An observational study on electrolyte disorders in the acute phase of ischemic stroke and their prognostic value

Development and validation of a nomogram for predicting 28-day mortality in patients with ischemic stroke

BACKGROUND/AIM

We aimed to construct a validated nomogram model for predicting short-term (28-day) ischemic stroke mortality among critically ill populations.

MATERIALS AND METHODS

We collected raw data from the Medical Information Mart for Intensive Care IV database, a comprehensive repository renowned for its depth and breadth in critical care information. Subsequently, a rigorous analytical framework was employed, incorporating a 10-fold cross-validation procedure to ensure robustness and reliability. Leveraging advanced statistical methodologies, specifically the least absolute shrinkage and selection operator regression, variables pertinent to 28-day mortality in ischemic stroke were meticulously screened. Next, binary logistic regression was utilized to establish nomogram, then applied concordance index to evaluate discrimination of the prediction models. Predictive performance of the nomogram was assessed by integrated discrimination improvement (IDI) and net reclassification index (NRI). Additionally, we generated calibration curves to assess calibrating ability. Finally, we evaluated the nomogram's net clinical benefit using decision curve analysis (DCA), in comparison with scoring systems clinically applied under common conditions.

RESULTS

A total of 2089 individuals were identified and assigned into training (n = 1443) or validation (n = 646) cohorts. Various identified risk factors, including age, ethnicity, marital status, underlying metastatic solid tumor, Charlson comorbidity index, heart rate, Glasgow coma scale, glucose concentrations, white blood cells, sodium concentrations, potassium concentrations, mechanical ventilation, use of heparin and mannitol, were associated with short-term (28-day) mortality in ischemic stroke individuals. A concordance index of 0.834 was obtained in the training dataset, indicating that our nomogram had good discriminating ability. Results of IDI and NRI in both cohorts proved that our nomogram had positive improvement of predictive performance, compared to other scoring systems. The actual and predicted incidence of mortality showed favorable concordance on calibration curves (P > 0.05). DCA curves revealed that, compared with scoring systems clinically used under common conditions, the constructed nomogram yielded a greater net clinical benefit.

CONCLUSIONS

Utilizing a comprehensive array of fourteen readily accessible variables, a prognostic nomogram was meticulously formulated and rigorously validated to provide precise prognostication of short-term mortality within the ischemic stroke cohort.

Prevalence of Electrolyte Imbalance in Patients With Acute Stroke: A Systematic Review

Electrolyte abnormalities are common in acute stroke patients and have a substantial impact on the course and prognosis of the disease. Electrolyte imbalances such as hyponatremia, hypokalemia, hypocalcemia, hypomagnesemia, and phosphate abnormalities are frequently seen in this patient population. The incidence, root causes, and medical ramifications of electrolyte abnormalities in acute stroke patients are investigated in this comprehensive study. According to our research, hyponatremia is the most prevalent electrolyte imbalance. The most common reason for hyponatremia in stroke patients is the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Higher mortality rates, longer hospital admissions, and less favorable functional outcomes are all linked to hyponatremia. Acute stroke patients also typically experience hypokalemia, which affects the severity of the stroke and the recovery of functional abilities. The review furthermore emphasizes the incidence and clinical consequences of hypercalcemia, hypomagnesemia, hypophosphatemia, and hypocalcemia in patients with acute stroke. The results highlight the significance of early electrolyte imbalance detection and treatment in acute stroke patients. To better comprehend therapeutic approaches, evaluate their influence on stroke outcomes, and analyze prognostic implications, more research is required.

Hyponatremia Is Associated With Post-thrombolysis Hemorrhagic Transformation and Poor Clinical Outcome in Ischemic Stroke Patients

Objective

Hyponatremia is the most common electrolyte disorder encountered in patients with neurological conditions, such as stroke. Studies have shown that it is associated with worse clinical outcomes and increased mortality in acute ischemic stroke (AIS). However, the role of hyponatremia has not been elucidated in patients with AIS who received intravenous thrombolysis (IVT) therapy. Therefore, this study aimed to investigate the effect of serum sodium levels on the clinical outcome and hemorrhagic transformation (HT) in patients with AIS who received thrombolytic therapy.

