Association between potassium concentrations, variability and supplementation, and in-hospital mortality in ICU patients: a retrospective analysis

Understanding adherence and deviations in potassium replacement protocols: A mixed method study

BACKGROUND

Potassium replacement protocols are commonly used in ICUs to standardise replacement and minimise harm. Yet, there is variability in potassium replacement practices.

AIMS

(i) To examine relationships between potassium levels, potassium administration, and the potassium replacement protocol; and (ii) to explore factors influencing potassium replacement decision-making.

METHODS

An exploratory mixed methods approach using retrospective audit and interviews was undertaken. Clinical data from two ICUs were extracted about potassium results, potassium administration and other related data from the first 72 h of ICU admission, for all patients admitted between January 2015 and December 2022. Critical care nurses were interviewed between January and March 2024, with interviews professionally transcribed and analysed using inductive content analysis.

RESULTS

From the sample of N = 10,613 patients, n = 132,507 potassium results were analysed. Potassium replacement was indicated for 39.7 % (n = 52,592) of potassium results. When replacement was indicated, potassium was administered within 2 h in 59.9 % (n = 31,508) of cases. Interviews with critical care nurses (n = 21) lasted 5-28 min (mean 12 min). Interview participants indicated that potassium replacement decisions were influenced by the patient's history and current condition, and colleague consultation. There was little concern over potential risks associated with potassium replacement. Greater clarity around the purpose and compulsoriness of potassium replacement protocols was desired.

CONCLUSION

These findings offer valuable insights into the intricacies of protocolised potassium replacement adherence and deviations across two ICU settings. Autonomy and interprofessional collaboration emerged as a key factor, with nurses exercising decision-making ability underpinned by patient specific considerations, assessment, and clinical judgement.

IMPLICATIONS FOR CLINICAL PRACTICE

When protocols are used to guide potassium replacement and other electrolytes, clear guidance as to the compulsoriness of the protocol is needed. Alternately, with safety a priority, when and how clinicians may use their clinical judgement and discretion in potassium replacement must also be explicit.

Electrolyte disorders in the critically ill: a retrospective analysis

Several electrolyte disorders have been associated with adverse outcomes, but data on the coincidence of multiple disorders, interactions between different electrolytes and the impact of substitution on electrolyte levels are scarce. This study aimed to describe electrolyte disorders' prevalence, incidence, and interaction in a consecutive cohort of ICU patients. Single-center retrospective study, including 2,056 consecutive adult ICU patients. Patients without laboratory data, those declining participation, and those receiving renal replacement therapy were excluded. Electrolyte levels and intravenous electrolyte administration were analyzed during the first 96 h after ICU admission using descriptive statistics, regression models and AUC-ROC analysis. Of 2392 admitted patients, 2056 were included. On admission, 312 patients (15.2%) had no electrolytes measured, 316 (15.4%) did not have any electrolyte disorder, 643 (31.3%) had one disorder, and 785 (38.2%) had multiple disorders. The most common electrolyte disorders on admission were hyperchloremia (56.0%, 977/1,744), hyperkalemia (18.7%, 326/1,744), hypophosphatemia (16.8%, 293/1,744), and hyperphosphatemia (16.4%, 286/1,744). Most patients (77.4%, 1,592/2,056) developed at least one new disorder during their ICU stay. A considerable number of patients (19.7%, 344/1,744) experienced electrolyte disorders in both directions ('hypo' and 'hyper') during their ICU stay. Linear regression models revealed that changes in one electrolyte level are often associated with alterations in other electrolyte levels. Most patients (99.2% 2,039/2,056) received intravenous electrolytes. Electrolyte overcorrection occurred in 89/365 patients (24.4%) for hypokalemia and 50/575 patients (8.7%) for hypophosphatemia. AUC-ROC analysis revealed cut-off points with the highest sensitivity and specificity at 30 mmol of potassium within 6 h and 45 mmol of phosphate within 15 h. Electrolyte disorders are highly prevalent in ICU patients, with significant co-incidence and interplay between these disorders. Knowledge regarding overcorrection risks may inform safe electrolyte administration protocols.

