Fluid and Electrolyte Disturbances Flashcards
1
Q
Body water is distributed between 2 major fluid compartments separated by cell membranes: _____ and _____.
A
ICF and ECF
2
Q
ECF can be divided into what compartments?
A
intravascular and interstitial
3
Q
The insterstitium includes what?
A
All fluid that is both outside cells and outside the vascular endothelium
4
Q
What is used to exchange Na for K?
A
membrane-bound adenosine triphosphate (ATP) dependent pump
5
Q
What is the ratio Na is exchanged for K?
A
3:2
6
Q
Where is potassium concentrated intracellularly or extracellulary?
A
Intracellular
7
Q
Where is sodium concentrated intracellularly or extracellulary?
A
extracellularly
8
Q
What is the most important determinant of intracellular osmotic pressure?
A
Potassium
9
Q
What is the most important determinant of extracellular osmotic pressure?
A
Sodium
10
Q
Interference with the Na-K-ATPase activity occurs during ____ or ____. WHat does it cause?
A
ischemia or hypoxia; progressive swelling of cells
11
Q
Intravascular volume is ECF or ICF?
A
ECF
12
Q
Why are changes in ECF volume related to changes in total body sodium content?
A
Sodium is a major determinant of extracellular oxsmotic pressure and volume
13
Q
T/F: Interstitial fluid is in teh form of free fluid.
A
false - very little interstitial fluid is normally in teh form of free fluid
14
Q
Interstitial water is in a chemical association with extracellular ____-, forming a ___.
A
proteoglycans; gel
15
Q
Is interstitial fluid pressure positive or negative?
A
Negative
16
Q
What happens when interstitial pressure rises due to interstitial volume increase?
A
It becomes positive - and free fluid in teh interstitial gel matrix increases rapidly and the result is expansion only of the interstitial fluid compartment
17
Q
Why is the protein content of interstitial fluid low?
A
only small quantities of plasma proteins can normally cross capillary clefts
18
Q
How is protein that enters the interstitial space returned to the vascular system?
A
the lymphatic system
19
Q
______ fluid is commonly referred to as plasma.
A
Intravascular fluid
20
Q
Most electrolytes can freely pass between ___ and ____.
A
(intravascular) plasma; interstitium
21
Q
____ is the random movement of molecules due to their kinetic energy and is responsible for the majority of fluid and solute exchange between compartments.
A
Diffusion
22
Q
Rate of diffusion depends on what 4 things?
A
- Permeability of that substance
- concentration difference between 2 sides
- pressure difference between either side (pressure imparts greater kinetic energy)
- electrical potential across membrane
23
Q
___,___, ____, and ____ can penetrate the cell membrane directly.
A
O2, CO2, water, and lipid-soluble molecules
24
Q
T/F: Cations such as Na, K, and CA penetrate the lipid membrane poorly and can diffuse only through channels.
A
True
25
___ and ___- diffuse with the help of membrane-bound carrier proteins.
Glucose and amino acids
26
What is the normal adult daily water intake?
2500 mL
27
What is daily water loss average of the adult?
2500 mL
28
___ mL lost in urine
1500 mL
29
____ mL in respiratory tract evaportion
400 mL
30
___ mL in skin evaporation
400 mL
31
___ mL in sweat
100 mL
32
____ ml in feces
100 mL
33
Evaporative loss accounts for what percentage of heat loss?
20-25%
34
How is sodium serum concentration maintained between 136 and 145?
by the aciton of vasopressin on water and osmolal hemoestasis
35
What are early signs of hyponatremia?
anorexia, nausea, malaise
36
What are late signs of hyponatremia?
seizures, brain herniation
37
How do you treat hypovolemic, hyponatremia?
Volume resusciation wtih NS
38
How do you treat euvolemic or hypervolemic hyponatremia?
Withhold free water and encourage free water excertion with loop diuretic
39
Do you correct acute symptomatic hyponatremia quickly or slowly?
Quickly
40
Do you correct chronic symptomatic hyponatremia quickly or slowly?
Slowly
41
Why do you correct chronic symptomatic hyponatremia slowing?
