Fluids And Electrolytes Flashcards
(253 cards)
1
Q
What are the causes of hypophasphatemia?PO4 < 2 mg/dL
A
Intestinal malabsorption related to vitamin D deficiency, magnesium/aluminum containing antacids, chronic alcohol misuse, malabsorption syndromes, respiratory alkalosis, increased renal excretion associated with hyperparathyroidism
2
Q
What is the primary cation in the extracellular fluid?
A
Sodium
3
Q
What does angiotensin 2 do in the body? (3 things)
A
- Vasoconstriction
- Stimulates renal tubules to reabsorb sodium and water.
- Stimulates the adrenal cortex to release aldosterone
4
Q
What does the ascending portion of the Frank Starling curve represent?
A
Preload dependence
5
Q
What area of the adrenal cortex releases aldosterone?
A
Zona glomerulosa
6
Q
What causes hypovolemic hypotonic hyponatremia?
A
Diuretics, ketonuria, Addison’s disease, vomiting, diarrhea, third spacing, excess sweating, salt loss nephropathy
7
Q
What is the gold standard for direct cardiac function and volume status monitoring?
A
TEE
8
Q
What can prophylactic fluid replacement on a healthy fasted patient lead to?
A
Disruption of the glycocalyx and fluid overload
9
Q
In consideration of the glycocalyx, would you administer colloids or crystalloids to increase intravascular volume?
A
Colloids
10
Q
What is the formula to calculate free water deficit?
A
[(Na/140)-1] x TBW
11
Q
How can we explain how hypotensive patients actually likely have an appropriate fluid status? (2)
A
Related to impaired cardiac function
Altered vascular tone
12
Q
What symptoms will we see with magnesium levels of 10?
A
Respiratory paralysis and coma
13
Q
What hormone maintains serum calcium levels?
A
Parathyroid hormone
14
Q
What is the most abundant form of calcium?
A
Ionized and physiologically active 50%
Bound to proteins 40%
Bound to anions 10%
15
Q
How do you calculate the estimated deficit?
A
Maintenance requirement (from 4-2-1) x fasting hours
16
Q
What is the gold standard for direct cardiac function and volume status monitoring?
A
TEE
17
Q
What is isotonic hyponatremia (pseudohyponatremia) serum osmolality 270-300 caused by?
A
Hyperlipidemia, hyperproteinemia, multiple myeloma, excess isotonic nonelectrolyte solutions
18
Q
A patient is considered fluid responsive if their pulse contour analysis value is what?
A
Greater than 13-15%
19
Q
What hormone maintains serum calcium levels?
A
Parathyroid hormone
20
Q
At sodium levels of 129-125 what are patients signs and symptoms?
A
Nausea, malaise
21
Q
What does parathyroid hormone insufficiency do to calcium levels?
A
Cause hypocalcemia
22
Q
What are benefits of crystalloids? (3)
A
Lack allergic potential
Easily metabolized and cleared
Preserve electrolyte balance
23
Q
If you notice biochemical evidence of Hyperkalemia and no ECG changes what is your interventions, their onset and mechanism?
A
K binding resins in the GI tract, onset 1-2 hours, GI excretion of potassium
Promotion of renal K excretion, Lasix 40mg, onset 15-30 minutes, renal excretion of potassium
24
Q
Which solution would you give to a patient with active blood loss that needs fluid but not a transfusion?
A
Albumin
25
What are the traditional nonspecific indicators of fluid balance?
MAP, CVP, and urine output
26
What substances are unable to freely move between the vascular and interstitial space?
Proteins like albumin and globulins
27
What happens to contractility for people with a normal Frank Starling curve, that are given fluids?
Contractility increases.
28
When potassium reaches >8 QRS widening can lead to what?
Sine waves, V fib and cardiac arrest
29
What is the value of sodium in the extracellular fluid?
142 mEq/L
30
Which electrolyte condition can make it difficult for the kidney to conserve potassium?
Hypochloridemia
31
The Frank Starling Mechanism is the relationship between which two variables?
LVEDV and myocardial contractility
32
What is the value of calcium in the extracellular fluid?