Associations between serum potassium variability and mortality in patients undergoing maintenance hemodialysis: a retrospective study

Dyskalemia are associated with an increased risk of mortality in patients undergoing maintenance hemodialysis (MHD). However, studies evaluating the impact of serum potassium variability on mortality in MHD patients are scarce. To investigate serum potassium variability and its association with prognosis in MHD patients, we conducted a retrospective study on maintenance hemodialysis patients from three campus of Renji Hospital between June 2018 and December 2022. The exposure of interest was serum potassium variability defined as the coefficient of variation of serum potassium levels (CVSP). Cox regression models and Kaplan-Meier survival analysis were used to assess the prognostic significance of serum potassium variability. In a subgroup analysis, the association between serum potassium variability and prognosis was investigated in patients within normal serum potassium concentration range. Total of 588 maintenance hemodialysis patients were included. During a median follow-up of 45 months (24, 54), 121 patients (20.6%) died. The survival analysis suggested significantly higher survival rates for both all-cause (p < 0.01) and cardiovascular (p < 0.01) death in patients in the highest group of CVSP (H-CVSP) compared with those in the the lowest group (L-CVSP). After adjustment, the all-cause mortality hazard ratio compared to L-CVSP was 2.17 [95% confidence interval (CI) 1.18, 3.97] for H-CVSP (p < 0.05) and was 2.53 [95%CI 1.03, 6.22] for cardiovascular mortality (p < 0.05). In the subgroup analysis, 493 patients (83.8%) presented normokalemia (the mean of serum potassium levels ≥ 3.5mmol/L and ≤ 5.0mmol/L) were included. Similar association was found between serum potassium variability and accumulated survival rates, and higher serum potassium variablity was remained an independent risk factor for cardiovascular mortality (2.69, 95% CI 1.07-6.78, p < 0.05) in patients within normal serum potassium concentration range. In conclusion, a higher serum potassium variability was associated with all-cause and cardiovascular mortality in maintenance haemodialysis patients, even in the normal range.

Inflammatory, Hematological, and Biochemical Biomarkers in COVID-19 Patients

INTRODUCTION

There are few accurate prognostic indications of the illness's development and severity for COVID-19, despite certain biomarkers having been investigated. The unexpected nature of COVID-19's course, which can quickly progress from asymptomatic to life-threatening symptoms, lies at the heart of the disease's intricacy. Predicting SARS-CoV-2 pathogenicity through laboratory biomarkers and as such, identifying the patients' illness severity at the time of their initial admission would be crucial in improving patient care. In this study, we sought to evaluate the potential of hematological, biochemical, and inflammatory biomarkers in predicting the course of COVID-19 at a tertiary hospital in western Kenya.

METHODS

This cross-sectional study involved 48 COVID-19 patients (16 asymptomatic; 16 moderate symptomatic; and 16 severe symptomatic) and 48 age-sex-matched COVID-19-negative clients attending the Moi Teaching and Referral Hospital, Kenya. Demographic information, self-reported chronic illnesses, symptoms, and laboratory results were collected at recruitment.

RESULTS

Significantly, the severity of COVID-19 was associated with; hemoglobin (p < 0.0001), white blood cells (p = 0.0022), hematocrit (p < 0.0001), blood urea nitrogen (p = 0.01), blood sodium (p = 0.0002), potassium (p = 0.0483), C-reactive protein (p = 0.0002), and Lactate Dehydrogenase (p < 0.0001). Regression analysis of CRP revealed a strong positive correlation (p = 0.0006) whereas LDH revealed a weak positive correlation (p < 0.0001) with COVID-19 disease severity. Discriminative accuracy was highest when asymptomatic was compared to severe COVID-19 for CRP and LDH (AUC: 0.8867, 95% CI: 0.7532-1.000) and (AUC: 1.000, 95% CI: 1.000-1.000) respectively.

CONCLUSION

The hematological indices, inflammatory and biochemical biomarkers studied have the potential to predict the course of COVID-19. These parameters may be useful in helping design appropriate care for COVID-19 patients.

