Urine specific gravity as a predictor of early neurological deterioration in acute ischemic stroke

Association of hydration status and in-hospital mortality in critically ill patients with ischemic stroke: Data from the MIMIC-IV database

BACKGROUND

Hydration plays a critical role in the pathophysiological progression of ischemic stroke. However, the impact of extreme hydration on the mortality of critically ill patients with ischemic stroke remains unclear. Therefore, our objective was to evaluate the association between hydration, as indicated by the blood urea nitrogen to creatinine ratio (UCR), and in-hospital mortality in critically ill patients with ischemic stroke.

METHODS

Data from the Medical Information Mart for Intensive Care (MIMIC-IV) database were utilized. Patients with ischemic stroke admitted to the Intensive Care Unit (ICU) for the first time were identified. The exposure variable was the hydration state represented by the UCR. The study outcome measure was in-hospital mortality. The primary analytical approach involved multivariate Cox regression analysis. Kaplan-Meier curves were constructed, and subgroup analyses with interaction were performed.

RESULTS

A total of 1539 patients, with a mean age of 69.9 years, were included in the study. Kaplan-Meier curves illustrated that patients in higher UCR tertiles exhibited increased in-hospital mortality. Accordingly, the risk of in-hospital mortality significantly rose by 29 % with every 10 units increase in UCR. Subgroup analysis indicated a robust association between UCR and in-hospital mortality in each subgroup, with no statistically significant interactions observed.

CONCLUSION

Hydration status is significantly associated with in-hospital all-cause mortality in critically ill patients with ischemic stroke. This finding underscores the importance of closely monitoring critically ill patients for adequate hydration and implementing appropriate rehydration strategies.

Beyond diagnosis: Leveraging routine blood and urine biomarkers to predict severity and functional outcome in acute ischemic stroke

Background

The initial severity of acute ischemic stroke (AIS) is a crucial predictor of the disease outcome. In this study, blood and urine biomarkers from patients with AIS were measured to estimate stroke severity and predict long-term stroke outcomes.

Methods

The medical records of patients with AIS between October 2016 and May 2020 were retrospectively analyzed. The relationships of blood and urine biomarkers with stroke severity at admission were evaluated in patients with AIS. Predictive models for initial stroke severity and long-term prognosis were then developed using a panel of identified biomarkers.

Results

A total of 2229 patients were enrolled. Univariate analysis revealed 12 biomarkers associated with the National Institutes of Health Stroke Scale scores at admission. The area under the curve values for predicting initial stroke severity and long-term prognosis on the basis of these biomarkers were 0.7465, 0.7470, and 0.8061, respectively. Among multiple tested machine-learning, eXtreme gradient boosting exhibited the highest effectiveness in predicting 90-day modified Rankin Scale scores. SHapley Additive exPlanations revealed fasting glucose, albumin, hemoglobin, prothrombin time, and urine-specific gravity to be the top five most crucial biomarkers.

Conclusion

These findings demonstrate that clinically available blood and urine biomarkers can effectively estimate initial stroke severity and predict long-term prognosis in patients with AIS. Our results provide a scientific basis for developing tailored clinical treatment and management strategies for AIS, through incorporating liquid biomarkers into stroke risk assessment and patient care protocols for patients with AIS.

An observational study on salivary conductivity for fluid status assessment and clinical relevance in acute ischemic stroke during intravenous fluid hydration

The body fluid status in acute stroke is a crucial determinant in early stroke recovery but a real-time method to monitor body fluid status is not available. This study aims to evaluate the relationship between salivary conductivity and body fluid status during the period of intravenous fluid hydration. Between June 2020 to August 2022, patients presenting with clinical signs of stroke at the emergency department were enrolled. Salivary conductivities were measured before and 3 h after intravenous hydration. Patients were considered responsive if their salivary conductivities at 3 h decreased by more than 20% compared to their baseline values. Stroke severity was assessed using the National Institutes of Health Stroke Scale, and early neurological improvement was defined as a decrease of ≥ 2 points within 72 h of admission. Among 108 recruited patients, there were 35 of stroke mimics, 6 of transient ischemic attack and 67 of acute ischemic stroke. Salivary conductivity was significantly decreased after hydration in all patients (9008 versus 8118 µs/cm, p = 0.030). Among patients with acute ischemic stroke, the responsive group, showed a higher rate of early neurological improvement within 3 days compared to the non-responsive group (37% versus 10%, p = 0.009). In a multivariate logistic regression model, a decrease in salivary conductivity of 20% or more was found to be an independent factor associated with early neurological improvement (odds ratio 5.42, 95% confidence interval 1.31-22.5, p = 0.020). Real-time salivary conductivity might be a potential indicator of hydration status of the patient with acute ischemic stroke.