5 mEq/L
33
Why can you administer plasmalyte, isolyte, and normosol with blood products?
They do not contain calcium
34
What are treatment options for hypercalcemia?
```
Infusion of NS to increase secretion
Loop diuretics
Bisphosphonates
Mithramycin
Calcitonin
Glucocorticoids
Phosphate salts
Hemodialysis for life threatening hypercalcemia
```
35
What is the goal Potassium range before surgery?
Potassium > 4
| Potassium < 5.5
36
Which medication will facilitate redistribution of potassium into the intracellular space
Insulin
37
What is the most consequential effect of hyponatremia?
Cerebral edema, cells swell. There is limited diffusion of solutes across the BBB, preventing equilibrium.
38
What is the goal Potassium range before surgery?
Potassium > 4
| Potassium < 5.5
39
What causes transcellular shifts leading to hyperkalemia?
Acidosis (due to hydrogen ions), hypertonicity, insulin deficiency, beta blockers, digitalis, succinylcholine, exercise, hyperkalemia periodic paralysis
40
What is one likely explanation for a normovolumic patient having low urine output?
High levels of ADH. They are retaining fluid.
41
What mechanisms control phosphate balance? (3)
Parathyroid hormone
Vitamin D
Calcitonin
42
What is interstitial hydrostatic pressure?
Hydrostatic pressure of interstitial fluid. (Pushes fluid into the capillary)
43
What is the effect on contractility for people with decreased cardiac function who are given fluids?
They can only respond to small volumes without compromise.
44
What are the two functions of ADH?
1. Cause aquaphorin channels in the kidney to reabsorb water
| 2. Potent arterial vasoconstrictor
45
Which medications cause hypomagnesium?
Aminoglycosides, amphotericin, beta-agonists, cisplatin, cyclosporine, diuretics, foscarnet, pentamidine, PPI, theophylline
46
What measures global tissue oxygen balance by comparing blood gases with oxygen consumption and delivery?
Measures of tissue oxygenation
47
What is the osmolality, tonicity and pH of Plasmalyte?
294 mOsm
Isotonic
PH 7.4
Contains potassium, magnesium, acetate, and gloconate
48
For infants 0-10kg what is the 4-2-1 fluid replacement?
4mL/kg/hr
49
Concentration of phosphate in the plasma is inversely proportional to which electrolyte?
Calcium
50
What are the GI signs of hypercalcemia?
Nausea vomiting, anorexia, peptic ulcers, pancreatitis, constipation/ileus
51
What electrolytes are in the intracellular fluid?
Potassium, magnesium, calcium, phosphate
52
What arrhythmias are causes by a serum potassium < 3.5
1st and 2nd degree blocks, atrial or ventricular fibrillation, asystole
53
Which hormone stimulates the excretion of potassium?
Aldosterone
54
What are the cardiovascular signs of hypercalcemia?
HTN, St segment elevation, sinus bradycardia/arrest, AV block, short Qt, BBB, ventricular dysrhythmias, potentiation of digoxin toxicity
55
What are the 6 complications of under resuscitation?
```
Hypovolemia
Decreased perfusion/O2 delivery
PONV
Renal Dysfunction
Myocardial ischemia
Hemoconcentration/thrombotic events
```
56
Hypokalemia caused by renal losses is due to what?
Diuretics, drugs, steroids, metabolic acidosis, hyper aldosterone, renal tubular acidosis, DKA, alcohol consumption
57
What is the value of magnesium in the extracellular fluid?
3 mEq/L
58
The increased sodium load of Normal Saline causes what effects on the vascular space and bowel? (3)
Water retention
Hemodilution
Interstitial edema
Decreased bowel motility
59
How does the glycocalyx impact administration of crystalloids?
Crystalloids are able to freely cross the glycocalyx
60
What is the treatment of hyponatremia?
Fluid restriction, diuresis
61
What mechanism causes laparoscopic surgery to stimulate ANP?
Mechanical suppression of splanchnic blood flow and ischemia which also predisposes to reperfusion injury, shunts blood to the thorax -> increasing CVP.
62
How do we correcting hypernatremia over 24 hours?
