Quiz1 Fluid Electrolytes & Acid Base Flashcards
1
Q
Functions of body fluid
A
- Surrounds and permeates the cells
- Lubricate and solvent for metabolic chemical reactions
- Transport oxygen, nutrients, chemical messengers, and waste products to their destinations
- Important in regulating body temperature
2
Q
A
3
Q
Percentage of body weight for an infant in fluid?
A
75%
4
Q
Percentage of body fluid for Woman vs. Man
A
Men 60%
Women 50%
different based on body mass
5
Q
Fluid intake is triggered by thirst is controlled by:
A
ECF osmolality (concentration)
6
Q
Where does fluid absorption take place?
A
Small bowel
7
Q
What are the two major fluid compartments?
A
- ECF - Extra Cellular Fluid
- Intracellular Fluid
8
Q
ECF
Extra Cellular Fluid
A
- Fluid outside the cell
- 1/3 body fluid in adults
- Infants have more ECF as compared to ICF
- (Infants are EXTRA)
9
Q
ICF
Intracellular Fluid
A
- Inside the cell
- 2/3 body fluid in adults
10
Q
How does fluid distribution occur between interstitial and intracellular
A
Occurs by osmosis
Cell membranes are permeable to water but not electrolytes
11
Q
Water goes to
A
The area of higher osmolality (concentration
12
Q
Where is fluid excreted?
A
- Urinary tract (largest volume excreated)
- Bowels (inc. w/diarrhea)
- Lungs (exhalation)
- Skin (visible swear, insensible perspiration)
13
Q
How does the movement of fluid take place from interstitial space to vascular space?
A
Osmotic pressure
&
Hydrostatic Pressure
14
Q
Osmotic Pressure
A
inward- pulling force into the vascular space
15
Q
Hydrostatic pressure
A
Outward push of fluid into the interstitial space
16
Q
Occurs when particle concentration (Osmolality) of the interstitial fluid becomes higher than the particle concentration inside cells
A
Water moves out of the cells
17
Q
Occurs when the osmolality of the interstitial fluid becomes lower than the osmolality of the intracellular fluid
A
Water movement into the cells
18
Q
What controls the amount of fluid excreted in the urine:
A
- Antidiuretic Hormone (ADH)
- Aldosterone
- Natriuretic peptides (ANP & BNP)
19
Q
ADH
Antidiuretic Hormone
A
- Released from the posterior pituitary gland
- Controls reabsorption of H20
- Changes fluid reabsorption or excretion
- Concentrates or dilutes the urine
20
Q
Increased release of ADH
A
- Increased osmolality - high concentration of ECF - less vascular volume
- Results in decreased and concentrated urine and increased diluted vascular compartment
21
Q
Decreased release of ADH
A
- Decreased osmolality (low concentration) of ECF
- Causes a diluted large urine volume
22
Q
Aldosterone
A
- Secreted by cells in the adrenal cortex
- The release is stimulated by decreased blood volume
23
Q
The stimulus for the release of Aldosterone
A
- Decreased blood volume
- Angiotensin II from the renin-angiotensin system stimulates the release
- Increased concentration of potassium ions in the plasma
24
Q
Aldosterone causes renal tubules to reabsorb
_____ & _____
A
Sodium & Water
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ADH is the ____ \_\_\_\_\_ hormone and _____ body fluids
ADH is the _tap water_ hormone and _dilutes_ body fluids
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Aldosterone is the _____ hormone. It _____ ECF
Aldosterone is the _saltwater_ hormone and _expands_ ECF
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A-type Natriuretic Peptide (ANP)
Normally secreted from cells in the heart when the atria are stretched
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B-type natriuretic peptides (BNP)
Released from ventricular cells when ventricular diastolic pressure increases abnormally, as in heart failure.
