Thyrotoxic periodic paralysis after urethral dilatation.

Thyrotoxic periodic paralysis (TPP) is a rare and serious manifestation of thyrotoxicosis that causes flaccid paralysis. In severe cases, it can be life-threatening due to respiratory failure and cardiac arrhythmias. TPP is due to increased sodium/potassium ATPase activity during thyrotoxic states, which is due to mutations encoding potassium channels. It is precipitated by situations that cause a surge in catecholamines, insulin, or both. It can be treated with potassium supplementation and nonselective beta blockers, and it can be prevented by establishing euthyroid state. With the increasing numbers of outpatient procedures performed nowadays and the stress related to these procedures, patients with TPP may develop paralysis after these procedures, so clinicians should be aware of this condition and the importance of identifying it in patients presenting with flaccid paralysis.