To avoid the risk of osmotic demyelination
42
What is the main risk for induction of maintenance of anesthesia in hypovolemic hyponatremic patients?
HYPOTENSION
43
How is benign prostatic hyperplasia treated?
TURP
44
What does TURP stand for?
transurethral resection of the prostate
45
What is the irrigating fluid used during TURP?
a nearly isotonic nonelectrolyte fluid containing glycien or a mix of sorbitol and mannitol
46
What are the risks of irrigation during TURP?
Volume overload and hyponatremia b/c the irrigating fluid can be absorbed rapidly via open venous sinuses in the prostate gland
47
What 4 things increase the risk of TURP Syndrome?
1. resection >1. hour
2. irrigating fluid >40cm
3. hypotonic irrigation fluid
4. pressure in bladder >15
48
Resection longer than ____ is associated with increased risk of TURP syndrome.
1 hour
49
Irrigating fluid suspended higher than ____ above the operative field is associated with increased risk of TURP syndrome.
40 cm
50
HYpertonic or hypotonic irrigation fluid is associated with increased risk of TURP syndrome?
Hypotonic
51
Bladder pressure >____ is associated with increased risk for TURP syndrome.
15 cmH2O
52
What are 2 common findings in TURP syndrome?
HTN and pulmonary edema
53
What is the treatment for TURP syndrome?
Stop surgery, administer loop diuretics, and hypertonic saline (w/ severe neuro s/s or Na<120)
54
Hypernatremia induces the movement of water across the cell membrane into teh ___.
ECF
55
What are early S/S of hypernatremia?
restlessness, irritability, lethargy
56
What are late S/S of hypernatremia?
muscular twitching, hyperreflexia, tremors, ataxia
57
S/S of muscle spasitcity, seizures, and death occur with hypernatremia when the osmolaity increases above ___.
325
58
S/S of hypernatremia are more severe with acute or chronic high sodium levels?
acute
59
How is hypovolemic hypernatremia treated?
Water deficit is replenished with NS or electrolyte solution
60
How is hypervolemic hypernatremia treated?
Diuresis with loop duretic
61
How is euvolemic hypernatremia treated?
PO water replacement or 5% Dextrose IV
62
Acute hypernatremia should be corrected over _____.
several hours
63
Chronic hypernatremia should be corrected over ____.
2-3 days
64
What happens if you correct chronic hypernatremia too quickly?
cerebral edema
65
Potassium plays a major role in regulating membrane potential as well as in ___ and ___ synthesis.
carbohydrate and protein
66
Renal excretion of potassium can. vary from ___ to ___ mEq/L.
5-100
67
Nearly all the potassium filtered in glomeruli is normally reabsorbed in the ____________ and ________.
proximal tubule and loop of henle
68
T/F: Plasma potassium concentration typically correlates poorly with the total potassium deficit.
True
69
When does hypokalemia due to the intracellular movement of potassium occur?
alkalosis, insulin therapy, beta agonists, hypothermia, and hypokalemic periodic paralysis
70
What are renal related causes of hypokalemia?
Hypomagnesemia, renal tubular acidosis, ketoacidosis, salt-wasting nephropathies, amphotericin B
71
Why is hypokalemia due to decreased potassium intake not common?
B/c of the kidneys ability to decrease urinary potassium excretion to as low as 5-20
72
Most patients are asymptomatic with hypokalemia until K falls below ____.
3
73
What are the CV effects of hypokalemia?
abnormal EKG, arrhythmias, decreased contractility, liable BP (d/t autonomic dysfunction)
74
What type of IV solutions should be used with hypokalemia and why?
Glucose-free; b/c glucose stimulates K+ movement into the cell
75
Hyperventilation or hypoventilation should be avoided with hypokalmia?
Hyperventilation
76
There might be an increased sensitivity to ____ drugs with hypokalemia.