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Natriuetic peptides ____ urine sodium excreation and _____ Aldosterone
Natriuretic peptides _increase_ urine sodium excretion and _oppose_ Aldosterone
30
Infant Variations in Fluid Balance
* Glomerular filtrate is lower than in adults
* Kidneys have limited ability to concentrate urine = unable to excrete large loads of urine effectively or conserve fluids when needed
* Focus on tension of fontanelles
31
Geriatric variations of fluid and electrolyte balance
* Decreased GFR
* Kidneys less able to concentrate urine = less able to conserve fluid when needed - contributes to nocturia
* Reduced thirst response may lead to dehydration
*
32
Transcellular Fluids
In body compartments ( peritoneal cavity, joint spaces, CSF)
33
Cations +++++++
Positive charge
## Footnote
* Sodium (Na+)
* Potassium (K+)
* Calcium (Ca++)
* Magnesium (Mg++)
34
Anion ----------
Negative charge
* Chloride (CL-)
* Bicarb (HC03-)
35
Sodium, Chloride, and Bicarb control osmotic pressure in the
ECF
36
Potassium, ATP, and Phosphate control osmotic pressure in the
ICF
37
Controls colloid osmotic pressure also known as oncotic pressure
Albumin
38
\_\_\_\_\_ have high hydrostatic pressure to push into interstitial space and cells
Arterioles
39
\_\_\_\_\_ have high _____ pressure to pull fluid from the interstitial space back into capillaries
Venules have high oncotic pressure to pull fluid from the interstitial space back into capillaries
40
Isotonic fluid
Concentration equal to vascular compartment so fluid shifts into cells
41
Hypotonic fluids
Lower concentration than vascular compartment so fluid shifts into cells
42
Hypertonic fluids
Higher concentration than vascular compartment so fluid shifts from cells into the vascular space
43
Hypovolemia
Hypervolemia
Hypovolemia - decreased intravascular volume
Hypervolemia - increased intravascular volume
44
Clinical manifestations of fluid and electrolyte imbalances
Fluid Excess
Often a problem with fluid distribution, not overload.
Edema - hydrostatic forces greater than osmotic (push vs pull)
45
Clinical Manifestations of Fluid Excess
* Edema
* Dyspnea
* Bounding pulse, tachycardia, hypertension
* Jugular vein distension
* Bulging fontanelles
46
Water intoxication
Fluid excess in the intracellular space
Ingesting water faster than it's eliminated
Kidney excretion abilities
47
Fluid deficit
* Decreased skin turgor
* Dry MM
* Postural blood pressure with tachycardia
* Flat neck veins
* Lightheadedness
* Dizzyness & Syncope
* Oliguria or small volume of concentrated urine
48
Most common issue with fluid deficit
Too little sodium with inability to retain water
49
Sodium
Na+
Serum Sodium 135 - 145
## Footnote
* most significant cation
* most electrolyte in ECF
* controls serum osmolality and water balance
* helps maintain acid/base balance when combined with bicarb
* regulated by kidneys and the SNS (Aldestrone and RAAS)
* Sodium Potassium pump for transport across cell membrane
50
Hyponatremia
\< 135
## Footnote
* Lethargy, HA, confusion, irritability, seizures, and coma
* Imbalance and dizziness in elderly
* Caused by - inadequate dietary intake, diuretics
* Management focused on treating underlying cause
51
Hypernatermia
\> 145
## Footnote
* Lethargy, HA, confusion, irritability, seizures, coma
* caused by excessive dietary intake and hyperaldosteronism
52
Chloride
(CL-)
98 -108
Mineral electrolyte
Extracellular anion
53
Potassium
(K+)
3.5 - 5
## Footnote
* Primary intracellular cation
* Electrical conduction, acid-base balance, metabolism
* Excreted by kidneys
54
Hyperkalemia
\>5
## Footnote
* Muscle & cardiac excitability - increased DTR's and cardiac arrhythmias