Development and performance evaluation of a clinical prediction model for sepsis risk in burn patients

Sepsis is a common and severe complication in burn patients and remains one of the leading causes of mortality. This retrospective study aimed to develop a predictive model for the risk of in-hospital sepsis among burn patients treated at Guangzhou Red Cross Hospital between January 2022 and January 2024, with the goal of improving clinical outcomes through early prevention based on risk stratification. A total of 302 eligible patients were randomly divided into training and validation cohorts in a 7:3 ratio for model development and validation, respectively. Predictive factors were initially selected using LASSO regression, followed by logistic regression analysis to establish the prediction model and construct a nomogram. The final model incorporated 4 independent predictors: burn area (odds ratio [OR] = 1.043, 95% confidence interval [CI]: 1.026-1.062/1%), hemoglobin (OR = 0.968, 95% CI: 0.954-0.980/1 g/L), diabetes (OR = 10.91, 95% CI: 2.563-56.62), and potassium (OR = 3.091, 95% CI: 1.635-6.064/1 mmol/L). The areas under the receiver operating characteristic curve were 0.875 and 0.861 for the training and validation cohorts, with Youden indexes of 0.634 and 0.600, respectively. The calibration curve and decision curve analysis demonstrated good predictive accuracy and clinical utility of the model. These findings suggest that our developed model exhibits robust predictive performance for the risk of in-hospital sepsis in burn patients, and early prevention strategies based on risk stratification may potentially improve clinical outcomes.

The impact of serum potassium ion variability on 28-day mortality in ICU patients

OBJECTIVE

Potassium ion disorders are prevalent among patients in Intensive Care Units (ICUs), yet there is a notable deficiency in established protocols and supplemental plans for potassium management. This retrospective study conducted at a single center aims to explore the relationship between potassium levels, their variability, and the 28-day mortality rate in ICU patients.

METHODS

This study analyzed data from patients admitted to the ICU of the First Affiliated Hospital of Guangxi Medical University between October 2022 and October 2023. We assessed serum potassium variability using the coefficient of variation and categorized it into four quartile groups (Q1, Q2, Q3, Q4). Additionally, patients were classified into six groups based on serum potassium concentrations. The associations between these categories and the 28-day mortality rate were evaluated using binary logistic regression, adjusting for potential confounders.

RESULTS

A total of 506 patients and 12,099 potassium measurements were analyzed. The group with the lowest potassium variability (Q1) exhibited the lowest mortality rate at 21% (P<0.01). It is noteworthy that within 28 days in the intensive care unit (ICU), the coefficient of variation (CV) of potassium levels significantly increased among deceased patients compared to surviving patients (P < 0.01).

CONCLUSION

Significant variability in potassium levels is associated with an increased risk of 28-day mortality among ICU patients, underscoring the need for stringent monitoring and management of potassium levels in this population.

The relationship between potassium levels and 28-day mortality in sepsis patients: Secondary data analysis using the MIMIC-IV database

Objective

The goal of the research is to investigate the link between serum potassium levels and death after 28 days in sepsis patients, utilizing an extensive sample of patients from the multi-center Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Current research on serum potassium levels and 28-day mortality in sepsis patients is questionable. This study adds to the growing body of evidence linking serum potassium levels to the 28-day possibility of death in patients with sepsis.

Methods

We collected 349,08 patients with sepsis from the retrospective cohort MIMIC-IV database, using serum potassium level on the first day of admission to the intensive care unit as the exposure variable and mortality at 28 days as the outcome variable. And controlled for confounding characteristics including gender, age, ethnicity, and vital signs during admission.

Results

Serum potassium has a U-shaped connection with 28-day mortality in patients suffering from sepsis. The turning point was 4.10 mmol/L (95 % confidence interval: 4.03 to 4.22). Serum potassium and 28-day mortality were negatively linked on the inflection point's left side (OR: 0.72; 95 % CI: 0.63 to 0.83, P < 0.0001); on the opposing side of the point of inflexion, serum potassium was enthusiastically attached to 28-day mortality. (OR: 1.13; 95 % CI: 1.06 to 1.21, P < 0.0001).

Conclusion

The research conducted found that too high or too low potassium levels were linked to a 28-day risk of mortality in humans with sepsis.