NMB
77
When does hyperkalemia occur due to extracellular movement of potassium?
acidosis, cell lysis following chemo, hemolysis, rhabdo, massive tissue trauma, hyperosmolality, digitalis OD, hyperkalemic periodid paralysis, Sux, BB, and arginine hydrochloride
78
When does hyperkalemia due to decreased renal excretion of potassium occur? (3)
1. reduced GFR
2. Decreased aldosterone activity
3. defect in K+ secretion in the distal nephron
79
Skeletal muscle weakness with hyperkalemia is generally not seen until K+ is >____
8
80
Cardiac manifestations of hyperkalemia are due to ______.
delayed depolarization
81
Cardiac manifestations are consistently present when plasma K+ level is >_____
7
82
Because of its lethal potential, hyperkalemia exceeding ___ should always be corrected.
6
83
Which is stronger Calcium chloride or gluconate?
chloride
84
What is the dose of calcium gluconate for hyperkalemia?
5-10 mL of 10% calcium gluconate
85
What is the dose of calcium chloride for hyperkalemia?
3-5 mL of 10% calcium chloride
86
_______ partially antagonizes the cardiac effects of hyperkalemia and is useful in symptomatic patients with marked hyperkalemia.
Calcium
87
What potentiates Digoxin toxicity?
Calcium
88
Only ___% of total body calcium is present in ECF. Where is the rest stored?
1; bone
89
What calcium is physiologically active?
ionized calicum in the extracellular space
90
Ionized calcium concentrations are affected by _____ concentration and ___.
albumin; pH of plasma
91
What 3 hormones regulate calcium metabolism?
1. parathyroid
2. calcitonin
3. vitamin D
92
How does parathyroid hormone regulate calcium?
increases bone reabsorption and renal tubular reabsorption of calcium
93
How does calcitonin regulate calcium?
inhibitis bone resorption
94
How does vitamin D regulate calcium?
augments intestinal absorption of calcium
95
_____ reduceds the iCa concentration, so therefore, iCa may be significantly reduced after _______ administration.
alkalosis; bicarbonate
96
Significantly reduced iCa may be seen with hyperventilation or hypoventilation?
hyperventilation
97
What are S/S of hypocalcemia?
Paresthesias, irritability, seizures, hypotension, myocardial depression
98
What is an electrolyte concern in the post-op period following thyroid or parathyroid resection?
Hypocalcemia-induced laryngospasm
99
How do you treat acute symptomatic hypocalcemia (seizures, tetany, CV depression)?
IV calcium
100
Treatment of hypocalcemia in teh presence of ____ is ineffective.
hypomagnesmia
(Mg must also be replenished)
101
If acidosis is present with hypocalcemia, what should be corrected first?
Calcium level (b/c correcting acidosis w/ bicarb or hyperventilation will exacerbate hypocalcemia)
102
What is normal iCa level?
1.1-1.2
103
At what iCa level should you treat hypocalcemia?
0.8 or less
104
At an iCa of ____ S/S will occur.
0.7
105
Sudden decreases in iCa level may be seen in early post-op period after ___ or _____ surgery. What can this cuase?
thyroidectomy or parathyroidectomy; laryngospasm
106
A decrease in iCa levels should always be considered during MTP of blood containing ____.
citrate
107
When does hypercalcemia occur?
1. increased GI absorption
2. decreased renal excretion
3. increased bone resorption
108
When does increased calcium absorption from teh GI tract occur?
1. milk-alkali syndrome
2. vitD intoxication
3. granulomatous disease such as sarcoidosis
109
When does increased bone resorption of calcium occur?
primary or secondary hyperparathyroidism
hyperthyroidism
immobilization
110
What are S/S of hypercalcemia?
confusion, hypotonia, depressed DTR, lethargy, abdominal pain, N/V
111
Hypercalcemia is frequently associated wtih hyper or hypovolemia? This is secondary to _____.
hypovolemia; poluria
112
What is the anesthetic management for emergency surgery in the patient with hypercalcemia?
Restoring intravascular volume before induction and increase urinary excretion of calcium with loop diuretics
113
What type of diuretic should be avoided wtih hypercalcemia?