Methods

Patients diagnosed with AIS who received IVT therapy between May 2015 and December 2020 were included in this study. All patients were screened for serum sodium levels immediately after hospital admission, before IVT therapy. The occurrence of HT was evaluated using computed tomography (CT) 24 ± 2 h after thrombolysis. Then, 3-month clinical outcomes were obtained by telephone calls or outpatient visits, and poor 3-month clinical outcomes were defined as modified Rankin Scale scores ≥3. The effects of serum sodium levels on the clinical outcome and HT were assessed using the multivariate logistic regression analysis.

Results

Of the 963 included patients, 82 (8.5%) had hyponatremia, 157 (16.3%) developed HT, and 333 (34.6%) had poor 3-month outcomes. Of the 82 patients with hyponatremia, 21 (25.6%) developed HT, and 39 (47.6%) had poor 3-month outcomes. Patients with hyponatremia had a higher incidence of post-thrombolysis HT (25.6 vs. 15.4%, p = 0.017) and worse clinical outcome (47.6 vs. 33.4%, p = 0.01) than those with normal serum sodium levels. Patients had significantly lower serum sodium levels in those with HT [138.4 (136.4–140.3, IQR) vs. 139.0 (137.2–140.7, IQR) mmol/L, p = 0.019] and poor 3 month outcome [139.0 (137.2–140.7) vs. 138.4 (136.7–140.3) mmol/L, p = 0.005] than those without. After adjusting for major covariates, the multivariate logistic regression analysis revealed that lower serum sodium levels were independently associated with an increased risk of HT [odds ratio (OR) = 1.804; 95% CI: 1.048–3.105] and poor 3-month outcome (OR = 1.647; 95% CI: 1.012–2.679).

Conclusion

Lower serum sodium level was an independent risk factor for post-thrombolysis HT and poor clinical outcome in patients with AIS who received thrombolytic therapy.

The association between serum glucose to potassium ratio on admission and short-term mortality in ischemic stroke patients

High serum glucose to potassium ratio (GPR) at admission is implicated for a poor outcome in acute brain injury, acute intracranial hemorrhage, and aneurysmal subarachnoid hemorrhage. However, the relationship between GPR and the outcome of ischemic stroke (IS) remains unknown. In all, 784 IS patients from a large emergency Norwegian cohort were included for secondary analysis. The exposure and outcome were GPR at baseline and all-cause mortality within 30 days after the first admission. Multivariable logistic regression analysis was performed to estimate the risk of 30-day mortality based on GPR levels. In addition, we examined whether there was a nonlinear relationship between admission GPR and 30-day mortality using two-piecewise linear regression with a smoothing function and threshold level analysis. The results of multivariable regression analysis showed that GPR at baseline was positively associated with the 30-day mortality (OR 2.01, 95% CI 1.12, 3.61) after adjusting for potential confounders (age, gender, department, serum sodium, serum albumin, serum-magnesium, hypertension, heart failure, chronic renal failure, and pneumonia). When GPR was translated to a categorical variable, the ORs and 95% CIs in the tertiles 2 to 3 versus the tertile 1 were 1.24 (0.60, 2.56) and 2.15 (1.09, 4.24), respectively (P for trend = 0.0188). Moreover, the results of the two-piecewise linear regression and curve fitting revealed a linear relationship between GPR and 30-day mortality. In IS patients, GPR is positively correlated with 30-day mortality, and the relationship between them is linear. The GPR at admission may be a promising predictor for the short-term outcome in IS patients.

Electrolytes and clinical outcomes in patients with acute ischemic stroke or transient ischemic attack

Background

Abnormal electrolytes were closely related to the prognosis of various diseases, the prognostic role of electrolytes in stroke has not been investigated well. We aimed to investigate the association between electrolytes and clinical outcomes in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA).

Methods

Data were recruited from the China National Stroke Registry III study. Patients were classified into three groups according to tertiles and the normal range of each electrolyte. Multivariable logistic and Cox proportional hazards regressions were adopted to explore the associations of electrolytes with poor functional outcomes [modified Rankin Scale (mRS) 3–6/2–6] and all-cause death at 3 months and 1 year.

