Exam 1: Fluids and Electrolyes Flashcards
What two compartments are body fluid located in?
Intracellular Space (Fluid in cells) and Extracellular Space (Fluid outside of cells)
What percentage of body is in ICF?
2/3’s
What is the ECF divided into?
Intravascular, Interstitial, and TRanscellular
Whats the Intravascular Space contain??
It contains plasma, with 3 L out of 6 L of blood made up of this. Remaining 3L made up of erythrocytes, leukocytes, and thrombocytes
Whats the Interstitial Space?
FLuid that surrounds the cell and totals about 11 to 12 L in an adult. Such as Lymph
WHat is TRanscellular Space?
Smallest division. 1 L. Cerospinal , Synovial, Intraocular, and PLeural Fluids
What is Third-Space Fluid Shift?
Loss of ECF into a space that does not contribute to equilibrium between ICF and ECF
Early evidence of third-space fluid shift?
Decrease in urine output despite adequate fluid intake. Kdineys recieve less blood and compensate by decreasing urine output.
Other signs and symptoms of third-space fluid shift?
Increased heart rate, decreased blood pressure, decreased central venous pressure, edema, increased body weight
Main cation in ECF?
Sodium ions. Retention of this is associated with fluid retention. Excessive loss of sodium is usually associated with decreased volume of body fluid
Main cation in ICF?
Potassium and Phosphate. ECF has low concentration of potassuium. This can cause trauma to ECF if released.
Sodium ECF Conventional Units?
135 - 145
Potassium ECF Conventional Units?
3.5-5.0
Chloride ECF Conventional Units?
98-106
Bicarbonate ECF Conventional Units?
24-31
CAlcium ECF Conventional Units?
8.5-10.5
Phosphorus ECF Conventional Units?
2.5-4.5
Magnesium ECF Conventional Units?
1.8-3.0
Sodium ICF Conventional Units?
10-14
Potassium ICF Conventional Units?
140-150
Chloride ICF Conventional Units?
3-4
BicarbonateICF Conventional Units?
7-10
Calcium ICF Conventional Units?
<1 mEq./L
Phosphorus ICF Conventional Units?
Variable
Magnesium ICF Conventional Units?
40 mEq/kg
What is Osmotic Pressure?
Amount of hydrostatic pressure needed to stop the flow of water by osmosis. Primarily determined by the concentration of solutes
What is Oncotic Pressure?
Is the osmotic pressure exeted by proteins
What is Osmotic Diuresis
Increase in urine output caused by the excretion of substances, such as glucose
General rule for urine output?
1 mL of urine per kilogram of body weight per hour
What is Osmolality?
The concentration of fluid that affects the movement of water between fluid compartments by osmosis
Factors Increase Serum Osmolality?
SevereDehydration Free Water Loss Diabetes Insipidus Hyperglycemia Stroke or Head Injury Alcholism
Factors Decreasing Serum Osmolality?
FVE SIADH Acute Kidney Injury Hyponatremia Overhydration
Factors Increasing Urine Osmolality?
FVD
DIADH
HEart Failure
Factors Decreasing Urine Osmolality
FVE
Diabetes Insipidus
Hyponatremia
What is BUN made up of?
Urea, which is the end product of the metabolism of protein by the liver
How is Urea made?
Amino acid breakdown produces large amounts of ammonia molecules, which are absorbed into the blood stream and converted to Urea
Normal BUN level?
10 to 20 mg/dL
Factors trhat increase BUN?
Decreased renal function, GI bleeding, Dehydration, increased protein intake, fever, sepis
Factors trhat decrease BUN?
End-stage liver disease, a low-protein diet, starvation
What is Creatine?
The end product of muscle metabolism. BEtter indicator of renal function
Normal serum creatinine?
0.7-1.4 mg/dL
Normal Hematocrit range?
42-52% for men, 35-47% for women
Conditions that increase Hematocrit?
Dehydration and polycythemia
Conditions that decrease Hematrocrit?
Overhydration and Anemia
What happens as sodium intake increases?
Urine excretion increases.
Normal Sodium levels?
75 to 200 mEq/24 hours.
How much fluid do kidneys filter on a normal day?
180 L
How much urine excreted in normal day?
1-2 L
Major functions of kidneys in maintaining normal fluid balance?
Regulation of ECF volume by selective retention
REgulation of normal electrolyte levels in ECF by selective electrolyte retention
Regulation pH by retention of hydrogen ions
Functions of ADH?
Maintaining osmotic presure of the cells by controlling the retention or excretion of water by the kidneys and by regulating blood volume
What happens with increased secretion of aldosterone?
Causes sodium retention, (this water retention) and potassium loss.
What does Cortisol do?
When secreted in large quantities, it can also produce sodium and fluid retention
What do Parathyroid Hormone do?
Influences bone reabsorption, calciun absorption from teh intenstines, and calcium reabsorption.
What does Renin do?
An enzyme that converts ANgiotensinogen, substance formed by liver, into angiotensin I. THis is due to decreased renal perfusion.
What convers Angiotensin I to Angiotensin II?
