Ch. 14 Flashcards
(74 cards)
1
Q
acid-base imbalances
A
- metabolic acidosis
- respiratory acidosis
- combined metabolic and respiratory acidosis
- metabolic alkalosis
- respiratory alkalosis
2
Q
metabolic acidosis
A
- Overproduction of hydrogen ions
- Under-elimination of hydrogen ions
- Underproduction of bicarbonate ions
- Over-elimination of bicarbonate ions
*too much H+, not enough HCO3
3
Q
causes of metabolic acidosis
A
- DKA
- Shock
- Severe Diarrhea
- Impaired kidney function
4
Q
clinical manifestations of metabolic acidosis
A
- neuro
- respiratory
- GI (vomiting, diarrhea)
- cardiac (EKG changes)
5
Q
respiratory acidosis results from
A
retention of CO
*too much CO2
6
Q
causes of respiratory acidosis
A
respiratory disorder
- resp. depression
- inadequate chest expansion
- airway obstruction (COPD)
- reduced alveolar-capillary diffusion
CNS depression
- sedation
- head injury
7
Q
acidosis: patient-centered collaborative care
A
- history
- CNS changes
- neuromuscular changes
- cardiovascular changes
- respiratory changes
- skin changes
- psychosocial assessment
8
Q
neuromuscular changes with acidosis
A
- decreased muscle tone
- decreased DTR
9
Q
cardiovascular changes with acidosis
A
early:
- increased heart rate
- cardiac output changes
worsening:
- hyperkalemia
- decreased heart rate
- T wave peaked
- QRS widened
- weak peripheral pulses
- hypotension
10
Q
respiratory changes with acidosis
A
Kussmaul respiration (deep and rapid breathing)
11
Q
skin changes with acidosis
A
(respiratory or metabolic acidosis)
- warm
- dry
- pink (vasodilation)
12
Q
interventions for respiratory acidosis
A
- focus on improving ventilation and O2, maintaining patent airway
- drug therapy
- O2 therapy
- pulmonary hygiene
- ventilation support
- prevention of complications
13
Q
drug therapy for respiratory acidosis
A
- bronchodilators
- anti-inflammatories
- mucolytics
14
Q
interventions for metabolic acidosis
A
- hydration
- drugs
15
Q
drug therapy for metabolic acidosis
A
- insulin to treat DKA
- antidiarrheal drugs
- bicarbonate only if serum bicarbonate levels are low
16
Q
combined metabolic and respiratory acidosis is ___ than either form alone
A
- more severe than either form alone
17
Q
uncorrected respiratory acidosis leads to
A
poor oxygenation and lactic acidosis
18
Q
example of a problem leading to combined metabolic and respiratory acidosis
A
cardiac arrest
19
Q
metabolic alkalosis
A
excessive base, and acid deficit
20
Q
causes of excessive base
A
- excessive intake antacids (sodium bicarbonate or calcium bicarbonate)
- citrates (blood transfusions)
- IV sodium bicarbonate
21
Q
causes of acid deficit
A
- prolonged vomiting
- excess cortisol
- hyperaldosteronism
- thiazide diuretics
- prolonged NG suction
22
Q
hallmark of base excess alkalosis
A
ABG result with increased pH and increased bicarbonate level with normal O2 and CO2 levels
23
Q
respiratory alkalosis is usually caused by
A
excessive loss of CO2 via hyperventilation
24
Q
causes of hyperventilation
A
- anxiety (anxiety attack- hyperventilating)
- fear
- improper vent settings
- stimulation of central respiratory center due to fever
- salicylates
25
alkalosis: patient-centered collaborative care
- assessment (same for metabolic and respiratory alkalosis)
- hypocalcemia
- hypokalemia
- CNS changes
- neuromuscular changes
- cardiovascular changes (elevated)
- respiratory changes (elevated)
26
CNS changes with alkalosis
- positive Chvostek's and Trousseau's signs
27
neuromuscular changes with alkalosis
- tetany
28
interventions for alkalosis
- prevent further losses of hydrogen, potassium, calcium, and chloride ions
- restore fluid balance
- monitor changes
- modify or stop gastric suctioning, IV solutions with base, drugs that promote hydrogen ion excretion
29
the lungs have one chemical:
CO2
30
what organ is sick during respiratory acidosis/alkalosis
the lungs
31
sick lungs =
respiratory acidosis or alkalosis
- problem due to CO2
32
what are the compensating organs in respiratory acidosis/alkalosis?
the kidneys
- secrete bicarbonate and excrete hydrogen, bring pH back to normal
33
kidneys are _____ in compensating for respiratory acidosis/alkalosis
slow but effective
34
what organ is sick during metabolic acidosis/alkalosis?
the kidneys
- cannot maintain pH
35
what are the problem chemicals with metabolic acidosis/alkalosis?
