Pathophysiology Exam 1 Flashcards
(118 cards)
1
Q
ICF
A
intracellular fluid
2
Q
ECF
A
extracellular fluid
3
Q
What determines solution concentration?
A
amount of water and solute
4
Q
Solute =
A
Na+ (there are more, but most important)
5
Q
Where does water move when the ICF & ECF are at equilibrium?
A
Water doesn’t move; no net water movement/fluid shift
6
Q
Normal fluid concentration range
A
280-300
7
Q
Isotonic
A
normal concentration
8
Q
Hypertonic
A
more concentrated, less dilute
9
Q
Hypotonic
A
less concentrated, more dilute
10
Q
Hypertonic caused by:
A
decrease water or increase solute or both
11
Q
Hypotonic caused by:
A
increase water or decrease solute or both
12
Q
Most common cause of hypertonic ECF
A
water loss
13
Q
What happens to the cell when the ICF is isotonic and the ECF is hypertonic?
A
It shrinks
14
Q
water always moves where?
A
from dilute to concentrated
15
Q
What happens to the cel when the ICF is isotonic and the ECF is hypotonic?
A
It swells/expands
16
Q
the total of all the water in the body
A
total body water (TBW)
17
Q
ICF is what fraction of TBW?
A
2/3
18
Q
ECF is what fraction of TBW?
A
1/3
19
Q
ECF two compartments
A
1) Interstitial fluid (btw cells)
2) Plasma (bloodstream)
20
Q
IF constitutes how much of the ECF?
A
80%
21
Q
Plasma constitutes how much of the ECF?
A
20%
22
Q
- pressure trying to push water out of the bloodstream
- established by BV
A
Plasma hydrostatic pressure
23
Q
- pressure trying to keep or attract water into the bloodstream
- established by albumin
A
Plasma oncotic pressure
24
Q
What causes water movement between the ECF compartments?
A
plasma hydrostatic and oncotic pressure
25
If hydrostatic pressure = oncotic pressure then what?
water doesn't move
26
Is BV at the arterial and venous ends of the capillary bed remain stable?
yes
27
accumulation of fluid in interstitial space
- distribution problem
Edema
28
4 factors that favor Edema formation
1) increase plasma hydrostatic pressure (increase BV)
2) decrease oncotic pressure (decrease albumin)
3) increase capillary permeability (increase leakiness)
4) Lymphatic obstruction
29
What can cause plasma hydrostatic pressure to increase?
anything that increases BV
- CHF; causes fluid retention, which increase BV
30
What can cause plasma oncotic pressure to decrease?
anything that decreases albumin
- liver failure
- protein malnutrition or protein absorption problem
31
What can cause capillary permeability to increase?
- inflammation: cells pull apart
- Trauma: direct vessel damage
32
What can cause lymphatic obstruction
- internal blockage
- external compression of lymphatic damage
Both: prevent drainage, leading to fluid accumulation
33
charged ionized particles
electrolytes
34
Normal blood Na+
135-145
35
Water follows what?
Na+
36
- emia
in blood stream
37
Hypernatremia
Na+ > 145
- 160 = severe
38
Hyponatremia
Na+ < 135
- <125 = severe
39
Most abundant ECF electrolyte
Na+
40
What do Na+ abnormalities impact?
ECF osmolarity & BV/BP
41
What regulates Na+ homeostasis?
GI tract, kidneys & endocrine system (aldosterone)
42
- most common in hospitalized patients & elderly
- almost always caused by decrease in water
- ECF becomes hypertonic
- Cells shrink
- In severe cases: CNS cells are damaged
Hypernatremia
43
- results from decrease Na + or increase water
- ECF becomes hypotonic
- Cells swell
- In severe cases: brain swells
Hyponatremia
44
What are common causes of hyponatremia?
- diuretic use
- diarrhea: decrease Na & decrease BV
- heart failure: increase water & increase BV
45
How should Hyponatremia be treated?
treated slowly: No more than 8 mEg/L of sodium in 24 hours
- rapid treatment could cause severe brain damage
46
Normal blood K+
3.5-5
47
What 2 hormones regulate K+?
1) aldosterone
2) insulin
48
Aldosterone
increase Na+ & decrease K+
49
Insulin
shift K+ from blood into ICF
50
K+ plays an important role in what?
neuromuscular excitability
51
Most abundant ICF electrolyte
K+
52
K+ homeostasis is regulated by what?
GI tract, kidneys & endocrine system (aldosterone & insulin)
53
Hyperkalemia
blood K+ > 5
54
Most dangerous electrolyte abnormality. Why?
hyperkalemia
- May develop lethal cardiac dysrhythmias: slow conduction velocity in heart. May lead the heart to stop beating (asystole) or cause ventricular fibrillation (Vfib)
55
Common causes of hyperkalemia
- increase K+ retention (ACE inhibitors & ARBs)
- renal impairment (decrease K+ excretion)
- Adrenal insufficiency (decrease K+ excretion)
- disorders causing K+ release from cells: burns, crush injuries, metabolic acidosis, cancer treatment
- hypoaldosteronism (low aldosterone)
56
Hyperkalemia treatment
IV insulin (shift K+ back into cells), glucose & Ca gluconate to protect the heart (Ca restores normal heart conduction velocity)
57
Hypokalemia
blood K+ < 3.5
58
Common causes of hypokalemia
- increase K+ loss in urine (diuretic use or hyperaldosteronism)
- increase K+ loss in GI tract
59
Primary manifestation of hypokalemia
decrease in neuromuscular excitability
60
Hypokalemia treatment
treat underlying cause
61
What is abundantly stored in bone and teeth?
calcium
62
Normal blood Calcium
8.5-10
63
Calcium abnormalities affect what?
