Fluid & Electrolytes Flashcards
(81 cards)
1
Q
Extracellular fluid compatments
A
interstitial fluid
blood
lymph
2
Q
Intracellular fluid compartment
A
cytosol
3
Q
osmolality
A
solute concentration of fluid # of particles per kg of water
4
Q
Fluid characteristics
A
volume
osmolality
5
Q
Important electrolytes
A
sodium
potassium
magnesium
calcium
6
Q
Primary site of calcium absorption
A
duodenum
7
Q
Physiological processes regulating F/E
A
intake & absorption
distribution
output
8
Q
Intake & absorption
A
process where fluids/electrolytes are physically brought into the body & enter the bloodstream
9
Q
Distribution
A
process where fluid/electrolytes move between fluid comparments
10
Q
Output
A
physical removal of F/E from the body
11
Q
Na+ levels
A
135-145 meq/L
12
Q
K+ levels
A
- 5-5.0 meq/L
* most K+ stored intracellularly
13
Q
Factors stimulating thirst
A
Angiotensin II
Dry oral mucous membranes
Arterial baroreceptors (hypovolemia)
Fluid osmolality
14
Q
Na+ fluid compartment
A
mainly located in the ECF
15
Q
K+ fluid compartment
A
98% of total body potassium stored intracellularly
16
Q
Ca++ compartment
A
bone
17
Q
Mg++ compartment
A
cells & bones
18
Q
Normal excretory routes
A
kidneys
lungs
skin
GI tract
19
Q
Abnormal excretory routes
A
emesis
hemorrhage
drainage through tubes or fistulas
clinical interventions
20
Q
3 Main causes of F/E imbalances
A
output > intake/absorption
intake/absorption > output
altered distribution
21
Q
Major electrolytes in ECF
A
sodium
bicarbonate
chloride
22
Q
Stimuli triggering thrist
A
osmoreceptors detecting change in serum osmolality
baroreceptors detecting change in effective circulating volume
ATII –> production of nonosmotic thirst
23
Q
Factors decreasing GFR
A
SNS activation
Angiotensin II
24
Q
Factors decreasing ADH rls
A
alcohol
25
Fluid compartments
ICF
ECF
Third space
26
Circulatory overload
caused by increase in blood volume
27
Causes of circulatory overlaod
increased Na+ retention
infusion of IV fluids
excessive blood transfusion
28
Effects of HF on F/E volume
decreased effective circulatory volume
decreased renal blood flow
compensatory Na+/H2O retention
29
Which organ metabolizes aldosterone
Liver
30
Liver Failure & F/E balance
decreased aldosterone metabolism
decreased effective circulating volume
decreased renal perfusion
31
Electrolyte definition
particles that dissociate into cations and anions in a solution
32
Cation
positive ion
33
Anion
negative ion
34
Acute onset hyponatremia
<48 hours
35
Osmotic demyelination syndrome
syndrome that occurs d/t rapid correction of hyponatremia in the brain
results in destruction of myelin of axons crossing the brainstem --> severe neurological injury & death
36
Types of Hyponatremia
Hypertonic hyponatremia
Hypovolemic hypotonic hyponatremia
Euvolemic hyponatremia
Hypervolemic hypotonic hyponatremia
37
3 types of dehydration
isotonic
hypertonic
hypotonic
38
Hypertonic dehydration
water loss exceeds sodium loss --> hypernatremia
| causes water to move from ICF --> ECF shrinking cells
39
Hypotonic dehydration
sodium loss exceeds water loss --> hyponatremia
| causes water to move from ECF --> ICF causing cells to swell
40
At risk populations for dehydration
```
older adults (diminished thirst response)
neonates
```
41
Third space compartment
fluid compartment that is not considered ICF or ECF
non-functional (ex: joints, serous membranes)
increase in third space is considered abnormal and takes away fluid volume for normal physiologic processes
42
S/S of dehydration
```
early:
thirst response
decreased urine output , dark urine
decreased sweating
headache, fatigue
dry mucous membranes
decreased skin turgor
```
```
late:
confusion
headache, dizziness, light-headedness
hypotension, tachycardia, tachypnea, fever
muscle cramps (ischemic injury)
```
rare:
hypovolemic shock
seizure
unconsciousness, death
43
Causes of dehydration
medication (esp diuretics)
inadequate intake
excessive output (diarrhea, vomiting)