Thiazide (b/c it increases renal tubular reabsorption of calcium)
114
Where is magnesium predominantly found?
intracellularly and in mineralized bone
115
Renal reabsorption and excretion of magnesium is ____.
passive
116
Hypomagnesium S/S are similar to S/S of _____
hypocalcemia
117
What are the S/S of hypomagnesemia?
dysrhythmias, weakness, muscle twitching, tetatny, apathy, seizures
118
Hypomagesemia is most commonly due to what 2 things?
reduced GI uptake or to renal wasitng of mg
119
How can you determine which is causing hypomagnesemia - decreased GI uptake or renal wasting?
by measuring urinary Mg excretion rate
120
With hypomagnesemia, if cardiac dysrhythmias or seizures are present what is the treatment? Include dose.
IV bolus of 2 grams Mg Sulfate
121
2 grams of Mg Sulfate = ____ mEq of Mg
8
122
What is a potential s/e of the treatment of hypomagnesemia?
hypermagnesemia
123
What is the anesthesia management for patients with hypomagnesemia?
attention to S/S, Mg supplementation, and treatment of refractory hypokalemia or hypocalcemia
124
____magnesium can enhance digitalis toxicity.
hypo
125
Magnesium >___ is considered hypermagnesemia
2.5
126
When is Mg given?
Torsades
127
T/F: Mg can be briskly excreted if renal function is normal, so hypermagnesemia is much less common.
True
128
Magnesium infusion is sometimes done during what procedure?
Pheochromocytoma surgery
129
What are first S/S of hypermagnesemia?
lethargy, N/V, facial flushing
130
When do the S/S of lethargy, N/V, facial flushing begin with hypermagnesemia?
At levels of 4-5
131
For hypermagnesemia, At levels >___, loss of DTR and hypotension occur.
6
132
At Mg levels >6, ____ and ___ occur.
loss of DTR and hypotension
133
What are 2 meds (besides IV Mg Sulfate) that could cause high Mg?
antacids and Mg-based enemas or cathartics
134
How can life-threatening signs of hypermagenesmia be temporarliy treated?
IV Calicum
135
How can mild forms of hypermagnesemia be treated?
Loop diuretics and diuresis with salien
136
_____ exacerbates hypermagnesemia so careful attention must be paid to ventilation and arterail pH.
Acidosis
137
Does acidosis or alklaosis exacerbate hypermagnesemia?
Acidosis
138
Phosphorus is required for the synthesis of what 3 things?
1. phospholipids and phosphoproteins in cell membranes
2. phosphonucleotides involved in protein synthesis and reproduction
3. ATP used for storage of energy
139
Hyperphosphatemia may be seen with ____ syndrome.
tumor lysis
140
What are examples of increased phosphorus intake associated with hyperphosphaemia?
abuse of phosphate laxatives or excessive admin of potssium phosphate
141
Significant hyperphosphatemia may produce ____ (other electrolyte imbalance).
hypocalcemia
142
How does hyperphosphatemia produce hypocalcemia?
Via phosphate chelation with plasma Ca2+
143
Hyperphosphatemia may produce _____ via parenchymal and tubular deposits of calcium-phosphate sats.
AKI
144
How do you treat hyperphosphatemia?
Phosphate-binding antacids
145
What are the two phosphate-binding antacids?
Aluminum hydroxide or aluminum carbonate
146
what can cause severe hypophophatemia?
1. Large doses of aluminum or Mg containing antacids
2. severe burns
3. insufficient Phos supplementation durign TPN
4. DKA
5. Alcohol withdrawal
6. prolonged respiratory alklaosis
147
____ mg/dL is considered mild to moderate hypophosphatemia
1.5-2.5
148
T/F: Mild to moderate hypophosphatemia is generally asymptomatic.
True
149
Severe hypophosphatemia is considered a phosphorus level <___.
1.0 mg/dL
150
Sever hypophophatemia is associated with increased ______ in critically ill.
morbidity and mortality
151
Is PO or parenteral phosphorus replacemetn preferred?
PO
152
Why is PO phosphorus preferred over parenteral?
B/c of the increased risk of phosphate precipitation w/ Ca
153
What is a post-op concern wtih severe hypophosphatemia?
Some pts may require mechanical ventilation b/c of muscle weakness