* Caused from: Renal failure, medication (K sparing diuretics, ACE inhibitors, ARBs
* Salt substitutes
* Diabetic keto acidosis
55
Hypokalemia
\<3.5
* Results in cardiac and muscle depression - decreased DTR's and cardiac arrhythmias
* Caused from: Thiazide and loop diuretics
* Vomiting and diarrhea
* Malnutrition and alchololism
56
Calcium
Ca++
8. 8 - 10.3 (measures all Ca bound and unbound)
4. 5 - 5.5 Ionized (unbound)
Requires Vit D for absorption
Binds with Vitamin Kin the bone
Inverse relationship with Phosphorus
57
3 forms of Calcium
1. Bound to plasma proteins (albumin)
2. Bound to small organic ions (citrate)
3. Unbound
58
Hypercalcemia
Causes
1. Increase Ca intake
2. Hyperparathyroidism, bone tumors
3. Thiazide diuretics cause decreaesd excretion
59
Hypercalcemia
Clinical Manifestations
* Decreased neuromuscular excitability
* Muscle weakness, diminished reflexes, cardiac dysrhythmias
* anorexia, emesis, fatigue
* Constipation
* Ha, confusion, lethargy
* Renal calculi
* Pathologic fractures
60
Hypocalcemia
Causes
* Poor diet (lack of Vit D)
* Decreased physiologic availability of calcium due to hypoparathyroidism
* Increased calcium excretion (steatorrhea & pancreatitis)
61
Hypocalcemia
Clinical Manifestations
Hyperexcitability of neuromuscular cells
Paresthesias, muscle twitching, and cramping
Hyperactive reflexes: carpal spasam (Trousseau sign)
Facial spasm (Chvoslak sign)
Tetany
Seizures
Cardiac dysrhythmias - Prolonged QT interval
62
Phosphorus
(P)
2.5 - 4.5
## Footnote
Bone and tooth mineralization
Cellular metabolism
Acid-base balance
Cell membrane formation
Regulated by urine excretion
Inverse relationship with calcium
63
Hyperphosphatemia
Causes:
\<2.5
Renal failure
Hypocalcemia
Hypoparathyroidism
Metabolic acidosis
Clinical manifestations similar to Hypocalcemia
64
Hyperphosphatemia
Causes:
\> 4.5
Hyperparathyroidism
Hypercalcemia
Vitamin D deficiency
Alcoholism
Metabolic alkalosis
Clinical manifestations similar to hypercalcemia
65
Magnesium
Mg++
1.8 - 3
Intracellular cation mostly stored in bone and muscle
Bound to protein in the vascular system
Functions: muscle and nerve fx, cardiac rhythm
Excretion through renal system
Direct relationship with Ca
66
Hypermagnesemia
Causes
\>3
Renal failure
Magnesium laxatives
Hypocalcemia
67
Hypermagnesemia
Clinical Manifestations
* Decreased neuromuscular and cardiovascular system effects
Decreased DTRs and ***_Shortened QT_*** interval, bradycardia
68
Hypomagnesemia
Causes
\>3
Alcoholism or malnutrition
Diuretics
Diarrhea
Hypocalcemia
69
Hypomagnesemia
Clinical Manifestations
Increased neuromuscular and cardiovascular system affects
Increased DTRs , tremors, muscle cramps
***_QRS widening_***
70
Bicarbonate-carbonic acid system
Most significant buffering mechanism
Process of the lungs and kidneys working together
71
Bicarbonate Buffer System
Most important buffer in the ECF
**_Primary_** defense against acid-base disorders
72
Components of the Barbconate Buffer System
Base: bicarbonate ions (HCO3-)
Weak acid: carbonate acid (H2CO3)
20:1 ratio of bicarbonate ions to carbonic acid necessary for a normal pH
73
Functions of Bicarbonic Buffer System
Too much acid
Bicarbonate (HCO3-) ions take up hydrogen ions (H+) released by the acid; become carbonic acid (H2CO3)
CARBONIC ACID RELEASED AS CARBON DIOXIDE THROUGH THE LUNGS
74
Bicarbonate Buffer System
Functions: Too little acid (alkaline)
Bicarbonate buffer releases hydrogen ions from the weak acid to decrease pH
75
Respiratory Contribution
Second defense against acid-base disorders
76
What is the respiratory contribution in maintaining acid/base balance?
