Adult ABG Certification - RIH Flashcards
1
Q
How long must you wait before taking an ABG post initiation/change in therapy?
A
20-30 minutes
2
Q
What to do if the patient is hyperactive, uncontrollable, or refuses the ABG?
A
Consider SpO2 monitor of oxygenation issues and venous pH (in well-perfused patients) for acid-base concerns
3
Q
If the patient is on anti-coagulants, when should you schedule the ABG?
A
30 minutes prior to next dose of anti-coagulants
4
Q
What might cause arteriospasm in regards to ABG sampling? (2)
A
Reflex secondary to pain or anxiety. Withdrawing too fast from an arterial line may create turbulent flow
5
Q
How many attempts per site?
A
2
6
Q
How can you prevent a vasovagal reaction to an ABG puncture?
A
reassure the patient, consider freezing, ask them about previous reactions to punctures
7
Q
What is analyzed when running a pleural fluid sample?
A
pH
8
Q
Adult pH panic value:
A
<7.30 or >7.50
9
Q
Adult PaCO2 panic value:
A
<20 or >60 (consider pt history)
10
Q
Adult PaO2 panic value:
A
<50 or >200
11
Q
Are ABG’s corrected for patient body temperature?
A
no
12
Q
What is the first branch off the aortic arch?
A
bracheocephalic artery
13
Q
The bracheocephalic artery divides to form which 2 arteries?
A
right subclavian artery and right common carotid artery
14
Q
Where does the right subclavian artery extend to? (2)
A
the first rib, then passes into the armpit (axilla)
15
Q
What 3 regions does the right subclavian artery supply?
A
arm, forearm, hand
16
Q
When the right subclavian artery reaches the axilla, it becomes the:
A
axillary artery
17
Q
When the axillary artery continues into the arm, what is it called?
A
brachial artery
18
Q
Where does the brachial artery divide?
A
antecubital fossa
19
Q
What 2 arteries does the brachial artery divide into?
A
ulnar artery and radial artery
20
Q
When the radial and ulnar arteries meet, what do they form? (2)
A
superficial palmar arches, deep palmar arch
21
Q
Where are the two small radial veins located?
A
On either side of the radial artery
22
Q
Where is the pronator quadratus muscle located and what is its function?
A
beneath the radial artery, to pronate the palm
23
Q
What does the lateral ante brachial cutaneous nerve do?
A
general sensory function for the skin on radial side of forearm
24
Q
What does the median nerve do? (2)
A
- Motor function to most flexor muscles of forearm and lateral 3 digits of the hand
- Sensory function to palmar aspects of lateral 4 digits of the hand
25
What does the superficial branch of the radial nerve do?
sensory supply to lateral 3 digits
26
What is the name for the fibrous membrane covering the bones?
periosteum
27
If a needle comes into contact with the periosteum, what happens?
Patient will feel sharp pain
28
What are 2 potential problems with a brachial artery puncture?
Accidental puncture of the median nerve or large veins in the area
29
How should the patient's arm be positioned for a brachial puncture?
arm extended completely with the palm up
30
What 2 structures is the brachial artery palpated between?
median nerve and biceps tendon
31
What 3 arteries provide collateral circulation if the brachial artery is obstructed?
deep brachial, superior and inferior ulnar arteries
32
Can the femoral puncture site be used in a newborn?
no
33
What is the risk of performing a femoral puncture on an infant or child?
the hip joint may be inadvertently entered and contaminated, which may lead to septic arthritis of the joint
34
What needle gauge is used for radial and brachial ABG punctures?
22-25
35
How long does flushing of the hand take for a positive result on the Modified Allen's Test?
5-15 seconds
36
How far away from the wrist crease should the puncture site be for a radial ABG?
1/2-1 inch proximal
37
Is it advised to use a rolled-up towel to extend the wrist for a radial ABG puncture?
yes
38
What angle is used for a radial ABG puncture?
45-60 degrees
39
What does lack of spontaneous filling indicate? (2)
low blood pressure or venous sample
40
If the artery is missed, what do you do?
slowly withdraw the needle until the bevel is just below the skin surface and repeat the attempt
41
What is a sufficient quantity of blood for an ABG?
1 ml
42
When should you ice an ABG sample?
if a delay of >15 mins is expected before analyzing
43
What length of needle is used for a femoral puncture?
1.5 inch
44
How should the patient be positioned for a femoral puncture?
supine with legs straight
45
What angle is used for a femoral puncture?
90 degrees
46
How long do you need to hold a femoral puncture site for (minimum)?
10 minutes
47
If pain, swelling, or hematoma occur post-femoral puncture, what do you do?
reapply pressure
48
For patients on anti-coagulants (femoral puncture) how long do you hold pressure for?
up to 15 minutes
49
How often do you need to check on a patient that is on anti-coagulants post-femoral puncture?
