5 - Potassium Disorders Flashcards
Normal Potassium level
3.5 - 5 mEq/L
(0.4% plasma)
Total body K+ = 50 mEq/kg
What affect on Plasma K+ ?
Insulin EXCESS
B2-Adrenergic AGONIST
albuterol, etc
- *A1 antagonist**
- ZOSINS
Aldosterone
DECREASE PLASMA K+
Mechanism:
Stimulate Na-K ATPase Pump
What affect on Plasma K+ ?
Insulin Deficit
B2-adrenergic Antagonist
A1 AGONIST
DIGOXIN TOXICITY
INCREASE K+
Mechanism:
INHIBITS Na-K ATPase Pump
What affect on Plasma K+ ?
Injury / Trauma
Exercise
Catabolism
HYPERosmolality
INCREASE K+
Mech:
Release of K+ from Cells
What affect on Plasma K+ ?
Anabolism
Metabolic Alkalosis
High pH // Basic
DECREASE K+
Mech:
IntraCellular Shift of K+
Acid-Base Status
What affect on Plasma K+ ?
- *Metabolic ACIDOSIS**
- low pH* // acidic
INCREASE K+
Acid Base status
What affect on Plasma K+ ?
ALDOSTERONE
DECREASE in K+
Aldosterone Stimulates the NaK ATPase Pump
K+ pumped out and excreted
also:
Insulin EXCESS
B2-Adrenergic Agonist
A1 antagonist
What affect on Plasma K+ ?
Insulin DEFICIT
INCREASE in Plasma K+
Low Insulin –> Inhibits NaK ATPase Pump
Increase of pH 0.1
effect on Potassium ?
↑ pH 0.1 –> ↑ K+ 0.6 mEq/L
- *Metabolic Acidosis**:
- *<7.35**
IC shift of H+ & EC shift of K+
H+ in // K+ OUT
Corrected Potassium Level
Due to:
Acid-Base Effect
Each 0.1 pH is a 0.6 K+ Change
Ex.
- *Measured pH = 7.0** // Measured K+ = 4.4
- *4x 0.1 pH** units –> 4x 0.6 K+ units
Corrected K+ = 4.4 - 4(0.6) = 2.0 K+
HypoKalemia
Serum K+ Levels
< 3.5 mEq / L
HypoKalemia
Susceptible Population
&
Outcomes
Left Ventricular Hypertrophy
Cardiac Aschemia // CHF
Nephrotic Syndrome
Outcomes:
Eseential HYPERtension
Ischemic / Hemorrhagic STROKE
Arrhythmias
Death
Causes of HypoKalemia
Insufficient DIETARY intake
Minimum daily + intake = 1.6-2gm (40-50 mEq)
IntraCellular Shift of K+
Medications
Metabolic ALKALOSIS
Excessive K+ LOSS
Diarrhea / Skin burn or sweat
Renal:
HYPERaldosteronism // Medications // Acidosis
HypoMagnesemia
Medications that cause a
INTRAcellular Shift of K+
HypoKalemia
B2 Adrenergic Agonist
Phosphodiesterase Inhibitors
Theophylline // Caffeine
INSULIN
Barium / Verapamil Overdose
Medications that cause
Excessive K+ LOSS - RENALLY
HypoKalemia
Diuretics / Osmotic Diuresis
High Dose:
Penicillin-Aminoglycosides - Amphotericin B
HYPERaldosteronism
Renal Tubular Acidosis Type 1+2
High Sodium Diet
How THIAZIDE DIURETICS
Cause HypoKalemia
Thiazide Blocks Na+ reabsorption–> urination
VVVV
This causes K+ to be brought back into COLLECTING DUCT
VVVV
To be EXCRETED / urinated
Mild - Moderate Symptoms
of HypoKalemia
Mild = 3.1 - 3.4
Moderate = 2.7-3.0
In order of INCREASING severity:
N/V
Tiredness
Minimal Muscle Weakness
Proximal Muscle Weakness
(lower > upper limbs)
Constipation
ECG changes
SEVERE Symptoms of
HypoKalemia
<2.7 mEq/L
ECG Changes
RHABDOMYOLYSIS
Ascending Symmetric Paralysis
with intact sensorium
Cardiac ARRHYTHMIAS
HYPERtension
STROKE
ECG Signs / Symptoms
of
HypoKalemia
ALL UP:
HYPERpolerization
Prolonged Action Potential
Prolonged Refractory Periods
INCREASED Automaticity & Excitability
T-WAVE INVERSION
goes from UP–> DOWN
Prominent U WAVE
QTintervalprolongation
ST segment depression
Goal K+ Level for HIGH RISK PATIENTS
HypoKalemia
Who are the High risk patients?
