BLOOD GASES Flashcards
1
Q
Is a substance that can
yield a hydrogen ion
(H+) when dissolved in
water
A
Acid
2
Q
Is a substance that can
yield hydroxyl ions
(OH-) when dissolved
in water
A
Base
3
Q
Relative strengths of acids and bases – their ability
to dissociate in water
A
- Dissociation Constant (K value)
4
Q
H+
A
weak acid
strong acid
5
Q
OH-
A
weak base
strong base
6
Q
Have pK values of less than _______
A
- Strong Acids - 3.0
7
Q
- Raising the pH above the pK will cause it to
dissociate and yield a H+
A
- Strong Acids
8
Q
- Have pK values of greater than ______
A
9.0 - strong base
9
Q
- Combination of a weak acid or weak base and its
salt - Resists changes in pH
A
Buffer
10
Q
Pressure or tension exerted by CO2 gas dissolved in
blood
* An index of efficiency of gas exchange in the lungs
* Not a measure of CO2 concentration in the blood
A
- Partial Pressure of CO2 (pCO2)
11
Q
- ______ – _____ mm Hg
A
- Partial Pressure of CO2 (pCO2) - 35 -45mm/hg
12
Q
- Total CO2 Content
- Refers to the total concentration of CO2 in the blood
- Consisting of ionized (HCO3-, CO3-, carbamino
compound) and unionized fraction (H2CO3) and
physically dissolved CO2
A
- Total Carbon Dioxide Concentration
13
Q
_________ mmol/L
A
- 23 – 27 - Total Carbon Dioxide Concentration
14
Q
The bicarbonate ion concentration in the blood that
has been equilibrated with CO2 at ____mm Hg at ____oC
_______ mmol/L
A
.Bicarbonate Ion Concentration
40 at 37 degrees celcius
22-26 mmol/L
15
Q
pH at which the
protonated and
unprotonated forms
are present in equal
conc.
A
pKa
16
Q
<7.35
A
acidosis or acidemia
17
Q
> 7.45
A
alkalosis or alkalemia
18
Q
– process in the body
A
osis
19
Q
-emia
A
state in blood
20
Q
refers to the process in the body or the
blood which causes the pH of the blood to increase or decrease
A
→ Acidosis / Alkalosis
21
Q
means that your blood is acidic or alkalotic
A
→ Acidemia / Alkalemia
22
Q
● In measurement of _________ are measured
parameters, while Bicarbonate ion concentration is a calculated __________
A
blood gases, pH, pCO2, and pO2
parameter
23
Q
The main sample used in blood gases is _________________
A
ARTERIAL BLOOD
24
Q
● index of the acidity or alkalinity of the blood
● it is inversely proportional to your hydrogen ion
concentration
A
pH
25
______ is directly proportional to the blood pH
Bicarbonate
26
related to the acidity of the blood
Hydrogen:
27
related to the capacity of the blood to become basic
Bicarbonate
28
→ this means that the__________ present in the blood,
the lesser the blood pH, and vice versa
more hydrogen ions
29
pH is ____________ to your hydrogen ion
concentration
inversely proportional
30
will cause alterations in the rates of chemical
reactions within the cell and affect the many metabolic
processes of the body
increase H+
31
36 – 44 nmol/L (pH 7.34 – 7.44)
Normal
32
increase H+ → Can lead to alterations in ______ (6)
consciousness, neuromuscular
irritability, tetany, coma, and death
CNITCD
33
→ ______ = proton acceptor (HCOs)
→ ______ = proton donor or weak acid (H2CO3)
→ ______= pH at which there is an equal concentration of protonated and unprotonated species
A, HA, pK'
34
_______ = pK’ of HCO3
_________ = the value for the combination of
the solubility constant for pCO2 and the factor to convert mm Hg to mmol/L
6.1
0.0307 mmol/L/mm Hg
35
→ Bronsted-Lowry’s definition of acid
▪ Acid is a substance that can _________ in the reaction
donate a proton (H+)
36
Acid is _________
base is ___________
Unprotonated
protonated
37
→ Bronsted-Lowry’s definition of base:
▪ Base is a substance that _________ in the reaction
accepts a proton
38
→ -log of the ionization constant
pK'
39
→ Dissociates completely
● Strong acids
40
→ Some will dissociate
Strong bases
41
→ Ratio of dissociated ions to the original acid
dissociation constant (k values)
42
WHAT IS THE DIFFERENCE BETWEEN STRONG AND WEAK
ACIDS/BASES?
When strong acid dissociates, it dissociates ___________
● In the case of weak acids, SOME will dissociate, while others ________
COMPLETELY
do not
43
→ First line of defense
● Buffer Systems
44
➢ Plays a role in both plasma and red blood cells
▪ Phosphate buffer system
45
→ For the buffer system in the intracellular fluid, this includes the
Phosphate buffer system and Protein buffer systems
PBS
PBS
46
Includes hemoglobin buffer system, amino acid buffers, and
plasma protein buffers
HAP
protein buffer system
47
❖ Acts as a buffer by transporting hydrogen ions from peripheral tissues to the lungs
♦ Hemoglobin buffer system
48
Most circulating proteins have a net negative charge,
which means that proteins are capable of binding with hydrogen ions.
