NUR 406 ACID BASE BALANCE Flashcards
(96 cards)
1
Q
What is pH?
A
the “potential” or “power” of Hydrogen
2
Q
What does [H+] mean?
A
The hydrogen ion concentration
3
Q
pH is the negative logarithm of?
A
Inverse ratio or proportion
When the [H+] goes up, the pH goes down
When the [H+] goes down, the pH goes up
4
Q
Acids have more?
A
H+ ions
5
Q
Bases have less?
A
H+ ions
6
Q
What is the most acidic area in the body?
A
The stomach
7
Q
What do strong acids do in solution?
A
Completely dissociate
8
Q
What do weak acids do in solutions?
A
Partially dissociate
9
Q
Why is hydrogen important in the body?
A
Helps maintain cell membranes
Helps with enzyme activity
Component of H20 and keeps the body hydrated
Helps in energy production
10
Q
Hydrogen is a component of?
A
Sugars
Proteins
Starch
Fats
11
Q
On an acid base scale, 7 is?
A
Neutral
12
Q
What is anormal pH?
A
7.35 - 7.45
13
Q
How do we measure the pH?
A
Serum blood
14
Q
How is the stomach uniquely designed to handle HCl?
A
Duodenum has a defense mechanism to neutralize the acid.
15
Q
What does the LES prevent?
A
Gastric acid from moving into the esophagus
16
Q
Why are there many different pH ranges in the GI tract?
A
Aids in digestion
17
Q
What is the pH of the skeletal muscle?
A
6.9-7.2
18
Q
What is the pH level of bone?
A
7.4
19
Q
What is the pH level of the liver
A
7.2
20
Q
What is the pH level of pleural fluid
A
7.6
21
Q
When do body systems function best?
A
pH range of 7.35-7.45
22
Q
What does acid base balance affect?
A
Electrolytes = Na, K, Cl
hormones
oxygen transport and delivery - oxygemoglobin dissociation curve
23
Q
What pH levels are incompatible with life?
A
<6.8 or >7.8
24
Q
How many types of acids are in the body and what are their names?
A
2 - volatile and non-volatile
25
What is a volatile acid?
Can be converted to gas
Excreted/eliminated by the lungs
26
What is the name of one violatile acid in the body?
Carbonic acid
27
What is the equation for carbonic acid?
H2CO3 <--->H2O + CO2
28
What are non-volatile acids?
Lactic acid
Phosphoric acid
Sulfur acid
Acetoacetic acid
Beta-hydroxybutyric
29
How are non-volatile acids eliminated?
Excreted by the kidneys.
Exception - lactic acid which is metabolized by the body primarily the liver and kidney
30
How does the body produce more acid than bases?
Ingest in food/drink
Metabolism of lipids and proteins
Cellular metabolism waste product - CO2 a volatile acid
31
Which imbalance is harder to correct and why?
Alkalosis - The hemoglobin hold on to oxygen more
32
How do we maintain acid-base homeostasis?
Buffers
Respiratory system
Renal system
33
What are buffers?
Chemicals in the body that combine with acid or base to change the pH
Accepts or release a H+
Almost instantaneous
Short-lived
34
What are the 3 main buffer systems
Bicarbonate - carbonic acid buffer
Phosphate buffer
Protein buffers - hemoglobin
35
What is Bicarbonate - Carbonic acid ?
main ECF buffer
CO2 byproduct of cellular metabolism
Combines with H2O in serum to form carbonic acid
36
What is carbonic anhydrase?
Enzyme that breaks down carbonic acid
In many tissues of the body, including lungs and kidneys
In lungs: H2O + CO2
In kidneys: H+ + HCO3-
37
What is a phosphate buffer?
Main intracellular buffer
H+ + HPO4 (-2) = H2PO4
Hydrogen + hydrogen phosphate = dihydrogen phosphate ion
38
What are protein buffers?
Nearly all proteins can function as buffer.
Carboxyl group (COOH) is a weak acid that gives up a H+
*Amino acid
*Acetic acid
Amino group (NH2-) accepts H+
*Amino acids have both a carboxyl group and an amino group
*Ammonia NH3
Hemoglobin is considered in this group
*Picks up CO2 at the cellular level
39
Increase in [H+] causes?
pH decrease - more acids
H+ move into the cell
More positvely charged ions in the cell
K+ moves out of the cell
Electrical neutrality is restored inside the cell
40
What is a temporary correction of the pH?
Process will reverse as the pH returns to normal
If the kidneys are working, they will excrete the excess K+
Body can have a depletion of K+
41
What is the respiratory mechanisms?
Body produces CO2
CO2 and H2O create carbonic acid
Exhalation excretes carbonic acid
It does not affect fixed acid (non-volatile acids) such as lactic acid
Body pH can be adjusted by changind the rate and depth of breathing
42
What happens with kidney excretion
Can eliminate large amounts of acid except carbonic acid
Can also excrete base
Can conserve and produce bicarb ions
Most effective regulator of pH
If kidneys, fail, pH balance fails
Depends on normal functioning of renal system
43
What are rates of correction?
Buffers function almost instantaneously
Respiratory mechanism takes several minutes to hours
Renal mechanisms take several hours to days
44
What is considered acidosis?
<7.35
45
What is considered alkalosis?
>7.45
46
The body's response to acid-base imbalance is called?
