxia (overcorrected Hypoxemia) www.dnbpediatrics.com
  48. 48. Q • Calculate Aa DO2 , FiO2 50% www.dnbpediatrics.com
  49. 49. A • 175 www.dnbpediatrics.com
  50. 50. www.dnbpediatrics.com https://www.facebook.com/groups/dnbpediatrics/

×