Blood Gases, pH, and Buffer Systems Flashcards
(115 cards)
1
Q
a substance that can yield a hydrogen ion (H+) or hydronium
ion when dissolved in water
A
Acid
2
Q
a substance that can yield hydroxyl ions (OH-)
A
Base
3
Q
substance that DONATES a proton in a reaction
A
Acid
4
Q
substance that ACCEPTS a proton in a reaction
A
Base
5
Q
the negative log of the ionization constant
A
pKa
6
Q
pH in which the protonated and unprotonated forms are present in equal concentrations
A
pKa
7
Q
Strong acids have pKa values of _____.
A
<3.0
8
Q
Strong bases have pKa values ______.
A
> 9.0
9
Q
For acids, raising the pH above the pKa will cause the acid to
_______ and yield ____.
A
dissociate, H+
10
Q
For bases, lowering the pH below the pKa will cause the base to
release _____.
A
OH-
11
Q
resists change in pH upon adding acid or base
A
Buffer
12
Q
the combination of a weak acid or weak base and its salt
A
Buffer
13
Q
Normal concentration for maintenance of H+ with pH
A
36 to 44 nmol/L, 7.34 to 7.44
14
Q
Outside of the normal range for maintenance of H+ could mean?
A
Alterations in consciousness
Neuromuscular irritability
Tetany
Coma
Death
15
Q
Arterial blood pH (nmol/L)
A
7.40 (40 nmol/L)
16
Q
pH is _______ proportional to H+
A
inversely
17
Q
the body’s first line defense against extreme changes in H+ concentration
A
Bicarbonate-carbonic acid system
18
Q
Bicarbonate-carbonic acid system is consist of a weak acid such as?
A
carbonic acid (H2CO3), and its salt/conjugate base
bicarbonate (HCO3)
19
Q
HCO3:H2CO3 ratio must be ____ to maintain normal pH
A
20:1
20
Q
plays a role in plasma and red blood cells and is involved in
the exchange of sodium ion in the urine H+ filtrate
A
Phosphate buffer system
21
Q
It is used for regulation of H+
A
Buffer systems
22
Q
imidazole groups of histidine
A
Plasma proteins
23
Q
most circulating proteins have a net ___________ and are
capable of __________.
A
negative charge, binding H+
24
Q
Lungs is through ____________ or ____________.
A
gas exchange, respiration
25
Lungs has _____ and ______ term compensation.
rapid, short
26
Lungs controls?
carbon dioxide (CO2)
27
Kidneys is through ___________ or __________________.
reabsorption, excretion of bicarbonate
28
Kidneys has a _______ but _____ term compensation.
slow, long
29
Kidneys controls?
bicarbonate (HCO3)
30
Expresses the acid-base relationships in a mathematical formula.
Henderson-Hasselbalch Equation
31
32
formula for pH wherein kidneys is the numerator and lungs is the denominator.
pH = 6.1 + log salt/acid or
pH = 6.1 + log HCO3/H2CO3
33
formula for H2CO3?
H2CO3 = pCO2 x 0.0307
34
formula for HCO3
HCO3 = Total CO2 - H2CO3
35
pH is _______ proportional to bicarbonate.
directly
36
pH is ________ proportional to the partial pressure of carbon dioxide.
inversely
37
pH - arterial blood gas reference range
7.35 to 7.45
38
pCO2 (mmHg) - arterial blood gas reference range
35 to 45
39
HCO3 - arterial blood gas reference range
22 to 26
40
Total CO2 content (mmol/L) - arterial blood gas reference range.
23 to 27
41
pO2 (mmol/L) - arterial blood gas reference range
80 to 110
42
SO2 (%) - arterial blood gas reference range.
>95
43
O2Hb (%) - arterial blood gas reference range.
>95
44
pH is less than the reference range
Acidemia
45
pH is greater than the reference range
Alkalemia
46
a disorder caused by ventilatory dysfunction (a change in pCO2, the respiratory component)
Primary Respiratory Acidosis or Alkalosis
47
a disorder resulting from a change in the bicarbonate level (a renal or metabolic function)
Nonrespiratory disorder
48
the body accomplishes to restore acid-base homeostasis by
altering the factor not primarily affected by the pathologic process.
Compensation
49
implies that the pH is has returned to the normal range
Fully compensated
50
implies that the pH is approaching normal. while compensation may successfully return the ratio to the normal 20:1, the primary abnormality is not corrected.
Partially compensated
51
pH is abnormal, pCO2 or HCO3 is normal, but not both
Uncompensated
52
pH of respiratory acidosis (increase or decrease)
decrease
53
pH of respiratory alkalosis (increase or decrease)
increase
54
pH of metabolic acidosis (increase or decrease)
decrease
55
pH of metabolic alkalosis (increase or decrease)
increase
56
disturbance in respiratory acidosis
hypoventilation, increased pCO2
57
disturbance in respiratory alkalosis
hyperventilation, decrease pCO2
58
disturbance in metabolic acidosis
decrease reabsorption and HCO-3, increase excretion
59
disturbance in metabolic alkalosis
increase reabsorption and HCO-3, decrease excretion
60
Compensation in respiratory acidosis
increase reabsorption, increase HCO-3
61
Compensation in respiratory alkalosis
increase excretion, decrease HCO-3
62
Compensation in metabolic acidosis
hyperventilation, decrease PCO2
63
Compensation in metabolic alkalosis
hypoventilation, increase pCO2
64
The amount of O2 available in atmospheric air depends on the?
