Prolonged elevated heart rate is a risk factor for adverse cardiac events and poor outcome after subarachnoid hemorrhage

Development of a predictive nomogram for 28-day mortality risk in non-traumatic or post-traumatic subarachnoid hemorrhage patients

OBJECTIVE

Subarachnoid hemorrhage (SAH) is associated with high rates of mortality and permanent disability. At present, there are few definite clinical tools to predict prognosis in SAH patients. The current study aims to develop and assess a predictive nomogram model for estimating the 28-day mortality risk in both non-traumatic or post-traumatic SAH patients.

METHODS

The MIMIC-III database was searched to select patients with SAH based on ICD-9 codes. Patients were separated into non-traumatic and post-traumatic SAH groups. Using LASSO regression analysis, we identified independent risk factors associated with 28-day mortality and incorporated them into nomogram models. The performance of each nomogram was assessed by calculating various metrics, including the area under the curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA).

RESULTS

The study included 999 patients with SAH, with 631 in the non-traumatic group and 368 in the post-traumatic group. Logistic regression analysis revealed critical independent risk factors for 28-day mortality in non-traumatic SAH patients, including gender, age, glucose, platelet, sodium, BUN, WBC, PTT, urine output, SpO2, and heart rate and age, glucose, PTT, urine output, and body temperature for post-traumatic SAH patients. The prognostic nomograms outperformed the commonly used SAPSII and APSIII systems, as evidenced by superior AUC, NRI, IDI, and DCA results.

CONCLUSION

The study identified independent risk factors associated with the 28-day mortality risk and developed predictive nomogram models for both non-traumatic and post-traumatic SAH patients. The nomogram holds promise in guiding prognosis improvement strategies for patients with SAH.

Prolonged elevated heart rate and 90-Day mortality in acute pancreatitis

Prolonged elevated heart rate (peHR) is recognized as a risk factor for poor prognosis among critically ill patients. However, there is currently a lack of studies investigating the association between peHR and patients with acute pancreatitis. Multiparameter Intelligent Monitoring in Intensive Care IV (MIMIC-IV) database was used to identify patients with acute pancreatitis. PeHR was defined as a heart rate exceeding 100 beats per minute for at least 11 out of 12 consecutive hours. Cox regression analysis was used to assess the association between peHR and the 90-Day mortality. A total of 364 patients (48.9%) experienced a peHR episode. The 90-day mortality was 25%. PeHR is an independent risk factor for 90-day mortality (HR, 1.98; 95% CI 1.53-2.56; P < 0.001). KM survival curves exhibited a significant decrease in the survival rate at 90 days among patients who experienced a peHR episode (P < 0.001, 84.5% vs. 65.1%). We revealed a significant association of peHR with decreased survival in a large cohort of ICU patients with acute pancreatitis.

Endocrine dysregulation in aneurysmal subarachnoid haemorrhage

INTRODUCTION

Aneurysmal Subarachnoid haemorrhage (aSAH) is one of the most common causes of neurocritical care admission. Consistent evidence has been suggestive of endocrine dysregulation in aSAH. This review aims to provide an up-to-date presentation of the available evidence regarding endocrine dysregulation in aneurysmal subarachnoid haemorrhage.

METHODS

A comprehensive literature search was performed using PubMed database. All available evidence related to endocrine dysregulation in hypothalamic-pituitary hormones, adrenal hormones and natriuretic peptides after aSAH, published since 2010, were reviewed.

RESULTS

There have been reports of varying prevalence of dysregulation in hypothalamic-pituitary and adrenal hormones in aSAH. The cause of this dysregulation and its pattern remain unclear. Hypothalamic-pituitary and adrenal dysregulation have been associated with higher incidence of poor neurological outcome and increased mortality. Whilst there is evidence that long-term dysregulation of these axes may also develop, it appears to be less frequent than the acute-phase dysregulation and transient in pattern. Increased levels of catecholamines have been reported in the hyper-acute phase of aSAH with reported inconsistent correlation with the outcomes and the complications of the disease. There is growing evidence that of a causal link between the endocrine dysregulation and the development of hyponatraemia and delayed cerebral ischaemia, in the acute phase of aSAH. However, the pathophysiological mechanism and pattern of endocrine dysregulation which could be causally associated with these complications still remain debatable.

