Electrolytes Flashcards
Define an ion
An ion is any atom or group of atoms that bears one or more positive or negative electrical charges
Define Cation
A positively charged ion
Define anion
A negatively charged ion
What are the 7 primary electrolytes?
Sodium
Potassium
Calcium
Magnesium
Chloride
Bicarb
Phosphorus
Define an electrolyte
A substance that has a positive or negative electrical charge when it is dissolved in water
T/F: electrolytes are passive solutes
False. Electrolytes are not passive solutes as they have charges and energy needs to be used in order to facilitate their movement
What is a non-electrolyte?
A chemical compound that when placed in a solution does not ionize
What is the normal value for sodium?
135-145 mEq/L
What are common non-electrolytes?
Sugar
Alcohol
What is the normal value for potassium?
3.5-4.5 mEq/L
What is the normal value for chloride?
90-100 mEq/L
What are the normal values for magnesium?
1.5-2.4 mEq/L
What are the normal values for bicarb?
22-26 mEq/l
What are the normal values for calcium?
4.5-5.5 mEq/dL
What is the standard test for analyzing electrolyte content in the blood?
Basic metabolic panel
BMP
What are the normal values for phosphorus?
3-4.5 mg/dL
What metabolic functions can be tested via a Basic metabolic panel (BMP)?
Kidney function
Fluid and electrolyte balance
Blood sugar levels
Acid and base balance
Metabolism
What is sodium primary role in the body
Primary role is regulating the distribution of water throughout the body
What is the most prevalent cation found in the extracellular compartment?
Sodium
What controls and regulates sodium levels?
The kidneys
What level of sodium is required to be considered hyponatremic?
Less than 135 mEq/L
What are common ways electrolytes are lost?
Vomiting
Diarrhea
Besides increased output, what are other ways that sodium content in the blood can be decrease?
Increases in fluid levels in the body can dilute sodium content
What disease processes commonly cause fluid retention?
CHF
Kidney failure
What level of sodium is required to be considered hypernatremic?
Greater than 145 mEq/l
What can cause hypernatremia?
Pure water loss or excretion
Diuretics
Excessive sweating
What is the main cation of the intracellular compartment?
Potassium
T/F: dehydration is not clinically confirmed with findings of hypernatremia
False
What can happen if potassium is too high or too low?
Serious cardiac dysrhythmias may develop
WHat are the most common causes of hypokalemia?
Urine
GI tract
Skin
NG tube output
Alcoholism, diuretics, laxatives
What is the role of potassium in the body?
Critical role is mediating electrical impulses in the nerves and muscles, including the heart
T/F: Potassium has no role in maintaining the acid base balance
False
What is the benchmark for being considered hypokalemic?
K+ less than 3.5 mEq/L
What are the symptoms of hypokalemia?
EKG changes
Muscle weakness
AMS (altered mental status)
How does hypokalemia change an EKG?
Decrease in the amplitude of the T waves
Decreased S-T segment
Prominent U waves
How is hypokalemia treated?
Eliminate beta agonists
KCl- for metabolic alkalosis
KHCO3- for renal tubular acidosis
What is the benchmark for hyperkalemia?
K+ > 4.5 mEq/L
What are the symptoms of hyperkalemia?
Muscle weakness
Changes in EKG
How does hyperkalemia change an EKG?
Tall narrow T waves (tent like)
Decreases amplitude of P wave (may disappear entirely)
Prolonged R-R interval
Prolonged QRS complex
May lead to asystole
What can cause hyperkalemia?
Pharmacologics
Lack of insulin
Renal insufficiency
What are treatment options for hyperkalemia?
insulin /glucose infusion
Calcium gluconate
Diuretics to promote K+ clearance
Kayexalate
Dialysis
Beta adrenergics
What drugs can cause hyperkalemia?
ACE inhibitors
Potassium sparing diuretics
NSAIDS
Heparin
What would the acid-base balance of a patient with hyperkalemia potentially look like?
Metabolic acidosis
What is the root cause of hyperkalemia?
Transcellular shift of K+ out of the cell
What is the most common clinical cause of hyperkalemia?
Impaired urine output
Or excessive intake
What does albuterol do to combat hyperkalemia?
May help shift potassium into the intracellular space by stimulating the sodium potassium pump
What drug can RTs administer to patients who are hyperkalemic?
Albuterol
How much can albuterol lower the serum potassium level of the blood?
0.5-1.5 mEq/L
What patients can benefit from albuterol administration for hyperkalemia?
Patients with renal failure who are fluid overloaded
What is the dosage of albuterol for patients with hyperkalemia?