Hypotonic solutions, 1-2mEq/hr
63
For adults > 20kg what is the 4-2-1 fluid replacement?
4mL/kg/hr for the first 10kg
2mL/kg/hr for the next 10kg
1mL/kg/hr for every kg > 20kg
64
What is the osmolality, tonicity and pH of NS?
308 mOsm
Isotonic
PH 5
65
What is the treatment suggestions of hyponatremia?
Correct 1-2mEq/L/hr with 3% saline at 1-2mL/kg/hr and not raised more than 10-15mmol/L in 24 hours.
66
What Utilizes individualized hemodynamics end points monitored by hemodynamics modalities to support oxygen transport balance, minimize oxygen demand, optimize CO, tissue oxygenation, capillary and micro vascular flow, oxygen/nutrient delivery and end organ perfusion?
Goal directed fluid therapy
67
What is the order of EKG changes related to hyperkalemia?
T wave changes, P wave and PR interval, QRS changes.
68
What does the ascending portion of the Frank Starling curve represent?
Preloads dependence
69
Explain the Renin-Angiotensin Aldosterone System response to hypotension. (4 steps)
1. Hypotension detected by baroreceptors
2. Sympathetic Nervous System stimulation of juxtaglomerular cells of the kidney to release renin.
3. Renin interacts with angiotensinogen creating angiotensin 1
4. Angiotensin Converting Enzyme converts angiotensin 1 to angiotensin 2
70
As preload increases, contractility.... according to the Frank Starling Law
Increases, up to a point
71
Hypernatremia with an serum osmolality of 401-430 will cause what signs and symptoms?
Hyperreflexia, muscle twitching/spasm
72
Which medication will facilitate redistribution of potassium into the intracellular space
Insulin
73
What maintains the osmotic equilibrium between ECV and ICV?
The cell membranes permeability to water
74
Why is magnesium used in the treatment of pheochromocytoma?
Reduces catecholamine release and dilates vasculature
75
What is the function of ANP?
1. Stimulate removal of sodium and water by the kidneys
2. Increase GFR
3. Inhibits release of renin and ADH
76
What are some miscellaneous causes of hypomagnesmia?
Pregnancy, excessive alcohol intake, citrate binding with blood administration
77
What patients should you avoid giving hydroxyethyl starches to?
Preexisting renal injury, sepsis, neurological injury, organ donors, CABG with CPB.
78
What are symptoms of a serum potassium < 2.5 mEq/L?
Parasthesia, depressed deep tendon reflexes, fasciculations, weakness, altered level of consciousness
79
What is the value of sulfate in the extracellular fluid?
1 mEq/L
80
What is the value of sulfate in the intracellular fluid?
2 mEq/L
81
What are the cardiovascular signs of hypocalcemia?
Bradycardia, angina, hypotension, CHF, cardiac arrest, digitalis insensitivity, Qt prolongation
82
Where is magnesium regulated?
Intestines and kidneys
83
What is the value of phosphates in the extracellular fluid?
4 mEq/L
84
How do you replace blood loss with colloids?
1:1 ratio
| 1mL of colloid for every 1mL of blood loss
85
Hypokalemia as a result of decreased intake is due to what?
Ethanol, malnutrition
86
What causes increased K intake/absorption leading to hyperkalemia?
K supplements, salt substitutes, stored blood, K containing medications
87
What solution contains macromolecules suspended in electrolyte solutions that promote volume expansion by directly increasing plasma oncotic pressure.
Colloids- hydroxyethyl starches
88
What is the dilution technique?
Administration of a fixed volume of injectate into the vascular space and measurement of CO based on area under a time-temperature or concentration-time curve.
89
What are the manifestations of hyphosphatemia? PO4<2mg/dL
Decreased oxygen transport and ATP creation, platelet dysfunction, bone reabsorption, altered nerve and muscle function, confusion, coma, seizures, muscle weakness, respiratory failure, cardiomyopathy
90
What can rapid correction of hyponatremia cause?
Neurological complications like central pontine myelinolysis.
91
Hypernatremia with an serum osmolality of 350-375 will cause what signs and symptoms?