Practice Patterns and Outcomes of Potassium Repletion Thresholds during Critical Illness

Rationale: Potassium repletion is common in critically ill patients. However, practice patterns and outcomes related to different intensive care unit (ICU) potassium repletion strategies are unclear. Objectives: 1) Describe potassium repletion practices in critically ill adults; 2) compare the effectiveness of potassium repletion strategies; and 3) compare effectiveness and safety of specific potassium repletion thresholds on patient outcomes. Methods: This was a retrospective analysis of the PINC AI Healthcare Database (2016-2022), including all critically ill adults admitted to an ICU on Hospital Day 1 and with a serum potassium concentration measured on Hospital Day 2. We determined the frequency of potassium repletion (any formulation) at each measured serum potassium concentration in each ICU, then classified ICUs as having threshold-based (a large increase in potassium repletion rates at a specific serum potassium concentration) or probabilistic (linear relationship between serum concentration and the repletion probability) patterns of repletion. Between patients in threshold-based and probabilistic repletion ICUs, we compared outcomes (primary outcome: potassium repletion frequency). We reported unadjusted percentages per exposure group and the adjusted odds ratios (from hierarchical regression models) for each outcome. Among patients in threshold-based ICUs with the most common repletion thresholds (3.5 mEq/L and 4.0 mEq/L), we conducted regression discontinuity analyses to examine the effectiveness of potassium repletion at each potassium threshold. Results: We included 190,490 patients in 88 ICUs; 35.0% received at least one dose of potassium on the same calendar day. Rates of potassium repletion were similar between 22 threshold-based strategy ICUs (33.5%) and 22 probabilistic strategy ICUs (36.4%). There was no difference in the adjusted risk of potassium repletion between patients admitted to threshold-based strategy ICUs versus probabilistic strategy ICUs (adjusted odds ratio, 1.09; 95% confidence interval [CI], 0.76-1.57). In regression discontinuity analysis, crossing the 3.5 mEq/L threshold from high to low potassium levels resulted in a 39.1% (95% CI, 23.7-42.4) absolute increase in potassium repletion but no change in other outcomes. Similarly, crossing the 4.0 mEq/L threshold resulted in a 36.4% (95% CI, 22.4-42.2) absolute increase in potassium repletion but no change in other outcomes. Conclusions: Potassium repletion is common in critically ill patients and occurs over a narrow range of "normal" potassium levels (3.5-4.0 mEq/L); use of a threshold-based repletion strategy to guide potassium repletion in ICU patients is not associated with clinically meaningful differences in outcomes.

Admission plasma potassium and length of hospital stay: a meta-analysis

OBJECTIVE

Hypokalaemia and hyperkalaemia ('dyskalaemia') are commonly seen in patients requiring emergency hospital admission. The adverse effect of dyskalaemia on mortality is well described but there are few data for the effect on hospital length of stay. We sought to determine the association of serum potassium concentration with in-hospital length of stay.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

A structured search of MEDLINE, PubMed and SCOPUS databases to 19 March 2021.

ELIGIBILITY CRITERIA

Observational cohort studies defining exposure of interest as serum potassium levels (at admission or within the first 72 hours) and with outcome of interest as length of hospital stay. Studies had to provide estimates of length of stay as a comparison between normokalaemia and defined ranges of hyperkalaemia or hypokalaemia.

DATA EXTRACTION AND SYNTHESIS

We identified 39 articles published to March 2021 that met the inclusion and exclusion criteria. Study selection, data extraction and quality assessment were carried out by two reviewers working independently and in duplicate, to assessed eligibility and risk of bias, and extract data from eligible studies. Random effects models were used to pool estimates across the included studies. Meta-analyses were performed using Cochrane-RevMan.

RESULTS

Five studies were included in the meta-analysis. Compared with the reference group (3.5-5.0 mmol/L), the pooled raw differences of medians were 4.45 (95% CI 2.71 to 6.91), 1.99 (95% CI 0.03 to 3.94), 0.98 (95% CI 0.91 to 1.05), 1.51 (95% CI 1.03 to 2.0), 1 (95% CI 0.75 to 1.25) and 2.76 (95% CI 1.24 to 4.29) for patients with potassium levels of <2.5, 2.5 to <3.0, 3.0 to <3.5, <5 to 5.5, <5.5 to 6 and >6.0 mmol/L, respectively.

CONCLUSION

Hospital length of stay follows a U-shaped distribution, with duration of admission being twofold greater at the extremes of the potassium range.

Risk factors for new-onset atrial fibrillation during critical illness: A Delphi study

Background

New-onset atrial fibrillation (NOAF) is common during critical illness and is associated with poor outcomes. Many risk factors for NOAF during critical illness have been identified, overlapping with risk factors for atrial fibrillation in patients in community settings. To develop interventions to prevent NOAF during critical illness, modifiable risk factors must be identified. These have not been studied in detail and it is not clear which variables warrant further study.

