ABG's Flashcards
(70 cards)
1
Q
Why are ABGs important?
A
ABGs help maintain the balance between acids and bases in the body to achieve homeostasis.
2
Q
ABG’s provide insights into the blood’s makeup ____ it is distributed to tissues.
A
BEFORE
3
Q
Normal pH
A
7.35 - 7.45
(slightly alkaline)
4
Q
Normal PaCO2
A
35 - 45 mm Hg
5
Q
Normal HCO3 (bicarbonate)
A
22 - 26 mEq/L
6
Q
Normal PaO2 (partial pressure of oxygen)
A
80 - 100 mmHg
7
Q
Normal SaO2
(% value)
A
96 - 100%
(arterial oxygen saturation)
8
Q
HCO3 is a component of what system?
A
Metabolic
- Acts as a buffer to neutralize excess acids, helping to regulate the pH of blood.
9
Q
PaCO2 is a component of what system?
A
RESPIRATORY
- indicator of how the respiratory system regulates the removal of carbon dioxide from the blood.
10
Q
PaO2 is found in what type of blood
A
ARTERIAL blood
- reflects the oxygen content in arterial blood, indicating how efficiently oxygen is being transported from the lungs to the bloodstream for tissue perfusion.
11
Q
SaO2 is found in what type of blood
A
Arterial (dont mix with SpO2)
- reflects how effectively oxygen is being transported in the blood. Important that organs receive sufficient O2.
12
Q
Types of solutions that help maintain a stable pH in the body.
A
Buffers
13
Q
3 examples of Buffers
A
- bicarbonate
- proteins
- hemoglobin
14
Q
System that ELIMINATES CO2 from body
A
Respiratory System
15
Q
Increased respirations leads to
A
- CO2 elimination from body
- ↓ CO2 in blood
(respiratory alkalosis)
16
Q
Decreased respirations leads to
A
- retained CO2
- ↑ CO2 in blood(respiratory acidosis)
17
Q
System that excretes or retains bicarbonate (HCO3), hydrogen ions (H+), and electrolytes
A
Renal System
18
Q
System that responds within minutes to hours.
A
Respiratory system
19
Q
System that responds within hours to days
A
Renal System
20
Q
What is the preferred site for obtaining an ABG sample.
A
radial or femoral artery.
21
Q
What test will need to be performed if using the Radial artery to obtain an ABG sample?
A
Allen’s Test
* ensure adequate blood flow from both ulnar and radial artery to hand & body.
22
Q
Steps for Allen’s Test:
A
- Elevate hand, make a fist for 20 seconds.
- Compress firmly on radial and ulnar arteries.
- Pt opens hand, hand should blanche (turn white)
- Examiner releases ONLY ulnar artery to ensure blood flow (hand turns pink again)
23
Q
What materials and conditions are necessary for obtaining arterial blood samples?
A
- A heparinized syringe
- place syringe in ice
- prompt delivery to the lab.
24
Q
Blood sample should include what 5 pieces of information?
A
- time drawn
- FiO2
- O2 delivery rate & method
-ventilator settings - patient temperature
- pulse O2 saturation
25
Method used to INTERPRET ABG's
first, middle, and last name
26
First name is
* Whether systemic compensation has maintained a normal pH
* **Compensate or Uncompensated?**
27
Middle name is
* System causing the disturbance
* **Respiratory or Metabolic?**
28
Last name is
* Type of disturbance
* **Acidosis or Alkalosis?**
29
*Interpretating ABG's*:
**1st step** is
Check for **Hypoxemia** - low O2 in **BLOOD**
* Normal **PaO2** (O2 in BLOOD) = **80-100 mmHG**
30
**Hypoxemia** is considered when **PaO2** is
less than 80 mmHg
31
**Highest priority** with **Hypoxemia**
Establish **airway** and **oxygenate**!!
your ABC's- KNOW
32
*Interpretating ABG's*:
**2nd step** is to
Analyze **pH**
* Any disturbances?
33
Analyzing pH will give you
FIRST & LAST names
34
pH < 7.35
acidosis
35
pH > 7.45
alkalosis
36
if **pH** is NORMAL we call it
**COMPENSATED**
*pH: 7.35-7.45*
37
if **pH** is **ABNORMAL** we call it
Uncompensated
38
pH number that is considered "in the middle"
pH = 7.40
39
pH < 7.35 =
pH > 7.45 =
Acidosis
Alkalosis
40
**3rd step** is to find out **Middle name** by determining if
The **PaCO2 levels** are causing the problem?
or
The **HCO3 levels** are causing the problem?
41
*Middle name*:
If **PaCO2 < 35** we say
Respiratory **alkalosis**.
42
*Middle name*:
If **PaCO2 >45** we say
Respiratory **acidosis**.
43
Middle name*:
If **HCO3 < 22** we call it
Metabolic acidosis
44
*Middle name*:
If **HCO3 >26** we call it
Metabolic alkalosis
45
**4th Step** is to determine
**ROME**
(Respiratory Opposite, Metabolic Equal)
46
*ROME*:
If **pH and PaCO2** go **opposite** ways we call it
**Respiratory** problem
* Respiratory acidosis: ↓ pH, ↑ PaCO2.