- bicarbonate
- hydrogen
36
what are the compensating organs with metabolic acidosis/alkalosis?
the lungs
- blow off or retain CO2 quickly to correct metabolic acidosis or alkalosis
37
with metabolic acidosis/alkalosis, what chemical do the lungs work with to compensate?
- CO2
- the acid
38
arterial blood gas (ABG) normal values: pH
7.35-7.45
39
arterial blood gas (ABG) normal values: PCO2
35-45 mmHg
40
arterial blood gas (ABG) normal values: HCO3
23-30 mEq/L
41
arterial blood gas (ABG) normal values: PaO2
80-100 mmHg
42
laboratory assessment values: metabolic acidosis
pH: <7.35
bicarbonate: < 23 mEq/L
PaO2: normal
PaCO2: normal or slightly decreased
serum potassium: high
43
laboratory assessment values: respiratory acidosis
pH: <7.35
PaO2: low
PaCO2: high
serum bicarbonate: variable
serum potassium: elevated if acidosis is acute
44
laboratory assessment values: metabolic alkalosis
pH: >7.45
bicaronate: >30 mEq/L
PaO2: normal
PaCO2: normal or slightly increased (compensation)
serum potassium: may be low
45
laboratory assessment values: respiratory alkalosis
pH: >7.45
PaO2: normal
PaCO2: low
serum bicarbonate: normal
serum potassium: may be low
46
analysis of ABG
- look at pH draw arrow if it is high or low
- look at PCO2 (respiratory) draw arrow low or high
- look at HCO3 (metabolic) draw arrow low or high
47
low ABG =
acidosis
48
high ABG =
alkalosis
49
(ABG analysis) if PCO2 arrows are in opposite direction =
respiratory acidosis or alkalosis
50
(ABG analysis) if pH arrow and HCO3 arrow are in the same direction =
metabolic acidosis or alkalosis
51
(ABG analysis) compensation is present if the arrows ____
if arrows of PCO2 and HCO3 are opposite
52
(ABG analysis) partial compensation is present if the arrows ____
if arrows of PCO2 and HCO3 are in the same direction
53
decreased pH =
- acidodic
- increased hydrogen ions
54
increased pH =
- alkalotic
- decreased hydrogen ions
55
normal blood pH
7.35-7.45
56
acids
release hydrogen ions when dissolved in water or bodily fluids
57
bases
bind with hydrogen ions in solutions and lower the amount of free hydrogen ions in solution
58
buffers
can react either as acid or base
59
bicarbonate (HCO3-) ions are a relationship between
CO2 and hydrogen ions
60
acid base balance compensation: 3 ways
1. buffers (bicarb, phosphate, protein, ammonium)
2. respiratory system (adjusts CO2)
3. renal system (controls bicarb)
61
which compensation method is the quickest response?
respiratory system
62
which compensation method is the longest response?
renal system (kidneys)
- takes 24-48 hours to respond
63
1st line of defense against changes in free hydrogen ion levels (pH)
buffers
64
common buffers
- bicarbonate (main buffer of ECF)
- phosphate
- blood proteins (albumin, globulins)
65
main buffer of ECF
bicarbonate
66
second line of defense against pH changes
respiratory system
- hypoventilation
- hyperventilation
67
physiologic conditions that lead the body's response to hypoventilation
- decreased rate and depth of respiration (hypoventilation)
- inhibition of central chemoreceptors
- decreased PaCO2
- decreased H+
68
physiologic conditions that lead the body's response to hyperventilation
- increased PaCO2
- increased H+
- stimulation of central chemoreceptors
- increased rate and depth of respiration (hyperventilation)
69
third line of defense against pH changes
renal system (kidneys)
70
strongest for regulating acid-base balance
the renal system (kidneys)
71
kidneys respond to pH changes by
movement of bicarbonate
72
compensation is when
body attempts to correct blood pH changes
73
fatal pH values
< 6.9 or > 7.8
74
homeostasis of acid-base regularity depends on
- hydrogen ion production being consistent and not excessive
- CO2 loss from the body through breathing, keeping pace with all forms of hydrogen ion production