Diagnosis and treatment of dehydration after stroke: A synthesis of existing evidence

Dehydration after stroke is associated with poor health outcomes, increased mortality, and poses a significant economic burden to health services. Yet research suggests that monitoring and assessment of hydration status is not routinely undertaken. In this commentary, we critically appraise a systematic review which aimed to synthesise the existing evidence regarding diagnosis and treatment of dehydration after stroke. The review discusses common measures of dehydration, describes studies evaluating rehydration treatments, and highlights the link between dehydration and poorer health outcomes in both human and animal studies. The reviewers suggest, future research should focus on determining a single, validated, objective measure to clinically diagnose dehydration in stroke patients. Research designs should include clearly defined patient characteristics, type and severity of stroke, and type and time point of dehydration measurement, to enable comparison between studies. Management of hydration status is a crucial element of acute stroke care which should be routinely practiced.

Differentiation of epilepsy and psychogenic nonepileptic events based on body fluid characteristics

OBJECTIVE

Differential diagnosis between epileptic seizures and psychogenic nonepileptic events (PNEEs) is a worldwide problem for neurologists. The present study aims to identify important characteristics from body fluid tests and develop diagnostic models based on them.

METHODS

This is a register-based observational study in patients with a diagnosis of epilepsy or PNEEs at West China Hospital of Sichuan University. Data from body fluid tests between 2009 and 2019 were used as a training set. We constructed models with a random forest approach in eight training subsets divided by sex and categories of tests, including electrolyte, blood cell, metabolism, and urine tests. Then, we collected data prospectively from patients between 2020 and 2022 to validate our models and calculated the relative importance of characteristics in robust models. Selected characteristics were finally analyzed with multiple logistic regression to establish nomograms.

RESULTS

A total of 388 patients, including 218 with epilepsy and 170 with PNEEs, were studied. The AUROCs of random forest models of electrolyte and urine tests in the validation phase achieved 80.0% and 79.0%, respectively. Carbon dioxide combining power, anion gap, potassium, calcium, and chlorine in electrolyte tests and specific gravity, pH, and conductivity in urine tests were selected for the logistic regression analysis. C (ROC) of the electrolyte and urine diagnostic nomograms achieved 0.79 and 0.85, respectively.

SIGNIFICANCE

The application of routine indicators of serum and urine may help in the more accurate identification of epileptic and PNEEs.

Admission Hydration Status and Ischemic Stroke Outcome-Experience from a National Registry of Hospitalized Stroke Patients

Reduced intravascular volume upon ischemic stroke (IS) admission has been associated with in-hospital complications, disability, and reduced survival. We aimed to evaluate the association of the urea-to-creatinine ratio (UCR) with disability or death at discharge, length of stay, in-hospital complications, and mortality during the first year. Using a national registry, we identified hospitalized IS patients without renal failure. Disability or death at discharge, length of stay, in-hospital complications, and mortality during the first year were studied by UCR, and associations between UCR levels and each outcome were assessed adjusting for age, sex, stroke severity, comorbidities, use of statins, and use of diuretics. In total, 2212 patients were included. Levels (median (25–75%)) for the main study variables were: urea 5.16 (3.66–6.83) mmol/L; creatinine 80 (64–92) µmol/L; and UCR 65 (58–74). Levels of UCR were significantly higher in patients with disability or death at discharge (p < 0.0001), those with complications during hospitalization (p = 0.03), those with infection during hospitalization (p = 0.0003), and those dead at 1 year (p < 0.0001). Analysis by UCR quartile showed that rates of disability or death at discharge, infections, complications overall, and death at 1 year in patients with UCR in the 4th quartile were significantly higher than in others. Risk-factor-adjusted analysis by UCR quartiles demonstrated an inconsistent independent association between UCR and disability or death after ischemic stroke. A high 1-year mortality rate was observed in IS patients with elevated UCR, yet this finding was not statistically significant after controlling for risk factors. Our study shows inconsistent associations between hydration status and poor functional status at discharge, and no association with length of stay, in-hospital complications (infectious and overall), and 1-year mortality.

Prognostic Value of Blood Urea Nitrogen/Creatinine Ratio for Septic Shock: An Analysis of the MIMIC-III Clinical Database

Background

Research has previously been done into the risk factors for mortality in septic shock patients. However, there has been no epidemiological study investigating the effect of the blood urea nitrogen/creatinine ratio (BCR) on the prognosis of critically ill septic shock patients. This study is aimed at determining the relationship between BCR and all-cause mortality in adult septic shock patients.

Methods

Data were extracted from the MIMIC-III database. The clinical endpoints were 28-, 90-, and 365-day all-cause mortality rates in critically ill septic shock patients. Cox proportional hazards models and subgroup analyses were used to analyze the relationship between BCR quartiles and all-cause mortality in septic shock patients. Receiver operator characteristic (ROC) curves and areas under the ROC curves (AUCs) were calculated to evaluate how accurately BCR predicts the mortality of septic shock patients.