The lungs excrete CO2 and Water (H20) from the body
Rid the body of carbonic acid (H2CO3)
Excessive carbonic acid accumulation increases the rate and depth of respiration to remove carbonic acid (hyperventilation - decreases acidity)
Insufficient carbonic acid decreases the respiratory rate and depth to allow carbonic acid to accumulate
(hypoventilation - increase acidity)
77
Respiratory Compensation
Respiratory response to an imbalance of any metabolic acid (except carbonic acid)
78
What is the Respiratory compensatory response to a acid/base disorder
Does not correct a pH disorder (have to find out underlying issue)
Does compensate for it by adjusting the pH back toward normal
79
Renal Contribution
3rd system
Third defense against acid/base disorder
Can excrete any acid from the body except CARBONIC ACID (carbonic acid can only be excreted by the lungs)
Slowest mechanism to react to changes but last the longest
80
Only system for removing hydrogen (acid) ions
Renal system
81
Urinary buffers necessary to eliminate hydrogen
Phosphate and ammnonia
82
Hydrogen is:
an acid
83
Increased excretion of hydrogen results in an increased production of ammonia, what happens next?
Hydrogen combines with ammonia and is excreted in the urine which raises the pH (alkaline)
84
A decreased excretion of hydrogen results in a decreased production of ammonia, what happens next?
Excrete less H; reasorb hydrogen back into the blood lowering the pH (acidic)
85
HCO3
Bicarb
(reflects the amount of metabolic acid in the blood)
86
Decreased HCO3-
Indicates a excess of metabolic acids in the blood
87
Increased HCO3
(Bicarb)
Indicates a deficit of metabolic acids in the blood
(less acids to buffer so you have an excess of base)
88
Renal response is for
Carbonic Acid imbalances
(Respiratory Problems)
89
When you have a high carbonic acid level the body...
Increases the excretion of metabolic acids and H (raise the pH)
Retain HCO3 (Bicarb)
90
91
When you have a low carbonic acid level (alkaline) to compensate your body.....
Decreases the excretion (retain) metabolic acids and Hydrogen (H+) (lower pH)
Excrete HCO3 (Bicarb)
92
Respiratory takes care of carbonic acid by
Blowing it off or saving it by adjusting your pH
93
Respiratory can only take care of carbonic acid by
Blowing off or saving to adjust pH
94
Kidneys can only control
H+ (hydrogen)
and
HCO3 (bicarb)
95
Metabolic Acidosis
Deficiency of bicarbonate or excess of hydrogen
pH \<7.35
96
Metabolic Acidosis
Causes:
* ketoacidosis
* starvation
* diabetes
* alcoholism
* severe hyperthyroidism
* burns
* circulatory shock
* oliguric renal failure
97
Metabolic Acidosis is caused by:
Anything that causes a decrease or removal in bicarbonate (base)
Examples: Diarrhea, Gastrointestinal fistula
98
Clinical manifestations of Metabolic Acidosis
* HA
* confusion, lethargy, stupor, coma
* Severe metabolic acidosis:
* tachycardia
* ventricular dysrhythmias (from myocardial intracellular acidity)
* decreased cardiac contractility
* death from brainstem dysfunction usually occurs in pH falls below 6.8
99
Three major mechanisms that regulate acid-base status of the body
1. Buffers
2. Respiratory System
3. Renal System
100
Arterial blood gas (ABG) measures acid-base status
in the ECF
101
Normal Range for;
PaCO2
The partial pressure of carbon dioxide
35-45
Respiratory Function
102
HCO3
Bicarbonate
Normal Range
22 - 26
Renal (metabolic) function
103
pH does not tell us what's going on _____ because we are measuring ______ \_\_\_\_\_\_\_
pH does not tell us what's going on inside the cell because we are measuring extracellular fluids (ECF)
104
What is the difference between compensated vs uncompensated
Acidosis or Alkalosis?