Q15min for 1 hour
50
What sizes of non-heparinized syringes can be used when doing an art line sample?
5 ml or 12 ml
51
How much blood and fluid mixture (waste syringe) do you need to draw before collecting an art line sample?
5 ml
52
What size heparinized syringe is used when collecting an art line sample?
3 ml
53
Why do we flush the art line in pulses after retrieving a sample?
to prevent complete displacement of blood to the hand with saline
54
What Law is used in spectrophotometry?
Beer's Law
55
What does Beer's Law state?
intensity of light absorbed while passing through a solution will be proportional to the concentration of the molecule within the solution
56
What does an oximeter measure? (2)
oxyhemoglobin and deoxyhemoglobin
57
What does a co-oximeter measure? (4)
reduced Hb, oxyHb, metHb, COHb
58
The affinity of CO for Hb is approximately ___x greater than the affinity of O2 for Hb.
218
59
What type of hypoxia is CO poisoning classified as?
anemic hypoxia
60
COHb shifts the oxyHb curve to the:
left
61
COHb can be caused by skin absorption of _______ from paint removers.
methylene chloride
62
COHb can be caused by incomplete combustion of ______ materials.
carbonaceous
63
What discoloration does COHb cause the blood to have?
cherry-red
64
__% saturation of COHb has the same effect as ______ with a Hb content of _____ml/dL
50%, anemia, 7.5
65
Patient's skin may appear ____ (color) if they have COHb
pink
66
FCOHb <10%
slight poisoning
67
FCOHb 10-20%
mild poisoning
68
FCOHb 20-40%
moderate poisoning
69
FCOHb 40-60%
severe poisoning
70
What is the treatment for COHb?
FiO2 of 1.0 immediately
71
Giving 1.0 FiO2 reduces the COHb half-life from _____ to _____
over 5 hours, 1 hour 20 minutes
72
Hyperbaric oxygen reduces COHb half-life to:
23 minutes
73
How is metHb formed in the RBC?
the ferrous ion loses an electron, is transformed into ferric state, Hb is oxidized (loses an electron) rather than oxygenated
74
Normal metHb concentration is approximately:
1%
75
Can metHb transport oxygen?
no
76
MetHb levels over ___% are sometimes well-tolerated and may not require treatment
35
77
Symptoms of metHb toxicity are related to:
anemic hypoxia
78
MetHb symptoms are generally more severe when the patient has:
pre-existing cardiovascular problems
79
Exposure to these drugs can produce metHb: (4)
amyl nitrate, nitroglycerin, sulfonamides, benzocaine
80
What dietary factor can affect infants under 6 months of age (regarding metHb)
well water that contains nitrates
81
Exposure to what chemical can produce metHb?
aniline dyes
82
If a person has large quantities of metHb, what color is their blood?
chocolate brown
83
What color is a person's skin if they have large quantities of metHb?
slate-grey
84
FMetHB 10-15% symptoms
seldom other than cyanosis and increased metHb levels
85
FMetHb 20-50% symptoms
cyanosis, weakness, headache, dizziness, tachycardia
86
FMetHb 50-60% symptoms
cyanosis, dyspnea, acidosis, bradycardia or other dysrhythmias
87
metHb treatment (3)
1 - supplemental O2 at FiO2 1.0
2 - removal of internal and external causes of life-threatening methemoglobinemia (emesis/lavage/activated charcoal, etc.)
3 - ascorbic acid or methylene blue 3-5 mg/kg which can accelerate metHb reduction.
88
When is treatment of metHb with ascorbic acid or methylene blue contraindicated?
if the metHb was induced by cyanide
89
Normal pleural fluid pH of a healthy person:
7.64
90
Pleural fluid pH >7.3 usually:
resolves with antibiotic therapy
91
Pleural fluid pH <7.3 indicates some possible problems: (4)
1. exudative effusion secondary to malignancy
2. rheumatoid arthritis
3. TB
4. hemothorax
92
Pleural fluid pH <7.3 associated with pneumonia or lung abscess usually:
requires chest tube drainage
93
Pleural fluid pH <7.2 may indicate:
an empyema
94
Pleural fluid pH <6.0 suggests:
esophageal rupture
95
Pleural fluid must be collected by withdrawing fluid into:
a heparinized syringe
96
Pleural fluid must be transported:
anaerobically
97
Should a pleural fluid sample be iced? Why or why not?
no, icing can precipitate proteins
98
Quality Assurance (QA)
total quality of reported results
99
Quality Control (QC)
maintenance and validation of the measuring system
100
Random error (dispersion)
an isolated result outside the control limits and has minor significance
101
Systematic error (trending)
progressive controls increase or decrease
102
Systematic error (shifting)
abrupt change in measurement followed by clustering
103
External QC
samples with unknown values are sent to each lab 3 times a year from a central distributor
104
Sources of pre-analytical error (4)
1. patient
2. sampling errors (AVERT)
3. hyperventilation
4. time
105
What does AVERT stand for?