Results

Among the 2484 septic shock patients extracted from the database, 619, 563, 677, and 625 fell into the first (<14.4 mg/dL), second (≥14.4 mg/dL and <20.0 mg/dL), third (≥20.0 mg/dL and <27.3 mg/dL), and fourth (≥27.3 mg/dL) quartiles of BCR, respectively. Male and white patients accounted for 53.8% (1336 patients) and 74.8% (1857 patients) of the population, respectively. The mean age of the population was 67.7 ± 15.8 years. An inverse M-shaped relationship between BCR and mortality in septic shock patients was identified, with a value of ≥27.3 mg/dL providing the highest risk (HR = 1.596, 95% CI: 1.396-1.824, P < 0.001). In the Cox regression model adjusted for different confounding variables, BCR values in the fourth quartiles were significantly associated with increased mortality, using the first quartiles as a reference. The areas under the ROC curves (AUCs) for BCR plus the Sequential Organ Failure Assessment (SOFA) score and BCR plus Acute Physiology Score III (APSIII) were 0.694 (95% CI: 0.673-0.716) and 0.724 (95% CI: 0.703-0.744), respectively.

Conclusion

An inverse M-shaped curve was determined between BCR and the mortality of septic shock patients. BCR was identified as a readily available and independent prognostic biomarker for septic shock patients, and higher BCRs were associated with increased mortality in these patients.

Admission Dehydration Is Associated With Significantly Lower In-Hospital Mortality After Intracerebral Hemorrhage

Background and Purpose: Our aim was to investigate the frequency of dehydration at admission and associations with in-hospital mortality in patients with intracerebral hemorrhage (ICH). Methods: Data of consecutive patients with ICH between August 2015 and July 2019 from the China Stroke Center Alliance (CSCA) registry were analyzed. The patients were stratified based on the blood urea nitrogen (BUN) to creatinine (CR) ratio (BUN/CR) on admission into dehydrated (BUN/CR ≥ 15) or non-dehydrated (BUN/CR < 15) groups. Data were analyzed with multivariate logistic regression models to investigate admission dehydration status and the risks of death at hospital. Results: A total number of 84,043 patients with ICH were included in the study. The median age of patients on admission was 63.0 years, and 37.5% of them were women. Based on the baseline BUN/CR, 59,153 (70.4%) patients were classified into dehydration group. Patients with admission dehydration (BUN/CR ≥ 15) had 13% lower risks of in-hospital mortality than those without dehydration (BUN/CR < 15, adjusted OR = 0.87, 95%CI 0.78-0.96). In patients aged <65 years, admission dehydration was associated with 19% lower risks of in-hospital mortality (adjusted OR = 0.81, 95%CI 0.70-0.94. adjusted p = 0.0049) than non-dehydrated patients. Conclusion: Admission dehydration is associated with significantly lower in-hospital mortality after ICH, in particular, in patients <65 years old.

A physiological perspective of the associations between hydration status and CTP neuroimaging parameters in hyper-acute ischaemic stroke patients

Hypohydration may be associated with vascular diseases, poor prognosis and worse outcomes in stroke. The underlying mechanisms have not yet been completely investigated, although some studies suggested potential associations with brain perfusion and collaterals status. Despite the potentially different mechanisms promoting serum or urine biomarkers of hypohydration, few studies have investigated both markers separately. A prospective descriptive study was conducted in stroke patients admitted to a stroke unit <4.5 h from symptoms onset. All patients underwent neurological evaluation and whole-brain computed tomography perfusion (CTP) upon admission. Blood and urine samples were immediately collected at admission, and patients were defined as "hypohydrated" (HYP) if blood urea nitrogen-to-creatinine ratio was >15 and "underhydrated" (UND) if urine osmolality was >500 mOsm/kg. CTP images were processed to calculate core, penumbra, their mismatch and total hypoperfused volume. Forty-six patients were included and were grouped according to hydration status. Despite no different NIHSS at baseline, at CTP HYP was independently associated with core-penumbra mismatch (β: -0.157, 95% CI: -0.305 to -0.009; p = .04), while UND was independently associated with the total hypoperfused volume (β: 31.502, 95% CI: 8.522-54.481; p = .01). Using CTP imaging, this study proposes a physiological insight of some possible mechanisms associated with the better outcomes observed in acute stroke patients when properly hydrated. These results suggest different associations between hydration status and CTP parameters depending on serum or urine biomarkers in the hyper-acute phase and encourage the association between hydration status and stroke characteristics.

Protecting Patient Safety and Preventing Modifiable Complications After Acute Ischemic Stroke

TOPIC

Protecting patient safety and preventing modifiable complications after acute ischemic stroke.

