Arterial Blood Gas Flashcards Preview

I&M for Anesthesia - Fall 2013 > Arterial Blood Gas > Flashcards

Flashcards in Arterial Blood Gas Deck (58):
0

Arterial blood gas is an essential part of diagnosing and managing

Oxygenation status
Ventilation failure
Acid base balance

1

Normal pH range

7.35-7.45

2

Normal PaO2 range

80-100 mmHg

3

Normal PaCO2 range

35-45 mmHg

4

Normal HCO3 range

22-26 mmol/L

5

Bicarbonate is a _________ value.

Calculated

6

The base excess indicates the amount of excess or insufficient level of

Bicarbonate

7

Normal range of BE
A negative BE indicates a base

-2 to 2 mEq/L
Deficit in the blood

8

Normal SaO2

>95%

9

A normal [H+] of ______ corresponds to a pH of 7.40

40 nEq/L

10

Changes in pH are inversely related to changes in [H+]. A decrease in pH is associated with

An increase in [H+]

11

How much CO2 does the body produce daily?

15,000 mmol

12

How much nonvolatile acids does the body produce daily?

50-100 mEq nonvolatile acids

13

What organs attempt to maintain balance of acids in the body?

Lungs and kidneys

14

These two buffers work in pairs

carbonic acid and base bicarbonate

H2CO3 and NaHCO3

15

The respiratory buffer response maintains that blood pH will change according to the level of ____ which triggers the lungs to

H2CO3
Increase or decrease the rate and depth of ventilation

16

Activation of the lungs to compensate for an imbalance starts to occur within

1-3 min

17

The renal buffer response is that kidneys excrete or retain bicarbonate. If blood pH decreases, the kidneys will compensate by

Entraining HCO3

18

How long can it take the renal system to correct an imbalance?

Hours to days

19

If decreased pH
Increased CO2
Decreased ventilation

Respiratory acidosis

20

What can cause respiratory acidosis

CNS depression
Pleural disease
COPD/ARDS
Musculoskeletal disorders
Compensation for metabolic alkalosis
All of these can decrease ventilation

21

What is the difference between acute and chronic respiratory acidosis?

Acute - little kidney involvement
Chronic - renal compensation via synthesis and retention of HCO3

22

With acute resp acidosis, pH decrease by ___ for 10 mmHg increase in CO2

0.08

23

Retention of CO2 results in decreased

Chloride

Can lead to hypochloremia because the body wants to balance charges

24

With chronic resp acidosis, pH decreases by __ for 10 mmHg increase in CO2

0.03

25

If increased pH
Decreased CO2
Increased ventilation

Respiratory alkalosis

26

What can cause respiratory alkalosis?

Inter cerebral hemorrhage
Salicylate and progesterone drug usage
Anxiety, which decreases lung compliance
Cirrhosis of the liver
Sepsis

27

What is the difference between acute and chronic respiratory alkalosis?

Acute - HCO3 decreases by 2 mEq/L for every 10 mmHg in PCO2
Chronic - HCO3 decreases by 4

28

Respiratory alkalosis causes decreased bicarb _____ and decreased ______ excretion to normalize pH

Reabsorption, ammonium

29

If decreased pH
Decreased HCO3

Metabolic acidosis

30

What is Winter's formula and what does it tell you?

PCO2 = 1.5(HCO3) + 8 +/- 2

The degree of compensation for metabolic acidosis

31

How long does it take for complete activation of respiratory compensation?

12-24 hours

32

For met acidosis, there is a decrease of ____ for every decrease of 1 mEq/L HCO3

1.2 mmHg

33

Causes of metabolic gap acidosis

Methanol
Uremia
DKA
Paraldehyde
INH
Lactic acidosis
Ethylene glycol
Salicylate

34

Causes of nongap metabolic acidosis

Hyperalimentation
Acetazolamide
RTA (calculate urine anion gap)
Diarrhea
Pancreatic fistula

35

If increased pH
Increased HCO3

Metabolic alkalosis

36

In metabolic alkalosis, PCO2 increases by ___ for every increase of 1 mEq/L in HCO3

0.7

37

Metabolic alkalosis is caused by

Vomiting
Diuretics
Chronic diarrhea
Hypokalemia
Renal failure

38

Mixed acid base disorders describes ___ acid base disorders at one time

Two or more

39

What is the delta gap? What value equals metabolic alkalosis?

Delta HCO3 = HCO3 + change in anion gap
> 24

40

What kind of respiratory problem is it if pH and PaCO2 move in opposite directions?

Primary

41

What kind of problem is it if pH and HCO3 are moving in the same direction?

Primary

42

What level of Pao2 indicates hypoxemia?

< 80 mmHg

43

Change in PaO2 is associated with a change in pH, the disorder is ______. If the compensatory process brings the pH to within the clinically acceptable range (7.30 - 7.50), the disorder is

Acute, chronic

44

The estimate of how much strong base or acid needed to correct the metabolic component of an acid base disorder is

Base excess

45

The formula for the amount needed to correct an acid base disorder is

0.3 x body weight x BE

46

Formula for anion gap

AG = (Na + K) - (Cl + HCO3)

47

T or F. The system does not have the ability to overcompensate.

False

48

If pH remains outside of the normal range after compensation, then it is

Partially compensated

49

In a compensated state, when the pH decreases, PaCO2 should also decrease because

The lungs are acting as a buffer response

50

Always strongly suggest a metabolic acidosis

High anion gap

51

Ketones present, diabetic ketoacidosis

Hyperglycemia

52

Hypokalemia and or hypochloremia

Suggests metabolic alkalosis

53

Common with normal anion gap acidosis

Hyperchloremia

54

Elevated creatinine and urea

Suggests uremic acidosis or hypovolemia (prerenal renal failure)

55

Elevated creatinine

Consider ketoacidosis

56

Consider ketoacidosis or hyperosmolar nonketotic syndrome

Elevated glucose

57

Urine dipstick test for glucose and ketones

Glucose - hyperglycemia
Ketones - ketoacidosis