Methods

We undertook an international three-round Delphi process using an expert panel to identify important predictors of NOAF risk during critical illness.

Results

Of 22 experts invited, 12 agreed to participate. Participants were located in Europe, North America and South America and shared 110 publications on the subject of atrial fibrillation. All 12 completed the three Delphi rounds. Potentially modifiable risk factors identified include 15 intervention-related variables.

Conclusions

We present the results of the first Delphi process to identify important predictors of NOAF risk during critical illness. These results support further research into modifiable risk factors including optimal plasma electrolyte concentrations, rates of change of these electrolytes, fluid balance, choice of vasoactive medications and the use of preventative medications in high-risk patients. We also hope our findings will aid the development of predictive models for NOAF.

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

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.

Serum potassium variability as a predictor of clinical outcomes in patients with cardiorenal disease or diabetes: a retrospective UK database study

Background

Hyperkalaemia is an electrolyte abnormality associated with adverse clinical outcomes; however, few studies have investigated the relationship with patterns of hyperkalaemia over time. This study explored the impact of time spent in a hyperkalaemic state and variability of serum potassium (sK+) on major adverse cardiovascular events (MACE) and all-cause mortality in patients with chronic kidney disease (CKD), resistant hypertension, heart failure and diabetes.

Methods

Cohorts comprised adult patients diagnosed with CKD stage 3+, resistant hypertension, heart failure or diabetes, and/or renin-angiotensin-aldosterone system inhibitor prescription, between 1 January 2003 and 30 June 2018, from the UK Clinical Practice Research Datalink. Associations between percentage of follow-up spent in a hyperkalaemic state (sK+ ≥5.0 mmol/L, ≥5.5 mmol/L, ≥6.0 mmol/L) or sK+ variability (standard deviation above or below median standard deviation) and all-cause mortality or MACE were investigated.

Results

For sK+ ≥5.0 mmol/L, time spent in a hyperkalaemic state was associated with reduced risk of all-cause mortality across all cohorts. For higher sK+ thresholds, this trend was attenuated or reversed; for time spent in a hyperkalaemic state at sK+ ≥6.0 mmol/L, an increased risk of mortality was seen in the overall cohort and for patients with diabetes, resistant hypertension or prescribed renin-angiotensin-aldosterone system inhibitors, with no consistent association seen for patients with CKD or heart failure. Risk of MACE in the overall cohort and in patients with CKD, diabetes or resistant hypertension increased with time spent in a hyperkalaemic state at all sK+ thresholds; however, no correlation was seen in patients with heart failure or those receiving dialysis. High sK+ variability was associated with a higher risk of MACE compared with low sK+ variability across most sK+ categories in the overall population and in all disease cohorts, except patients on dialysis; however, no association between sK+ variability and all-cause mortality was observed.

Conclusions

Patterns of hyperkalaemia, including time spent in hyperkalaemia and sK+ variability, are associated with adverse clinical outcomes. Regular monitoring of sK+ in high-risk populations in broader community, primary care and outpatient settings may enable guideline-recommended management of hyperkalaemia and help avoid adverse events.

Clinical features, risk factors and a prediction model for in-hospital mortality among diabetic patients infected with COVID-19: data from a referral centre in Iran

OBJECTIVES

The aim of this study was to identify risk factors of in-hospital mortality among diabetic patients infected with COVID-19.

STUDY DESIGN

This is a retrospective cohort study.

METHODS

Using logistic regression analysis, the independent association of potential prognostic factors and COVID-19 in-hospital mortality was investigated in three models. Model 1 included demographic data and patient history; model 2 consisted of model 1, plus vital signs and pulse oximetry measurements at hospital admission; and model 3 included model 2, plus laboratory test results at hospital admission. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were reported for each predictor in the different models. Moreover, to examine the discriminatory powers of the models, a corrected area under the receiver-operating characteristic curve (AUC) was calculated.