CLINICAL RELEVANCE

Stroke is a leading cause of death and disability in adults. Stroke survivors often experience a variety of deficits related to mobility, nutrition, immunity, mood, and cognition. These post-stroke complications and residual effects can adversely affect safety, placing the patient at risk for further injury. In order to develop a plan of care that protects patient safety, critical care and progressive care nurses must understand the unique needs of this patient population.

PURPOSE

To describe selected ischemic stroke-related physiological changes, how these changes contribute to safety risks, and methods of enhancing patient safety.

CONTENT COVERED

Stroke physiology and stroke-specific interventions that can enable nurses to reduce the risk of falls, dysphagia, malnutrition, dehydration, altered glucose metabolism, device-related infections, aspiration pneumonia, delirium, and depression.

Do initially non-dehydrated patients with acute ischemic stroke need fluid supplement?

Background: We previously found that dehydration is an independent predictor of early deterioration after acute ischemic stroke and rehydration helps to improve outcomes. There is limited evidence of how to treat patients who are initially non-dehydrated. In this study, we tested the hypothesis that rehydration therapy, based on the daily urine specific gravity, will improve the outcome of ischemic stroke patients who are initially non-dehydrated. Methods: We conducted a single-arm prospective study of patients with acute ischemic stroke with historical controls. For the first 5 days of study group, a daily urine specific gravity of > 1.020 g/ml was taken as indication for rehydration and patients were advised to drink water via oral or tubal feeding with a dose of 5 ml/kg body weight right away and after dinner. Control group patients were rehydrated without reference to urine specific gravity. An increase in National Institutes of Health Stroke Scale score of ≥ 4 within three days was defined as having stroke-in-evolution. Scores of ≤ 1 on the modified Rankin scale at 3 months were considered to indicate a favorable outcome. Results: A total of 125 patients were analyzed, 46 in the study group and 79 in the control group. The groups did not significantly differ in the stroke-in-evolution rate (4.3% vs. 8.2%, P = 0.474). The rate of favorable outcome at 3 months was significantly higher in the study group than in the control group (56.5% vs. 27.8%, P = 0.001). Conclusions: Urine specific gravity-based hydration might be a useful method to improve functional outcomes of patients with acute ischemic stroke who were non-dehydrated at admission.

Prevalence of hypohydration and its association with stroke severity and independence outcomes in acute ischemic stroke patients

Hypohydration has been suggested increasing the risk of vascular diseases, and it is associated with poor prognosis and worse functional outcome in stroke. Most studies have used blood parameters to determine patients' hydration status. The aim of this study was to measure urine osmolality (uOsm) and its influence on stroke severity and independence. A prospective descriptive study was conducted in stroke patients admitted to a stroke unit. All patients underwent neurological evaluation at admission and discharge using the National Institute of Health Stroke Scale (NIHSS). Independence at discharge was evaluated with the Barthel Index (BI) and the modified Rankin Scale (mRS). uOsm was measured at admission. Patients were grouped in "poor fluid intake" (PF) and "euhydration" (EU), the latter if uOsm ≤ 500 mOsm/kg. Among 119 included patients, the prevalence of PF was 52%, with no difference observed between groups in demographics or blood samples analyses. PF had higher chances of NIHSS > 8 at admission (OR: 4.7 95% CI: 1.3-17.0; p = 0.02), lower BI at discharge (β: -15.3 95% CI: -26.7 to -3.8; p = 0.01), and worse mRS at discharge (OR: 4.01 95% CI: 1.2-14.0; p = 0.02). These findings are consistent with previous results, suggesting that uOsm may be a factor significantly associated with stroke severity and independence outcome after acute ischemic stroke.

Contribution of dehydration to END in acute ischemic stroke not mediated via coagulation activation

OBJECTIVE

Dehydration is a risk factor for early neurological deterioration (END) after ischemic stroke, yet the underlying mechanism is unclear. Outbalanced coagulation activation may contribute to ischemia progression, concurrently with dehydration-induced blood viscosity change. We aimed to investigate whether the contribution of dehydration to END was mediated by blood coagulation activation.

METHODS

We retrospectively evaluated consecutive patients presenting with mild or moderate stroke (National Institutes of Health Stroke Scale score ≤14) within 24 hr of onset between Jan 2016 and Dec 2017. Dehydration was defined by a serum nitrogen to creatinine ratio (BUN/Cr) of ≥15 and blood coagulation activity was assessed with thromboelastography (TEG). The correlations between BUN/Cr and TEG parameters were assessed and their relationship in the development of END was analyzed.

RESULTS

Of 244 patients, 64 (26.2%) developed END within 3 days after admission. Patients with END had significantly higher BUN/Cr (19.2 ± 5.7 vs. 15.3 ± 2.9, p = 0.008), shorter R and K on TEG test (R: 3.9 ± 1.0 vs. 4.6 ± 1.1, p = 0.001; K: 1.3 ± 0.5 vs. 1.5 ± 0.4, p = 0.005). Comparison between patients with and without dehydration revealed no significant differences in TEG parameters. Multivariate regression suggested that dehydration status (OR 3.91, 95%CI 2.17-8.67, p = 0.008) and shorter R tercile on TEG (OR 3.18, 95% CI 1.23-7.90, p = 0.016) were independently associated with END; however, the odds ratio of R for END remained unchanged after adjustment for dehydration status.

