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Methods II > Acid/ Base Management > Flashcards

Acid/ Base Management Flashcards

1
Q

base excess refers to a patient’s (metabolic/ respiratory) acid/base status

A

metabolic

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2
Q

What does base excess tell us clinically?

A

an ABG value that reveals if patient has too much or too little base in the blood

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3
Q

Normal base excess

A

-2 to 2 mmol/L

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4
Q

What is negative base excess value?

What does it mean?

How do you treat it?

A

below -2mmol/L

there is not enough base in the body; metabolic acidosis

treated with bicarb

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5
Q

What is a positive base excess value?

What does it mean?

How do you treat it?

A

above 2mmol/L

there is too much base in the body; metabolic alkalosis

treated by reversing the cause of alkalosis

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6
Q

A high concentration of H+ ions will = (high/low) pH?

A

low= acidotic (acid)

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7
Q

a low concentration of H+ ions will = (high/low) pH?

A

high= alkalosis (basic)

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8
Q

What is the normal pH range?

A

7.35-7.45 (7.4)

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9
Q

pH > 7.45 = (acidosis/alkalosis)?

A

alkalosis

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10
Q

pH < 7.35= (acidosis/alkalosis)?

A

acidosis

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11
Q

What is pH determined by?

A

HCO3-/ PaCO2 ratio

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12
Q

6 consequences of Acidosis:

  1. contractility?
  2. catecholamines?
  3. bleeding?
  4. vasculature?
  5. arrythmias?
  6. ion concentrations?
A
  1. decrease cardiac contractility
  2. decrease the response to catecholamines
  3. impair coagulation and increase bleeding
  4. increase PVR
  5. Makes Vfib more likely
  6. increases plasm K+
    - H+ enters the cell and K+ exits
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13
Q

5 consequences of Alkalosis:

  1. hemoglobin?
  2. vasculature? (3)
  3. ion concentrations?
A
  1. Shifts the oxyhemoglobin dissociation curve to the left
    - hemoglobin will bind oxygen more tightly
  2. increase SVR
  3. Cerebral vasoconstriction
    - because of the left shift of the oxyhemoglobin curve
  4. Decreases PVR
  5. decreases plasma K+ concentration
    - H+ exits the cell and K+ enters
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14
Q

What is a normal venous CO2 measurement?

A

24-30 mEq/L

*includes both the CO2 dissolved in plasma and the HCO3- dissolved in plasma

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15
Q

What is a normal arterial HCO3- measurement?

A

22-26 mEq/L

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16
Q

normal PaCO2

A

35-45 mmHg

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17
Q

normal PvCO2

A

40-50 mmHg

~5 mmHg higher than PaCO2

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18
Q

What does the PaCO2 and PvCO2 gradient tell you about your patient?

A

If the PaCO2 and PvCO2 gradient increases, the patient is poorly perfused

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19
Q

PaO2 of the atmosphere (at sea level)

A

160mmHg

-O2 makes up 21% of atmospheric pressure 760mmHG

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20
Q

normal PaO2

A

70-100 mmHg

-decreases with age

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21
Q

normal PvO2

A

30-40mmHg

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22
Q

normal CaO2

A

16-20 mL/ dL

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23
Q

normal CvO2

A

12-16 mL/dL

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24
Q

normal DO2 (total delivery of oxygen per minute)

A

1000 mL of oxygen delivered per minutes

*assumes normal hemoglobin (15g/dL), normal SaO2 of (97.5%), and normal cardiac output (5 L/min)

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25
Q

normal mvO2

A

60-80% (in awake patients)

90% with 100% FiO2

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26
Q

normal SaO2

A

93-98%

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27
Q

normal ScvO2

A

70-75%

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28
Q

normal A-a gradient in room air

A

5-15mmHg

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29
Q

normal A-a gradient in elderly patients

A

15-25mmHg

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30
Q

normal A-a gradient on FiO2 of 100%

A

10-110mmHg

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31
Q

normal minute ventilation

A

7-8 L/min

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32
Q

normal Va

A

alveolar ventilation 2/3 of minute ventilation of healthy patient

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33
Q

normal Vd (dead space ventilation)

A

1/3 of minute ventilation in a healthy patient

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34
Q

normal VCO2 (CO2 production)

A

200 mL/min

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35
Q

how much does VCO2 decrease in GA?