Compensation
47
May be _____ if brought back within normal limits
Complete
48
_______ if range is still outside norms
Partial compensation
49
If the underlying problem is _____, hyperventilation or hypoventilation can help __________
Metabolic, respiratory compensation
50
If problem is ______, renal mechanisms can bring about ________
Respiratory, metabolic compensation
51
Remember the _____ buffer system responds in seconds
blood
52
Respiratory buffer responds in?
minutes to hours
53
______ are the primary controller of H2CO3 supply
Lungs
54
In the lungs, excess CO2 combines with H20 to form ______
Carbonic acid
55
______ is carried in the blood to the lungs
CO2
56
Carbonic acid triggers the lungs to do what?
increase or decrease the rate and depth of ventilation to adjust the pH
57
_____ is when CO2 is blown off and pH increases
hyperventilation
58
_____ is when CO2 is retained and pH decreases
Hypoventilation
59
Renal buffer responds in ______
Hours to days
60
Kidneys are the primary controller of _____ supply
HCO3
61
Kidneys control pH by adjusting the amount of HCO3 that is?
Reabsorbed into the bloodstream
Excreted into the urine
62
If blood is too acidic, kidneys will?
Reabsorb bicarb
63
If blood is too alkaline, kidneys will?
excrete bicarb
64
The ___, ____, and ____ all work together to maintain normal acid-base balance.
Blood, lungs, and kidneys
65
What does an arterial blood gas consist of?
pH, PaCO2, HCO3
66
What is PaCO2 and what is the normal level?
Respiratory parameter
35-45
67
What is HCO3 and what is the normal level
Metabolic parameter. Calculated on the ABG.
On a chemistry panel, HCO3 is reported as CO2
22-26
68
What does a venous blood gas consist of and what are the levels?
pH 7.31-7.41
PvCO2 41-51
HCO3
69
On a BMP, how is the HCO3 level interpreted?
Serum CO2
70
What is a primary event and what are examples?
The problem that initiates the acid-base imbalance.
Hypoventilation, hyperventilation, vomiting, diarrhea
71
What is a primary disorder and what are examples?
What results from the primary event.
Respiratory acidosis, metabolic alkalosis
72
If the lungs are the problem with imbalance, which organ will compensate?
Kidneys
73
If the kidneys are the problem with imbalance, which organ will compensate?
the lungs
74
What is the cause of metabolic imbalance?
HCO3 level changes secondary to metabolic alterations. The problem is metabolic in nature.
75
What is the cause of respiratory imbalance?
H2CO3 level changes secondary to respiratory alterations. The problem is respiratory in nature.
76
What is Metabolic acidosis?
Decreased HCO3, pCO2, pH
77
What is respiratory alkalosis?
Decreased pCO2 and HCO3, Increased pH
78
Respiratory acidosis?
Increased pCO2 and HCO3, decreased pH
79
Metabolic alkalosis?
Increased HCO3 and pH, normal PaCO2
80
What is metabolic alkalosis?
Too much bicarb or not enough carbonic acid
pH >7.48
PaCO2 35-45
HCO3 >26
81
What are causes of Metabolic Alkalosis?
Taking excess baking soda, alka seltzer.
Too much base results in hypokalemia causing hydrogen to shift out of the intracellular space and potassium goes into the cell
Prolonged vomiting, NG tube, Diuretics
82
Clinical manifestations of metabolic alkalosis?
CNS over excitability
Confusion
Tremors
Muscle cramps
Paresthesias
Coma
N/V/D
Resp depression
83
What is respiratory alkalosis?
H2CO3 deficit in ECF
pH >7.45
PaCO2 <35
HCO3 22-26
84
What causes respiratory alkalosis
Hyperventilation
Fever, sepsis
medications
acute anxiety
hypoxia
PE or lung disease
CNS lesions
Ventilator settings
85
Clinication manifestations of respiratory alkalosis
CNS over excitability
tachypnea
lightheadedness
confusion
blurry vision
paresthesia
hyperactive reflexes
seizures
coma
86
What is respiratory acidosis?
H2CO3 excess in ECF
pH <7.35
PaCO2 >45
HCO3 22-26
87
What causes respiratory acidosis?
Hypoventilation
88
HCO3 is within normal limits with ____ respiratory acidosis
acute - no time for kidneys to compensate
89
Clinical signs and symptoms of respiratory acidosis
CNS DEPRESSION which causes HYPOVENTILATION
90
Common causes of respiratory acidosis
Cardiopulmonary arrest
head injury
narcotic/sedatives
anesthesia
pulmonary disorders - acute asthma COPD exacerbation, PNE, resp failure
pain
abdominal distention
airway obstruction
chest wall deformities
neuromuscular problems
91
What is metabolic acidosis
HCO3 deficit in ECF
pH <7.35
PaCO2 35-45
HCO3 <22
92
If the lungs are compensating for metabolic acidosis, the CO2 will be
decreased
93
Clinical S/S
Lethargy, drowsy
confusion
tremors, muscle cramps
Parasthesias
Hypotension
Hyperkalemia
Deep breathing - kussmaul DKA
Fruity odor breath
94
Common causes of metabolic acidosis
Renal failure
fistulas
DM type 1
lactic acidosis
Prolonged diarrhea
Starvation
Medication overdose - aspirin
Shock and cardiac arrest
95
Respiratory Acidosis/Alkalosis Compensation are
The results of the respiratory alterations and the KIDNEY compensates by either
*Conserving (reabsorbing) HCO3 ions - acidosis correction
*Excreting HCO3 - alkalosis correction
96
Metabolic acidosis/alkalosis compensation are
The results of metabolic alterations and the LUNGS compensate by:
*Conserving CO2 ions - hypoventilation (alkalosis correction)
*excreting CO2 ions - hyperventilation (acidosis correction)
