Fluids & Electrolytes Flashcards
Hyperkalemia
Serum K+ > 5.5mEq
Sx of Hyperkalemia
Fatigue
Muscle weakness
EKG changes—> potentially life threatening arrythmias
Risk for sever negative outcomes increases as K+ levels increase
Causes of Hyperkalemia
Decreased renal excretion (renal failure)
Heart failure (due to decreased renal function)
Increased K+ intake
Shift of K+ from IC—> EC via
Β adrenergic blockade
Insulin deficiency
Acidosis
Medications that increase serum K+ (7)
Potasium sparing diuretics
ACE
NSAIDS
Digoxin Toxicity
ARBs
Sulfamethoxazole/Trimethoprim
If a patient has moderate elevation of serum K+ WITHOUT EKG changes, how would you treat his hyperkalemia?
Increase excretion of K+ via cation exchange resin or diuretics
Goals of treatment for a patient with severe (>6.5) hyperkalemia
Immediate stabilization of myocardial membrane
Rapid shifting of K+ to ICS
Increase K_+ elimination (d/c exogenous K+)
What is the medication and dose that is given to someone with SEVERE HYPERKALEMIA to stabilize their myocardial cell membrane?
IV Calcium 1g IVPG over 1 hour (IV piggy back)
**Calcium Gluconate preferred
Why is Calcium Gluconate preferred over calcium carbonate?
Calcium Carbonate—> Brady cardia and increased tissue damage & extravasation
What do we check within 30min-1 hour of administering IV insulin to a patient with hyperglycemia and why?
Check BG; because Insulin can cause hypoglycemia
Why do we give insulin to a patient with hypglycemia?
Shifts K+ from ECS—> ICS
When do we treat hyperkalemia with sodium bicarb
In the setting of acidosis
What does sodium bicarb do to treat hyperkalemia?
Shifts K+ from ECS to ICS
Raises systemic pH
What is the dose of sodium bicarb given to patients with hyperkalemia who are in acidosis?
50 mEq IV
What do Β 2 agonists do in the setting of hyperkalemia (2)?
Shift K+ from ECS—> ICS BY:
1) stimulating NaK-ATPase to promote intracellular K+
2) stimulates pancreatic B-receptors to increase insulin secretion
What β-2 agonist is used to treat severe hyperkalemia and how much?
Albuterol 10-20mg via nebula er over 10 min
Why are β-2. Agonists not recommended as solo treatment for hyperkalemia?
Some patients are resistant to the effects
Who are β-2 agonists less effective in?
Patients already on a non selective β blocker
Why are loop diuretics used in the setting of hyperkalemia?
They promote K+ excretion
What 2 loop diuretics are used in the setting of hyperkalemia? What are their doses?
Furosimide: 40-80mg IV
Bumetanide 2-4mg IV
When may loop diuretics be less effective in treating hyperkalemia?
Severe renal failure
How does SPS work to treat hyperkalemia?
Binds potassium in the GI tract to reduce absorption and increase elimination
Resting passes through intestines—> SPS exchanges 1mEq of Na+ for 1mEq K+ (1:1 equal exchange)
Why cant SPS be used ALONE in life- threatening hyperkalemia?
Takes too long to work
Onset= >2 hours
Who should we avoid using SPS in?
Patients with bowel problems
Since SPS works best when in the colon what cathartic is most commonly given with it?
Sorbitol
Sodium Zirconium Cyclosilicate
Potassium binder
Exchanges K+ for Both H+ and Na+
Onset:1 hr
Patiromer
Potassium binder
Exchanges Ca+ for K+
Onset: 7 hrs
What are the 3 potassium binders
Sodium polystyrene sulfonate
Sodium zirconium Cyclosilicate
Paritomer
What is the treatment of choice for hyperkalemia when pharmacologic treatments fail?
Dialysis
Definition of hypokalemia
Serum K+ <3.5
Causes of hypokalemia
Decrease in K+ intake
Increase in K+ loss (diuretics)
Excess GI loss (v/d)
Shifts from ECS (β adrenergic agents, insulin, alkalosis)
Signs and symptoms of hypokalemia
Often asx
Sx are nonspecific and predominantly related to muscular or cardiac function:
- weakness and fatigue
- muscle cramps and pain
- palpitations
- psychological sx
- EKG changes
- Dysrhythmias
- hypotension
What are the goals of treatment for hypokalemia?
Reduction of K+ losses
Replenishment of K+ stores
Methods of reduction of potassium loss?
D/c diuretics./ laxatives
Use K+ sparing diuretics
Treat diarrhea and vomiting
What methods can be used for K+ replenishment of MILD hypokalemia
Oral
What methods can be used for replenishment of K+ in MODERATE hypokalemia?
IV or Oral
What method can be used for K+ replenishment in SEVERE hypokalemia?
IV
Most commonly used salt in treatment of hypokalemia
KCl-
Serum K+ will increase ________ for every __________mEq of supplementation
.1mEq/L for ever 10mEq
T/F: oral and Parenteral K+ CANOT be used simultaneously
False
Try to limit oral single doses to 10-20mEq due to the risk of __________
GI irritation
Infusions >10mEq of Serum K replenishment require ______________
EKG monitoring
____________ is necessary for K+ uptake therefore it must be checked and replaced as needed in order to correct the potassium levels
Magnesium
Hyponatremia
Sr Na+ <135mEq/L
Mild Hyponatremia
Sr Na+ 130-134mEq
Moderate Hyponatremia
Sr Na+ of 120-129mEq/L
Severe Hyponatremia
Sr. Na+ <120mEq/L
Causes of Hyponatremia
Advanced kidney disease
SIADH
Heart Failure
True Volume depelation (Na and water loss GI tract or urine)
Medications- diuretics
S&S of mild Hyponatremia
Nausea and malaise
Sx of severe Hyponatremia
Lethargy
Decreased level of conciousness
Headache
(If severe) seziures and coma
Overt neurologic sx most often are due sodium levels that are:
<115mEq/L