Results

A total of 10,299 eligible patients were enrolled. After adjusted for confounding factors, the first tertile electrolytes were associated with increased risk of poor functional outcome (mRS score 3–6) at 1 year, the adjusted odds ratios (95% confidence intervals) were 1.33 (1.14–1.55) for potassium, 1.41 (1.20–1.60) for sodium, 1.27 (1.08–1.48) for chloride, compared with the second tertile. Similar results were found when poor functional outcome was defined as mRS score 2–6 and all-cause death. However, almost no significant association was present of calcium with these outcomes. All results were consistent when each electrolyte was classified into three groups according to the normal range and the outcomes timepoint was set at 3 months.

Conclusions

Lower levels of potassium, sodium, chloride but not calcium were associated with higher risk of poor functional outcomes and death in patients with AIS or TIA.

Oleuropein Protects Against Cerebral Ischemia Injury in Rats: Molecular Docking, Biochemical and Histological Findings

This study was designed to evaluate the underlying protective mechanisms of oleuropein involved in alleviating brain damage in a rat model of ischemic stroke. Male Wistar rats were divided into four groups; Control, stroke (MCAO), MCAO + clopidogrel (Clop) and MCAO + oleuropein (Ole). Results showed that the MCAO group evidenced significant brain edema (+ 9%) as well as increases of plasma cardiac markers such as lactate deshydrogenase (LDH), creatine kinase (CK-MB), fibrinogen and Trop-T by 11 %, 43%, 168 and 590%, respectively, as compared to the control group. Moreover, infarcted rats exhibited remarkable elevated levels of angiotensin converting enzyme (ACE), both in plasma and brain tissue, with astrocyte swelling and necrotic neurons in the infarct zone, hyponatremia, and increased rate of thiobarbituric acid-reactive substances (TBARS) by 89% associated with decreases in the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (Cat) by 51%, 44 and 42%, respectively, compared to normal control rats. However, MCAO rats treated with oleuropein underwent mitigation of cerebral edema, correction of hyponatremia, remarkable decrease of plasma fibrinogen and cardiac dysfunctional enzymes, inhibition of ACE activity and improvement of oxidative stress status in brain tissue. Furthermore, in silico analysis showed considerable inhibitions of ACE, protein disulfide isomerase (PDI) and TGF-β1, an indicative of potent anti-embolic properties. Overall, oleuropein offers a neuroprotective effect against ischemic stroke through its antioxidative and antithrombotic activities.

Prognostic Significance of Hyponatremia in Acute Stroke: A Systematic Review and Meta-Analysis

<b><i>Objective:</i></b> Hyponatremia is a common electrolyte disorder in patients with stroke, which leads to various fatal complications. We performed a systematic review and meta-analysis to investigate the outcomes of acute stroke patients with hyponatremia. <b><i>Methods:</i></b> We searched MEDLINE, EMBASE, and the Cochrane Library databases for relevant literature in English published up to March 2020. Two review authors independently screened and selected the studies by assessing the eligibility and validity based on the inclusion criteria. Mortality at 90 days was set as the primary end point, and in-hospital mortality and length of hospital stay were set as the secondary end points. We conducted the data synthesis and analyzed the outcomes by calculating the odds ratio (OR) and mean difference. <b><i>Results:</i></b> Of 835 studies, 15 studies met the inclusion criteria (<i>n</i> = 10,745). The prevalence rate of stroke patients with hyponatremia was 7.0–59.2%. They had significantly higher 90-day mortality (OR, 1.73; 95% confidence interval (CI), 1.24–2.42) and longer length of hospital stay (mean difference, 10.68 days; 95% CI, 7.14–14.22) than patients without hyponatremia. Patients with hyponatremia had a higher tendency of in-hospital mortality than those without hyponatremia (OR, 1.61; 95% CI, 0.97–2.69). <b><i>Conclusions:</i></b> The development of hyponatremia in the clinical course of stroke is associated with higher short-term mortality and a longer hospital stay. Although the causal relationship is unclear, hyponatremia could be a significant predictor of poor outcomes after stroke.