ACE
What does Angiotensin II do?
increases arterial perfusion pressure and stimulates thirst.
What do Osmoreceptors do?
Sense changes in sodium concentration. AS this pressure increases, neurons become dehydrated and quickly release impulses to the posterior pituitary which increases release of ADH
How many Natriuretic Peptides are tehre?
Four
What are the four Natiuretic Peptides?
Atrial Natriuretic Peptide (ANP)
Brain Natriuretic Peptide (BNP)
C-Type Natriuretic Peptide (CNP)
D-Type Natriuretic Peptide (DNP)
What actives ANP?
Any condition that results in volume expansion, calorie restriction.
What does ANP do?
Its action decreases water, sodium, adipose loads. Directly opposite of RAAS .
Alternate name for FVD?
Hypovolemia
When does Hypovolemia occur?
When loss of ECF volume exceeds the intake of fluid. Water and electrolytes are lost in the same proportion as they exist in nrmal body fluids
Causes of FVD?
Abnormal fluid losses, GU Suctioning, and Sweating, Third-Space fluid shifts, or edemas.
FVD contributing factors
Loss of water and electrolytes such as vomiting, diarrhea, gi suctioning,
decreased intake as in anorexia, nausea,
diabetes insipidus and uncontrolled diabete
FVD Signs/Symptoms
Acute weight loss, decreased skin turgor, capillary filling time prolonged, decreased bp, flattened neck veins
FVD Labs
Increased hemoglobin and hematocrit
Increased serum and urine osmolality and SpG
Decreased urine sodium
Increased BUN and Creatinine
FVE altername name?
Hypervolemia
FVE Contributing FActors
Compromised regulatory mechanisms such as Kidney injury, heart failure
Over-administration of sodium-containing fluids and fluid shifts. Severe Stress
FVE Signs/Symptoms
Acute weight gain, peripheral edema, distended jugular veins, cracjkes, increased bp, bounding pulse, increased respiratory rate and cough
FVE Labs
Decreased hemoglobin and hematocrit, decreased serum and urine osmolality.
Decreased urine sodium and SpG
Normal BUN to serum creatinine concentration?
10:1
What happens to a BUN to serum creatinine concentration in a volume-depleted patient?
BUN elevated out of proportion, greater than 20:1
Hematocrit level in hypovolemia?
Increased, because there is a decreased plasma volume
When does Hypokalemia occur?
With GI and Renal Losses
When does Hyperkalemia occur?
With adrenal insufficiency
When does Hyponatremia occur?
With increased thirst and ADH release
When does Hypernatremia occur?
Results from increased insensible losses and diabetes insipidus
First choice for treating those with FVD?
If fluid losses acute or severe, IV route required. Isotonic solutions, such as 0.9% NaCl are the first-line choice because they expand plasma volume.
FVD - What happens if patient becomes normotensive, ?
Administer a hypotonic electrolyte solution (0.45% NaCl) Used to provide both electrolytes and water for renal excretion of metabolic wastes.
Test administered to patient with severe FVD when oliguric?
Fluid Challenge Test. 100-200 mL of normal saline solution given over 15 minutes. The goal is to have increased urine output and blood pressure and central venous pressure
Alternate name for FVE?
Hypervolemia
What is FVE?
REfers to an isotonic expansion of the ECF caused by the abnormal retention of water and sodium in approximately the same proportions in which they normally exist in ECF
FVE may be related to?
Simple fluid overload or diminished function of the homeostatic mechanisms responsible for regulating fluid balance
Contributing factors of FVE?
Heart Failure, Kidney Injury, and Cirrhosis of the liver
Clinical Manifestations of FVE?
Edema, Distended neck veins and crackles
BUN and Hematocrit levels in FVE?
Decreased because of plasma dilution, low protein intake, and anemia
When are thiazide diuretics typically prescribed?
Prescribed for mild to moderate hypervolemia
When are loop diuretics typicaly assigned?
For severe hypervolemia
HYpokalemia can occur with all diuretics except those that work in
the last distal tubule of the neprhons. Potassium supplements can be prescribed to avoid this complication
FVE - When can Hyperkalemia occur?
This can occur with diuretics that work in the distal tubes, especially those with decreased renal function
When does Hyponatremmia occur?
With administration of loop and thiazide duretics due to decreased reabsorption and increased excretion of magnesium by the kidney
What is Azotemia?
Increase nitrogen levels in blood, that can occur withFVE when urea and creatinine are not excreated
When is Dialysis used?
When other things don’t work, this is used to remove nitrogenous wastes and control potassium and acid-base balance and to remove sodium and fluid
Treatment of FVE usually involves dietary restriction of
sodium
What is a frequent cause of the increased ECF volume?
Sodium retention
wHAT IS Sodium responsible for?
Water regulation and balance
What is potassium responsible for?
nerve impulse transmission, muscle contraction, plasma, acid-base balance, normal heart rhyth,
what is calcium responsible for?
Muscle activity, blood coagulation
What is magnesium responsible for?
nerve impulse transmission and muscle contraction
What is phosphate responsible for?
ATP production
What is chloride responsible for?
hychloric acid production, acid-base balance