* Respiratory alkalosis: ↑ pH, ↓ PaCO2.
47
ROME:
If **pH and HCO3** go the **same** way
**Metabolic** problem
* Metabolic acidosis: ↓ pH, ↓ HCO3.
* Metabolic alkalosis: ↑ pH, ↑ HCO3.
48
*Step 5 we check compensation:*
In **Acidosis**, the **kidneys increase**
**HCO3** to compensate.
49
**Respiratory Acidosis** can occur due to:
List 6 causes
* Hypoventilation
* COPD
* over-sedation: *depress CNS leading to slow breathing*
* drug overdose
* neuromuscular diseases (resp. muscle weakness)
* head trauma.
50
**Respiratory Acidosis:**
**pH and PaCO2** results
* **pH < 7.35**
* **PaCO2 > 45** (retaining CO2)
51
*Step 5 we check compensation:*
In **Alkalosis**, the **respiratory** system **retains**
CO2 to compensate.
52
**Respiratory Acidosis** is **ALWAYS** due to
**respiratory** problems **unable to remove CO2**
53
How does the body compenssate in **RESPIRATORY ACIDOSIS**
Kidneys **conserve HCO3- in the blood stream** (does not excrete into urine) and **excrete H+** into urine.
(H+ are acidic)
54
S/S of **Respiratory Acidosis**
**SUDDEN** Increase of:
* ↑ pulse
* ↑ respiratory rate
* ↑BP: *speeds up CO2 circulation to lungs for removal*
* Mental changes: *feeling of fullness in the head*
55
Interventions for **Respiratory Acidosis**
* Treat the underlying cause of acidosis
* Improve ventilation, maintain patent airway, give O2
56
What causes **Respiratory Alkalosis**?
Hyperventilation from:
* anxiety
* pain
* septicemia: *serious bloodstream infection*
* PE: *blocks O2 to be received in lungs*
* CNS lesions: *affects respiratory center*+
* severe anemia: *less hgb to carry O2 to body*
57
How does the **body compensate** during **Respiratory Alkalosis**
Rarely occurs because WE treat the underlying cause (hypoxemia) early and aggressively that the body doesnt have time to compensate.
* we treat hypoxemia bc pt starts to breath faster (getting rid of CO2 fast) leading to respiratory alkalosis
58
S/S of **Respiratory Alkalosis**
* Lightheadedness: *low CO2 reduces blood flow to head*
* inability to concentrate: *low CO2 affects brain function*
* numbness/tingling: *more alkaline = affects Calcium levels & nervous system*
* sometimes loss of consciousness
59
Interventions for **Respiratory Alkalosis**
* Slow down RR
* breathe into a **paper bag**- (*rebreath the CO2 inside bag*)
* reassess ventilator settings
* Treat the underlying cause.
60
**pH and PaCO2** results in **Respiratory Alkalosis**
pH > 7.45
PaCO2 < 35.
61
What causes **Metabolic Acidosis**
**Kidney injury** due to:
* **Diabetic ketoacidosis**- *most common*
* renal failure
* **severe diarrhea**
* Anaerobic metabolism (shock)
* severe dehydration
* starvation
* Salicylate ingestions-*aspirin overdose*
* **severe diarrhea**
**Remember**: *Vomit acid but poop base- if we poop all our base, then we become ACIDIC.*
62
How does the **body compensate** in **Metabolic Acidosis**
* Lungs **increase** CO2 excretion
* **Kussmaul respirations**: hyperventilation- deep and rapid to exhale CO2
-every-time we exhale, we get rid of CO2
63
S/S of **Metabolic Acidosis**
* Headache: *’A for Acid Affects the Brain’*
* confusion
* drowsiness
* ↑ RR and ↑ depth
* ↓BP: *acidic blood affects heart function*
* dysrhythmias
64
**pH and HCO3** results in **Metabolic Acidosis**
* pH < 7.35
* HCO3 < 22
65
What causes **Metabolic Alkalosis**
* Prolonged **vomiting**
* GI suctioning- *too high or not intermittent
* long-term diuretic therapy (hypokalemia)
* hypochloremia
-vomit acid, poop base
66
Interventions for **Metabolic Acidosis**
* Hydration
* antidiarrheal
* bicarbonate administration if needed.
* **treat underlying cause** (*e.g., insulin for diabetic ketoacidosis, why are they hyperventilating in the 1st place?*),
67
**pH and HCO3** for **Metabolic Alkalosis**
* pH > 7.45
* HCO3 > 26
68
How does the body compensate for **Metabolic Alkalosis**
* Decreased respiratory rate to **retain** plasma CO2.
69
S/S of **Metabolic Alkalosis**
* Respiratory depression
* tachycardia
* hypo**k**alemia
* hypo**ca**lcemia
70
Interventions for **Metabolic Alkalosis**
* Fluid and electrolyte replacement
* antiemetics
* modify gastric suctioning
