Pre-dialysis and post-dialysis levels of serum potassium in patients with hemodialysis

Objective To analyze retrospectively the pre-dialysis and post-dialysis levels of serum potassium and their changes in hemodialysis patients.Methods Data on hemodialysis patients from Hemodialysis Room of Zhangzhou Municipal Hospital Affiliated to Fujian Medical University were analyzed retrospectively The serum potassium levels of hemodialysis patients before and after hemodialysis in 2019 were analyzed with month as unit time.Hyperkalemia was defined as serum potassium ion ≥ 5.5 mmol/L.Serum potassium ≥ 6.5 mmol/L was defined as severe hyperkalemia.Hypokalemia was defined as serum potassium ion ≤ 3.5 mmol/L.Paired t-test was used to compare the serum potassium levels of the same patient before and after dialysis,P<0.05 was regarded as statistically significant difference.Results In 2019,359-383 patients received hemodialysis treatment in our hospital every month.Among all of patients undergoing hemodialysis,63.76%~81.79% patients received tests of serum potassium levels in every month.The mean value of pre-dialysis serum potassium levels was 4.71~5.08 mmol/L.In 2019,the serum potassium measurement value ranged from 2.8 to 8.69 mmol/L.The prevalence of hypokalemia was 0.4%~4.49% (9 months).In 2019,6.79%~13.74% of patients had a level of serum potassium between 3.5 and 4.0 mmol/L.The prevalence of hyperkalemia was 13.74% to 27.8% (11 months).Totally 1.22%~7.5% of patients had a higher level of serum potassium ion (≥ 6.5 mmol/L).After dialysis,the level of serum potassium decreased significantly (P<0.05).Compared to that before dialysis,the level of blood potassium decreased by 27.01%~29.05% after dialysis.The level of post-hemodialysis serum potassium was 2.15~5.56 mmol/L.The prevalence of post-hemodialysis hypokalemia was 40.08%~54.59%.The level of post-hemodialysis serum potassium was<2.5 mmol/L in 8 patients and 2.5~3 mmol/L in 50 patients,retrospectively.Conclusions Monthly,some certain proportion of patients with maintenance hemodialysis still experience the complication of hypokalemia.Concern about serum potassium levels of those patients,and individualized selection of dialysate potassium concentration for different patients may be helpful.