202. Hyperkalemic Periodic Paralysis

Question 1

What is Hyperkalemic periodic paralysis (HyperPP)?

Answer 1

A hereditary neuromuscular disorder characterized by episodes of skeletal muscle weakness associated with elevated potassium levels

First described in 1951, HyperPP is classified as a skeletal muscle channelopathy.

Question 2

How common is HyperPP?

Answer 2

Approximately 1:200,000

It is less common than hypokalemic periodic paralysis (HypoPP).

Question 3

What is the inheritance pattern of HyperPP?

Answer 3

Autosomal dominant

Caused by mutations in the NaV1.4 voltage-gated sodium channel.

Question 4

What are the key anesthetic considerations for HyperPP?

Answer 4

Preventing hyperkalemia and hypoglycemia

Question 5

What is the gold standard for diagnosing HyperPP?

Answer 5

Genetic testing for known mutations

Question 6

What happens to sodium channels in patients with HyperPP?

Answer 6

They open normally but fail to appropriately inactivate, causing sodium to leak into the muscle cell

Question 7

What is the role of potassium in muscle cell function?

Answer 7

Important in repolarizing the cell and terminating the action potential via potassium efflux

Question 8

What triggers attacks of HyperPP?

Answer 8

Potassium levels rising above 5.0–5.5 mEq/L

Question 9

Describe the typical duration of HyperPP attacks.

Answer 9

Usually ranges from minutes to an hour, but can last as long as a month

Question 10

What is myotonia?

Answer 10

Delayed muscle relaxation after contraction

Question 11

Which muscle groups are typically spared during HyperPP attacks?

Answer 11

Respiratory muscles, especially the diaphragm

Question 12

True or False: The central nervous system and consciousness are affected during HyperPP attacks.

Answer 12

False

Question 13

What are common triggers for HyperPP attacks?

Answer 13

• Exercise, especially strenuous
• Hypothermia
• Fasting
• Metabolic acidosis
• Meals high in potassium
• Potassium-rich intravenous fluids
• Stress
• Potassium-raising medications

Question 14

What dietary measures can help prevent HyperPP attacks?

Answer 14

Low potassium, high carbohydrate, high salt

Question 15

What medications can be used prophylactically for HyperPP?

Answer 15

• Carbonic anhydrase inhibitors (e.g., acetazolamide, dichlorphenamide)
• Thiazide diuretics

Question 16

What is the first-line treatment for acute HyperPP attacks?

Answer 16

Mild activity or glucose-rich food or drink

Question 17

What should be monitored during the intraoperative period for HyperPP patients?

Answer 17

Potassium and glucose levels

Question 18

What is a common ECG finding during HyperPP attacks?

Answer 18

Peaked T waves

Question 19

What is the recommended fasting policy for HyperPP patients preoperatively?

Answer 19

Liberal fasting policy, allowing clear carbohydrate drinks up to 2 hours before surgery

Question 20

What type of intravenous fluids should be considered during surgery for HyperPP patients?

Answer 20

Dextrose-containing, potassium-free intravenous fluids

Question 21

What should be avoided in sensitive HyperPP patients during anesthesia?

Answer 21

Potassium-raising medications, such as succinylcholine

Question 22

What should be done for high-risk HyperPP patients in the postoperative period?

Answer 22

Continue monitoring potassium levels and glycemic levels

Question 23

Fill in the blank: The prolonged sodium channel current in HyperPP leads to ______.

Answer 23

[myotonia and paralysis]