Confusion, restlessness, agitation, headache
92
What are the manifestations of hyperphosphatemia? PO4 > 4.7 mg/dL
*Symptoms related to hypocalcemia*
| chronic calcification of soft tissues (joints, lungs, kidneys)
93
How is fluid in the interstitial space returned to the circulation?
Via lymph
94
What is the value of sodium in the intracellular fluid?
10 mEq/L
95
What is the value of chloride in the extracellular fluid?
103 mEq/L
96
Why do hydroxyethyl starches carry a black box warning?
Renal injury
97
What is normal total serum calcium?
8.5-10.5 mg/dL
98
How does the hypothalamus respond to increased serum osmolality?
1. Osmoreceptors in the hypothalamus detect the increased osmolality
2. Stimulate thirst
99
What is the value of phosphates in the intracellular fluid?
75 mEq/L
100
What affects do magnesium have on dysrhythmias?
Blocks calcium influx decreasing SA node activity and prolonging AV conduction time
101
What causes hypertonic hyponatremia (serum osmolality > 300)?
Hyperglycemia, mannitol excess glycerol therapy
102
What are the neurological signs of hypercalcemia?
Fatigue, weakness, confusion, lethargy, seizures, coma, hypotonia, diminished deep tendon reflexes
103
Which electrolyte condition can make it difficult for the kidney to conserve potassium?
Hypochloridemia
104
What is the most prominent protein in the body? The primary force of osmotic pressures.
Albumin
105
Which crystalloids are the most isotonic of the salt solutions?
Plasmalyte, normosol R, isolyte S
106
What isotonic solution is the least similar to physiologic fluid?
Normal Saline
107
Hydroxyethyl starches can cause severe non histamine related pruritis and nephrotoxicity due to what?
Interstitial colloid deposits
108
What is the value of potassium in the extracellular fluid?
4 mEq/L
109
What is the primary determinant of serum osmolality and water transport?
Sodium
110
What does the intracellular phosphate do?
Component of ATP, and 2,3 DPG
| Acts as a buffer in acid base balance
111
How can we explain how hypotensive patients actually likely have an appropriate fluid status? (2)
Related to impaired cardiac function
| Altered vascular tone
112
Hypokalemia caused by renal losses is due to what?
Diuretics, steroids, metabolic acidosis, hyper aldosterone, renal tubular acidosis, DKA, alcohol consumption
113
What electrolyte is responsible for the majority of osmotic activity in the ECF and effects ECV and ICV osmolality
Sodium
114
Is Normal Saline or Lactated Ringers more effecting at preserving intravascular volume?
Lactated Ringers
115
How does hyponatremia affect the movement of water between the ECV and ICV?
(Sodium is extracellular) ECV is hypo-osmolar, so water moves into the ICV. Cells swell.
116
What is the principle electrolyte in the ICV
Potassium
117
What is an antagonist for hypermagnesmia?
Calcium gluconate 10-15mg/kg
118
What are the 9 complications of over-resuscitation?
```
Vascular overload
Micro vascular congestion/ decreased O2 delivery
Endothelial glycocalyx damage
Hypo-coagulation
Anemia, thrombocytopenia
Poor wound healing
Decreased organ perfusion and congestion
Pulmonary edema
Compartment syndrome
```
119
Which hormone is stimulated during hypervolemia?
ANP
120
What most likely causes hypocalcemia inter-op?
Hyperventilation, and rapid massive blood transfusion
121
How does the body maintain sodium balance?
Restrict or expand water volume
| Supplement or eliminate sodium
122
What is the primary anion in the extracellular fluid?
Chloride
123
What are some negative effects of hydroxyethyl starches?
Dose dependent coagulopathy from hemodilution
binding of clotting factors
Interference with platelet adhesion
Alterations in plasma viscosity
124
What is the bodies response to increased osmolality? (4 steps)
1. Posterior pituitary secretes ADH
2. ADH causes aquaphorin channels in the kidney to reabsorb water
3. Circulating volume increases
4. Urine osmolality and concentration increases
125
What is the normal range of magnesium?
1.5-3 mEq/L
126
A patient is considered fluid responsive if their pulse contour analysis value is what?
