Dr. P's Lytes Flashcards
(60 cards)
1
Q
D5W
A
- 5% Dextrose in H2O
- HYPOTONIC
- Osmolality = 250
- 50gm/L of glucose
- 170cal
- Used to replace free body water
- Can be used in tx of hypernatremia
- Or TKO IVs
2
Q
Normal Saline
A
- 154 mEq/l Cl
- 154 mEq/l Na
- 0.9%NaCl
- ISOTONIC
- Osmolality = 300
- Used to replace total circulating volume
- Only fluid you can use with blood products
- Replaces NaCl deficit
3
Q
Lactated Ringers
A
- Na, Cl, K (4), Ca (4), Bicarb (in the form of lactate)
- ISOTONIC
- Osmolality = 270
- Used to replace total circulating volume
4
Q
Human Cell Tonicity
A
275-290
5
Q
Isotonic Solutions tonicity
A
240-340 mOsm/L
6
Q
Hypotonic Solutions tonicity
A
<240mOsm/L
7
Q
Hypertonic Solutions tonicity
A
> 340mOsm/L
8
Q
ANP mechanism?
A
Increased Na+ secretion
9
Q
Increase Aldosterone?
A
Increase Sodium uptake
10
Q
Serum Na+ think…
A
H2O
11
Q
Extracellular volume think…
A
Na+
12
Q
Acute Hyponatremia
A
massive intake of H2O (drinking contest)
13
Q
Persistant Hyponatremia due to….(2)
A
- Oral or IV intake of water that can’t be excreted
- SIADH
- Reduced circulating blood volume: diarrhea, vomiting
- Renal or heart failure
14
Q
CNS symptoms with extreme hyponatremia (<120)
A
stupor, seizures, coma
15
Q
Urine Na+ magic number?
A
20meq/l
16
Q
Urine Na+ with depleted circulating blood volume?
A
<20meq/l
17
Q
Urine Na+ with SIADH?
A
Normal at >40meq/l
18
Q
Hypotonic Hyponatremia
A
Too much H2O!! Caused by:
- IV fluids
- Water intox
- SIADH
19
Q
Rapid correction of hyponatremia could result in?
A
Central Pontine Demyelination Syndrome
20
Q
Tx for life threatening hyponatremia?
A
1) Bring pt to 125 with hypertonic saline (3%)
2) then proceed slowly…48-72hrs
21
Q
Hypertonic Hyponatremia
A
Increase of another solute --> Increase of H2O --> Decrease serum Na+ Causes: 1. hyperglycemia 2. mannitol 3. serum lipids
22
Q
Hypernatremia symptoms
A
lethargy, irritability, seizures, coma, “dehydration” = water deficit,
23
Q
Rapid Correction of hypernatremia?
A
cerebral edema
24
Q
Diabetes Insipidus
A
peeing out water!
25
"Fluid Resusciation"
correcting/replacing circulating blood volume
26
Hypovolemic Hypernatremia (5)
1. No access to H2O
2. GI or nasogastric losses
3. DI
4. Diaphoresis
5. Hyperglycemia
27
Hypervolemic Hyponatremia (3)
1. Heart Failure
2. Cirrhosis
3. Renal Failure
28
Hypervolemic Hypernatremia (2)
1. NAHCO3 administration
| 3. 3% NS
29
Hypotonic Hyponatremia (3)
1. SIADH (euvolemic)
2. Water Intox
3. Too much hypotonic IV solution
30
Hypertonic Hyponatremia (3)
1. Hyperglycemia
2. Hyperproteins (myeloma)
3. Serum lipids
31
Isotonic Hypovolemia (3)
1. Hemorrhage
2. Burns, 3rd spacing
3. GI Losses
32
Causes of Hyperkalemia (4)
1. renal failure
2. Iatrogenic (K+ sparing diuretics)
3. Tissue destruction (rhabdo)
4. Acidosis (H+ and K+ exchange in cells)
33
S and SX of Hyperkalemia
EKG changes!