CONCLUSION

Our findings suggested that the contribution of dehydration to END after ischemic stroke was mediated by blood coagulation activation.

Impact of hydration status on haemodynamics, effects of acute blood pressure-lowering treatment, and prognosis after stroke

Aims

Although high blood pressure (BP) is common in acute stroke and associated with poor outcome, the Efficacy of Nitric Oxide in Stroke (ENOS) trial showed no beneficial effect of antihypertensive treatment in this situation. Antihypertensive agents have accentuated effects in dehydrated patients. We assessed the impact of dehydration on haemodynamics, the effects of antihypertensive treatment, and prognosis in the ENOS trial.

Methods

ENOS randomized 4011 patients with acute stroke and raised systolic BP to a glyceryl trinitrate (GTN) patch or no GTN patch, and to continue or to stop existing antihypertensive treatment within 48 h of onset. The primary outcome was functional outcome (modified Rankin Scale, mRS) at day 90. Blood markers of dehydration at baseline were collected at two sites (n = 310) and their relationship with haemodynamics and outcome was assessed.

Results

There were no significant associations between dehydration markers and fall in blood pressure from baseline to day 1, and no significant interaction with allocated treatment. Overall, increasing urea was associated with an unfavourable shift in mRS [odds ratio 3.43, 95% confidence interval (CI) 1.42, 8.32; P = 0.006] and increased risk of death at day 90 (hazard ratio 4.55, 95% CI 1.51, 13.66; P = 0.007).

Conclusions

Blood pressure‐lowering treatment was safe in dehydrated patients, with no precipitous changes in BP, thus supporting its use in acute stroke prior to blood markers of dehydration becoming available. Increased baseline urea was associated with poor prognosis after stroke.

Primary 'dehydration' and acute stroke: a systematic research review

BACKGROUND AND PURPOSE

Hydration status at the time of stroke has been acknowledged as an important determinant in early stroke recovery. However, the diagnosis of dehydration, or more accurately, a volume-contracted state, at the time of stroke is challenging since there are currently no consensus diagnostic criteria. In this systematic review, we gather the available evidence about diagnosis and treatment of dehydration after stroke.

METHODS

Studies of hospitalized ischemic stroke patients that reported rates of dehydration from January 1997 to March 2017 were screened for inclusion via a systematic search of PubMed, CINAHL, Cochrane, and Scopus using keywords hydration, dehydration, hemodilution, viscosity, volume status, and thirst.

RESULTS

Twenty-five studies of 8699 acute stroke patients were included. Nineteen studies reported on the diagnostic approach to dehydration. Findings are synthesized into four main categories of available research including studies that specify: (1) biological mechanisms using animal models to investigate the relationship between dehydration and stroke; (2) measures of dehydration in the acute human stroke population; (3) rehydration therapies after stroke; and (4) outcomes after stroke in dehydrated patients.

CONCLUSIONS

We found considerable variation in terminology specific to hydration status, diagnostic approach to dehydration, and few prospective studies of treatment strategies with varying results. This review supports the need for consensus development of operational diagnostic criteria, standardization of language, and the opportunity for prospective study of rehydration strategies to impact outcome after stroke.

Pilot study of volume contracted state and hospital outcome after stroke

BACKGROUND

An increasing body of research suggests that acute stroke patients who are dehydrated may have worsened functional outcomes. We sought to explore the relationship between a volume contracted state (VCS) at the time of ischemic stroke and hospital outcomes as compared with euvolemic patients.

METHODS

We enrolled a consecutive series of ischemic stroke patients from a single academic stroke center within 12 hours from stroke onset. VCS was defined via surrogate markers (blood urea nitrogen/creatinine ratio >15 and urine specific gravity >1.010). The primary outcome was change in NIH Stroke Scale (NIHSS) score from admission to discharge. Multivariable analyses included adjustment for demographics and infarct size.

RESULTS

Over an 11-month study period, 168 patients were eligible for inclusion. Of the126 with complete laboratory and MRI data, 44% were in a VCS at the time of admission. Demographics were similar in both the VCS and euvolemic groups, as were baseline NIHSS scores (6.7 vs 7.3; p = 0.63) and infarct volumes (12 vs 16 mL; p = 0.48). However, 42% of patients in a VCS demonstrated early clinical worsening, compared with 17% of the euvolemic group (p = 0.02). A VCS remained a significant predictor of worsening NIHSS in adjusted models (odds ratio 4.34; 95% confidence interval 1.75-10.76).

