Ch 14: Fluid and Electrolytes Quiz Flashcards
(59 cards)
1
Q
Osmosis
A
movement of water across semi-permeable membrane from low solute concentration to high solute concentration.
2
Q
Osmolality
A
of particles of solute in a unit of fluid based on weight (blood, urine)
3
Q
Osmolarity
A
of particles of solute in a unit of fluid based on volume. (Spec. gravity)
4
Q
Tonicity
A
ability of solutes to cause an osmotic driving force and promote water movement from one compartment to another.
5
Q
Adrenal gland
A
releases aldosterone in response to decreased Na+, or increased K+ or renin.
6
Q
Parathyroid
A
regulates calcium and phosphate. Secretes PTH which causes bone resorption, calcium absorption from intestines, calcium reabsorption from renal tubules.
7
Q
Renin-Angiotensin-Aldosterone System
A
- Renin = enzyme that converts angiotensinogen into angiotensin I. (liver)
- Renin is released by the juxtaglomerular cells of kidneys in response to decreased renal perfusion
- ACE converts angiotensin I to angiotensin II
- Vasoconstriction increases arterial perfusion pressure and stimulates thirst.
- Sympathetic nervous system stimulates release of aldosterone in response to increase renin
- Aldosterone regulates volume
8
Q
Atrial Natriuretic Peptide (ANP)
A
opposite of renin-angiotensin-aldosterone system
9
Q
Gerontologic considerations for increased risk of F&E disorders
A
- decreased renal and pulmonary function
- altered ratio of body fluid to muscle mass
- Altered response to F&E changes
* Atypical
* Rapid onset - Changes in acid-base balance
10
Q
Gerontologic Assessment Considerations
A
- Thirst mechanism
- NPO risk
- Test preps
- Cardiac, kidney, lung, adrenal function
- Attention to intake/output and DAILY WEIGHTS
- Medication effects
11
Q
Fluid gains/losses
A
Gain: PO, IV, SQ, Enteral
Loss: Kidneys: 1500mL/day - urine
**normal u/o = 1 ml/kg/day
Insensible loss:
*Skin 600 mL/day
*Lungs 400 mL/day
* GI tract 100-200 mL/day
12
Q
S/S of hypovolemia
A
- weight loss
- thirst, dry mucous membranes
- poor skin turgor
- Decreased LOC
- HR, orthostatic hypotension
- Hemoconcentration, increased urine spec. grav., decreased u/o.
- flat jugular veins, time for veins to fill
13
Q
Causes of hypovolemia
A
- decreased intake
- blood loss/ hemorrhage
- GI: V/D/ GI suction
- Renal: diuretics, Addison’s, diabetes insipidus, osmotic diuresis
- 3rd space shift: decreased oncotic pressure
- Ascites
14
Q
The nurse would best assess the adequacy of fluid volume replacement in a patient with hypovolemia by monitoring:
A
Vital signs and daily weights
15
Q
S/S of hypervolemia
A
- rapid weight gain
- Ascites, decreased serum proteins
- Decreased serum and ua osmolality
- decreased urine Na+
- Dyspnea
- HTN, edema, JVD, time for veins to empty
16
Q
Causes of hypervolemia
A
- excess fluid intake
- excess Na+ intake
- increased retention of sodium & water
- renal failure
- SIADH (increased ADH) - heart failure
- liver failure
- decreased serum proteins
- liver failure
- malnutrition
- burns
- nephrotic syndrome
17
Q
Normal Sodium levels
A
135-145 mEq/L
18
Q
Functions of Sodium
A
- # 1 ECF cation
- Major determinant of ECF osmolality
- Muscle contraction/nerve impulse transmission
- Controls water distribution
19
Q
Hyponatremia
A
Sodium less than 135
Severe = less than 120
20
Q
Causes of hyponatremia
A
- Na+ deficit
- net gain of water (w/o salt)
- *Causes of Na+ deficit
- decreased intake
- increased loss
- diuretics
- GI suction
- Excess sweating
- decreased aldosterone
21
Q
S/S of hyponatremia
A
s/s dependent on:
rate of fall
duration of low Na+ levels
ECF volume
- GI: anorexia, N/V, cramping
- Neuro: h/a, lethargy, confusion, seizures caused by H2O moving into brain cell
- Low serum and urine osmolality
22
Q
Hypernatremia
A
sodium level greater than 145
23
Q
Causes of hypernatremia
A
- decreased fluid intake
- hypertonic tube feeding without adequate water
- increased water losses
- increased insensible losses
- diabetes insipidus (decreased ADH)
- Increased sodium
- increased aldosterone
- corticosteroids
- excess sodium bicarb. or sodium chloride
24
Q
S/S of hypernatremia
A
- thirst
- dry mucous membranes
- elevated temp, flushed skin
- change of LOC
- seizures
- 3rd spacing: edema
- hypotension
- increased deep tendon reflexes
- increased serum and urine osmolality
25
Potassium
Normal values 3.5-5.5 mEq/L
26
Function of potassium
- #1 intracellular cation
- active transport I Na+-K+ pump
- muscle contraction
- nerve impulse transmission
- acid/base blanace
Regulated by:
kidneys
aldosterone
27
Hypokalemia
potassium (K+) less than 3.5
28
Causes of hypokalemia
```
decreased intake
IV fluids w/o K+
Increased losses
-GI
-diuresis (thiazides)
