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Flashcards in Disorders of Salt and Water Deck (22)
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What is hypernatremia by definition?

The water content of the body fluid is deficient in relation to the sodium content (serum sodium >145). There is either way to much salt or not enough water.


What causes hypernatremia?

Inadequate fluid intake or excess fluid loss


What are the clinical features of hypernatremia?

Neurological manifestations include thirst, restlessness, irritability, disorientation, lethargy, delirium, convulsions, and coma. Brain cells shrink!

Other findings include dry mouth and dry mucous membranes, flushed skin, tachycardia, hypotension, fever hyperreflexia and oliguria and anuria.


Diabetes insipidus is usually indicated diagnostically by....

Low urine sodium and polyuria


How is hypernatremia treated?

Hypernatremia should be treated on an inpatient basis. Free water may be administered orally or IV/SQ. Hypovolemia should be treated first and then hypernatremia second.


What is a caution when treating hypernatremia?

Rapid correction of hypernatremia can cause pulmonary or cerebral edema, especially in patients with DM.


What is hyponatremia?

Plasma sodium concentration of less than 135. Signs and symptoms may not occur until the concentration falls below 125.


What are the clinical features of hyponatremia?

Symptoms include lethargy, disorientation, muscle cramps anorexia, hiccups, n/v, and seizures.

Signs include weakness agitation, hyporeflexia, orthostatic hypertension, and cheyne-stokes respirations.


How is hyponatremia treated?

treat hypovolemia on an impatient basis, especially if symptomatic or if serum sodium is less than 125. Treatment usually requires fluid restriction.


What is a caution while treating hyponatremia?

Overly rapid correction can cause central pontine myelinolysis, resulting in neurologic damage.


What is diabetes insipidus?

DI is a disorder of water, the neurogenic form is caused by deficient secretion of arginine vasopressin (ADH) from th eposterior pituitary. The nephrogenic form is caused by kidneys that are unresponsive to normal vasopressin levels.


What are the clinical features of DI?

polyuria, nocturia and polydipsia are the main symptoms


What is the treatment for DI?

Neurogenic or central DI is best treated with parenteral or intranasal desmopressin. Diuretics, chlorpropamide, or carbamazepine can be used in patients with mild disease.


What are the characteristics of volume depletion?

Volume depletion occurs when body fluids are lost from the extracellular component at a rate that exceeds intake.


What are the clinical features of volume depletion?

volume depleted patients become thirsty, and urinary output decreases. Mild volume depletion can cause increased heart rate, fatigue, and muscle cramps. Severe hypovolemia results in general hypotension , signs of ischemia and shock.


How do you treat hypovolemia?

Mild hypovolemia can be treated by increasing salt and water intake


What is hyperkalemia?

hyperkalemia refers to an elevated serum potassium level higher than 5.0. It is most commonly associated with renal failure.


What are the clinical features of hyperkalemia?

Severe hyperkalemia can result in dysrythmias and cardiac arrest.

Neurologic symptoms include numbness, tingling, weakness and flaccid paralysis

ECG shows peaked T waves


How do we treat hyperkalemia?

In severe hyperkalemia, calcium gluconate should be given IV to antagonize the effects of hyperkalemia on the heart. Sodium Bicarbonate, glucose and isulin may be administered to drive K back into the cells.

Kayexalate is used to remove potassium from the body when levels are extremely high.


What is hypokalemia?

Defined as a decrease in serum potassium level (<3.5). It can result from a shift of potassium into the intracellular compartment or from potassium losses of extrarenal or renal origin. It most commonly occurs with use of diuretics, renal tubular acidosis, or GI loses.


What are the clinical features of hypokalemia?

Ventricular arrythmias, hypotension and cardiac arrest. Neuromuscular manifestations include mailase, skeletal muscle weakness, cramps and smooth muscle involvement, leading to ileus and constipation.

Other manifestations include polyuria, nocturia and rhabdo

ECG shows flattened or inverted T waves, and an increased prominence of U waves.


How is hypokalemia treated?

It is not an emergency unless cardia manifestations are present. In nonemergent conditions oral potassium therapy is preferred (potassium chloride)