CONCLUSIONS

Acute stroke patients in a VCS demonstrate worse short-term outcomes compared to euvolemic patients, independent of infarct size. Results suggest an opportunity to explore current hydration practices.

Dehydration is a strong predictor of long-term prognosis of thrombolysed patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Dehydration was found to be involved in the poor prognosis of patients with acute ischemic stroke. It is unclear whether dehydration status before onset is related with prognosis of thrombolysed patients with acute ischemic stroke. If it is the case, quickly hydrating may improve the prognosis. The present study was designed to explore the issue.

METHODS

Eligible 294 patients with acute ischemic stroke after thrombolysis were enrolled in the present study according to inclusion/exclusion criteria. According to the modified Rankin scale (mRS) 90 days post stroke, the patients were divided into two groups: mRS 0-2 (n = 191) and mRS 3-6 (n = 103). In the present study, BUN/Cr ≥ 15 combined with USG > 1.010 or either of them were chosen as dehydration marker. Clinical data were analyzed between two groups. Univariate and multivariate statistical analyses were carried out.

RESULTS

Age, fibrinogen, blood glucose, BUN/Cr, NIHSS score at admission, the systolic blood pressure (SBP) before thrombolysis, dehydration status (BUN/Cr ≥ 15 plus USG > 1.010), hyperlipidemia, USG and D-dimer on admission day, and TOAST classification showed significant difference between two groups (p < .05). Further stratification analysis showed that BUN/Cr ≥ 15, NIHSS ≥ 6, blood glucose ≥8, and SBP > 150 were markedly associated with poor outcome (mRS 3-6, p < .05). After adjusting for age, fibrinogen, USG, D-dimer, dehydration status, NIHSS, blood glucose, SBP, hyperlipidemia, and BUN/Cr at admission, multivariate logistic regression showed that dehydration status, higher NIHSS, higher blood glucose, and higher SBP at admission were independent risk factors for predicting the long-term poor prognosis of thrombolysed patients.

CONCLUSIONS

The present findings suggest that BUN/Cr ≥ 15 combined with USG > 1.010 as a marker of dehydration status was an independent risk factor for long-term poor prognosis of thrombolysed patients with acute ischemic stroke.

A randomized controlled study of intravenous fluid in acute ischemic stroke

OBJECTIVE

To compare the outcome of patients with acute ischemic stroke who received or did not receive intravenous fluid.

PATIENTS AND METHODS

This study was a prospective, multicenter, randomized, open-label trial with blinded outcome assessment. We enrolled acute ischemic stroke patients without dehydration aged between 18 and 85 years with NIH Stroke Scale score (NIHSS) score from 1 to 18 who presented within 72h after onset. Patients were randomly assigned to receive 0.9% NaCl solution 100ml/h for 3days or no intravenous fluid.

RESULTS

On the interim unblinded analysis of the safety data, significant excess early neurological deterioration was observed among patients in the non-intravenous fluid group. Therefore, the study was prematurely discontinued after enrollment of 120 patients, mean age 60 years, 56.6% male. Early neurological deterioration (increased NIHSS ≥3 over 72h) not of metabolic or hemorrhagic origin was observed in 15% of the non-IV fluid group and 3.3% of the IV fluid group (p=0.02). Predictors of neurological deterioration were higher NIHSS score, higher plasma glucose, and increased pulse rate. There was no difference in the primary efficacy outcome, NIHSS≤4 at day 7, 83.3% vs 86.7%, p=0.61 or secondary efficacy outcomes.

CONCLUSION

Administration of 0.9% NaCl 100ml/h for 72h in patients with acute ischemic stroke is safe and may be associated with a reduced risk of neurological deterioration. These study findings support the use of intravenous fluid in acute ischemic stroke patients with NIHSS less than 18 who have no contraindications.

Urine-Specific Gravity-Based Hydration Prevents Stroke in Evolution in Patients with Acute Ischemic Stroke

BACKGROUND

Early neurological deterioration after ischemic stroke (stroke-in-evolution [SIE]) is associated with poorer outcomes. Previous studies have demonstrated a link between hydration status and the development of SIE. In this study, we tested the hypothesis that rehydration therapy, administered on the basis of urine-specific gravity (USG) findings, might reduce the development of SIE.

METHODS

We conducted a single-arm prospective study of patients with acute ischemic stroke with historical controls. For the study group, a USG higher than 1.010 was taken as an indication for rehydration. Control group patients were rehydrated without referring to USG. An increase in National Institutes of Health Stroke Scale (NIHSS) score of 4 or higher within 3 days was defined as having SIE.

RESULTS

A total of 445 patients were analyzed, 167 in the study group and 278 in the control group. The proportion of patients who developed SIE was numerically, but not significantly, lower in the study group (5.9%; 10 of 167) compared with the control group (11.5%; 32 of 278). Among patients with a USG higher than 1.010 at admission, the SIE rate was significantly reduced in the study group compared with the control group (6.1% versus 16.0%; P = .021), while the rate of SIE was similar in those with a USG of 1.010 or lower at admission. Multivariate logistic regression analysis confirmed that USG-based hydration was an independent factor associated with reducing SIE.