> 4.0 mEq/L
for
HypoKalemic HYPERTENSIVE patients
due to:
STROKE RATE 2-3x HIGHER for them
- *Increase in K+ intake** is
- inversely related to Blood Pressure*
Treatment Algorithm
HypoKalemia
First:
Treat the Underlying Cause
Treat HypoMagnesemia
AVOID drugs that lower K+
Second:
Assess Severity of Hypokalemia
Mild Asymtomatic // Moderate Asymptomatic // SEVERE SYMPTOMATIC
Do NOT treat based on K+ Levels
TREAT BASED ON SYMPTOMS
- *Estimation of Potassium Deficit**
- *HypoKalemia**
if:
K+ > 3.0 mEq/L
Each ↓ 0.1 mEq/L K+
vvvv
10 mEq Deficit
Ex for Normal Patient:
- *Measured K+** = 3.5 –> Goal = 3.0
3. 5 - 3.0 = 0.5 = 5 x 10 –> 50 mEq
- *Estimation of Potassium Deficit**
- *HypoKalemia**
K+ <3.0 mEq/ L
2- STEP PROCESS
Each ↓ 0.1 mEq/L K+
VVVV
20 mEq Deficit
Ex. CARDIAC PATIENT
Measured K+ = 2.2 –> Goal = 4.0 (cardiac pt)
3.0 - 2.2 = 0.8 = 8x20 = 160 mEq
4.0 - 3.0 = 1.0 = 10x10 = 100 mEq
Total 260 mEq
- *Hypokalemia Example**:
- *Estimation of K+ Deficit**
**K+ = 2.0 pH = 7.5**
For a Cardiac Patient
GOAL for Cardiac Patient = 4.0
K+ = 2.0 //pH = 7.5
1st, Correct the K+:
pH = 7.5 - 7.4 (normal) = 0.1
0.1 x 0.6 = + 0.6 K
Corrected K+ = 2.6
2nd Estimate K+ deficit for <3.0
3.0 - 2.6 (corrected K+) = 0.4 –> 4x20 = 80 mEq
3rd Estimate K+ deficit for >3.0
4.0 - 3.0 = 1.0 –> 10x10 = 100mEq
Total K+ Deficit = 180 mEq
Foods High in K+
Typically takes days to increase potassium
HIGHEST
Dried FIGS // MOLASSES
Very High = >12.5 mEq / 100gm
Dried Fruits = Dates + Prunes
Nuts / Avocados / Lima Beans
Bran / Cereals / Wheat Germ
High = 6.2 mEq /100gm
- *Veggies** = Spinach / Tomato / brocolli / beet / carrot / potatoes
- *Fruits** = banana / cantaloupe / kiwi / orange / mango
- *Meats =** ground beef / steak / pork / veal / lamb
ORAL Treatment Dose
for HypoKalemia
Most Commonly:
KCL TABLET
DIVIDE DOSE into no more than:
<40 mEq doses
at a time, every:
q3-4 hours
This is to reduce GI ADR
other ADR:
N/V/D
Ab pain/discomfort
GI ulceration / bleeding /Esophageal Irritation
Oral PROPHYLACTIC Dose
for HypoKalemia
10-20 mEq / day
and titrate as needed
ADRs:
N/V/D
Ab pain/discomfort
GI ulceration / bleeding /Esophageal Irritation
Parenteral Potassium Supplement DOSE
for:
Peripheral Access or Non-Cardiac Monitoring
&
MAX
10 mEq/hr
Route has to be at some type of RATE:
IVPB or Continuous Infusion
NEVER IM - IVP - SC
- Too FAST or TOO MUCH –>
- CARDIAC ARRYTHMIAS**
MAX Concentration, must be DILUTED
Max IVPB = 40 mEq/250mL
Max Continuously flowing IV fluids = 40-60 mEq/1000 mL
Parenteral Potassium Supplement DOSE
for HypoKalemia
Central Access w/ Cardiac Monitoring
20 mEq/hr
Route has to be at some type of RATE:
IVPB or Continuous Infusion
NEVER IM - IVP - SC
Too FAST or TOO MUCH –>
CARDIAC ARRYTHMIAS
Max Concentration, must be DILUTED
Cardiac Monitoring = 40 mEq/100 ml
Parenteral Potassium
SALT FORMS
Chloride vs Acetate vs Phosphate
K+ Chloride
MOST COMMON
K+ Acetate
Use where chloride is contraindicated
K+ Phosphate
Use only in patients with concomitant
HypoKalemia & HypoPhosphotemia
MAX CONCENTRATION