A

by 60%

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36
Q

VO2 (oxygen consumption)

A

250mL/min (for a normothermic 70kg adult)

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37
Q

VO2 (oxygen consumption) in infants

A

6-8mL/kg/min in infants

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38
Q

VO2 (oxygen consumption) in adults

A

3-4mL/kg/min in adults

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39
Q

%MetHb (methemoglobin) on an ABG sample

A

<2%

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40
Q

%COHb (carboxyhemoglobin) on an ABG sample

A

<3%

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41
Q

HCO3-/PaCO2 ratio

A

20: 1

- An abnormal HCO3-/PaCO2 ratio will always lead to an abnormal pH

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42
Q

PaO2/FiO2 ratio

A

480

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43
Q

Anion Gap

A

8-16mEq/L

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44
Q

Serum lactate concentration

A

<2mmol/L

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45
Q

Lactic acidosis value

A

Serum lactate > 5mmol/L

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46
Q

CaO2 equation

A

CaO2 = (SaO2)(Hb)(1.34) + (PaO2)(0.003)

*can calculate CvO2 from venous sample

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47
Q

What are the 2 primary determinants of CaO2?

A

SaO2 and Hb

-have the same effect on CaO2

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48
Q

What is the primary determinant of arterial oxygen content?

A

SaO2

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49
Q

Fick equation (for cardiac output)

A

Cardiac Output = “VO2” /”(CaO2−CvO2)(10)”

*measures cardiac output by oxygen consumption

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50
Q

DO2 equation

A

DO2 = (CaO2)(Cardiac Output)(10)

10 converts mL/d to mL/L

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51
Q

What does DO2 represent?

A

the amount of oxygen available for tissue perfusion

delivery of oxygen to tissues per minute

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52
Q

According to the DO2 equation, what is tissue perfusion most dependent on?

A

tissue perfusion (delivery of oxygen) is mostly dependent on the SaO2 and hemoglobin concentration (minimally determined by PaO2)

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53
Q

what is PiO2

A

pressure of inspired oxygen

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54
Q

3 things that determine PiO2

A
  1. FiO2
    - if this increases, PiO2 increases
  2. The pressure of air in the atmosphere (barometric/atmospheric pressure
    - If atmospheric pressure INCREASES (elevation decreases), the pressure of oxygen we inspire INCREASES (and vice versa)
  3. Water vapor pressure (WVP)
    - As the water vapor pressure in the air INCREASES, the pressure of oxygen we inspire DECREASES (and vice versa)
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55
Q

PiO2 equation

A

PiO2 = (FiO2)(Barometric Pressure - Water Vapor Pressure)

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56
Q

at sea level:
barometric pressure= _____
Water vapor pressure =________

so, PiO2 equation is?

A

760 mmHg
47 mmHg
760-47=713

PiO2 = (FiO2)(713)

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57
Q

Alveolar Gas equation (PAO2)

A

PAO2 = PiO2 – (1.2)(PaCO2)

*if the FiO2 is greater than 60%, don’t need to use 1.2

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58
Q

At sea level, a patient has a nasal cannula placed at 4L/min. A recent arterial blood gas shows a PaCO2 of 40mmHg. What is the partial pressure of oxygen in this patient’s alveoli?

A

PAO2 = (0.35)(713) – (1.2)(40) = 201.55mmHg

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59
Q

What is PAO2 primarily determined by?

A

FiO2

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60
Q

What is the estimation for PAO2?

A

PAO2 = 102 - “(Age)” /”3”

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61
Q

Minute ventilation equation

A

TV X RR

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62
Q

equation for dead space ventilation (Vd/Vt)

A

Vd/Vt = (Vd)(RR)

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63
Q

The amount of dead space a patient has is proportional to what 2 values?