CONCLUSIONS

USG might be a convenient and useful method for guiding fluid therapy in patients with acute ischemic stroke. USG-based hydration reduced the incidence of SIE among patients with a USG higher than 1.010 at admission.

The influence of dehydration on the prognosis of acute ischemic stroke for patients treated with tissue plasminogen activator

Background

Many studies have determined that dehydration is an independent predictor of outcome after ischemic stroke (IS); however, none have determined if the use of thrombolytic therapy modifies the negative impact of poor hydration. To inform the stroke registry established at our institution, we conducted a retrospective study to determine if dehydration remains a negative prognostic factor after IS patients treated with tissue plasminogen activator (tPA).

Methods

Between 2007 and 2012, we recruited 382 subjects; 346 had data available and were divided into 2 groups on the basis of their blood urea nitrogen/creatinine (BUN/Cr) ratio. Dehydrated subjects had a BUN/Cr ratio ≥ 15; hydrated subjects had a BUN/Cr < 15. The primary outcome was impairment at discharge as graded by the Barthel Index (BI) and the modified Rankin Scale (mRS).

Results

The dehydration group had a greater mean age; more women; lower mean levels of hemoglobin, triglycerides, and sodium; and higher mean potassium and glucose levels. A favorable outcome as assessed by the mRS (≤2) was significantly less frequent among dehydrated subjects, but a favorable outcome by the BI (≥60) was not. Logistic regression and multivariate models confirmed that dehydration is an independent predictor of poor outcome by both the mRS and the BI; however, it was not predictive when patients were stratified by Trial of Org 10,172 in Acute Stroke Treatment subtype.

Conclusions

Our findings indicate that use of thrombolytic therapy does not eliminate the need to closely monitor hydration status in patients with IS.

Dehydration Status is Associated With More Severe Hemispatial Neglect After Stroke

BACKGROUND

Many stroke patients are clinically dehydrated at the time of hospital presentation, which could lead to an increase in blood viscosity and alteration in cerebral perfusion. Impaired cerebral perfusion can cause hemispheric dysfunction, which can be rapidly quantified with bedside tests of hemispatial neglect. We hypothesized that hospitalized patients with laboratory markers consistent with dehydration or a volume contracted state (VCS) would have more severe cerebral dysfunction defined by greater degree of neglect.

METHODS

Subjects were a consecutive series of right-handed patients with acute right hemispheric stroke admitted within the Johns Hopkins Health System. All participants had clinical syndrome and magnetic resonance imaging consistent with acute infarction. The primary definition of a VCS was a urea/creatinine ratio >15, with secondary definition including urine specific gravity over 1.010. Acute infarct volume was measured on magnetic resonance imaging. Neglect was evaluated using a standardized battery of bedside tests.

RESULTS

Of 201 patients meeting inclusion criteria, 131/201 (65%) had elevated BUN/creatinine ratios at admission. Approximately 61% (122/201) had some degree of neglect. Elevated BUN/creatinine ratio was associated with an increased odds of severe neglect in unadjusted models (OR=4.1; 95% CI, 1.2, 14.4), with loss of significance in adjusted models (OR=4.43; 95% CI, 0.99, 19.8) after adjustment for age, infarct volume, sex, and NIHSS score.

CONCLUSIONS

Our data suggest that patients who are in a VCS at the time of stroke may have more frequent and severe neglect, with attenuation of results after adjustment for factors related to stroke size and age. If proven clinically relevant, a formalized rehydration strategy based on objective lab markers may represent an opportunity for improvement in outcome with low-cost, broadly available treatment for acute stroke patients.

Optimizing Outcomes for Mechanically Ventilated Patients in an Era of Endovascular Acute Ischemic Stroke Therapy

Endovascular mechanical thrombectomy is a new standard of care for acute ischemic stroke (AIS). The majority of these patients receive mechanical ventilation (MV), which has been associated with poor outcomes. The implication of this is significant, as most neurointerventionalists prefer general compared to local anesthesia during the procedure. Consequences of hemodynamic and respiratory perturbations during general anesthesia and MV are thought to contribute significantly to the poor outcomes that are encountered. In this review, we first describe the unique risks associated with MV in the specific context of AIS and then discuss evidence of brain goal-directed approaches that may mitigate these risks. These strategies include an individualized approach to hemodynamic parameters (eg, adherence to a minimum blood pressure goal and adequate volume resuscitation), respiratory parameters (eg, arterial carbon dioxide optimization), and the use of ventilator settings that optimize neurological outcomes (eg, arterial oxygen optimization).