20 mg
Where is the potassium concentration typically higher, outside the cell or inside the cell?
Inside the cell
Intracellularly
What is the resting membrane potential?
Difference of electrical voltage inside to the outside of the cell
What is the resting membrane potential dependent upon?
The functionality of the sodium potassium pump
Where is sodium concentration typically higher, outside the cell or inside the cell?
Outside the cell
Extracellularly
Describe the movement of sodium and potassium in a single “cycle” of the sodium potassium pump
The pump binds 3 sodium ions and 1 molecule of ATP
The ATP provides energy to change the shape of the channel and the sodium is excreted into the extracellular space
The new shape of the channel allows 2 potassium ions to bind
A release of phosphate allows the channel to revert to its original shape and release the potassium into the cell
What are the functions of magnesium in the body?
Plays important role as coenzyme in the metabolism of proteins and carbs
Helps regulate neuromuscular irritability
What is magnesium used to treat?
Torsade de pointes
Smooth muscle relaxation effects (asthma)
How is lactate used clinically?
Represents a clinically obtainable surrogate marker of tissue hypoxia and disease severity independent of blood pressure
What are normal serum lactate levels?
0.5-2.0 mmol/L
What causes an increase in serum lactate?
Anaerobic metabolism due to lack of oxygen delivery to the tissues
What ions are generally found in the extracellular compartment?
Sodium
Chloride
Bicarbonate
What ions are generally found in the intracellular compartment?
Potassium
Magnesium
Phosphate
Describe the relationship between hypervolemia and hyponatremia
In hypervolemia, the total body fluid has increased lowering the concentration of sodium in the blood
Describe the relationship between hypovolemia and hyponatremia
In hypovolemia the total body fluid has decreased resulting in decreased amounts of sodium
What causes hypernatremia?
Water loss exceeding sodium loss
Pure water loss
Increases in total body sodium
In what situations would water loss exceed sodium loss resulting in hypernatremia?
Diuretics
Sweating
Diarrhea
What conditions cause pure water loss resulting in hypernatremia?
Diabetes insipidus
Excessive sweating
hat can cause an increase in total body sodium resulting in hypernatremia?
Cushing syndrome
Hypertonic sodium bicarb administration
When is hypertonic sodium bicarbonate administered?
CPR
T/F: 90% of total body potassium is found extracellularly
False. 90% of total body potassium is found intracellularly
What can cause hypokalemia?
GI losses
Diuretics
insulin/ B2 agonists
Malnutrition
Alcoholism
What can cause hyperkalemia?
Acute or chronic renal failure
NSAIDS, diuretics, ACE inhibitors
Blood transfusion
What rhythm is associated with hypokalemia?
V-fib
Torsades de points
What is the role of calcium in the body?
Bone development
Blood clotting
Neuromuscular activity
Muscle contraction
What muscular symptoms might an individual with improper calcium levels experience?
Muscle irritability
Convulsions
Compromise of cardiac contractility
What is the anion gap?
The anion gap is the difference between the measured cations and the unmeasured anions in the blood
What is diagnosed if the anion is greater than normal?
High anion gap metabolic acidosis is diagnosed
What are the unmeasured anions?
Protein
Phosphate
Sulfate
Organic acids
What are the unmeasured cations
Potassium
Calcium
Magnesium
Trace
What is the normal anion gap?
Less than or equal to 15
How do you calculate the anion gap?
Unmeasured anions - unmeasured cations = anion gap
What are the options for fluid replacement?
Crystalloids
Colloids
Blood products
What is the first choice of fluid replacement for resuscitation, maintenance, solvent for drug administration?
Crystalloids
What are crystalloids primarily used for?
Resuscitation
maintenance
Solvent for drug administration
What fluid replacement is used as a plasma substitute?
Colloids
What are the benefits of crystalloids?
Do not exert an osmotic effect
Increase fluid levels without causing significant fluid shifts
what are common crystalloids?
normal/hyper/hypotonic saline
Dextrose
Lactated ringer
What are examples of colloids?
Albumin
Hesban
Hetastarch
What are the benefits of colloids?
Believed to remain in IV space and be more effective at maintaining oncotic pressure
What are blood products commonly used for?
Replacement therapy or hematocrit or hemoglobin
When are blood products typically used?
Rapid infusion protocol for trauma patients
What are the kinds of blood products?
Packed red blood cells
Fresh frozen plasma
Platelets
Cryoprecipitate
Whole blood
Why are blood transfusions considered risky?
Risk for adverse reactions
What are the 4 standard categories of diuretics?
Thiazides
Potassium sparing diuretics
Osmotic diuretics
Loop diuretics