A

PaCO2 and EtCO2

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64
Q

alternate equation for dead space ventilation

A

Vd/Vt = “(PaCO2−EtCO2)” /”(PaCO2)”

65
Q

equation for alveolar volume

A

Alveolar Volume = Vt– Vd

66
Q

equation for alveolar ventilation

A

VA = (Vt– Vd)(RR)

67
Q

PaCO2 equation

A

PaCO2 = “(VCO2)(0.863)” /”Va”

68
Q

A patient has an alveolar ventilation of 4.5L/min and a CO2 production of 200mL/min. What is their estimated PaCO2?

A

PaCO2 = “(200)(0.863)” /”4.5” = 38.35L/min

69
Q

What is the estimated alveolar ventilation of a patient if they have a CO2 production of 200mL/min and a PaCO2 of 50mmHg?

A

Va = “(200)(0.863)” /”50” = 3L/min

70
Q

Carbonic anhydrase equation

A

CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO3-

71
Q

henderson hasselbalch equation in how it relates to pH

A

“(HCO3−)” /”(PaCO2)”

72
Q

What are 4 things that increase the A-a gradient?

A
  1. impaired gas exchange (COPD)
  2. age
  3. supplemental oxygen
    - 100% O2, A-a gradient can vary from 10-110mmHg
  4. Right to left intracardiac shunt
73
Q

2 disadvantages of the A-a gradient

A
  1. anesthetist has to calculate PAO2

2. it can very greatly in patients who are breathing supplemental oxygen

74
Q

What is an alternative to the A-a gradient in assessing the patient’s lung function

A

PaO2/ FiO2

75
Q

What is a normal PaO2/ FiO2 ratio?

76
Q

a normal PaO2 on room air in a healthy patient is roughly ______ times the amount of FiO2 on room air

A

5X

a shortened way of doing the PaO2 to FiO2 ratio is to just see if the PaO2 is close to 5x the patient’s FiO2

77
Q

a PaO2/ FiO2 ratio of less than ____ indicates acute lung injury

78
Q

a PaO2/ FiO2 ratio of less than _____ is diagnostic of ARDS

79
Q

What are 2 advantages of using PaO2/ FiO2 over the A-a gradient?

A
  1. the anesthetist does’t have to calculate PAO2

2. The PaO2/FiO2 ratio doesn’t vary as much as the A-a gradient does with supplemental oxygen administration

80
Q

Which of the following is least likely to lower a patient’s alveolar PO2?

Increase in altitude
Elevated PaCO2
A left to right intracardiac shunt
None of the above

A

left to right intracardiac shunt

81
Q

What is the maximum value attainable by adding the values obtained for SaO2, %COHb, and %MetHb from a single blood sample?

100%
150%
200%
300%

82
Q

If the PaCO2 and FiO2 of a patient both increase by 50%, what is most likely to happen to their PAO2?

Increase
Decrease
Remain the same
Impossible to determine from the information provided

83
Q

If both barometric pressure and the PaCO2 of a patient fall by half, what is most likely to happen to their PAO2?

Increase
Decrease
Remain the same
Impossible to determine from the information

84
Q

At 10:00am, a patient has a PaO2 of 85mmHg, and SaO2 of 98%, and a Hb of 14g/dL. At 10:05am, she suffers a severe hemolytic reaction that suddenly leaves her with a Hb of 7g/dL. Assuming no lung disease occurs from the hemolytic reaction, what is most likely to occur with her PaO2, SaO2, and CaO2?

PaO2 unchanged, SaO2 unchanged, CaO2 unchanged
PaO2 unchanged, SaO2 unchanged, CaO2 reduced
PaO2 reduced, SaO2 unchanged, CaO2 reduced
PaO2 reduced, SaO2 reduced, CaO2 reduced

A

PaO2 unchanged, SaO2 unchanged, CaO2 reduced

85
Q

Which of the following is least likely to change the PAO2 of a patient?

