Incidence rate of hypokalemic and its associated factors for patients undergoing noncardiac surgery: a retrospective analysis

Background: Hypokalemia is common in hospitalized patients. In fact, untreated hypokalemia is associated with the incidence and mortality of adverse cardiac events. Timely recognition and treatment of these diseases are essential. Indeed, a little research has been conducted on the level of K+ in perioperative patients. In this study, by comparing the changes of K+ from when patients were admitted to hospital and to after they had entered the operating room, we analyzed the related factors of K+ disorder after operating-room entry and identified factors related to the occurrence of perioperative K+ disorder. Methods: This single-center retrospective study included non-cardiac surgery patients who underwent admission blood gas analysis and blood gas analysis upon entering the operating room in the China-Japan Union Hospital of Jilin University between June 2019 and September 2020. Results: Among the 258 patients who underwent non-cardiac surgery with anesthesia, 19 cases (7.4%) were hypokalemic on admission, and 102 cases (39.5%) were hypokalemic after admission to the operating room. The K+ levels after operating-room entry were positively correlated with the K+ concentration at admission (r=0.363; P<0.05). Female sex [odds ratio (OR) =0.451; 95% CI: 0.263–0.775; P=0.004], hypertension (OR =0.499; 95% CI: 0.281–0.885; P=0.017), and preoperative bowel preparation (OR =0.471; 95% CI: 0.258–0.860; P=0.014) were risk factors for hypokalemia for patients after operating-room entry. Conclusions: Hypokalemia was found to be common in patients after operating-room entry. Even patients with normal K+ at admission could have hypokalemia due to undergoing an operation, with female sex, hypertension, and bowel preparation being the risk factors for this condition.