1. Tall peaked T waves
2. Wide QRS
3. Sine wave
4. asystole :-(
34
Slow tx of Hyperkalemia
1. Discontinue K+ supplements, diuretics, IVs
2. Hydration with loop diuretics
3. Kayexalate binds K+ in gut, evacuated in bowel
35
Rapid tx of Hyperkalemia
Insulin and Glucose! Drives K+ into cells
36
Psuedo hyperkalemia
hemolysis of RBCs during collection of blood
37
Causes of Hypokalemia (K+<3.3meq/l)
1. Diuretics
2. GI losses
3. Renal losses
4. Burns
5. Intracellular shift (alkolosis/insulin therapy)
38
S and SX of Hypokalemia
Moderate = flattening of T Waves, more prominant U WAVES.
| Muscle weakness; esp. respiratory muscles
39
Tx of Hypokalemia
Oral or IV
| *Take much caution with IV! Can damage veins. Is cardiotoxic in central line**
40
Hypokalemia is often accompanied by________?
Hypomagnesemia and must be correct to successfully correct K+
41
Serum Ca+ ______%ionized, _____%unionized
60%unionized (bound to proteins), 40% ionized (unbound)
42
3 major factors influencing serum Ca+
1. PTH - secreted in response to the smallest of changes in Ca+ -->works on GUT, KIDNEYS, BONE
2. Vitamin D - need it to absorb Ca+
3. Calcium ion and phosphate
43
Hypocalcemia (3)
1. Low PTH
2. Disorder of Vit D and High PTH
3. Hypoproteinemia (hypoalbuminemia)
- -acidosis = reduces Ca+/Protein binding = hypercalcemia
- alkolosis = hypocalcemia
44
Hypocalcemia w/ Low PTH
Parathyroid surgery, removal, autoimmune, radiation etc.
45
Hypocalcemia w/ High PTH
1. Vit D deficiency (poor diet)
2. Hyperphosphatemia = RENAL FAILURE!; too much bound Ca+
3. Hypomagnesemia, which impairs release of PTH
46
S and SX of Hypocalcemia
1. Tetany
2. Trousseau's sign
3. Chvostek's sign
4. Seizures
5. Myocardial Infarction
47
Tx of Hypocalcemia
1. TX metabolic abnormalities
2. Vit D supplement
3. Oral/IV Ca
4. Correct hypomagesemia
48
Hypercalcemia
Ca+ entry into serum exceeds excretion or uptake into bone
49
Causes of hypercalcemia
1. Hyperparathyroidism due to an adenoma that secretes too much PTH
2. Malignancy; breast cancer that scrounges Ca+ out of bone
3. High intake milk
50
Sx of Hypercalcemia
```
Constipation
Polyuria/Polydipsia
Anorexia
Muscles weakness
Renal calculi - reccurent
Renal failure
```
51
Tx of Hypercalcemia
Moderate/Severe:
1. Aggressive saline
2. Calcitonin; decreses action of PTH
3. Bisphosphonates; inhibits Ca+ release from bone
52
Magnesium equilibrium
Balance of dietary intake and renal excretion only!
53
Hypermagensemia (3)
1. Renal insuff
2. Iatrogenic
3. Excess use of meds (Maalox)
54
Sx of Hypermagnesemia
HYPOREFLEXIA, Hypotension, Bradycardia, Arrhythmias
55
Hypomagnesemia
Common! Usually associated with hypokalemia and hypocalcemia.
56
Hypomagnesemia usually assoc. with which demographic?
Alcoholics, chronic diarrhea, loop diuretics.
57
Sx of hypomagnesemia?
Tetany
Chvostek's sign
Trousseau signs
ECG: prolong PR interval; diminution of T waves, QRS widening
58
Severe hypomagnesemia classically results in ________?
Hypocalcemia
59
6 ways we gauge volume status in pts?
1. PE: BP, orthostatics
2. Urine output (.5-1 ml/kg/hr)
3. Daily weight
4. I&O's
5. Central Venous Pressure
6. Labs!
- Specific Gravity vs. Osmolality
- Urine NA
- HcT (rising Hct may indicate hemoconcentration)
- Changing Cr and BUN
60
What electrolyte does the parathyroid depend on to function?
Magnesium! The parathyroid needs magnesium to release PTH.