SaO2
PaCO2
Barometric pressure
FiO2

86
Q 
A patient has the following ABG values:
Hb = 8mg/dL
PaO2 = 100mmHg
SaO2 = 60%
PaCO2 = 65mmHg
Which of the following would have the greatest impact on increasing oxygen delivery to the tissues?

Increasing the PaO2 from 100mmHg to 500mmHg
Increasing the SaO2 from 60% to 90%
Hyperventilating a patient down from a PaCO2 of 65 to a PaCO2 of 30
Increasing the patient’s hemoglobin from 8mg/dL to 10mg/dL

A

Increasing the SaO2 from 60% to 90%

87
Q

Which of the following situations would be most likely to lower the PaO2 of a patient?

Carbon monoxide poisoning
Abnormal hemoglobin that holds oxygen with twice the affinity of normal hemoglobin
Anemia
Lung disease with intrapulmonary shunting

A

Lung disease with intrapulmonary shunting

88
Q

CaO2 is reduced in all of the following situations EXCEPT:

Severe anemia
Carbon monoxide poisoning
Severe V-Q imbalance
High altitude
None of the above
A

None of the above

89
Q

What does the PaCO2 equation tell us?

A

That the higher the initial PaCO2, the greater it is affected by minute ventilation
-with each minute of apnea, CO2 will increase exponentially

90
Q

If HCO3- and PaCO2 double from their normal baseline values, what is most likely to happen to the patient’s pH?

Stay the same
Increase
Decrease
Cannot determine from the information provided

A

stay the same

91
Q

What does the Henderson-Hasselbalch equation predict will happen if a patient’s PaCO2 increases from 40-60mmHg?

That pH will fall
That bicarbonate will fall
That bicarbonate will rise
Cannot determine from the information provided

A

the pH will fall

92
Q

A patient’s Va is 8.63L/min and their VCO2 is 300mL/min. How much will their PaCO2 rise if their Va drops 1L/min?

What is the initial PaCO2?

What is the PaCO2 after a decline a 1L/min drop in alveolar ventilation?

What is the total change in CO2 after a 1L/min drop in alveolar ventilation?

A

30 mmHg

33.9 mmHg

4 mmHg

93
Q

A patient’s Va is 3.8L/min and their VCO2 is 300mL/min. How much will their PaCO2 rise if their Va decreases 1L/min?

What is the initial PaCO2?

What is the PaCO2 after a decline a 1L/min drop in alveolar ventilation?

What is the total change in CO2 after a 1L/min drop in alveolar ventilation?

A

68 mmHg

92 mmHg

24 mmHg

94
Q 
A patient has the following respiratory parameters:
Tidal Volume = 500mL
Respiratory Rate = 12
Alveolar Ventilation = 3L/min
What is this patient’s dead space volume (the amount of dead space in one breath)?
150mL
200mL
250mL
300mL
95
Q

A patient has a respiratory rate of 24, a tidal volume of 300mL, a dead space volume of 150mL, and a CO2 production of 300mL/min. Based on this information, what is the patient’s PaCO2?

24.9
39.5
55.7
71.9
Impossible to determine from the information provided

96
Q

The Bohr effect refers to _____ being displaced from hemoglobin as PaCO2 increases

A

oxygen

*right shift

97
Q

The Haldane effect refers to ____ being displaced from hemoglobin as oxygen concentration increases

98
Q

refers to impaired oxygen perfusion

99
Q

refers to any decrease in blood oxygen content (CaO2)

100
Q

A patient is diagnosed with respiratory acidosis if they have?

A
  1. A low pH, and

2. A high PaCO2

101
Q

Whenever a patient is in respiratory acidosis (high PaCO2, high H+ concentration, low pH), what does the body do to compensate? why is this a problem?

A

Kidney will try to reabsorb more bicarb
shift reaction to left
will decrease H+ (good)
but will INCREASE CO2 (already a problem)

102
Q

What is the best way the anesthetist can treat respiratory acidosis?

