Paradoxical hypokalemia refers to a paradoxical drop in serum potassium level when potassium is given for severe hypokalemia. It was reported initially in a patient with thyrotoxic periodic paralysis.1 In this issue, Sung et al2 report paradoxical hypokalemia in patients with hypokalemic paralysis due to renal or gastrointestinal loss of potassium, or so called hypokalemic “nonperiodic” paralysis, a term used to distinguish it from hypokalemic periodic paralysis caused by an acute intracellular shift of potassium. Although hypokalemic nonperiodic paralysis has been well recognized, this is the first prospective study that provides the etiologies and responses to treatment of 58 cases, collected over 7 years at a tertiary medical center in Taiwan.2 The response to potassium replacement in hypokalemic nonperiodic paralysis and thyrotoxic periodic paralysis are markedly different (Table) due to different mechanisms of hypokalemia. The data on thyrotoxic periodic paralysis are taken from a similar prospective study by the same group of investigators.3 The presenting serum potassium levels and the potassium levels at time of recovery from paralysis are slightly lower in patients with nonperiodic paralysis, but these patients required fourfold greater potassium supplement and twice as much time to recover from paralysis.
Lien, Y. H. H. (2015, March 1). Paradoxical hypokalemia: Where has all the potassium gone? American Journal of Medicine, 128(3), 217–218. https://doi.org/10.1016/j.amjmed.2014.10.037