Hypo/hypercalcemia, hypo/hyperkalemia, hypo/hypernatremia, hypo/hypermagnesemia

Hypocalcemia

[Ca < 8.5 or ionized Ca level < 4.6mg/dL (1.2mmol/L)]

Hypocalcemia causes

1. Nutritional deficiencies

2. Lack of dairy or green leafy vegetables -Lack of Vitamin D needed for Ca absorption

3. Renal failure - decreased production of activated vitamin D & hyperphosphatemia

4. Hypoparathyroidism

5. Alkalosis decreased ionized Ca by binding more calcium to proteins, less

   Ca available for stabilization of the neuromuscular membrane

Hypocalcemia Manifestations

1. increased excitability & repetitive responses to 1 stimulus

   1. Neuro – paresthesia, muscle spasms, tetany, hyperactive reflexes

   2. CV – hypotension, HF, long QT, cardiac arrhythmias

   3. Skeletal - Fractures (chronic)

Hypocalcemia Assessment

1. Tapping on facial nerve, spazzing of lip/nose/face

2. Bp cuff above 10 mm - retraction of hand/fingers

Hypercalcemia

[Ca > 10.5]

Hypercalcemia Causes

1. Malignancy

   1. cancer destroys bone thereby releasing calcium into body

   2. tumors produce PTH which increase Ca levels

2. Hyperparathyroidism

3. Other causes – prolonged immobilization, excessive doses of vitamin D, and meds such as lithium & thiazide diuretics

Hypercalcemia Manifestations

decreased neuronal excitability & muscle function

1. Neuro – lethargic, behavioral changes, coma

2. CV – HTN, increased contractility, arrhythmias

3. GI – N/V, constipation

4. GU – high output, renal calculi

Hypokalemia

[K < 3.5 mEq/L] a lower than normal potassium level in your bloodstream

Hypokalemia causes

inadequate intake via diet – less than 40mEq/ day.

1. Fad diets, eating disorders & elderly who have difficulty chewing foods that are high in K (Foods high in potassium – broccoli, green beans, bananas)

ii. excessive loss

1. diuretic therapy, metabolic acidosis, excessive GI loss from

   vomiting & diarrhea.

2. Primary aldosteronism caused by tumor of adrenal cortex will

   abnormally excrete aldosterone into circulation.

3. Transcelluar shifts such as Treatment of DKA which will talk about

   later. (insulin pulls K back into cells)

Hypokalemia manifestations

1. Neuro – weakness (mild), fatigue, paresthesia (mild)

2. CV - * ECG changes, peaked T waves (mild) lethal arrhythmias cardiac arrest

3. GI – Diarrhea, cramps (mild) Muscle weakness (severe)

4. GU - polyurea (kidneys are going to attempt to reabsorb K, so

   sodium will be exchanged for K and water will follow → dilute

   urine)

Hyperkalemia

a potassium level in your blood that's higher than normal

Hyperkalemia causes

1. Decreased renal elimination

1. GFR is less than 10ml/minute (90-120ml/minute)

2. Chronic Renal Failure

3. Acute Renal Failure with lactic acidosis or ketoacidosis

4. Aldosterone – mediated potassium elimination

a. Aldosterone is depressed causing sodium to be excreted + K retained.

b. Adrenal insufficiency & decreased renin release

2. Movement of K from ICF to ECF

   1. Acidosis - K moves out of cell into the ECF for unknown reasons

   2. tissue injury (burns & crushing trauma) release intracellular K into

      ECF from cell death

3. Excessive rapid rate of administration

Hyperkalemia manifestations

1. Neuro – weakness (mild), fatigue, paresthesia (mild), tingling of

   fingers

2. CV - * ECG changes, peaked +narrow T waves (mild) lethal

   arrhythmias cardiac arrest, shortened QT interval

1. Severe - prolonged PR interval, widened QRS which will

delay repolarization of cells → Vbif → cardiac arrest

3. R – dyspnea (muscle weakness)

4. GI – Diarrhea, cramps (mild) Muscle weakness (severe), lost of muscle tone (severe)

c. Mild > 5.0 mEq/L ; severe > 6.0 mEq/L

Hyponatremia [sodium < 135 mEq/L]

[sodium < 135 mEq/L]

Hyponatremia Types

Hypotonic- dilution

Hypertonic-osmotic shift form ICF to ECF

Hyponatremia - Hypotonic

1. Excessive sweating, GI losses, SIADH, heart failure

2. Water is used as a replacement for electrolyte containing fluid

Hyponatremia- hypertonic

1. Hyperglycemia

2. Sodium in ECF becomes diluted as water moves out of body cells

in response to osmotic effects of elevated blood glucose levels

Hyponatremia manifestations

body is going to attempt to compensate by pulling water into the cell, so some of

2. the symptoms have to a lot to do with muscle bc sodium laters the ability of the cells to depolarize and repolarize normally

   1. Depend on severity and onset

   2. Muscle cramps

   3. Motor weakness

   4. Fatigue

   5. Headaches

   6. Confusion

   7. Seizures (<120 sodium)

1. Cerebral edema from influx of fluids into the cells

Hypernatremia

[sodium > 145 mEq/L & Serum Osmolality >295]

Hypertonicity of ECF & intracellular dehydration
i. Intracellular water pulled into ECF component → cells shrink

Hypernatremia causes

Disproportionate loss of body H2O in relation to Na

1. At risk individuals - ventilator, elderly, babies (patients who have the inability to obtain a drink of water)

ii. sodium gain

Hypernatremia manifestations

1. Thirst - early symptom

2. Low urine output + increased urine osmolality

3. Weak, thready, elevated pulse

4. Low bp

5. Dry mucous membranes

6. Dry and rough tongue

7. Difficulty swallowing

8. Irritability

9. Restlessness

10. Headache

11. Muscle spasms

12. Seizures

Hypomagnesemia

[Serum Magnesium < 1.3 mg/dL + S&S occur when < 1.0 mg/dL]

-similar to hypocalcemia

Hypomagnesemia causes

1. Decreased intake or malnutrition

2. Loss – diarrhea, decreased absorption, NG output, diuretics

Hypomagnesemia Increased neuromuscular excitability:

1. Personality changes

2. Muscular weakness & tremors

3. Hyperactive reflexes

4. Seizures – increased irritability of nervous tissue

Hypomagnesemia cardiovascular effects

1. Tachycardia

2. Hypertension

3. Ventricular arrhythmias

   Leads to a reduction in intracellular potassium and interferes the kidney’s ability to concentrate potassium

Hypermagnesemia

[Serum Magnesium > 2.1 mg/dL + S&S occur when > 4.0 mg/dL]

Hypermagnesemia causes

Renal insufficiency or failure
1. Can’t be excreted from body

ii. Injudicious use of magnesium containing drugs

Use antacids

Hypermagnesemia causes

Renal insufficiency or failure
1. Can’t be excreted from body

ii. Injudicious use of magnesium containing drugs

Use antacids

Hypermagnesemia neural and muscle effects

1. Lethargy

2. Hyporeflexia & muscle weakness – from decreased acetylcholine release

   at myoneural junction

1. Myoneural junction – junction between a nerve fiber and muscle it

supplies
iii. Confusion, may lead to coma

Hypermagnesemia cardiovascular effects

1. Hypotension

2. Cardiac arrhythmias

3. Cardiac arrest

4. When hypomagnesemia occurs, it leads to reduction in intracellular K and impairs the ability of the kidneys to conserve K, leading to hypokalemia

5. When hypomagnesemia is present, hypokalemia is unresponsive to potassium replacement therapy.