Avoid hypothermia – In all cases. Interventions to maintain normothermia should be considered even in patients undergoing cardiac bypass.

Avoid triggers – High carbohydrate loads, stress, hypothermia, Beta agonist drugs (eg. albuterol), and potassium-wasting diuretics can cause potassium shifts.

Neuromuscular Blockade – Nondepolarizing muscle relaxants are safe. Succinylcholine is recommended for short procedures where not contraindicated.

Rule out secondary hypokalemia – If the patient is suspected of having an episode, draw an ABG and CMP. Metabolic acidosis or alkalosis would be more indicative of a secondary hypokalemia than hypokalemic periodic paralysis.

Treatment – Acetazolamide is the treatment of choice. Aggressive treatment of potassium chloride may be administered up to 40 mEq/h. Take caution if you’re considering administration of potassium as hyperkalemia may result after the episode resolves.

Avoid hypophosphatemia & hypomagnesemia – hypophosphatemia combined with hypokalemia can cause acute paralysis. Hypomagnesemia can further increase renal potassium excretion.

This is neuromuscular disorder caused by a defect in skeletal voltage-gated calcium ion channels. In most cases it is hereditary (autosomal dominant inheritance). In other cases, it can be an acquired disorder in patients that have thyrotoxicosis.

Hypokalemic periodic paralysis is hypokalemia while total body stores of potassium remain normal. Potassium has shifted from the extracellular to the cellular compartments.

Rare – 1:100,000. 3-4 times more common in males. Onset of symptoms is usually in the adolescent and teenage years.

Symptoms – This condition is characterized by acute, transient, and generalized muscle weakness, which can be precipitated by a high carbohydrate meal, exercise, and/or fasting. In this case, the muscle weakness is also associated with a low potassium level and will demonstrate EKG findings typical of hypokalemia (ST depression, decrease in T wave amplitude, and increase in U wave amplitude). Patients over the age of 50 will also experience myopathy as the episode subsides.

Symptom duration – once the symptoms have begun, it can last minutes to days. Time between episodes is typically weeks to months.

Potassium levels – serum blood potassium levels during an attack are an average of 2.4 mEq/L

Diagnosis – If the patient is demonstrating symptoms and there’s a family history of this disorder, there is typically sufficient evidence to make the diagnosis. However, muscle biopsies can be performed even prior to the onset of symptoms to make the diagnosis. Potassium levels and muscle strength will typically normalize between episodes of periodic paralysis. Furthermore, if weakness is provoked by a glucose-insulin infusion, this would confirm hypokalemic periodic paralysis.