for
Central Access Parenteral K+ Supplement
must be DILUTED
- *Central Access w Cardiac Monitoring:**
- *40 mEq / 100 mL**
MAX Concentration
for
PERIPHERAL Access K+ Parenteral Supplementation
must be DILUTED
- *Continuously FLowing IV Fluids**
- *40-60 mEq / 1000mL**
- *IVPB**
- *40 mEq / 250ml**
HYPERkalemia
Level
> 5 mEq/L
Susceptible Population:
Acute + Chronic RENAL DISEASE
HYPERKalemia:
Etiology
Pseudo-HyperKalemia
Hemolysis / K+ EDTA in collecting tubes
Thrombocytosis / leukocytosis / Erythrocytosis
Increase Potassium load
Dietary Source / Protein supplements
Medications = PENICILLIN
Transcellular Shift
Hyperosmolality - GLUCOSE
Smatstatin
Impaired K+ Excretion
MEDICATIONS / HRHA / Adrena insufficiency
Increase Potasium Load
HYPERkalemia Etiology
Dietary Source
Various Veggies / Fruits / Salt substitutes
PENICILLIN
Protein-Calorie Supplements
Stored Blood
Increase K+ 1 mEq/L/day
Anaerobic Excercise
Rhabdomyolysis
Transcellular Shift
HYPERkalemia Etiology
- *HYPERosmolality** (solute drag)
- *Glucose / Mannitol**
- *Somatostatin**
- decrease INSULIN secretion*
SuccinylCholine
EXERCISE
B-Adrenergic blockers
HYPERkalemic Periodic paralysis
Impaired K+ Excretion
MOST COMMON CAUSE
HYPERkalemia Etiology
Medications
Spironolactone // Amiloride // eplerenone / triamterene
Trimethoprim / Tacrolimus / Cyclosporine
NSAIDs
ACE-I / ARB
- *HypoReninemic HypoAldosteronism = HRHA**
- *DM** / sle / obstructive uropathy / sickle nephropathy
Adrenal Insufficiency
Autoimmune adrenal destruction, hemorrhage, metasteses
HYPERkalemia
CARDIAC S/Sx
Decreased / slow ALL:
Depolarizes Cell membrane
Slow Ventricular Conduction
Decreased Duration of APs
ARRHYTHMIAS
TALL PEAKED T-WAVE
Prolonged PR Interval
BI-phasic trace
HYPERkalemia
Neuromuscular S/Sx
Neuromuscular
Muscle TWITCHING
Cramping
Paraesthesias
Generalized WEAKNESS
Flaccid Paralysis
Decreased or absent Deep Tendon Reflexes
HYPERkalemia
TREATMENT ALGORITHM
First:
Treat UNDERLYING CAUSE
Assess for PSEUDO-HYPERkalemia
PSUEDO - caused by burst cells, NOT TRUE HYPERK
Second - Assess for SEVERITY:
Mild = 5.5-6.4
Moderate = 6.5-8.0
SEVERE + SYMPTOMS
>8.0
have Min-Hours to SAVE LIFE
Mild HYPERkalemia
K Level + Treatment
5.5 - 6.4 mEq/L
treat MODERATELY
Kayexalate
= Sodium Polystyrene, Elimination Drug
+/- Redistribution Drugs
Insulin + Glucose
beta 2 agonist // NaHCO3
Moderate HYPERkalemia
K+ Level // Treatment
6.5 - 8.0 mEq/L
treat Moderately
Kayexalate
= Sodium Polystyrene Sulfonate
- *Redistribution Drugs**
- *Insulin + glucose** // beta agonist / NaHCO3
Furosemide
also an Elimination drug
3 Things to Treat for
SEVERE / LIFE THREATENING
HYPERkalemia
>8.0
Cardiac Symptoms –> EKG Changes TALL PEAKED T-WAVE
Neuromuscular –> Cramping / Paralysis / Twitching
- *Membrane Stabilization**
- Reduce the* threshold potential of cardiac myocytes
- -> restore the normal gradient w/ resting membrane potential
Intracellular Shifting
Stimulate Na-K ATPase
–> INCREASES serum pH
Elimination
Cation-Exchange resin
INCREASE delivery of Na + urine flow rate
