First 24-Hour Potassium Concentration and Variability and Association with Mortality in Patients Requiring Continuous Renal Replacement Therapy in Intensive Care Units: A Hospital-Based Retrospective Cohort Study

Abstract

Serum potassium (K+) levels between 3.5 and 5.0 mmol/L are considered safe for patients. The optimal serum K+ level for critically ill patients with acute kidney injury undergoing continuous renal replacement therapy (CRRT) remains unclear. This retrospective study investigated the association between ICU mortality and K+ levels and their variability. Patients aged >20 years with a minimum of two serum K+ levels recorded during CRRT who were admitted to the ICU in a tertiary hospital in central Taiwan between January 01, 2010, and April 30, 2021 were eligible for inclusion. Patients were categorized into different groups based on their mean K+ levels: <3.0, 3.0 to <3.5, 3.5 to <4.0, 4.0 to <4.5, 4.5 to <5.0, and ≥5.0 mmol/L; K+ variability was divided by the quartiles of the average real variation. We analyzed the association between the particular groups and in-hospital mortality by using Cox proportional hazard models. We studied 1991 CRRT patients with 9891 serum K+ values recorded within 24 h after the initiation of CRRT. A J-shaped association was observed between serum K+ levels and mortality, and the lowest mortality was observed in the patients with mean K+ levels between 3.0 and 4.0 mmol/L. The risk of in-hospital death was significantly increased in those with the highest variability (HR and 95% CI = 1.61 [1.13–2.29] for 72 h mortality; 1.39 [1.06–1.82] for 28-day mortality; 1.43 [1.11–1.83] for 90-day mortality, and 1.31 [1.03–1.65] for in-hospital mortality, respectively). Patients receiving CRRT may benefit from a lower serum K+ level and its tighter control. During CRRT, progressively increased mortality was noted in the patients with increasing K+ variability. Thus, the careful and timely correction of dyskalemia among these patients is crucial.

Explainable Machine Learning-Based Risk Prediction Model for In-Hospital Mortality after Continuous Renal Replacement Therapy Initiation

“…Furthermore, the results revealed that a higher APACHE II score, potassium levels, lactate levels, sodium levels, and respiratory rate; multiple organ support use and medication use; and older age as well as lower SPO2, MAP, platelet count, BMI, and O2 saturation were positively correlated with in-hospital death. The findings regarding the importance of variables are consistent with those of a previous study [ 7 , 11 , 12 , 32 , 33 , 34 ]. In this study, an inverse relationship was noted between diabetes mellitus and in-hospital mortality.…”

Impact of the prognostic nutritional index on renal replacement therapy–free survival and mortality in patients on continuous renal replacement therapy

“…Therefore, PNI, which measures albumin and lymphocytes, is a simple and effective method that can be used to assess nutritional status and predict outcomes in clinical settings.The study population was divided into two distinct groups based on the established median values of the PNI: low PNI (< 27.28) and high PNI (≥ 27.28).The demographic and clinical information of patients, including age, sex, BMI, Acute Physiology and Chronic Health Evaluation (APACHE) II score at ICU admission, diagnostic criteria for AKI, the timing of CRRT initiation, vital signs within 24 h of CRRT initiation, urine output, pre-CRRT medication, serum biochemical data, presence of comorbidities, and use of PN, was collected from the CCHRD. These clinical confounders have been discussed in previous articles [9,23].…”

“…The demographic and clinical information of patients, including age, sex, BMI, Acute Physiology and Chronic Health Evaluation (APACHE) II score at ICU admission, diagnostic criteria for AKI, the timing of CRRT initiation, vital signs within 24 h of CRRT initiation, urine output, pre-CRRT medication, serum biochemical data, presence of comorbidities, and use of PN, was collected from the CCHRD. These clinical confounders have been discussed in previous articles [9,23].…”