Neuromuscular excitability
64
Calcium homeostasis is regulated by what?
GI tract, kidneys, skeletal system & endocrine system (PTH & VitD)
65
Hypercalemia
blood Ca > 10.5
66
Common cause of hypercalcemia
hyperparathyroidism and cancer
67
What does hypercalcemia cause?
- decrease NM excitability (moves threshold further from RMP)
- possible constipation
- hypercalcuria (increase urinary Ca) with kidney stones
68
Severe cases of hypercalcemia cause
skeletal muscle weakness, confusion & coma
69
Hypercalcemia treatment
treat underlying cause
- may include a loop diuretic to increase calcium urinary excretion
70
Hypocalcemia
blood Ca < 8.5
71
Common cause of hypocalcemia
- hypoparathyroidism
- Vit D deficiency
- Renal failure
72
Mild cases of hypocalcemia
asymptomatic or muscle cramps
73
Severe cases of hypocalcemia
- tetany (continuous contractions)
- hyperreflexia (increased reflexes)
- parathesias (tingling) of the tongue, lips, fingers, feet
- seizures
74
Treating mild hypocalcemia
oral Ca supplements
75
treating severe tetany
IV Ca gluconate
76
pH of arterial blood
7.35-7.45
77
Maintaining acid base balance:
1) buffer systems work to resist pH changes
2) kidneys regulate acid/base excretion as needed
3) Lungs regulate CO2 (volatile acid) excretion as needed
78
What is responsible for the metabolic regulation of acid-base balance?
buffer systems & kidneys
79
What reflects the function of the metabolic component of acid-base regulation?
Bicarbonate ion (HCO3-) levels
80
What is responsible for the respiratory regulation of acid-base balance?
Lungs
81
what reflects the function of the respiratory component of acid-base regulation?
CO2 levels
82
HCO3- is a
base
83
CO2 is a
acid
84
what does an acid-base disturbance indicate?
something is wrong with the buffer systems, kidneys, or lungs (most commonly lungs or kidneys)
85
Hypokalemia NM effects
decrease NM excitability: Nervous, smooth, skeletal
Increase NM excitability: cardiac
86
Hyperkalemia NM effects
Increase NM excitability: Nervous, skeletal, smooth
Decrease NM excitability: cardiac
87
K+ levels in blood determine what?
Resting membrane potential (RMP)
88
Ca 2+ levels in blood determines what?
threshold
89
In the case of hyperkalemia, RMP is moved closer to threshold, which does what?
increase NM excitability
90
- Heart protective
- No impact on K+ levels
- moves threshold
Ca 2+ gluconate
91
Shifts K+ into cells
Insulin
92
- Maintains blood sugar
- prevents hypoglycemia
- given with insulin to treat hyperkalemia
glucose
93
PTH
increases blood calcium
94
Increases PTH, which increase calcium levels
hyperparathyroidism
95
Can cause bone breakdown, which increases calcium levels
cancer
96
Decrease PTH, which decreases blood calcium
hypoparathyroidism
97
ABG
arterial blood gas
98
What can cause acidosis (in terms of acid and base)?
increase acid and/or decrease base
99
What can cause alkalosis (in terms of acid and base)?
decrease acid and/or increase base
100
ABG readings
pH = 7.30
CO2 = 53
HCO3- = 25
Respiratory acidosis
101
Respiratory acidosis causes
- COPD (chronic obstructive pulmonary disease); traps air
- Acute asthma attack; can't exhale CO2 fast enough
- Opioids; slows down ventilation, increasing CO2
102
AGB readings
pH = 7.3
CO2 = 40
HCO3- = 14
Metabolic acidosis
103
pH normal range for ABG
7.35 - 7.45
104
CO2 normal range for ABG
35-45
105
HCO3- normal range for ABG
22-28
106
- measure negative ions in blood that aren't normally measured
- narrows potential causes of metabolic acidosis
Anion Gap (AG)
107
Normal AG range
3-12
108
Potential causes of metabolic acidosis with a normal AG
HCO3- loss
- prolonged diarrhea
109
Elevated AG range
> 12
110
Potential causes of metabolic acidosis with an elevated AG
accumulation of non-volatile acid; "Mud Piles"
- Uremia
- DKA (diabetic ketoacidosis)
- Lactic acidosis
111
associated with chronic kidney disease
Uremia
112
acute complication of type 1 diabetes
Diabetic Ketoacidosis (DKA)
113
associated with hypoxia (reduced tissue oxygenation)
Lactic acidosis
114
ABG readings
pH = 7.28
CO2 = 27
HCO3- = 12
Metabolic acidosis w/ respiratory compensation
115
Metabolic acidosis and respiratory compensation formula
CO2 = (1.5 x HCO3-) + 8 +/- 2
116
ABG readings
pH = 7.22
CO2 = 27
HCO3- = 8
Metabolic acidosis w/o respiratory compensation
117
Anion Gap (AG) calculation
AG = blood Na+ - (blood Cl- + HCO3-)
118
ABG readings
pH = 7.53
CO2 = 29
HCO3- = 33
Respiratory and metabolic alkalosis
