Metabolic alkalosis is related to delayed response to treatment of hypokalemia in non-surgical critically ill patients.

: Potassium (K+) homeostasis is closely related to acid - base disorders. The aim of this study is to analyze the possible causes of hypokalemia non-surgical critically ill patients including acid - base disorders and its relationship with response to K+ supplementation. : We performed a retrospective cohort study of 122 consecutive non-surgical patients admitted to the Intensive Care Unit during July 2016 Patients were classified according to the presence of hypokalemia or not. Demographic data, morbidities associated with hypokalemia, with emphasis in acid-base disorders and response to treatment were described and analyzed. : Hypokalemia was observed in 32,7% (n = 40) of the patients included. Hypokalemic group had a higher value of base excess (median of -0.65 [IQR -3.3-5.2] Vs -3.2 [IQR -5.1--1.4]; p < 0.001). The patients with hypokalemia that achieved normal serum K+ in more than 25 h had a higher value of excess base than those who did so in less than 24 h (median of 4.3 [IQR -2.1-5.5] vs -1.9 [IQR -4.8-3]; p < 0.05). Neither the degree of hypokalemia, the time to development, route of administration or solution concentration, speed of infusion, the amount of K+ administered per day per kg of weight were related with the response of treatment. : Hypokalemia is a common disorder in non-surgical critically ill patients. Hypokalemic patients had a higher incidence of metabolic alkalosis. Patients with hypokalemia and metabolic alkalosis needed a higher amount of potassium administration and higher time to achieve correction.