QT interval prolongation in patients with acute ischemic stroke: a report in northwest China

Aims

QT interval prolongation is common in patients with stroke and increases the risk of malignant arrhythmia and sudden death. Our aim was to analyze differences in the QT interval and electrocardiogram abnormalities between acute ischemic stroke patients and controls.

Methods

We retrospectively collected data from 273 patients with acute ischemic stroke from the neurological intensive care unit and 495 controls from other departments. A standard 12-lead electrocardiogram was recorded within 24 hours of hospitalization. Clinical information, the QT interval corrected for heart rate (QTc), and the incidence of electrocardiogram abnormalities were compared between groups.

Results

There was no difference in age, sex, or the prevalence of hypertension or diabetes mellitus between the acute ischemic stroke group and controls. Acute ischemic stroke patients showed a significantly longer QTc and a higher incidence of both sinus bradycardia and ST-T changes compared with controls. We also showed that the changes in electrocardiogram results observed in acute ischemic stroke might be transient.

Conclusion

Acute ischemic stroke patients may have a longer QT interval and a higher incidence of electrocardiogram abnormalities. In clinical practice, careful attention should be paid to acute ischemic stroke patients to prevent malignant arrhythmia.

Clinical Spectrum of Hyponatremia in Patients with Stroke

Introduction

Hyponatremia is a common electrolyte imbalance, which is readily observed in patients with ischemic as well as hemorrhagic stroke. It is mostly hypoosmolal and may be due to syndrome of inappropriate anti-diuretic hormone (SIADH) or cerebral salt wasting syndrome (CSWS). The aim of this study was to evaluate the clinical spectrum of hyponatremia in patients of both hemorrhagic and ischemic strokes.

Methods

In this prospective observational study, all patients admitted with stroke were screened for serum sodium levels right after hospital admission. Patients with serum sodium levels <135 mEq/L were included. Their demographic characteristics, type of stroke, etiology of hyponatremia, and site of hemorrhage/vascular territory ischemia was included.

Results

Hyponatremia was diagnosed in 34.2% of patients. Their mean serum sodium level was 130.4 ± 3.5 (mEq/L). Ischemic stroke was more common in the hyponatremia group (67.7%), and SIADH was a more common cause of hyponatremia (71.1%). In hyponatremic patients with hemorrhagic stroke, right putamen hemorrhage was seen in 50% of patients with SIADH, and right thalamus was seen in 73.3% patients with CSWS. In hyponatremic patients with ischemic stroke, left middle cerebral artery ischemia was seen in 47% patients with SIADH and right middle cerebral artery ischemia was seen in 55% patients with CSWS.

Conclusion

In patients with hyponatremia secondary to stroke, ischemic stroke is a common entity. SIADH remains a more frequently witnessed underlying pathology in hyponatremic stroke patients.

Acid-Base and Electrolyte Changes Drive Early Pathology in Ischemic Stroke

Emergent large vessel occlusion accounts for 20-40% of ischemic strokes and is the most debilitating form of stroke. Some of the earliest changes in response to ischemic stroke occur in blood gases and electrolytes. These biochemical changes occur within minutes after occlusion in experimental models of stroke and can be utilized to predict stroke outcomes. The majority of ELVO stroke patients are middle-aged to elderly and are of both sexes, revealing that there is an age and sex mismatch between ischemic stroke patients and animal models, since most experimental studies use young male rats. Rethinking of the animal models should be considered, especially in encouraging the use of aged male and female rats with comorbidities to more closely mirror human populations. Mechanical thrombectomy provides a unique opportunity for researchers to further this work by expanding the collection and analysis of blood samples that are adjacent to the thrombus. To understand the complexity of stroke, researchers can analyze these tissues for different molecular targets that occur in response to ischemic stroke. This information may aid in the reduction of symptom burden for individuals diagnosed with ischemic stroke. Investigators should also focus on data from ischemic stroke patients and attempt to discover target molecules and then in animal models to establish mechanism, which will aid in the development of new stroke therapies. This review discusses the translation of these studies to the human patient to develop the capability to predict stroke outcomes. Future studies are needed to identify molecular targets to predict the risk of worsened long-term outcomes and/or increased risk for mortality.