Greater than 13-15%
127
How is water balance regulated?
Antidiuretic Hormone
128
What is the normal range of ionized calcium?
2-2.5 mEq/L
129
Based on traditional guidelines for fluid replacement, what is the preferred combination of replacement of 500mL of blood loss?
750mL LR and 250mL albumin
500 of blood to replace
750mL of LR replaces half of the blood loss; 3 x 500 = 1500/2 = 750
Still need to replace 50% of the blood loss. So if colloids replace blood at a 1:1 ratio, giving 250mL of albumin would replace the other half of the blood.
130
What is pulse contour analysis?
Measure preload responsiveness by quantifying change in arterial, capo graphs, or pulse oximetry waveform
131
If using negative base excess as a guide to Normal Saline fluid replacement what is the risk?
Fluid overload
132
How does parathyroid hormone resistance states affects calcium levels
Cause hypocalcemia
133
Which hormone is inhibited during hypervolemia?
ADH
134
What are the 3 forms of hypotonic Hyponatremia with a serum osmolality < 270?
Hypovolemic hypotonic hyponatremia
Isovolemic hypotonic hyponatremia
Hypervolemic hypotonic hyponatremia
135
Which fluid pressures favor absorption/retention of fluid within the vascular space?
Interstitial hydrostatic pressure
| Capillary oncotic pressure
136
What syndromes causes hypercalcemia?
Primary hyperparathyroidism, granulomatous disorders, nonparathyroid endocrine disorders, immobilization, idiopathic hypocalcemia of infancy
137
Which two pressures favor absorption of fluid into the interstitial space?
Interstitial oncotic pressure
| Capillary hydrostatic pressure
138
What causes renal loss of magnesium?
Renal failure, postobstructive diuresis, tubular necrosis, glomerulonephritis, interstitial nephropathy, transplant
139
What are the psychiatric signs of hypocalcemia?
Anxiety, depression, irritability, confusion, psychosis, dementia
140
How is a serum sodium osmolality of 270-300 classified.
Isotonic hyponatremia (pseudohyponatremia)
141
What modalities help us monitor goal directed fluid therapy?
Dilution techniques, pursue contour analysis, echocardiogram, esophageal Doppler, tissue oxygenation monitoring.
142
What is capillary oncotic pressure?
Osmotic force of proteins within the vascular space. (Pulls fluid into the capillary)
143
What is the value of magnesium in the intracellular fluid?
58 mEq/L
144
What are the benefits of buffered solutions like plasmalyte, normosol, and isolyte?
Less acid base alterations
| Require less blood product infusions
145
Which form of calcium replacement provides the most rapid correction?
```
Calcium chloride (272 mg elemental calcium)
But can cause tissue necrosis and venous irritation
```
Calcium gluconate: 10 mL (93mg of elemental Calcium)
146
What does the plateau portion of the Frank Starling curve represent?
Preload independence
147
What endocrine disorders causes hypomagnesium?
DM, hyperaldosteronism, hyperthyroidism, hyperparathyroidism, acute poryphyria
148
What is the osmolality, tonicity and pH of D5NS?
560 mOsm
Hypertonic
PH 4
Contains glucose
149
What is the effect on contractility for people with decreased cardiac function who are given fluids?
They can only respond to small volumes without compromise.
150
What is the osmolality, tonicity and pH of LR?
273 mOsm
Isotonic
PH 6.5
Contains potassium, calcium, and lactate
151
How is hyperphosphatemia treated? What does it do?
Aluminum hydroxide which binds phosphate in the GI tract
152
What are causes of GI loss of magnesium?
Chronic diarrhea, NG suction, short bowel syndrome, protein calorie deficit, bowel fistula, TPN, pancreatitis
153
Do not infuse LR with what type of infusion products due to risk of coagulation
Citrated.
| Do not use with blood products
154
How do we classify a serum sodium osmolality > 300?
Hypertonic hyponatremia
155
What is pulse contour analysis?
Measure preload responsiveness by quantifying change in arterial, capo graphs, or pulse oximetry waveform
156
Why should you avoid infusing large volumes of LR in diabetics?