Membrane Stabilizing
HYPERkalemia TREATMENT
CALCIUM
- *1gm** IVP over 2-3 min
- can repeat in 5-10 min*
Monitor EKG
All this does is:
WORK ON ACTION POTENTIAL + _REVERSE EFFECT_of POTASSIUM
ADR:
Phlebitis / Tissue Necrosis / HYPERcalcemia
(gluconate or chloride)
Intracellular Shift
HYPERKalemia TREATMENT
INSULIN +/- Glucose
glucose is given to combat hypoGlycemia
- *10 units IV** +/- 50mL D5W
- *10-20 min** onset // 4-6 hr duration
Beta 2 Agonist = Albuterol
10‐20 mg in 4mL saline nebulized over 10‐20 min
can lead to LOSS of B2 selectivity ->Tachycardia / Tremor
NaHCO3**
Only used for **Metabolic Acidosis
ELIMINATION
HYPERkalemia TREATMENT
SODIUM POLYSTYRENE SULFONATE
= Kayexalate
Needs to be RECTALLY ELMINIATED to work + LAXATIVE
Furosemide or Thiazide
20-40 mg IV
IV to work FASTER, not good if KIDNEYS DONT WORK –>dialysis
Dialysis
only done if Bad Kidneys
Chance for REBOUND HYPERkalemia
Sodium Polystrene Sulfonate
Kayexalate for HYPERkalemia Elimination Treatment
Needs to be RECTALLY ELIMINATED to work,
typically given w/ laxative
- *15‐30 Gm PO** in 70% sorbitol - PO Onset = 2 hours
- *30‐60 Gm PR - Rectal Onset = 1 hour**
ADRS:
COLONIC NECROSIS (drug sits in the colon –> need LAXATIVE)
HYPERnatremia
Nausea + Constipation
Potassium Disorder
TREATMENT APPROACH
1) Recognize Electrolyte Abnormality = Values
2) Assess S/Sx associated w/ disorder
* *Urgent vs non-ugent** // symptoms or not
3) Treat the Underlying Cause AND:
a) Urgent –> Aggresive normalization electrolyte
b) Non-Urgent: Conservative ^
c) No symptoms = no ACTIVE intervention
4) MONITOR Electrolyte + treatment
A) Urgent = q 2-4hr
B) Non-Urgent = q12-24 hr
c) no symp= q24-72hr +
What Chronic Electrolyte disorder leads to
HypoKalemia?
HypoMagnesemia
- *Magnesium** is a cofcator for the Na+ K+ pump
- *TREAT MAGNESIUM FIRST!**
Which Electrolyte Disorder?
Nausea / vomiting / Tiredness
Minimal muscle weakness / Proximal muscle weakness
(lower > upper limbs)
Constipation
Rhabdomyolysis
Ascending symmetric paralysis with intact sensorium
Cardiac arrhythmias / Hypertension / Stoke
HypoKalemia
As Potassium DECREASES
symptoms become MORE SEVERE
MUSCLE & HEART
SIDE EFFECTS
ECG CHANGES
INVERTED T WAVE
*ALL UP
- *What DRUGS** are known to cause
- *HypoKalemia**?
- *DIURETICS**
- *Loop & Thiazide Diuretics**
Insulin
B2 - Adrenergic Agonist = High Dose ALbuterol
High Dose Penicillin
HyperAldosteronism
HypoMagnesemia
- *You determine a DEFICIT** for
- *which Electrolyte Disorder**?
Also ADJUST ON pH
HypoKalemia = POTASSIUM
First:
Adjust Based on pH
(pH) - 7.4 –> Each 0.1 = +/- 0.6 change in K+
Second:
For K+ >3.0 –> Each ↓0.1 K+ = 10 mEq Deficit
For K+ <3.0 –> Each ↓0.1 K+ = 20 mEq deficit
Goal for HT patients = K+ of 4.0
HYPER vs Hypo K+
SYMPTOMS
HypoKalemia
Cardiac:
HYPERtension / Arrhythmias / INVERTED T-wave
Neuromuscular:
CONSTIPATION / Rhabdo / Paralysis
STROKE
HYPERKalemia
Cardiac:
PEAKED T-WAVE / Arrhythmias
Neuromuscular:
Twitching / Cramping / Weakness
Paraesthesias=Tingling/Prickling/Deep Tendon Reflexes
