Abstract:

Severe hypokalemia is defined as the concentration of serum potassium lower than 2.5 mmol/L, which may lead to serious arrhythmias and cause mortality. We report an unusual case of potentially fatal ventricular arrhythmias induced by severe hypokalemia in a patient undergoing laparoscopic partial nephrectomy in Peking University Third Hospital due to irregular use of indapamide before operation. Indapamide is a sulfonamide diuretic with vasodilative and calcium antagonistic effects, which enhances sodium delivery to the renal distal tubules resulting in a dose-related increase in urinary potassium excretion and decreases serum potassium concentrations. The electrolyte disorder caused by the diuretic is more likely to occur in the elderly patients, especially those with malnutrition or long-term fasting. Hence, the serum potassium concentration of the patients under indapamide therapy, especially elderly patients, should be monitored carefully. Meanwhile, the potassium concentration measured by arterial blood gas analysis is different from that measured by venous blood or laboratory test. According to the previous research, the concentration of potassium in venous blood was slightly higher than that in arterial blood, and the difference value was 0.1-0.5 mmol/L. This error should be taken into account when rapid intravenous potassium supplementation or reduction of blood potassium level was carried out clinically. In the correction of severe hypokalemia, the standard approach often did not work well for treating severe hypokalemia. The tailored rapid potassium supplementation strategy shortened the time of hypokalemia and was a safe and better treatment option to remedy life-threatening arrhythmias caused by severe hypokalemia with a high success rate. Through the anesthesia management of this case, we conclude that for the elderly patients who take indapamide or other potassium excretion diuretics, the electrolyte concentration and the general volume state of the patients should be comprehensively measured and fully evaluated before operation. It may be necessary for us to reexamine the serum electrolyte concentration before anesthesia induction on the morning of surgery in patients with the history of hypokalemia. For severe hypokalemia detected after anesthesia, central venous cannulation access for individualized rapid potassium supplementation is an effective approach to reverse the life-threatening arrhythmias caused by severe hypokalemia and ensure the safety of the patients.

Key words: Hypokalemia, Indapamide, Arrhythmia, Anesthesia