Association of Hyponatremia and Risk of Short- and Long-Term Mortality in Patients with Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Hyponatremia is the most common electrolyte disorder in the clinic practice and it is closely related to the prognosis of various diseases. Studies reported that hyponatremia increased the risk of stroke mortality while yielded inconsistent findings during the follow-up period. Thus, a systematic review and meta-analysis to assess the relationship between hyponatremia and the short-term (within 90 days) and long-term (more than 1 year) prognosis of stroke patients was conducted.

METHODS

A computerized systematic literature search was performed before November of 2018 for relevant articles evaluating the relationship between hyponatremia and all-cause mortality risk in stroke patients. Pooled relative risk (RR) and hazard risk (HR) with 95% confidence interval (CI) were calculated using DerSimonian-Laird random-effects model. Subgroup analyses were performed according to the follow-up period, types of stroke, different controls, sample size, and sampling time.

RESULTS

A total of 12 studies with 21,973 patients were identified. Compared to the nonhyponatremia patients, hyponatremia was associated with a higher risk of all-cause mortality in short-term (RR 1.61, 95% CI 1.33-1.96; HR 1.78 95% CI 1.19-2.75) and long-term follow-up (RR 1.77, 95% CI 1.27-2.47; HR 2.23,95% CI 1.30-3.82). Subgroups analysis showed the similar results in most subgroups.

CONCLUSIONS

This meta-analysis concludes that hyponatremia has a significant prognostic value for short- and long-term prognosis to stroke patients.

Early acid/base and electrolyte changes in permanent middle cerebral artery occlusion: Aged male and female rats

BACKGROUND

Early changes in acid/base and electrolyte concentrations could provide insights into the development of neuropathology at the onset of stroke. We evaluated associations between acid/base and electrolyte concentrations, and outcomes in permanent middle cerebral artery occlusion (pMCAO) model.

METHODS

18-month-old male and female Sprague-Dawley rats underwent pMCAO. Pre-, post- (7 min after occlusion), and at 72 hr of pMCAO venous blood samples provided pH, carbon dioxide, oxygen, glucose, hematocrit, hemoglobin, and electrolyte values of ionized calcium, potassium, and sodium. Multiple linear regression determined predictors of infarct and edema volumes from these values, Kaplan-Meier curve analyzed morality between males and females at 72 hr, and a Cox regression model was used to determine predictors for mortality.

RESULTS

Analysis indicated significant differences in acid/base balance and electrolyte levels in aged rats not dependent on sex between the three time points in the pMCAO model. Changes in pH (from pre- to post and post- to 72 hr) and changes in sodium and ionized calcium (from post- to 72 hr) were predictors of infarct volume and edema volume, respectively. Cox Regression revealed there is a 3.25 times increased risk for mortality based on changes in bicarbonate (pre- to post-MCAO).

CONCLUSIONS

These early venous blood changes in acid/base balance and electrolytes can be used to predict stroke outcomes in our rat model of stroke. This study provides potential biomarkers to be examined in the human condition that could provide profound prognostic tools for stroke patients.

Evaluation of Hyponatremia in Ischemic Stroke Patients in a Tertiary Care Hospital of Karachi, Pakistan

Introduction Electrolyte disturbances are commonly found in acute stroke settings. Hypernatremia, hyponatremia and hypokalemia are the commonest types of electrolyte disturbances. Data on electrolyte changes in neurological disorders like stroke is insufficient in Asia. This study aims to quantify the decrease in sodium levels in patients of ischemic stroke and to see whether the presence of co-morbidities like hypertension and diabetes result in decrement in the sodium level of the patients admitted. Methodology This is a cross-sectional study conducted in Ruth M Pfau Civil hospital Karachi on 132 consenting patients diagnosed with ischemic stroke on a clinical and radiological basis using a preformed questionnaire with all the necessary information to evaluate the objective like gender, level of sodium and co-morbidities. The data was analyzed using Chi‑squared test using SPSS (Statistical Package for Social Science) software version 22 (IBM, NY, USA). Result The study showed that the majority of the patients (25%) had mild hyponatremia (130-134 mMol/L), only a few (9.8%) had moderate (125-129 mMol/L) or profound (<125) hyponatremia (3.8%) and 17 out of 44 patients who were hypertensive had their sodium levels changed while only 10 out of 17 diabetics had fluctuating sodium levels (p-value = 0.00). We also found out that most of the patients with altered sodium levels were male in the age range of above 55. Conclusion Patients with ischemic stroke do develop hyponatremia, but only with a slight alteration in the sodium levels.

