The Incidence And Risk Factors of Serum Hypokalemia After Primary Total Joint Arthroplasty

Background: Regular monitoring of serum potassium after total joint arthroplasty (TJA) is a routine examination, which can detect abnormal serum potassium and reduce adverse events timely caused by postoperative hypokalemia. In this study, we aimed to investigate the incidence and risk factors of hypokalemia after primary total hip and knee replacement.Methods: This study included patients who underwent unilateral total knee or hip arthroplasty in our department from April 2017 to March 2018. The serum potassium level before and after operation was collected and retrospectively analyzed. The differences in age, BMI and other factors between hypokalemia patients and non-hypokalemia patients at different time points after surgery were compared, and then the risk factors of postoperative hypokalemia were analyzed based on multiple logistic regression.Results: The total incidence of postoperative hypokalemia was 53.1%, while the respective rate on the first, third and fifth postoperative day was 12.5%, 40.7% and 9.6%. The serum potassium level on the first, third and fifth postoperative day was 3.84±0.32mmol/l, 3.59±0.34mmol/l and 3.80±0.32mmol/l, while among which, the level on the third day was the lowest (p=0.015). The independent risk factors for hypokalemia after total hip and knee replacement were the level of preoperative serum potassium (p=0.011), preoperative red blood cells (p=0.027), and a history of diabetes (p=0.007).Conclusion: Regular monitoring of serum potassium should be performed after TJA due to hypokalemia was a very common complication. We need to pay more attention to patients’ preoperative potassium and red blood cells, especially patients with diabetes.