Metabolic byproduct lactate causes gluconeogenesis
157
What does the plateau portion of the Frank Starling curve represent?
Preload independence
158
What impact does hyperkalemia have on aldosterone?
Increases synthesis and release of aldosterone
159
What impact does the glycocalyx have on colloids?
Colloids are unable to cross the glycocalyx. Increasing intravascular volume.
160
How do you replace blood loss with crystalloids?
3:1
| 3mL for every 1 mL of blood loss
161
If you notice ECG evident of Potassium excess (peaked T waves), what medications do you give, their dose, onset, and mechanism?
Glucose and insulin infusion: 50mL of D50, 10 units insulin, onset 30 minutes, shifts K intracellular
Immediate hemodialysis
162
Why are crystalloids preferred for correcting dehydration?
Contribute to hydration of the entire extracellular volume
163
What symptoms will we see with magnesium levels 4-5?
Decreased deep tendon reflexes
164
The Frank Starling Mechanism is the relationship between which two variables?
LVEDV and myocardial contractility
165
Rapidly occurring hypernatremia leads to what?
Shrinking of the brain and traction on intercranial veins/venous sinuses, leading to intercranial hemorrhage
166
Which hormone is stimulated during hypovolemia?
ADH
167
What causes impaired renal excretion of potassium leading to hyperkalemia?
Renal failure, tubular defects, nephropathy, obstructive jeopardy, nephritis, pyelonephritis, K-sparing diuretics, hypoaldosteronism, SLE, addisons, adrenal hyperplasia, drugs
168
Which solution should you avoid in TBI and neurovascular insults because it promotes cerebral edema and hypo-osmolality.
Lactated Ringers
169
Hypernatremia with an serum osmolality of 376-400 will cause what signs and symptoms?
Ataxia, tremors, weakness
170
What causes hypokalemia in the form of increased nonrenal loss?
Sweating, diarrhea, vomiting, laxatives
171
What affect does acidemia and alkalemia have on calcium?
Acidemia decreases protein bound calcium and increases ionized
Alkalemia increases proteins bound calcium and decreases ionized
172
What is one likely explanation for a normovolumic patient having low urine output?
High levels of ADH. They are retaining fluid.
173
Surgical trauma/tissue injury promotes endothelial release of inflammatory mediators which contribute to what?
Hyperthermia
Increase O2 demands
Altered microcirculatory flow
174
What causes intracellular shifts leading to hypokalemia?
Hyperventilation, metabolic alkalosis, beta adrenergic agonists, theophylline
175
If you notice ECG evidence of impending arrest (loss of P wave, QRS widening) what are the medications you give, their dose, onset and mechanism?
10mL of 10% CaCl or CaGluc over 10 minutes, onset is 1-3 minutes, membrane stabilization
50-100 mEq of HCO3- over 10-20 minutes, onset 5-10 min, shifts intracellular potassium
176
What does hypermagnesmia do to nondepolarizing neuromuscular blockers?
Potentiates their action
177
What causes endocrinopathy leading to hypokalemia?
Cushing disease, bartter syndrome, insulin therapy
178
Is hyperkalemia or hypokalemia more common?
Hypokalemia
179
Hypernatremia with an serum osmolality of >430 will cause what signs and symptoms?
Coma, seizures, death
180
What is the most abundant form of calcium?
Ionized and physiologically active 50%
Bound to proteins 40%
Bound to anions 10%
181
What does vitamin D insufficiency do to calcium levels
Cause hypocalcemia
182
Hypocalcemia most likely stimulates which action?
A decrease in PTH release
Increased renal reabsorption of calcium
Decreased intestinal absorption of calcium
Activity of osteoblasts
*Increased renal absorption of calcium
Activity of osteoclasts
183
What signs and symptoms will be see with sodium levels < 115?
Seizures, coma, respiratory arrest, cerebral herniation
184
What happens to contractility for people with a normal Frank Starling curve, that are given fluids?
Contractility increases.
185
What is the value of calcium in the intracellular fluid?
<1 mEq/L
186
The high chloride load of Normal Saline has what effects on the kidney? (2)
Decreased GRF
| Impaired renal handling of HCO3
187
What symptoms will we see with magnesium levels 10-20?