A

increase the minute ventilation

-hyperventilate the patient

103
Q

A patient is diagnosed with respiratory alkalosis if they have:

A

. A high pH, and

2. A low PaCO2

104
Q

Whenever a patient is in respiratory alkalosis, what does the body do to compensate? why is this a problem?

A

kidney will excrete more HCO3-
shift the reaction to the right
will increase H+( good)
the excretion of HCO3- DECREASES CO2 (already a problem)

105
Q

What is the best way for an anesthetist to treat respiratory alkalosis?

A

decrease the minute ventilation

-hypoventilation

106
Q

What is the cause of metabolic acidosis?

A

decrease in HCO3-

107
Q

What are 2 ways HCO3- can decrease( Metabolic acidosis)?

A
  1. actual loss of HCO3- (diarrhea)

2. Indirect loss of HCO3- from the increase in H+
H+ bind HCO3-
-lactic acidocis
-ketoacidosis

108
Q

a patient is diagnosed with metabolic acidosis if they have:

A
  1. low pH

2. low HCO3-

109
Q

Whenever a patient is in metabolic acidosis, they will “compensate” by?
Why is this a problem?

A

increasing their ventilation and lowering their PaCO2
drive reaction to the left and decrease H+ (good)
but hyperventilation causes HCO3- to decrease even more

110
Q

the correct treatment for metabolic acidosis is?

A

to give HCO3-

111
Q

What is the Sodium Bicarb dose?

A

Bicarb dose = (0.3)(kg)(base excess)

112
Q

A 50kg patient has a base excess of -3. What is the dose of bicarb recommended to correct the base excess?

40mEq
45mEq
50mEq
55mEq

113
Q

2 ways in which you can get Metabolic Alkalosis?

A
  1. direct loss of H+ from the body
    vomiting, diuretics, gastric drainage, bowel obstruction

2.buildup of HCO3- in the body
massive blood transfusion, where the citrate preservative is converted to HCO3-

114
Q

Therefore, a patient is diagnosed with metabolic alkalosis if they have

A
  1. A high pH and

2. A high HCO3-

115
Q

Whenever a patient is in metabolic alkalosis they will “compensate” by? Why is this bad?

A

decreasing their ventilation and increasing PaCO2
shifts the reaction to the right and increases H+ (good)
but hypoventilation will increase HCO3- even more

116
Q

What is the best treatment for metabolic alkalosis?

A

Reverse what is causing it

-Zofran or fluids if they have had lots of diarrhea or vomiting

117
Q 
Respiratory acidosis (↑ PaCO2)
For each 10mmHg increase in PaCO2:

HCO3- should increase _____ (if acute)

HCO3- should increase ___ (if chronic)

A

1 mEq/L

4 mEq/L

118
Q 
Respiratory alkalosis (↓ PaCO2)
For each 10mmHg decrease in PaCO2:

HCO3- should decrease _____ (if acute)

HCO3- should decrease ____(if chronic)

A

2 mEq/L

4 mEq/L

119
Q 
Metabolic acidosis (↓ HCO3-)
PaCO2 should decrease \_\_\_ the HCO3- decrease
120
Q 
Metabolic alkalosis (↑ HCO3-)
PaCO2 should increase\_\_\_\_the HCO3- increase
121
Q

assume that a normal starting PaCO2 is 40mmHg and a normal starting HCO3- is 24mEq/L

A75-year-old woman is scheduled to undergo ORIF of the wrist.  Medical history includes COPD and type II diabetes.  She takes Flovent and albuterol twice per day and wears 2L/min oxygen at night.  Preoperative blood gas analysis shows pH is 7.37 and PaCO2is 60 mmHg.Which of the following isthe expected bicarbonate level?
31mEq/L
30mEq/L
27mEq/L
24meq/L
21mEq/L
122
Q

assume that a normal starting PaCO2 is 40mmHg and a normal starting HCO3- is 24mEq/L

A60-year-old man is scheduled to cystoscopy for stent placement.  He is currently septic.  Preoperative blood gas analysis reveals the following: pH = 7.35, HCO3- = 16mEq/L, and lactate = 10mmol/L.  Assuming maximum respiratory compensation, which of the following isthe expected PaCO2 level?
50mmHg
45mmHg
35mEq/L
30mEq/L
24meq/L
21mEq/L
123
Q

What is elevated lactate indicative of?

