Fluids and Electrolytes Flashcards
Acidosis
An acid–base imbalance characterized by an increase in H+ concentration
Ascites
A type of edema in which fluid accumulates in the peritoneal cavity
Active transport
Physiologic pump that moves fluid from an area of lower concentration to one of higher concentration; active transport requires ATP for energy
Alkalosis
An acid–base imbalance characterized by a reduction in H+ concentration
Diffusion
The process by which solutes move from an area of higher concentration to one of lower concentration; does not require energy
Homeostasis
Maintenance of a constant internal equilibrium in a biologic system that involves positive and negative feedback mechanisms
Hydrostatic Pressure
The pressure created by the weight of fluid against the wall that contains it.
Hypertonic Solution
A solution with an osmolality higher than that of serum. Moves fluid out of cells into the vasculature.
Hypotonic Solution
A solution with an osmolality lower than that of serum. Causes fluids to move from interstital spaces into cells. More water, less electrolytes.
Isotonic Solution
A solution with the same osmolality as serum and other body fluids. Expands ECF volume.
Osmolality
The number of milliosmoles (the standard unit of osmotic pressure) per kilogram of solvent; expressed as milliosmoles per kilogram (mOsm/kg)
Osmolarity
The number of milliosmoles (the standard unit of osmotic pressure) per liter of solution; expressed as milliosmoles per liter (mOsm/L); describes the concentration of solutes or dissolved particles
Osmosis
The process by which fluid moves across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration; the process continues until the solute concentrations are equal on both sides of the membrane
Tonicity
Fluid tension or the effect that osmotic pressure of a solution with impermeable solutes exerts on cell size because of water movement across the cell membrane (hypotonic, hypertonic, isotonic)
Third spacing
When fluid moves out of either the intracellular and extracellular spaces and into areas that don’t maintain homeostasis (Ex. edema)
How many compartments do extracellular fluid have? What are they?
- Intravascular
- Interstitial: surrounds the cells
- Transcellular: various, often smaller spaces
Sodium Concentration Range
135-145 mEq/L
Potassium Concentration Range
3.5-5.0 mEq/L
Chloride Concentration Range
98-106 mEq/L
Bicarbonate Concentration Range
24-31 mEq/L
Calcium Concentration Range
8.5-10.5 mg/dL
Phosphorus Concentration Range
2.5-4.5 mg/dL
Magnesium Concentration Range
1.8-3.0 mg/dL
Osmostic Pressure
Amount of pressure needed to stop the flow of water, determined by the concentration of solutes.
Oncotic Pressure
Pressure extended by proteins.
Osmotic Diuresis
Increase in the urine output caused by the excretion of substances.
Osmoles
Particles in our bodies that affect the movement of water
Hyponatremia
Serum sodium less than 135 mEq/L
Causes of Hypoatremia
Imbalance of water, losses by vomiting, diarrhea, sweating, diuretics, adrenal insufficiency, certain medications, SIADH
Hypernatremia
Serum sodium greater than 145 mEq/L. Occurs when there is a gain in sodium or an excessive loss of water.
Hypokalemia
Potassium serum levels less than 3.5 mEq/L
Causes of hypokalemia
GI lossses, medications, alterations of acid-base balance, etc
Manifestations of hypokalemia
ECG changes, dysrhythmias, dilute urine, thirst, muscle weakness etc.