decreased blood colloid oncotic pressure (inadequate albumin production)
decreased blood osmolarity (hyponatremia)
44
Older Adult Risk Factors
decreased muscle mass (muscle holds water)
diminished thirst response
dysphagia/swallowing difficulties
inadequate food intake
increased output d/t chronic conditions (diabetes)
cognitive deficits
fear of incontinence
45
Dehydration treatment
```
increased oral intake
IV fluids (rehydrate & replace lost electrolytes)
treat underlying condition
```
46
Insensible water loss
water evaporation from skin (not consciously perceived)
| increased with fever
47
Primary sources of water loss
sweating
urination
excretion
abnormal: vomiting, diarrhea, hemorrhage
48
Normal serum osmolality
285-295 mOsm/kg
49
Crystalloid
a solution with particles small enough to pass through cell membranes
ex: NaCl infusion
50
Colloids
a solution where the particles are too large to pass through the cell membrane
ex: albumin infusion
51
Risk of output > intake
```
increased osmolality (hypernatremia)
fluid volume deficit (dehydration
hypokalemia
```
52
Risk of intake > output
edema (dependent, pulmonary)
increase in the third space compartment
decreased osmolality (hyponatremia)
hyperkalemia
53
Osmotic Demyelination syndrome
rapid Na+ resuscitation can cause demyelination in the CNS
this is b/c neurons adapt to electrolyte imbalances by changing concentration of intracellular osmolytes to prevent fluid shift. this process takes time to correct which is why rapid infusion can damage neurons
54
Hypernatremia
>145 mEq/L
| occurs when water loss > intake
55
S/S of Hypernatremia
```
thirst
neurologic symptoms d/t loss of water from brain cells
confusion
neuromuscular excitability
seizures
coma
```
56
Normal daily urine output
1-2 L
57
Osmotic pressure
amount of hydrostatic pressure needed to stop osmotic movement into an area. determined by solute concentration
58
Oncotic pressure
osmotic pressure exerted by proteins (albumin)
59
Osmotic diuresis
increase in urine output d/t increased excretion of solutes (draws water with it)
60
Serum osmolality solutes
sodium, BUN, glucose
61
Urine osmolality solutes
urea, creatinine, uric acid
62
Normal serum osmolality
275-300 mmol/L
63
Normal urine osmolality
250-900 mmol/L
64
Normal urine specific gravity
1.010-1.025
65
Urine Specific Gravity
a functional kidney test
measures kidney's ability to reabsorb water --> concentrate water
decreased urine specific gravity --> decreased water reabsorption (increased risk of dehydration)
66
Normal BUN levels
3.6-7.2 mmol/L
67
Factors increasing BUN
```
decreased renal function
GI bleeding
dehydration
increased protein intake
fever
sepsis
```
68
Factors decreasing BUN
end-stage liver disease
low-protein diet
starvation
fluid excess
69
Normal serum creatinine
60-130 mmol/L
| used to indirectly measure GFR
70
Hematocrit
total volume percentage of RBC in whole blood
71
Normal hematocrit
men: 0.440-0.520
women: 0.397-0.470
72
Factors increasing hematocrit
dehydration
| polycythemia
73
Factors decreasing hematocrit
anemia
| overhydration
74
Hypotonic dehydration
loss of water with reduced osmolality of blood plasma
caused by excess loss of body fluids replaced with hypotonic fluids
causes a shift from the ECF --> ICF (cellular swelling)
75
Hypertonic dehydration
loss of water assoc with increased osmolality of body plasma
caused by excessive loss of body fluids (sweating, tachypnea, emesis)
causes a shift from ICF --> ECF (cellular dehydration)
76
Isotonic dehydration
solutes and water are lost in equal concentrations
| causes a loss of blood plasma (hypovolemia) but does not cause a fluid shift between ICF & ECF
77
How rapidly should sodium be increased
1 mEq/L/kg
78
NICE Fluid Assessment
HR, BP, Cap refill, central venous pressure
peripheral edema
orthostatic hypotension
79
Normal BUN
3.6-7.2
80
Normal Creatinine
50-110
81
S/S of Circulatory overload
```
tachycardia, increased BP
venous distension
increased central venous pressure
edema
SOB, cough
```