A

tissue hypoxia/ hypoperfusion

124
Q

What is type A lactic acidosis?

A

inadequate oxygen delivery to tissues

125
Q

What is type B lactic acidosis?

A

adequate oxygen delivery, but the tissues cannot use the oxygen normally

126
Q

4 causes of lactic acidosis

A
  1. sepsis
  2. shock/ inadequate cardiac output/perfusion
  3. hepatic failure
  4. exercise
127
Q

2 treatments for lactic acidosis/sepsis?

A
  1. restore normal pH

2. . Improve tissue oxygenation (perfusion) with fluids and/or vasopressors

128
Q

Anion gap equation

A

AG = unmeasured anions – unmeasured cations
Anion Gap = measured cations – measured anions
Anion Gap = (Na+) – (HCO3- + Cl-)
Anion Gap = (≈140mEq/L) – (≈102mEq/L + ≈28mEq/L) = ≈10mEq/L

129
Q

What is a normal anion gap (w/o K+)

A

12 ± 4mEq/L

130
Q

What is an high (elevated, widened) anion gap?

A

when there has been an increase in the number of UNMEASURED anions

These “unmeasured” anions dissociate from H+ and are considered acids because they increase the H+ ion concentration

(lactic acidic/lactic acidosis, ketoacids/ketoacidosis, etc)

131
Q

2 reasons the anion gap will increase

A
  1. when there is an increase in the number of unmeasured anions
  2. when there has been an decrease in the number of measured anions (HCO3-)
132
Q

A normal anion gap is caused by a direct loss of ____

A

HCO3-

-This can happen with a GI loss of HCO3− (diarrhea) or with renal dysfunction (and subsequent excretion of HCO3-)

133
Q

Why doesn’t the anion gap increase when there is a direct loss of HCO3- (measured anion)?

A

whenever there is a direct loss of HCO3-, it is typically replaced by a chloride ion

134
Q

Acidosis with an increase in the chloride concentration is referred to as ____ and is typically seen with a (normal/elevated) anion gap

A

“hyperchloremic metabolic acidosis”

normal anion gap

135
Q

What is the most common cause of hyperchloremic, normal anion gap metabolic acidosis?

A

excess 0.9% N/S administration

This is apparently due to the fact that sodium normally reabsorbs with HCO3-, but with excess saline administration, sodium reabsorbs more with Cl-, which causes HCO3- excretion (hence the acidosis)

Since we’re gaining a measured anion (Cl-) and losing a measured anion (HCO3-), the anion gap remains unchanged in this type of acidosis

136
Q

What is a low anion gap frequently caused by?

A

hypoalbuminemia ( liver failure)
-negatively charged protein

Loss of albumin from the plasma results in the retention of other negatively charged ions such as chloride and bicarbonate

Since the patient is losing unmeasured anions (Albumin) and increasing measured anions (HCO3-, Cl-), the anion gap decreases

137
Q

HCO3- = 36 mEq/L

PaCO2 = 40mmHg
Compensated or uncompensated?

PaCO2 = 50mmHg
Compensated or uncompensated?

PaCO2 = 30mmHg
Compensated or uncompensated?

A

uncompensated

compensated

uncompensated

138
Q

PaCO2 = 25mmHg

HCO3- = 20mmHg
Compensated or uncompensated?

HCO3- = 24mmHg
Compensated or uncompensated?

HCO3- = 32mmHg
Compensated or uncompensated?