-increased aldosterone
-K+ shifting from ECF to ICF
-alkalosis
-insulin excess
```
29
S/S of hypokalemia
- anorexia, N/V
- ileus
- muscle weakness or cramps
- paresthesia
- digoxin toxicity
- dysrhythmias: PVCs, V-tach
30
Hypokalemia memory jogger
```
S - skeletal muscle weakness
U - u wave (ECG change)
C - constipation
T - toxic effects of digoxin
I - irregular, weak pulse
O - orthostatic hypotension
N - numbness (paresthesia)
```
31
Hyperkalemia
K+ greater than 5.5
32
Causes of hyperkalemia
- increased intake
- decreased loss
- renal failure
- decreased aldosterone
- K+ shifting from ICF to ECF
- hemolysis
- burns
- crushing injury
- chemotherapy
- acidosis
- insulin deficiency
33
S/S hyperkalemia
- N/V/D
- abdominal cramps
- muscle weakness
- decreased reflexes
- paresthesias
- paralysis
- acidosis: decreased pH
- insulin deficit: increased glucose
- EKG: peaked t waves, prolonged PR interval, Wide QRS, V-tach
34
Calcium
Normal levels are 8.5 - 10.5
-plasma proteins affect level
Has an inverse relationship with phosphorus
35
Causes of hypocalcemia
- decreased intake
- decreased absorption
- laxative abuse
- diarrhea
- malabsorption
- decreased vit d
- decreased PTH
- increased phosphorus
- increased losses
- diuresis
- pancreatitis
- decreased albumin
- alkalosis
- blood transfusion
36
S/S of hypocalcemia
- paresthesia
- tetany
- Chovostek's sign
- Trousseau's sign
- increased deep tendon reflexes
- seizures
- laryngeal stridor
- irritability
- anxiety
- impaired clotting
- alkalosis
37
Chvostek's sign
An indicator of hypocalcemia. It is a twitch of the facial muscles following gentle tapping over the facial nerve in front of the ear that indicates hyperirritability of the facial nerve.
38
Trousseau's Sign
An indication of latent tetany in which carpal spasm occurs when the upper arm is compressed by a bp cuff or the like for 3 minutes. An indicator of hypocalcemia.
39
Hypercalcemia
Calcium greater than 10.5
40
Causes of hyeprcalcemia
```
increased calcium resorption from bones
increased calcium absorption from gut
decreased calcium excretion by kidneys (most common)
Acidosis
Decreased PO4
```
41
S/S of hypercalcemia
- Anorexia, N/V
- abdominal pain, cramping
- Ileus
- constipation
- confusion
- decreased LOC from lethargy to coma
- decreased reflexes
- hypertension
- bone pain
- risk of digoxin toxicity
- increased u/o with thirst
- decreased PO4
- EKG: short QT interval
42
Magnesium
Normal levels 1.5-2.5 mg/dL
| -competes with calcium for GI absorption
43
Functions of magnesium
```
nerve/muscle function
allows heart and vascular relaxation
protects heart from ischemia
metabolic processes
needed for absorption and utilization of K+
Regulated by GI absorption and kidneys.
```
44
Hypomagnesemia
Mg+ less than 1.5 mg/dL
45
Causes of hypomagnesemia
decreased intake
decreased GI absorption
increased GI losses
increased renal losses
46
S/S of hypomagnesemia
muscle weakness, twitching, tremors, tetany
dysphagia
altered LOC: confusion, hallucinations, seizures
Increased reflexes
Chovostek's sign
Trousseau's sign
Common to have low K+ and Ca++ concurrently
EKG changes: prolonged QT, wide QRS, V-tach
47
Hypomagnesemia memory jogger
```
Seizures
Tetany
Anorexia, arrhythmias
Rapid heart rate
Vomiting
Emotional lability
Deep tendon reflexes increased
```
48
Hypermagnesemia
Mg+ greater than 2.5 mg/dL
49
Causes of hypermagnesemia
```
renal failure
increased intake (pills)
```
50
S/S of hypermagnesemia
```
weakness
decreased reflexes
decreased LOC: confusion, lethargy, coma
Resp. depression > 15
N/V
decreased b/p, decreased HR
```
51
Muscular twitching & hyperirritability of the nervous system indicate tetany. The nurse would identify these as symptoms (sx) of which electrolyte imbalance?
Low calcium level
52
Phosphorus
Normal level is 2.5 - 4.5
- functions: ATP energy production, nerve/muscle activity, promotes release of oxygen from Hgb
- regulated by kidneys (primary), PTH, vit d
53
Hypophosphatemia
Phos less than 2.5 mg/dL
54
Causes of hypophosphatemia
decreased intake/absorption
increased losses
increased phosphate utilization
55
S/S of hypophosphatemia
altered LOC: lethargy irritability, apprehension, confusion
Muscle weakness: respiratory, cardiac
Ileus
***belly surgery, reintroduction of food = increased risk for hypophosphatemia.***
56
Hyperphosphatemia
Phos greater than 4.5 mg/dL
57
Causes of hyperphosphatemia
decreased excretion
increased intake
phosphate shifting from ICF to ECF
58
S/S of hyperphosphatemia
Dry, itchy skin
| s/s of hypocalcemia from Ca++ binding with PO4-
59
Chloride
Normal levels = 96-106
Function: regulates acid/base balance by combining with other ions
Imbalances associated with sodium and/or acid/base imbalances.