Heart block and cardiac arrest
188
What causes hypokalemia in the form of increased nonrenal loss?
Sweating, diarrhea, vomiting, laxatives
189
What electrolyte disturbance is usually the result of impaired water intake?
Hypernatremia
190
What is the goal Potassium range before surgery?
Potassium > 4
| Potassium < 5.5
191
What are the pulmonary signs of hypocalcemia?
Bronchospasm, laryngospasm
192
How does SNS stimulated release of catecholamines affect fluid status?
Release ADH
| Excretion of potassium and reabsorption of water
193
At sodium levels of 135-150 what are the signs and symptoms we will see?
Little or no symptoms, may see mild neurologic signs
194
Vomiting, diarrhea, continuous GI suctioning, and osmotic diuresis causes what type of hypernatremia?
Hypernatremia with dehydration and low total body sodium
195
What does magnesium for preeclampsia do to the fetus?
It crosses the placenta and can cause neonatal lethargy, hypotension, and respiratory depression
196
What functions does magnesium have?
Enzymatic processes, Na/K pump, protein synthesis, and neuromuscular excitability
197
What are symptoms of a serum potassium < 3.5
Palpitations, skeletal muscle weakness and pain
198
How are sodium levels maintained?
GI tract absorption, renal excretion and reabsorption
199
How does the body maintain sodium balance?
Restrict or expand water volume
| Supplement or eliminate sodium
200
What is the primary anion in the intracellular fluid?
Phosphate
201
What is the value of potassium in the intracellular fluid?
140 mEq/L
202
Which direction does water move in an attempt to maintain equilibrium?
Areas of low solute concentration to areas of higher solute concentration
203
What does rapid administration of free water used to treat hypernatremia lead to?
Cerebral edema
204
What is interstitial oncotic pressure?
Osmotic force of proteins within the interstitial space. (Pulls fluid out of the capillary)
205
What are symptoms of hypomagnesium?
Inhibits Na/P pump decreasing ICV potassium, N/V, tetany, flat T wave, U wave, prolonged Qt, wide QRS, arrhythmia
206
What are the neuromuscular signs of hypocalcemia?
Paresthesia, muscle weakness, muscle spasm, tetany, Chvosteks sign (facial/eye muscle twitching) trousseau’s sign (carpopedal spasm), hyperreflexia, seizures
207
What are the EKG changes noted in hyperkalemia?
Tall peaked T wave, depressed ST segment, wide QRS, prolonged PR, decreased R wave
208
What maintains the resting membrane gradient?
Na/P ATPase pump
209
What value of potassium in the ICF and ECF?
ICF 150-160 mEq/L
| ECF 3.5-5 mEq/L
210
What is the osmolality, tonicity and pH of D5 .45% NS?
406 mOsm
Hypertonic
PH 4
Contains glucose
211
Which solution has a pH closest to physiologic pH?
Plasmalyte
212
What does plasmalyte, normosol, and isolyte do better than NS?
Preserves renal function
213
What types of cell injury lead to hyperkalemia?
Rhabdomyolysis, severe intravascular hemolysis, acute tumor lysis syndrome, burns and crushing injuries.
214
What are the alkalizing buffers in plasmalyte, normosol, and isolyte? (2)
Sodium gluconate and sodium acetate
215
Which type of solution has the risk of allergic potential? Why?
Hydroxyethyl starches.
| Made from starchy plants
216
What is the value of HCO3 in the extracellular fluid?
28 mEq/L
217
Diabetes, neurogenic, renal disease, sick cell disease and aminoglycosides cause which type of hypernatremia?
Hypernatremia with low total body water and normal total body sodium
218
What causes hypervolemic hypotonic hyponatremia
Nephrotic syndrome, cirrhosis, CHF, renal failure
219
What is the osmolality of the extracellular fluid?
281 mOsm/L
220
What is capillary hydrostatic pressure?
Intravascular blood pressure driven by CO and impacted by vascular tone. (Pushes fluid out of the capillary)
221
What is the value of HCO3 in the intracellular fluid?