Has the other system kicked in the help
105
Metabolic Alkalosis
pH \>7.45
106
Causes of Metabolic Acidosis
**_Increase in base_**
* Antacids (Baking soda)
* Transfusion with citrated blood
* LR infusion
**_Decrease in acid_**
* Emesis or gastric sx
* Hyperaldosteronism - excretes H+
* Hypokalemia - causes H+ to shift into cells
* Excessive diuretics cause H+ loss
107
Metabolic Alkalosis
Clinical Manifestations
Postural hypotension
Hypokalemia - bilateral muscle weakness
Cardiac dysrhythmias
Increased neuromuscular excitability - Paraesthesia of fingers & toes, tetany - seizures, ionized hypocalcemia
Severe metabolic alkalosis - central nervous system depression; confusion, lethargy, coma, death usually occurs if pH rises to 7.8
108
Respiratory Acidosis
Causes
Any condition that causes an excess of carbonic acid (retain CO2)
Caused by impaired removal of carbonic acid by the lungs - impaired gas exchange
* COPD
* Pneumonia
* Severe Asthma
* Pulmonary edema
* Drug overdose - Anesthesia
* Acute respiratory distress syndrome
109
Respiratory Acidosis
Clinical Manifestations
Headache
Tachycardia
Cardiac dysrhythmias
Neurologic abnormalities - blurred vision, tremors, vertigo, disorientation, lethargy, somnolence
Severe respiratory acidosis - peripheral vasodilation with hypotension
110
Respiratory Alkalosis
Causes:
Any condition that tends to cause a carbonic acid deficit (decreased CO2)
## Footnote
* Hyperventilation
* Hypoxemia
* Acute pain
* Fever
* Anxiety, psychological distress
111
Respiratory Alkalosis
Clinical Manifestations
Dizziness
Syncope
Confusion
Paresthesia
Twitching
Tetany
Seizures
112
When interpreting ABG's in what order do you access the lab values
1st check the pH for Acidosis \<7.35 or Alkalosis \>7.45
2nd check the PaCO2 for Acidosis or Alkalosis
3rd Examine the HCO3 for Acidosis or Alkalosis
If pH is low or high you will know if it is acidosis or alkalosis if the PaCO2 is abnormal it will be respiratory if the HCO3 is abnormal it will be metabolic
when one is abnormal the other is still normal it is because it is UNCOMPENSATED
113
Geriatric Variations
At risk for respiratory acidosis b/c drugs (Barbiturates) build up in system (increased half-life)
At risk for metabolic acidosis: kidneys less able to excrete large acid load, chronic laxative overuse that results in chronic diarrhea, use a lot of homemade remedies for reflux
114
John is a 54 yo male seen in the ER due to sign pain form an ankle fx. He is SOB.
ABGs show
pH 7.48 PaCO2 32 HCO3 25
What acid/base abnormality does he have?
1. Respiratory Acidosis - compensated
2. Respiratory Alkalosis - compensated
3. Respiratory Acidosis - uncompensated
4. Respiratory Alkalosis - uncompensated
4. Respiratory Alkalosis - uncompensated
115
Mary is a 55 yo female who presents to the office with c/o headache and diarrhea for 2 days. She admits to using a colon cleanse to lose weight while dieting.
ABGs show:
pH 7.33 PaCO2 40 HCO3 - 20
1. Metabolic alkalosis - compensated
2. Metabolic acidosis - compensated
3. Metabolic alkalosis - uncompensated
4. Metabolic acidosis - uncompensated
4. Metabolic acidosis - uncompensated
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