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Flashcards in acid base, blood gas interpretation Deck (24)
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1
Q

Why look at blood gas levels

A

not a primary disease: reflects disease state, need to address underlying cause

early indicator of change-pulmonary function, metabolic balance

POC monitors more common now

2
Q

pH

A

acidemia: <7.35
alkalemia: >7.45

3
Q

PCO2

A

normal 35-45 mmHg

4
Q

Partial pressure of O2

A

measures oxygen dissolved in plasma

normals vary with percentage of O2 inspired

5
Q

PaO2

partial pressure of Oxygen in arteries

A

reflects ventilation/respiratory function

increased–>hyperoxia

decreased–>hypoxia/hypoxemia

6
Q

hypoxia numbers

A

<80 mmHg moderate

<60 mmHg severe

7
Q

PvO2

partial pressure of oxygen in veins

A

reflects tissue oxygen use

8
Q

HCO3

A

bicarbonate level

normal values variable

carnivores: 16 to 24
herbivores: 24 to 30

9
Q

Total CO2

A

95% is HCO3

5% is carbonic acid and dissolved CO2

normal is within 2 units of HCO3

10
Q

Base Excess/base deficit

A

indicates the amount of HCO3 below or above normal

difference between normal buffer base and actual buffer base

11
Q

What are the buffers in the body?

A

HCO3

Hemoglobin

phosphate

ammonium

serum proteins

12
Q

SAT/SaO2

A

percent oxygen saturation

same as pulse oximeter reading

13
Q

What is a normal SaO2 reading? Abnormal?

A

perfect: 100
normal: >95

serious hypoxemia: <90

severe hypoxemia: <70

lethal hypoxemia: <60

14
Q

Will a patient be cyanotic if their SaO2 is at 90?

A

NO!

15
Q

respiratory acidosis

A

increase in PCO2 (hypercapnia)

increases denominator causing a decrease in pH

16
Q

rule outs for respiratory acidosis

A

respiratory depression from general anesthesia or CNS trauma/disease

primary respiratory compromise (pneumonia, pneumothorax, respiratory muscle weakness, restricted chest wall movement related to pain, upper airway obstruction)

malignant hyperthermia (increased CO2 production)

17
Q

respiratory alkalosis

A

decreased PCO2 (hypocapnia)

decreases denominator to increase pH

18
Q

rule outs for respiratory alkalosis

A

excessive manual or mechanical ventilation during general anesthesia

anxiety, directly stimulating respiratory centers

hypoxic stimulation in compromised patient

pain

19
Q

metabolic acidosis

A

decreased HCO3

results in an increase in numerator to cause a decrease in pH

20
Q

rule outs for metabolic alkalosis

A

shock, poor tissue perfusion resulting in anaerobic tissue metabolism

DKA, poisoning

diarrhea, renal tubular acidosis

21
Q

metabolic alkalosis

A

increase in HCO3

increase in numerator leads to increase in pH

22
Q

rule outs for metabolic alkalosis

A

primary gastric vomiting

potassium wasting diuretics, decreased fluid volume/dehydration

excessive endogenous sodium bicarbonate therapy

23
Q

PaO2 normals

A

room air: 85 to 105 mmHg

33% O2: 150 mmHg

nasal O2: 200 mmHg

pure O2: 500 mmHg

24
Q

BE normals

A

-4 to +4