10 mEq/L
222
What causes isovolemic hypotonic hyponatremia?
SIADH, renal failure, hypothyroidism, drugs, water intoxication, porphyria, pain, stress, PPV
223
How does pseudo hyperkalemia occur?
Hemolysis of the sample, leukocytosis, thrombosis, clinching of the fist during law draw
224
What medications can be used to treat hyponatremia?
Vasopressin antagonists like tolvaptan and conivaptan
225
What are the primary causes of hypercalcemia?
Primary hyperparathyroidism
Granulomatous disorders
Nonparathyroid endocrine disorders
226
Which crystalloids have the most favorable acid base profile?
Plasmalyte, normosol R, isolyte S
227
What is the value of chloride in the intracellular fluid?
4 mEq/L
228
What signs and symptoms will we see at sodium levels of 124-115?
Headache, lethargy, altered LOC
229
What symptoms will we see with magnesium levels 5-7?
Hypotension
230
What electrolyte is responsible for the majority of osmotic activity in the ECF and effects ECV and ICV osmolality
Sodium
231
What is the osmolality, tonicity and pH of D5 LR?
525 mOsm
Hypertonic
PH 4.9
Contains potassium, calcium, glucose, and lactate
232
How does hyponatremia affect the movement of water between the ECV and ICV?
(Sodium is extracellular) ECV is hypo-osmolar, so water moves into the ICV. Cells swell.
233
Crystalloids, being low molecular weight favor loss of 80% of the interstitial space through which mechanisms? (3)
Hemodilution of plasma proteins
Loss of capillary oncotic pressure
Increase in capillary hydrostatic pressure
234
How is a serum sodium osmolality of 270-300 classified.
Isotonic hyponatremia (pseudohyponatremia)
235
What causes hypertonic hyponatremia (serum osmolality > 300)?
Hyperglycemia, mannitol excess glycerol therapy
236
What are the renal signs of hypercalcemia?
Polyuria, polydipsia, dehydration, loss of electrolytes, prerenal azotemia, nephrolithiasis, nephrocalcinosis
237
What are the causes of hyperphosphatemia? PO4> 4.7 mg/dL
*Metastatic Disease*
Acute/chronic renal failure, treatment of metastatic tumor, long-term use of laxatives/enemas containing phosphates, hypoparathyroidism
238
What affect does acidemia and alkalemia have on calcium?
Acidemia decreases protein bound calcium and increases ionized
Alkalemia increases proteins bound calcium and decreases ionized
239
What are other uses for magnesium?
Relieve bronchospasm, arrhythmia, decrease post-op pain
240
What is normal total serum calcium?
8.5-10.5 mg/dL
241
What electrolytes does the extracellular fluid contain?
Sodium and chloride
242
Why does LR contribute to cerebral edema and hypo-osmolality?
It is slightly hypotonic
243
What is the primary cation in the intracellular fluid?
Potassium
244
What measures global tissue oxygen balance by comparing blood gases with oxygen consumption and delivery?
Measures of tissue oxygenation
245
Which direction does water move in an attempt to maintain equilibrium?
Areas of low solute concentration to areas of higher solute concentration
246
Total calcium is largely dependent on concentration of what?
Albumin
247
What is the dilution technique?
Administration of a fixed volume of injectate into the vascular space and measurement of CO based on area under a time-temperature or concentration-time curve.
248
How does hyperglycemia affect the vasculature and fluid volume?
It disrupts the glycocalyx, allowing crystalloids and colloids to freely move out of the intravascular space.
249
Due to the large chloride load of normal saline, what are some concerns?
Hyperchloremic metabolic acidosis
| Alterations in base excess
250
Hypertonic saline infusion, Cushing syndrome, conn syndrome and hemodialysis causes which type of hypernatremia?
Hypernatremia with increased total body sodium
251
What is the osmolality of the intracellular fluid?
281 mOms/L
252
For toddlers 11-20kg what is the 4-2-1 fluid replacement?
4mL/kg/hr for the first 10kg
| 2mL/kg/hr for every kg > 10
253
Which hormone is inhibited during hypovolemia?
ANP