Barometric pressure (BP)
65
Partial pressure of O2 at sea level (in the body)
(760 mm Hg – 47 mm Hg) x 20.93%
149 mm Hg (at 37ºC)
66
Partial pressure of CO2 at sea level (in the body)
(760 mm Hg – 47 mm Hg) x 0.03%
2 mm Hg (at 37ºC)
67
1 Adult Hemoglobin (A1) can combine reversibly with up to __
molecules of O2.
4
68
Hemoglobin not bound to O2 but capable of forming a bond when O2 is available.
Deoxyhemoglobin (HHb; reduced hemoglobin)
69
Hemoglobin bound to CO. The bond between CO and Hb is reversible but is 200 times as strong as the bond between O2 and Hb.
Carboxyhemoglobin (COHb)
70
Hemoglobin unable to bind O2 because iron (Fe) is in an oxidized rather than reduced state.
Methemoglobin (MetHb)
71
The Fe3+ can be reduced by the enzyme __________________, which is found in the red blood cells.
methemoglobin reductase
72
Shift to the right ODC if there's an increased in?
body temp
hydrogen
CO2
2,3-DPG concentration
73
shift to the left ODC if there's _______ in body temp, hydrogen, pCO2, and 2,3-DPG concentration.
decrease
74
in shift to the left ODC, if there's an increased pCO2 is due to?
cigarette smoking
fetal hemoglobin
75
Anticoagulant used in sample collection for arterial blood.
0.5 mL heparin/mL of blood (lyophilized)
76
if there's an excess heparin, there's false _______ in blood pH
decrease
77
Liquid form of heparin would cause erroneous results because?
excessive amount can dilute or possibly contaminate the sample if equilibrated with room air.
78
Arterial and venous blood differ in ___, ____, and _____.
pH
pCO2
pO2
79
Samples should be processed immediately within?
30 minutes
80
Placing the blood sample in ice water quickly after the draw
reduces ________________ and ______________________.
cellular metabolism, accumulation of acidic by-products
81
Glycolysis could result to _______ blood pH.
decreased
82
Excess heparin causes ________ shift of blood pH
downward
83
Low temperature can cause ________ oxygen solubility in blood and make a ________ in the oxyhemoglobin curve.
increased, left-shift
84
used as sensing devices to measure pO2, pCO2, and pH.
Electrodes
85
used in measuring pO2; the amount of current flow is an indication of the oxygen present
Amperometric
86
used in measuring pCO2 and pH; a change in voltage indicates the activity of each analyte
Potentiometric
87
negative electrode
cathode
88
site to which cations tend to travel
cathode
89
a site at which reduction occurs
cathode
90
the gain of electrons by a particle (atom, molecule, or ion)
Reduction
91
positive electrode
anode
92
site to which anions migrate
anode
93
site at which oxidation occurs
anode
94
the loss of electrons by a particle (atom, molecule, or ion)
Oxidation
95
formed when two opposite electrodes are immersed in a liquid
that will conduct a current.
Electrochemical cell
96
measure the amount of current flow in a circuit that is related to amount of O2 being reduced at the cathode.
Clarke electrodes
97
A ____________ placed in the circuit between the anode cathode
measures the movement of electrons (current).
microammeter
98
determines blood pH by the potential difference between a
measuring electrode and a reference electrode
Sanz glass electrode
99
reference electrodes:
Ag-AgCl electrode
Calomel (Hg2C12)
100
use to measure pCO2
Severinghaus Electrode
101
an outer semi-permeable membrane that allows CO2 to diffuse into a layer of electrolyte, usually a bicarbonate buffer, covers the glass pH electrode.
Severinghaus Electrode
102
the most important factor that influences the assay
Temperature
103
for each degree of fever in the patient, pO2 will fall___ and pCO2
will rise ___.
7%, 3%
104
Lactic acidosis is the excessive accumulation of lactic acid in plasma, either due to __________, ________________ by the renal and hepatic, or _______________.
overproduction
defective removal
underutilization
105
It is produced from pyruvic acid by the action of LDH and NAD.
Lactic acidosis
106
Lactic acidosis is usually seen in cases of ___________.
tissue hypoxia
107
Lactic acidosis is characterized by _______________ and ___ blood pH (____).
elevated anion gap, low (<7.35)
108
Common cause of Lactic acidosis:
L-lactate
109
Reference range: venous blood lactate
5 to 20 mg/dl
110
Reference range: arterial blood lactate
3 to 7 mg/dL
111
Interpretation:
indication of sepsis
>18 mg/dL
112
What is the form of L-lactate?
levorotatory
113
What is the form of D-lactate?
dextrorotatory
114
Type of lactic acidosis that is related with decreased oxygenation with tissue hypoxia.
Type A-Hypoxic Lactic Acidosis
115
Type of lactic acidosis that is associated with diseases and high demand of cellular oxygen, no tissue hypoxia.
Type B-Metabolic Lactic Acidosis