Fluid and energy intake in stroke patients during acute hospitalization in a stroke unit

Proper hydration and nutrition have been found to be contributing factors to a better recovery in patients after stroke. A better knowledge of factors influencing fluid and energy intake may contribute to a better care of the acute stroke patient. Aim of this study was to describe hydration status, fluid intake, and energy intake of stroke patients during acute hospitalization in a stroke unit. A retrospective descriptive study was conducted in stroke patients admitted to a stroke unit. All patients received neurological evaluation and urinary osmolality (uOsm) measure at admission and discharge. During stroke unit stay patients received a day-by-day diary to record data about beverages, food, and therapy. Water and energy content were then reported based on a national nutritional database. Ninety-five patients were included in the analysis. uOsm did not differ between patients with or without dysphagia, with uOsm > 500 mosm/kg in 58.1% at admission and 57.8% at discharge. Inadequate fluid intake was found in 41.2% of the sample with no difference between groups. Insufficient energy intake was found in 95.6% of the sample, with no patients with dysphagia reaching the minimum suggested amount. Our results suggest that a relevant proportion of stroke patients with and without dysphagia may not improve their hydration status during the first days after admission. Diet and therapy were insufficient to achieve recommended fluid intake and energy intake in a large proportion of patients, suggesting a more careful monitoring of hydration and nutrition needs.

Translational Evaluation of Acid/Base and Electrolyte Alterations in Rodent Model of Focal Ischemia

BACKGROUND AND PURPOSE

Acid/base and electrolytes could provide clinically valuable information about cerebral infarct core and penumbra. We evaluated associations between acid/base and electrolyte changes and outcomes in 2 rat models of stroke, permanent, and transient middle cerebral artery occlusion.

METHODS

Three-month old Sprague-Dawley rats underwent permanent or transient middle cerebral artery occlusion. Pre- and post-middle cerebral artery occlusion venous samples for permanent and transient models provided pH, carbon dioxide, oxygen, glucose, and electrolyte values of ionized calcium, potassium, and sodium. Multiple regression determined predictors of infarct volume from these values, and Kaplan-Meier curve analyzed morality between permanent and transient middle cerebral artery occlusion models.

RESULTS

Analysis indicated significant differences in the blood gas and electrolytes between pre- to post-middle cerebral artery occlusion. A decrease in pH and sodium with increases in carbon dioxide, potassium, ionized calcium, and glucose changes were found in both middle cerebral artery occlusion models; while hematocrit and hemoglobin were significant in the transient model. pH and ionized calcium were predictors of infarct volume in the permanent model, as changes in pH and ionized calcium decreased, infarct volume increased.

CONCLUSIONS

There are acute changes in acid/base balance and electrolytes during stroke in transient and permanent rodent models. Additionally, we found pH and ionized calcium changes predicted stroke volume in the permanent middle cerebral artery occlusion model. These preliminary findings are novel, and warrant further exploration in human conditions.

Effect of Hypokalemia on Functional Outcome at 3 Months Post-Stroke Among First-Ever Acute Ischemic Stroke Patients

Background

Hypokalemia has been confirmed to be a predictor of adverse cardiovascular and renal outcomes. There is a paucity of studies focusing on the potential connection between the serum K⁺ level and the outcome after acute ischemic stroke (AIS). This study investigated whether hypokalemia in the acute stroke stage contributes to worse functional outcome in AIS patients.