Increased Blood Viscosity in Ischemic Stroke Patients with Small Artery Occlusion Measured by an Electromagnetic Spinning Sphere Viscometer

BACKGROUND AND PURPOSE

High blood viscosity causes blood stagnation and subsequent pathological thrombotic events, resulting in the development of ischemic stroke. We hypothesize that the contribution of blood viscosity may differ among ischemic stroke subtypes based on specific pathological conditions. We tried to verify this hypothesis by measuring blood viscosity in acute ischemic stroke patients using a newly developed electromagnetic spinning sphere (EMS) viscometer.

METHODS

Measurements in acute ischemic stroke patients were performed 4 times during admission and data were compared with those obtained from 100 healthy outpatient volunteers.

RESULTS

We enrolled 92 patients (cardioembolism: 25, large artery atherosclerosis: 42, and small artery occlusion [SAO]: 25) in this study. Comparisons of blood viscosity between the ischemic stroke subgroups and control group revealed that blood viscosity at the date of admission was significantly higher in the SAO group (5.37 ± 1.11 mPa⋅s) than in the control group (4.66 ± .72 mPa⋅s) (P < .01). Among all subtype groups showing a reduction in blood viscosity after 2 weeks, the SAO group showed the highest and most significant reduction, indicating that SAO patients had the most concentrated blood at the onset.

CONCLUSIONS

Blood viscosity was significantly increased in the SAO group at the date of admission, which indicated the contribution of dehydration to the onset of ischemic stroke. The importance of dehydration needs to be emphasized more in the pathogenesis of SAO. The clinical application of the EMS viscometer is promising for understanding and differentiating the pathogenesis of ischemic stroke.

Effect of dehydration on the development of collaterals in acute middle cerebral artery occlusion

BACKGROUND AND PURPOSE

Recent large series studies have demonstrated that dehydration is common amongst stroke subjects and is associated with poor outcome. However, the effects of hydration status on the development of collaterals have never been discussed. In this study, the hypothesis that hydration status is an important factor for developing collaterals after acute middle cerebral artery (MCA) infarction was tested.

METHODS

Eighty-seven patients with acute infarction due to occlusion of the MCA were enrolled. Two collateral markers, posterior cerebral artery (PCA) laterality and fluid-attenuated inversion recovery hyperintense vessels (HVs) were assessed from magnetic resonance imaging. Dehydration status was defined by a nitrogen to creatinine ratio ≧ of 15. The associations between dehydration status and the development of collaterals were estimated.

RESULTS

Sixty-one of 87 patients (70.1%) were identified as dehydrated. The development of PCA laterality and HVs shows a significant difference between dehydrated and euhydrated patients. A serum nitrogen to creatinine ratio <15, diastolic blood pressure and the presence of a dense MCA on computed tomography were significantly associated with the development of PCA laterality. A serum nitrogen to creatinine ratio <15, the initial National Institutes of Health Stroke Scale score, the presence of a dense MCA and calcifications of the internal carotid artery on computed tomography were significantly associated with the development of HVs. Dehydration remained an independent negative predictor for the development of PCA laterality and HVs in the multivariate analysis.

CONCLUSIONS

Hydration status is associated with the development of collateral flow after acute MCA occlusion. This preliminary study provides an imaging clue that hydration status and early hydration therapy could be important for acute stroke management.

Dysphagia, nutrition, and hydration in ischemic stroke patients at admission and discharge from acute care

Dysphagia may predispose stroke patients toward undernutrition and hydration. These comorbidities increase patient risks for reduced functional outcome and short-term mortality. Despite this impact, available information on relationships among dysphagia, nutrition, and hydration status in acute stroke is limited and conflicted. This study evaluated nutrition and hydration status in ischemic stroke patients with versus without clinically significant dysphagia at admission and at discharge from acute care. Sixty-seven patients admitted to the stroke unit in a tertiary-care hospital provided data for this study. On the day of hospital admission and upon discharge or at 7 days post admission, serum biochemical measures were obtained for nutrition (prealbumin) and hydration status (BUN/Cr). Clinical evaluation for dysphagia, nutrition status, and stroke severity were completed an average of 1.4 days following hospital admission. Dysphagia was identified in 37 % of the cohort. At admission 32 % of patients demonstrated malnutrition based on prealbumin levels and 53 % demonstrated evidence of dehydration based on BUN/Cr levels. No differences in nutrition status were attributed to dysphagia. Patients with dysphagia demonstrated significantly higher BUN/Cr levels (greater dehydration) than patients without dysphagia at admission and at discharge. Dehydration at both admission and discharge was associated with dysphagia, clinical nutrition status, and stroke severity. Results of this study support prior results indicating that dysphagia is not associated with poor nutrition status during the first week post stroke. Dehydration status is associated with dysphagia during this period. The results have implications for future confirmatory research and for clinical management of dysphagia in the acute stroke period.