Principles of perioperative management:
(1) Identify patient prior to surgery if possible.
(2) Consider serum TSH in preoperative screening to detect thyrotoxic hypokalemic periodic paralysis, especially in patients of Asian descent.
(3) Avoid conditions that may trigger muscle weakness and paralysis (see below).
(4) Monitor serum potassium before, during and after surgery.
(5) Promptly treat hypokalemia.
(6) Monitor for signs of respiratory distress.
(7) Consider prophylactic therapy to reduce the risk of hypokalemia. This may include acetazolamide (induces a metabolic acidosis) or spironolactone (potassium-sparing).
(8) Use of premedication to reduce anxiety and stress.
(9) Aggressive pain management.
(10) Careful and selective use of non-depolarizing neuromuscular blocking agents with monitoring of neuromuscular function. Avoid depolarizing muscle relaxants. Use a short-acting muscle relaxant.
(11) Selection of anesthetic agent and method that minimizes risk of an attack. Total intravenous has been used successfully in high risk patients.
(12) Maintenance of body temperature, using a blood and infusion warmer. Avoid hypothermia if possible. Monitor the patient more closely if hypothermia required and minimize duration.
(13) Monitor the ECG for signs of cardiac arrhythmia.
(14) Take steps to minimize the risk of surgical site and postoperative infection.
(15) Avoid drugs that may induce hypokalemia such as potassium-wasting diuretics. Be careful in the use of insulin.
(16) Avoid alkalosis.
(17) Minimize any carbohydrate load, especially intravenous glucose solutions.
(18) Minimize sodium load in selection of intravenous solutions.
Factors that may cause hypokalemia and trigger muscle weakness:
(1) emotional stress or anxiety
(2) physical stress or exertion
(3) exposure to cold
(4) high carbohydrate load, including intravenous glucose solutions
(5) high sodium load
(6) infection
(7) metabolic alkalosis
(8) any drug associated with hypokalemia (administration of insulin, potassium-wasting diuretic, etc)