RESULTS

Among 560 patients with diabetes (men = 291) who were hospitalised for COVID-19, the mean age of the study population was 61.8 (standard deviation [SD] 13.4) years. During a median length of hospitalisation of 6 days, 165 deaths (men = 93) were recorded. In model 1, age and a history of cognitive impairment were associated with higher mortality; however, taking statins, oral antidiabetic drugs and beta-blockers was associated with a lower risk of mortality (AUC = 0.76). In model 2, adding the data for respiratory rate (OR 1.07 [95% CI 1.00-1.14]) and oxygen saturation (OR 0.95 [95% CI 0.92-0.98]) slightly increased the AUC to 0.80. In model 3, the data for platelet count (OR 0.99 [95% CI 0.99-1.00]), lactate dehydrogenase (OR 1.002 [95% CI 1.001-1.003]), potassium (OR 2.02 [95% CI 1.33-3.08]) and fasting plasma glucose (OR 1.04 [95% CI 1.02-1.07]) significantly improved the discriminatory power of the model to AUC 0.86 (95% CI 0.83-0.90).

CONCLUSIONS

Among patients with type 2 diabetes, a combination of past medical and drug history and pulse oximetry data, with four non-expensive laboratory measures, was significantly associated with in-hospital COVID-19 mortality.

Serum potassium variability is associated with increased mortality in a large cohort of hospitalized patients

BACKGROUND

Few studies have examined the role of serum potassium concentrations [K+] variability on clinical outcomes is still poorly investigated. Aim of our study was to analyze the association between serum potassium concentrations ([K+]) disorders, with focus on [K+] variability, and mortality in a large, unselected cohort of hospitalized patients.

METHODS

We performed a retrospective observational cohort study on the inpatient population admitted to Fondazione Policlinico Universitario A. Gemelli IRCCS between January 1, 2010 and December 31, 2014 with inclusion of adult patients with [K+] measurements ≥2. The outcome of interest was in-hospital mortality. The exposures of interest were [K+] fluctuations and hypo-hyperkalemia and mixed dyskalemia during hospital stay. [K+] variability was evaluated using the coefficient of variation (CV). Logistic regression models were fitted to obtain odds ratios (ORs) and 95% confidence intervals (CIs) for the association between the exposures of interest and in-hospital death.

RESULTS

Overall, 64,507 patients met our inclusion criteria. During a median follow-up of 8 days, 965 patients (1.5%) died. Multivariable adjusted logistic models suggested a higher risk for death in patients in the 3rd (OR 1.45, 95% CI 1.13, 1.88, p = 0.003) and 4th (OR 3.30, 95% CI 2.64, 4.16, p < 0.001) highest quartiles of [K+] CV compared with those in the lowest quartile with a significant linear trend across quartiles (p-trend <0.001) Results did not change after restricting the analyses to patients with normokaliemia (NK). All [K+] disorders were independently associated with an increased risk of in-hospital death compared with NK.

CONCLUSIONS

High [K+] variability is an independent risk factor of in-hospital mortality, even within the normal [K+] range.

Update on management of hypokalemia and goals for the lower potassium level in patients with cardiovascular disease: A review in collaboration with the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

Hypokalaemia is common in patients with cardiovascular disease. In this review, we emphasize the importance of tight potassium regulation in patients with cardiovascular disease based on findings from observational studies. To enhance the understanding, we also describe the mechanisms of potassium homeostasis maintenance, the most common causes of hypokalaemia and present strategies for monitoring and management of low potassium levels. We propose elevation of potassium in asymptomatic patients with lower normal concentrations and concurrent cardiovascular disease. These proposals are intended to assist clinicians until more evidence is available.

Predialysis Potassium Variability and Postdialysis Mortality in Patients With Advanced CKD

Introduction

Patients with advanced non–dialysis-dependent chronic kidney disease (NDD-CKD) are prone to potassium (K) imbalances due to reduced kidney function. Both hypo- and hyperkalemia are associated with increased mortality; however, it is unclear if K variability before dialysis initiation is associated with outcomes after dialysis initiation.

Methods

We identified 34,167 US veterans with advanced NDD-CKD transitioning to dialysis between October 1, 2007, through March 31, 2015, who had at least 1 K measurement each year over a 3-year period before transition (3-year prelude). For each patient, a linear mixed-effects model was used to regress K over time (in years) over the 3-year prelude to derive K variability (square root of the average squared distance between the observed and estimated K). The main outcomes of interest were 6-month all-cause and cardiovascular mortality after dialysis initiation. Multivariable Cox and Fine-Gray competing risk regression adjusted for 3-year prelude K intercept, K slope (per year), demographics, smoking status, comorbidities, length of hospitalizations, body mass index, vascular access type, medications, average estimated glomerular filtration rate, and number of K measurements over the 3-year prelude were used to assess the association of K variability (expressed as quartiles) with all-cause and cardiovascular mortality, respectively.