Material/Methods

This retrospective cohort study included consecutive patients with first-ever AIS admitted between June 2015 and March 2016. Patients were divided into 2 groups: hypokalemia (K⁺ <3.5 mmol/L) and normokalemia (3.5 mmol/L ≤K⁺ ≤5.5 mmol/L). Primary outcome measure was poor outcome at 3 months (modified Rankin scale >2). Univariate and multivariate logistic regression analyses were used to assess the association between hypokalemia and poor outcome. Receiver operating curve (ROC) analysis was performed to determine the optimal cutoff point of serum K⁺ level for predicting poor outcome.

Results

The percent of patients with poor outcome at 3 months was higher in the hypokalemic group (62.9%) than in the normokalemic group (45.5%). Hypokalemic patients tended to have lower fasting glucose at admission, lower Glasgow coma scale score, and longer time from symptom onset to treatment compared with normokalemic patients. Hypokalemia was associated with poor outcome at 3 months after adjusting for potential confounders (odds ratio=2.42, 95% confidence interval=1.21–4.86, P=0.013). ROC analysis showed that the optimal threshold for serum K⁺ level was 3.7 mmol/L.

Conclusions

Hypokalemia at the initial admission is associated with poor prognosis at 3 months in first-ever AIS patients.

Addition of sodium criterion to SOAR stroke score

OBJECTIVES

To examine the usefulness of including sodium (Na) levels as a criterion to the SOAR stroke score in predicting inpatient and 7-day mortality in stroke.

MATERIALS AND METHODS

Data from the Norfolk and Norwich University Hospital Stroke & TIA register (2003-2015) were analysed. Univariate and then multivariate models controlling for SOAR variables were used to assess the association between admission sodium levels and inpatient and 7-day mortality. The prognostic ability of the SOAR and SOAR Na scores for mortality outcomes at both time points were then compared using the Area Under the Curve (AUC) values from the Receiver Operating Characteristic curves.

RESULTS

A total of 8493 cases were included (male=47.4%, mean (SD) 77.7 (11.6) years). Compared with normonatremia (135-145 mmol/L), hypernatraemia (>145 mmol/L) was associated with inpatient mortality and moderate (125-129 mmol/L) and severe hypontraemia (<125 mmol/L) with 7-day mortality after adjustment for stroke type, Oxfordshire Community Stroke Project classification, age, prestroke modified Rankin score and sex. The SOAR and SOAR-Na scores both performed well in predicting inpatient mortality with AUC values of .794 (.78-.81) and .796 (.78-.81), respectively. 7-day mortality showed similar results. Both scores were less predictive in those with chronic kidney disease (CKD) and more so in those with hypoglycaemia.

CONCLUSION

The SOAR-Na did not perform considerably better than the SOAR stroke score. However, the performance of SOAR-Na in those with CKD and dysglycaemias requires further investigation.

Hyponatremia predicts mortality after stroke

Background

Hyponatremia, the commonest electrolyte imbalance encountered in clinical practice, is associated with adverse outcomes. Despite this, understanding of the association between hyponatremia and stroke mortality outcome is limited.

Aims

To investigate the association between admission serum sodium and mortality at various time-points after stroke.

Methods

Cases of acute stroke admitted to Norfolk and Norwich University Hospital consecutively from January 2003 until June 2013 were included, with mortality outcomes ascertained until the end of December 2013. Odds ratios or hazards ratios for death were constructed for various time-points (within seven-days, 8-30 days, within one-year, and over full follow-up).

Results

There were 8540 participants included (47.4% male, mean age 77.3 (±12.0) years). Point prevalence of hypernatremia and hyponatremia were 3.3% and 13.8%, respectively. In fully adjusted models controlling for age, gender, prestroke modified Rankin score, stroke type, Oxford community stroke project class, and laboratory biochemical and hematological results, the odds ratio (up to one-year)/hazards ratio (for full follow-up) for the above time-points were 1.00, 1.11, 1.03, 1.05 for mild hyponatremia; 1.97, 0.78, 1.11, 1.2 for moderate hyponatremia; 3.31, 1.57, 2.45, 1.67 for severe hyponatremia; and 0.47, 1.23, 1.30, 1.10 for hypernatremia. When stratified by age groups, outcomes were poorer in younger hyponatremic patients (aged <75 years).