A

compensated

uncompensated

uncompensated

139
Q

Patient
pH = 7.25
PaCO2 = 36
HCO3- = 14

Acid Base status

A

Uncompensated Metabolic Acidosis

140
Q

Patient
pH = 7.29
PaCO2 = 60
HCO3- = 29

Acid Base Status

A

Compensated Respiratory Acidosis

141
Q

Patient
pH = 7.26
PaCO2 = 28
HCO3- = 16

Acid Base Status

A

compensated metabolic acidosis

142
Q

Patient
pH = 7.53
PaCO2 = 42
HCO3- = 34

acid base status

A

uncompensated metabolic alkalosis

143
Q

Patient
pH = 7.37
PaCO2 = 37
HCO3- = 24

acid base status

A

normal acid base status

144
Q

Patient
pH = 7.25
PaCO2 = 24mmHg
HCO3- = 14

A

compensated metabolic acidosis

145
Q

Which type of diabetics have diabetic ketoacidosis?

What is diabetic ketoacidosis?

A

Type 1

lack of insulin

  • The lack of insulin causes the cells of the body to become starved (despite high blood sugar)
  • The body responds to this starvation by breaking down lipids in an effort to create sugar
  • fat breakdown = acidic ketone bodies (metabolic acidosis)
146
Q

6 symptoms of diabetic ketoacidosis

A
  1. Hyperglycemia
    - lack of insulin
  2. acidosis
    - protein/fat breakdown and production of ketones
  3. Hypovolemia
    - Polyuria from increased oncotic pressure (from sugar) in renal tubules
  4. Potassium disturbances
    - hyperkalemic (lack of insulin and acidosis)

(some may be hypokalemic from polyuria =rare)

  1. Sodium disturbances
    - Hyponatremia (polyuria induced Na+ loss)

(hypernatremia from diuresis & water loss =rare)

  1. hyperosmolarity (dehydration and hyperglycemia)
    - Symptoms include cell shrinkage, cerebral edema, altered consciousness, increased blood viscosity, and possible thrombosis
147
Q

What is the treatment for diabetic ketoacidosis?

What should their K+ level be to do this?

A

administer insulin
-feed cells and reverse ketone production

only if K+ is >3.3 mEq/L

148
Q

Once the glucose gets down to______, add glucose to the insulin infusion to keep the glucose above that level until the acidosis is corrected

A

250-300 mg/dL

-prevents too rapid of correction of hyperglycemia which can lead to cerebral edema

149
Q

What amount should be given for a glucose/insulin infusion?

A

give ≈5 units of insulin per amp of D50 (2.5-5g glucose per unit of insulin)

150
Q

In diabetic ketoacidocis, how should you treat the acidosis? (normalize the pH)

A

administer bicarb as needed

151
Q

In diabetic ketoacidosis, how should you treat the hypovolemia?

What is the average fluid loss in DKA?

What type of resuscitation fluids are preferable?

A

goal is to replace the total volume loss within 24–36 hours with 50% of resuscitation fluid being administered during the first 8–12 hours

Fluid loss averages approximately 6–9 L in DKA

Normal saline
-higher incidence of hyponatremia

152
Q

In DKA treatment, how do you prevent insulin induced hypokalemia?

A

Administer a potassium drip as necessary

If the patient is initially hypokalemic due to excessive diuresis, correct the patient’s potassium level prior to starting insulin therapy

153
Q

What is the effect of air on a PaCO2 sample?

A

Air will cause the blood sample to have a falsely lowered PaCO2, which will cause a falsely elevated pH

154
Q

What is the effect on air in a PaO2 sample on room air?

A

Air will cause the blood sample to have a falsely elevated PaO2

155
Q

What is the effect on air in a PaO2 sample on 100% FiO2?

A

Air will cause the blood sample to have a falsely lowered PaO2

156
Q

What is the effect on cold temperature of an ABG?

A

Cold blood samples will be warmed and thus have a falsely elevated PaO2/PaCO2

157
Q

What is the effect on warm temperature of an ABG?

A

Warm blood samples will be cooled and thus have a falsely reduced PaO2/PaCO2

158
Q

What are 2 things you should tell the lab before sending them an ABG sample?

A

The temperature and the patients FiO2

Methods II (11 decks)

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