Results

Higher prelude K variability was associated with higher multivariable-adjusted risk of all-cause mortality but not cardiovascular mortality (adjusted hazard/subhazard ratios [95% confidence interval] for highest quartile [vs. lowest] of K variability, 1.14 [1.03–1.25] and 0.99 [0.85–1.16] for all-cause and cardiovascular mortality, respectively).

Conclusion

Higher K variability is associated with higher all-cause mortality after dialysis initiation.

Hypernatremia and moderate-to-severe hyponatremia are independent predictors of mortality in septic patients at emergency department presentation: A sub-group analysis of the need-speed trial

STUDY OBJECTIVE

Early risk stratification of septic patients presenting to the emergency department (ED) is challenging. The aim of the study was to evaluate the prognostic role of plasmatic sodium level (_PNa⁺) derangements at ED presentation in septic patients.

METHODS

According to _PNa⁺ at ED presentation patients were divided in eunatremic (136-145 mEq/L), hypernatremic (>145 mEq/L) and hyponatremic (<136 mEq/L). Hyponatremic patients were subsequently divided in mild (130-135 mEq/L), moderate (125-129 mEq/L) and severe (<125 mEq/L). 7 and 30-day mortality was evaluated according to _PNa⁺ derangements and the degree of hyponatremia. The same analysis was then performed only in respiratory tract infection-related (RTI-r) sepsis patients.

RESULTS

879 septic patients were included in this analysis, 40.3% had hyponatremia, 5.7% hypernatremia. Hypernatremia showed higher mortality rates at both endpoints compared to eunatremia and hyponatremia (p<0.0001 for both). Eunatremia and mild hyponatremia were compared vs. moderate-to-severe hyponatremia showing a significant difference in terms of 7 and 30-day survival (p = 0.004 and p = 0.007, respectively). The Cox proportional model identified as independent predictors of 7 and 30-day mortality moderate-to-severe hyponatremia (HR 4.89[2.38-10.03] and 1.79[1.07-3.01], respectively) and hypernatremia (HR 3.52[1.58-7.82] and 2.14[1.17-3.92], respectively). The same analysis was performed in patients with respiratory tract infection-related sepsis (n = 549), with similar results.

CONCLUSION

Both hypernatremia and moderate-to-severe hyponatremia at ED presentation independently predict mortality in septic patients, allowing early risk stratification and suggesting more aggressive therapeutic strategies.

Association Between Average Plasma Potassium Levels and 30-day Mortality During Hospitalization in Patients with COVID-19 in Wuhan, China

Background: Coronavirus disease 2019 (COVID-19) has resulted in more than 610,000 deaths worldwide since December 2019. Given the rapid deterioration of patients' condition before death, markers with efficient prognostic values are urgently required. During the treatment process, notable changes in plasma potassium levels have been observed among severely ill patients. We aimed to evaluate the association between average plasma potassium (K_a ⁺) levels during hospitalization and 30-day mortality in patients with COVID-19. Methods: Consecutive patients with COVID-19 hospitalized in the Zhongfaxincheng branch of Tongji Hospital in Wuhan, China from February 8 to 28, 2020 were enrolled in this study. We followed patients up to 30 days after admission. Results: A total of 136 patients were included in the study. The average age was 62.1±14.6 years and 51.5% of patients were male. The median baseline potassium level was 4.3 (3.9-4.6) mmol/L and K_a ⁺ level during hospitalization was 4.4 (4.2-4.7) mmol/L; the median number of times that we measured potassium was 4 (3-5). The 30-day mortality was 19.1%. A J-shaped association was observed between K_a ⁺ and 30-day mortality. Multivariate Cox regression showed that compared with the reference group (K_a ⁺ 4.0 to <4.5 mmol/L), 30-day mortality was 1.99 (95% confidence interval [CI]=0.54-7.35, P=0.300), 1.14 (95% CI=0.39-3.32, P=0.810), and 4.14 (95% CI=1.29-13.29, P=0.017) times higher in patients with COVID-19 who had K_a ⁺ <4.0, 4.5 to <5.0, and ≥5.0 mmol/L, respectively. Conclusion: Patients with COVID-19 who had a K_a ⁺ level ≥5.0 mmol/L had a significantly increased 30-day mortality compared with those who had a K_a ⁺ level 4.0 to <4.5 mmol/L. Plasma potassium levels should be monitored routinely and maintained within appropriate ranges in patients with COVID-19.