Conclusion

Hyponatremia is prevalent in acute stroke admissions and is independently associated with higher mortality in patients <75 years).

Are patients admitted to hospitals from care homes dehydrated? A retrospective analysis of hypernatraemia and in-hospital mortality

OBJECTIVES

To compare risks of hypernatraemia on admission to hospital in persons who were with those who were not identified as care home residents and evaluate the association of hypernatraemia with in-hospital mortality.

DESIGN

Retrospective observational study.

SETTING

A National Health Service Trust in London.

PARTICIPANTS

A total of 21,610 patients aged over 65 years whose first admission to the Trust was between 1 January 2011 and 31 December 2013.

MAIN OUTCOME MEASURES

Hypernatraemia on admission (plasma Na > 145 mmol/L) and in-hospital death.

RESULTS

Patients admitted from care homes had 10-fold higher prevalence of hypernatraemia than those from their own homes (12.0% versus 1.3%, respectively; odds ratio [OR]: 10.5, 95% confidence interval [CI]: 8.43-13.0). Of those with hypernatraemia, nine in 10 cases were associated with nursing home ECOHOST residency (attributable fraction exposure: 90.5%), and the population attributable fraction of hypernatraemia on admission associated with care homes was 36.0%. After correcting for age, gender, mode of admission and dementia, care home residents were significantly more likely to be admitted with hypernatraemia than were own-home residents (adjusted odds ratio [AOR]: 5.32, 95% CI: 3.85-7.37). Compared with own-home residents, care home residents were also at about a two-fold higher risk of in-hospital mortality compared with non-care home residents (AOR: 1.97, 95% CI: 1.59-2.45). Consistent with evidence that hypernatraemia is implicated in higher mortality, the association of nursing homes with in-hospital mortality was attenuated after adjustment for it (AOR: 1.61, 95% CI: 1.26-2.06).

CONCLUSIONS

Patients admitted to hospital from care homes are commonly dehydrated on admission and, as a result, appear to experience significantly greater risks of in-hospital mortality.

Prevalence of severe hypokalaemia in patients with traumatic brain injury

INTRODUCTION

Patients with traumatic brain injury (TBI) are more vulnerable to develop hypokalaemia, we sought to investigate the prevalence, and the relationship between severe hypokalaemia and the mortality of traumatic brain injury patients.

METHODS

Isolated traumatic brain patients who had hypokalaemia (serum potassium <3.5mmol/L) and age≥14yrs were recruited into the study between January 2008 and March 2013. Hypokalaemia was defined as potassium level in the blood <3.5mmol/L during the hospitalisation, which was classified by severity: mild (3.0mmol/L≤K<3.5mmol/L), moderate (2.5mmol/L≤K<3.0mmol/L) and severe (K<2.5mmol/L). Multivariable logistic regression was performed to find the impact of hypokalaemia on mortality.

RESULTS

A total 375 cases were included in analysis. The peak incidence of severe hypokalaemia occurred in the first 24-96h. TBI patients with severe hypokalaemia had significantly higher serum sodium and lower serum phosphorus than those patients with mild or moderate hypokalaemia (p<0.001). Compare to other groups, the severe hypokalaemia group had the worst outcome. Moreover, the patients (n=15) who had severe hypokalaemia, hypernatraemia (Na>160mmol/L), and hypophosphataemia (P<0.3mmol/L) all died in hospital. Multiple logistic regression analysis resulted in decrease of GCS (OR=1.27; 95% CI=1.15-1.41; p<0.001) and potassium (OR=4.35; 95% CI=2.04-9.26; p<0.001) being associated with significant increased risk of mortality.

CONCLUSIONS

The peak incidence of severe hypokalaemia occurred in the first 24-96h. TBI patients with severe hypokalaemia are more vulnerable to develop hypophosphataemia and hypernatraemia than patients with mild and moderate hypokalaemia. Severe hypokalaemia are the independent risk factors for mortality in TBI patients.