❖ If you have too much hydrogen ions inside your body, it would indicate that your blood is acidic, the proteins will now bind with you hydrogen ions to regulate your blood pH
♦ Plasma protein buffers
49
➢ considered as the main buffer system of the extracellular fluid
▪ Carbonic acid-bicarbonate buffer system
50
The following organs are the main organs which participate in the
regulation of the acid-base status in the body
_________ and __________
lungs and kidney
51
_________ : Respiratory component
__________: Metabolic component
Lungs and kidney
52
________= equilibrium between H2CO3 and CO2 in plasma
__________= proportional to the pCO2
___________= are measured in blood gas analysis
1:800
cH2CO3
pH and PCO2
53
→ pH less than 7.35 – 7.45
→ Reflects excess acid or H+ concentration
ACIDEMIA
54
→ pH greater than 7.35 – 7.45
→ Reflects excess base
● ALKALEMIA
55
Normal ratio: _________ (bicarbonate : carbonic acid)
20:1
56
→ Caused by ventilatory dysfunction (a change in pCO2
● Primary Respiratory Disorder (PRD)
57
→ Resulting from a change in the HCO3 -
ion level
● Metabolic (Nonrespiratory) Disorder (MND)
58
→ The body tries to restore acid-base homeostasis whenever
an imbalance occurs
Compensation
59
Body accomplishes this by altering the factor not primarily
affected by the pathologic processes
▪ If the imbalance is of metabolic origin, the body
compensates by altering the ventilation
Compensation
60
→ For disturbances of the RESPIRATORY COMPONENT, the
kidneys compensate by selectively excreting or reabsorbing
anions and cations
lungs
61
→_______ can compensate immediately, but the response is
short term and often incomplete
lungs
62
________ are slower to respond (2-4 days), however, the
response is long term and potentially complete
63
→ Implies that the pH has returned to the normal range (the
20:1 ratio has been restored)
fully compensated
64
→ Implies that the pH is approaching normal
partially completed
65
There are times wherein the compensation may return the ratio to
normal, but the primary abnormality or disorder is not _________
corrected
66
Decrease in bicarbonate, resulting in a decreased pH as a
result of the ratio for the nonrespiratory to respiratory
component less than 20:1
● PCO2 is ________
Primary metabolic acidosis
normal
67
In hyperventilation, the breathing rate increases for it to exhale more
__________ and the level of________ will decrease
CO2
PCO2
68
Results from a decrease in alveolar ventilation (hypoventilation),
causing a decreased elimination of CO2 by the lungs
● pCO2 is __________
primary respiratory acidosis
69
→ destructive changes in the airways and alveolar walls
increase the size of the alveolar air spaces, with the resultant
reduction of the lung surface area available for gas exchange
As a result, CO2 is retained in the blood, causing ___________
● Chronic Obstructive Pulmonary Diseases (COPD)
chronic hypercarbia
70
→ gas exchange is impeded because of the secretions, WBCs,
bacteria, and fibrin in the alveoli
Bronchopneumonia
71
→ caused by drugs, mechanical obstruction, and asphyxiation,
will increase blood pCO2
levels
● Bronchopneumonia
72
→ less blood presented to the lungs for gas exchange, and
therefore, an elevated pCO2
● Decreased cardiac output (CHF)
73
● Results from a gain in HCO3-
, causing an increase in the
nonrespiratory component and increase in the pH
B.1 Primary Metabolic Alkalosis
74
● Results from an increased rate of alveolar ventilation causing
excessive elimination of carbon dioxide by the lungs
Primary Respiratory Alkalosis
75
Popular treatment for hysterical hyperventilation:
: breathing into a paper bag
76
→ consume oxygen, leading to a false decrease in the pO2
● Bacterial contamination
77
(amount of current flow)
Amperometric
78
(Change in voltage)
Potentiometric
79
refers to the process in the body
which causes the pH of the blood to increase or
decrease
Acidosis / Alkalosis
80
pO2 -
pH -
pCO2
- decrease by 7%
decrease by 0.015
increase by 3%
81
Samples are stable for only ______ minutes at room temperature
15 minutes
82
→ If ever the specimen is allowed to stand at room temperature for
more than _____ minutes, there will be glycolysis, thus falsely
30 minutes
83
Specimen collection for ABG is done by _________ , not
by medical technologists
respiratory therapists
84
___________ with the use of ice chips to
prevent O2 consumption by the RBC and release of acidic
metabolites
Blood samples should be chilled
85
the main site which retains the kidney is the
PROXIMAL
CONVOLUTED TUBULE
86
The carbon dioxide in the plasma will diffuse into the tubule, this will
then combine with a water to become _________
carbonic acid
87
the enzyme responsible for the production of carbonic acid from
carbon dioxide and water is the __________
Carbonic anhydrase
88
if the hydrogen ion binds with ammonia, its end product
would be
ammonium
89
If the hydrogen ion binds with the monohydrogen
phosphate, the end product would be ___________
Dihydrogen phosphate
90
The end product will be excreted through the __________
urine
91
Bicarbonate will be reabsorbed in the _________
blood
92
▪ Hydrogen ions will go the the ___________
lumen of the tubule