Hyperkalemia
Serum potassium greater than 5.0 mEq/L
Causes of hyperkalemia
Impaired renal function, rapid administration of potassium, hypoaldosteronism, medications, tissue trauma, acidosis
Manifestations of hyperkalemia
Cardiac changes and dysrhythmias, muscle weakness, paresthesias, anxiety, GI manifestations
Hypocalcemia
Serum level less than 8.5 mg/dL
Cause of hypocalcemia
Hypoparathyroidism, malabsorption, osteoporosis,
pancreatitis, alkalosis, transfusion of citrated blood, kidney
injury, medication
Hypercalcemia
Serum level greater than 10.5 mg/dL
Causes of hypercalcemia
Malignancy and hyperparathyroidism, bone loss related to
immobility, diuretics
Clinical manifestations of hypercalcemia
Polyuria, thirst, muscle weakness, intractable nausea, abdominal cramps, severe constipation, diarrhea, peptic ulcer, bone pain, ECG changes, dysrhythmias
Hypomagnesemia
Serum level less than 1.8 mg/dL
Manifesations of Hypomagnesmia
Apathy, depressed mood, psychosis, neuromuscular irritability, muscle weakness, tremors, ECG changes and dysrhythmias
Hypermagnesemia
Serum level greater than 3.0 mg/dL
Causes of hypermagnesemia
Kidney injury, diabetic ketoacidosis, excessive administration of magnesium, extensive soft tissue injury
Manifestations of hypermagnesemia
Hypoactive reflexes, drowsiness, muscle weakness,
depressed respirations, ECG changes, dysrhythmias, and cardiac arrest
Hypophosphatemia
Phosphorus Serum level below 2.5 mg/dL
Causes of Hypophosphatemia
Alcoholism, refeeding of patients after starvation, pain, heat stroke, respiratory alkalosis, hyperventilation, diabetic ketoacidosis, hepatic encephalopathy, major burns, hyperparathyroidism, low magnesium, low potassium, diarrhea, vitamin D deficiency, use of diuretic and antacids
Manifestations of Hypophosphatemia
Neurologic symptoms, confusion, muscle weakness, tissue hypoxia, muscle and bonevpain, increased susceptibility to infection
Hyperphosphatemia
Phosphorus Serum level above 4.5 mg/d
Causes of Hyperphosphatemia
Excess phosphorus, excess vitamin D, acidosis, hypoparathyroidism, chemotherapy
Manifestations of Hyperphosphatemia
Soft-tissue calcifications, symptoms occur due to associated hypocalcemia
Hypochloremia
Chlorine Serum level less than 98 mEq/L
Causes of Hypochloremia
Addison disease, reduced chloride intake, GI loss, diabetic ketoacidosis, excessive sweating, fever, burns, medications, metabolic alkalosis
Manifestations of Hypochloremia
Agitation, irritability, weakness, hyperexcitability of muscles, dysrhythmias, seizures, coma
Hyperchloremia
Chlorine Serum level more than 106 mEq/L
Causes of Hyperchloremia
Excess sodium chloride infusions with water loss, head injury, hypernatremia, dehydration, severe diarrhea, respiratory alkalosis, metabolic acidosis, hyperparathyroidism, medications
Hypovolemia
Dehydration or fluid volume deficit
Fluid volume deficit
Loss of ECF including both serum electrolytes and water are lost in same proportion.
Dehydration
Dehydration is the rapid loss of body
weight due to the loss of water.
Risk Factors for Dehydration
Abnormal renal losses
Altered intake
Hyperventilation
Diabetic ketoacidosis
Clinical Causes for Fluid Volume Deficit
Abnormal GI loss: vomiting, nasogastric suctioning, diarrhea
▪ Abnormal skin loss: diaphoresis
▪ Abnormal renal losses: diuretic therapy, diabetes insipidus renal disease, adrenal insufficiency osmotic diuresis
▪ Third spacing: peritonitis, intestinal obstruction, ascites, burns
▪ Hemorrhage
Typical Vital Signs for FVD
Hyperthermia, tachycardia, weak pulses, hypotension, tachypnea
Fluid Volume Excess
Edema
o JVD (distended neck veins)
o Crackles on lung auscultation
o Productive cough
o Weight gain
o Lethargy
o CNS disturbances/changes
Colloids
Increase vascular space without excess fluid.
* Example: someone who has third spacing meaning more fluid in the interstitial space than intravascular space. Providing
this fluid will draw that fluid back into the vasculature.
Types of colloids
Albumin, blood, plasma, Dextran 40
When to give colloids
- To increase osmostic gradient
- Increase intravacular volume without giving an excessive amount of volume to patient
- Hemorrhage
- When regulatory organs are compromised
Crystalloids types
Isotonic, hypotonic, hypertonic
When will a isotonic solution be used?
In hypovolemic states, shock, mild Na deficit, resuscitative efforts, and hypercalcemia etc
0.9% NaCl is considered normal saline.
When are hypotonic solutions used?
To treat hyperotnic dehydration, Na+ and Cl- depletion, and gastric fluid loss
0.45% NaCl
When are hypertonic solutions used?
Used to decrease cellular swelling.
3% and 5% NaCl
When to give crystalloids?
Patients requring fluid resuscitation and other situations depending on the tonicity of the patient.
When to be cautious with fluid resucitation?
Organ dysfunction lifke kidney failure, heart failure, pulmonary edema, head trauma, children, and the elderly.