The Association Between Variability in Electrolytes and the In-Hospital Mortality in Critically Ill Children in Pediatric Intensive Care Units

Objective: This study aimed to explore the association between the variability in electrolytes and the in-hospital mortality in critically ill children admitted into intensive care units (ICUs). Design: This is a retrospective case-control study. Setting and Participants: Total of 11,245 children have been admitted to ICUs of Children's Hospital of Zhejiang University from 2010 to 2018. Methods: The coefficient of variation (CV), standard deviation (SD), and variability independent of the mean (VIM) were calculated as variability indices. High variability was defined as having values in the highest quartile for each parameter. Age, sex, diagnoses of disease, and surgical treatment were adjusted in the multivariable-adjusted logistic regression model. Results: A total of 11,245 children were included, and 660 patients died in the hospital. The median (P25, P75) potassium, sodium, and chloride of all patients were 3.8 (3.58, 4.09), 136.83 (135.11, 138.60), and 108.67 (105.71, 111.17), respectively. U-shaped relationships between the mean, lowest, and highest levels of potassium, sodium, and chloride and the in-hospital mortality were observed. The lowest mortality was noted when serum potassium, sodium, and chloride were between ~3.5 and 5.0, 135 and 145, and 105 and 115 mmol/l, respectively. The areas under the curve (AUCs) of three indices of variability in electrolytes were larger than those of the mean and lowest levels of electrolytes in predicting the in-hospital mortality. In the multivariable-adjusted model, the odds ratios and 95% confidence interval (CI) of the in-hospital mortality were 3.14 (2.44-4.04) for one parameter, 5.85 (4.54-7.53) for two parameters, and 10.32 (7.81-13.64) for three parameters compared with subjects having no parameters of high variability measured as the CV. The results were consistent when the variability was determined using the SD and VIM (all P for trend <0.001). Consistent results were noted in various subgroup analyses. Conclusions: This study showed that individuals with higher variability of each parameter were related with higher risk of in-hospital mortality. There was a linear association between the number of high variability parameters and the in-hospital mortality. The variability of electrolytes might be a good predictor for in-hospital mortality of children in ICUs.

Serum Potassium Levels at Hospital Discharge and One-Year Mortality among Hospitalized Patients

Background and Objectives: The optimal range of serum potassium at hospital discharge is unclear. The aim of this study was to assess the relationship between discharge serum potassium levels and one-year mortality in hospitalized patients. Materials and Methods: All adult hospital survivors between 2011 and 2013 at a tertiary referral hospital, who had available admission and discharge serum potassium data, were enrolled. End-stage kidney disease patients were excluded. Discharge serum potassium was defined as the last serum potassium level measured within 48 h prior to hospital discharge and categorized into ≤2.9, 3.0–3.4, 3.5–3.9, 4.0–4.4, 4.5–4.9, 5.0–5.4 and ≥5.5 mEq/L. A Cox proportional hazards analysis was performed to assess the independent association between discharge serum potassium and one-year mortality after hospital discharge, using the discharge potassium range of 4.0–4.4 mEq/L as the reference group. Results: Of 57,874 eligible patients, with a mean discharge serum potassium of 4.1 ± 0.4 mEq/L, the estimated one-year mortality rate after discharge was 13.2%. A U-shaped association was observed between discharge serum potassium and one-year mortality, with the nadir mortality in the discharge serum potassium range of 4.0–4.4 mEq/L. After adjusting for clinical characteristics, including admission serum potassium, both discharge serum potassium ≤3.9 mEq/L and ≥4.5 mEq/L were significantly associated with increased one-year mortality, compared with the discharge serum potassium of 4.0–4.4 mEq/L. Stratified analysis based on admission serum potassium showed similar results, except that there was no increased risk of one-year mortality when discharge serum potassium was ≤3.9 mEq/L in patients with an admission serum potassium of ≥5.0 mEq/L. Conclusion: The association between discharge serum potassium and one-year mortality after hospital discharge had a U-shaped distribution and was independent of admission serum potassium. Favorable survival outcomes occurred when discharge serum potassium was strictly within the range of 4.0–4.4 mEq/L.