```
Air bubble in sample
Venous admixture/venous sampling
Excessive anticoagulant
Rate of metabolism
Temperature alterations
```
106
What happens if there is an air bubble in a sample? Give details regarding PCO2, pH, PaO2, HCO3, BE.
PCO2 decreases (room air has 0)
pH increases
PaO2 migrates to 150 mmHg (room air has 150)
HCO3 may decrease due to hydrolysis >> decrease in BE
107
1/10 of a sample contaminated with venous blood will result in an overshoot equal to a ___% reduction in ______.
25% reduction in PaO2
108
What happens if there is too much heparin in a sample? Give details regarding PCO2, pH, PaO2
PCO2 decreases
pH decreases
PaO2 usually remains the same
109
Heparin is a weak _____
acid
110
What is the anticoagulant of choice and why?
lithium heparin is least likely to cause equipment problems due to the formation of small fibrils in the sample
111
At room temperature (20-24°C) the expected change in the sample's pH after 1 hour is:
decrease by 0.025
112
At room temperature (20-24°C) the expected change in the sample's PaCO2 after 1 hour is:
increase by 2.5 mmHg
113
At room temperature (20-24°C) the expected change in the sample's PaO2 after 1 hour is:
decrease by 10 mmHg (If initial PaO2 <150 mmHg)
114
What may occur in samples taken from patients with leukemia/leukocytosis?
leukocyte larceny (increased O2 consumption by WBCs and immature RBC's >> decreased PaO2)
115
Why does leukocytosis create changes in PaO2 in samples?
It is an increase in WBCs which consume O2 at a high rate
116
Increased body temperature results in a(n) _______ in pH, PaCO2, and PaO2
increase
117
Not correcting for an increased body temperature will provide results that are _______ than actual
lower
118
Decreased body temperature results in a(n) ______ in pH, PaCO2, PaO2
decrease
119
Not correcting for a decreased body temperature will provide results that are _______ than actual
greater
120
ABG values that are corrected for body temperature fail to consider:
the metabolic and cardiovascular changes that accompany the changes in body temperature
121
Why is there a limit of 2 attempts per site? (5)
to reduce the incidence of:
1. peripheral nerve damage
2. vascular occlusion
3. vascular trauma
4. thrombosis
5. emboli
122
Checklist prior to sampling: (6)
1. Written physician order (or verbal written by RT)
2. Review patient's chart for contraindications
3. Bleeding risk (drugs, blood conditions)
4. Diagnosis and reason for sample
5. Previous ABG results
6. Collateral circulation
123
What arises from the palmar arches?
Digital arteries
124
The median nerve runs parallel to:
the radial artery
125
The radial nerve runs:
underneath the radius as it approaches the wrist
126
Where is the origin and insertion of the pronator quadratus muscle?
origin: lower quarter of the ulna
insertion: lower quarter of the radius
127
Where is the site for a brachial artery puncture?
above the elbow crease, in the antecubital fossa
128
How do you stabilize the brachial artery for a puncture?
Between your index and middle fingers
129
What angle of approach is used for a brachial artery puncture?
45 degrees
130
Where must the femoral puncture site be located?
distal to the inguinal ligament at the level of the inguinal crease. (choose a site approx. 2 cm below the inguinal ligament or near the inguinal fold)
131
How do you stabilize the femoral artery for a puncture?
Between your index and middle fingers
132
Can a mixed venous sampling from the pulmonary artery be performed by an SRT?
no
133
SRT's that are certified may draw samples from ______ and _______ only. Other sites require _______.
Adult radial arteries and arterial lines only.
| Other sites require direct supervision by an RRT
134
Fractional Hb saturation
Fractional saturation (FO2Hb) is the fraction of total hemoglobin which happens to be oxygenated
135
Functional Hb saturation
Functional saturation (sO2) is the fraction of effective hemoglobin which is oxygenated
136
If a person has CO intoxication, what happens to their PO2, PCO2, and pH?
```
PO2 = normal
PCO2 = normal or slightly decreased
pH = may be decreased
```
137
Normal accepted limits of variation for routine quality control measure are:
+/- 2 standard deviations (95%) from the mean
138
Sources of analytical error: (5)
1. Recording results before the sample can stabilize and ensure complete electrode response
2. Neglecting to mix the sample prior to introduction into the analyzer
3. Failure to mix iced sample (may raise pH by as much as 0.11 units)
4. Protein contamination/aging electrodes
5. Air introduced during insertion of sample
139
Sources of post-analytical error: (4)
1. Recording of data on requisition and/or chart
2. Clinical consistency check
3. Transmission/reporting of results (poor verbal transmission)
4. Essential legal consideration (poor handwriting)