CONCLUSION

The evidence, mainly from small observational and heterogeneous in methodology studies, is suggestive of adverse effects of the endocrine dysregulation on the outcome and the incidence of complications of the disease. However, the cause of this dysregulation and a pathophysiological mechanism that could link its presence with the development of acute complications and the outcome of the aSAH remain unclear. Further research is warranted to elucidate the clinical significance of endocrine dysregulation in subarachnoid haemorrhage.

XGBoost Machine Learning Algorithm for Prediction of Outcome in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Patients suffered aneurysmal subarachnoid hemorrhage (aSAH) usually develop poor survival and functional outcome. Evaluating aSAH patients at high risk of poor outcome is necessary for clinicians to make suitable therapeutical strategy. This study is conducted to develop prognostic model using XGBoost (extreme gradient boosting) algorithm in aSAH.

METHODS

A total of 351 aSAH patients admitted to West China hospital were identified. Patients were divided into training set and test set with ratio of 7:3 to testify the predictive value of XGBoost based prognostic model. Additionally, logistic regression model was also constructed and compared with XGBoost based model. Area under the receiver operating characteristic curve (AUC), sensitivity and specificity were calculated to evaluate the value of XGBoost and logistic regression.

RESULTS

There were 74 (21.1%) non-survivors and 148 (42.1%) patients with unfavorable functional outcome. Non-survivors had older age (p=0.025), lower Glasgow coma scale (GCS) (p<0.001), higher World Federation of Neurosurgical Societies WFNS score (p<0.001), mFisher score (p<0.001). The incidence of intraventricular hemorrhage (IVH) (p=0.025) and delayed cerebral ischemia (DCI) (p<0.001) was higher in non-survivors than survivors. The AUC of XGBoost model for predicting mortality and unfavorable functional outcome were 0.950 and 0.958, which were higher than 0.767 and 0.829 of logistic regression model.

CONCLUSION

XGBoost based model is more precise than logistic regression model in predicting outcome of aSAH patients. Using XGBoost prognostic model is helpful for clinicians to identify high-risk aSAH patients and therefore strengthen medical care.

Aneurysmal Subarachnoid Hemorrhage: the Last Decade

Aneurysmal subarachnoid hemorrhage (SAH) affects six to nine people per 100,000 per year, has a 35% mortality, and leaves many with lasting disabilities, often related to cognitive dysfunction. Clinical decision rules and more sensitive computed tomography (CT) have made the diagnosis of SAH easier, but physicians must maintain a high index of suspicion. The management of these patients is based on a limited number of randomized clinical trials (RCTs). Early repair of the ruptured aneurysm by endovascular coiling or neurosurgical clipping is essential, and coiling is superior to clipping in cases amenable to both treatments. Aneurysm repair prevents rebleeding, leaving the most important prognostic factors for outcome early brain injury from the hemorrhage, which is reflected in the neurologic condition of the patient, and delayed cerebral ischemia (DCI). Observational studies suggest outcomes are better when patients are managed in specialized neurologic intensive care units with inter- or multidisciplinary clinical groups. Medical management aims to minimize early brain injury, cerebral edema, hydrocephalus, increased intracranial pressure (ICP), and medical complications. Management then focuses on preventing, detecting, and treating DCI. Nimodipine is the only pharmacologic treatment that is approved for SAH in most countries, as no other intervention has demonstrated efficacy. In fact, much of SAH management is derived from studies in other patient populations. Therefore, further study of complications, including DCI and other medical complications, is needed to optimize outcomes for this fragile patient population.

Electrocardiographic changes following intracranial haemorrhage: a retrospective cohort study

OBJECTIVE

To improve the understanding of the association between electrocardiographic (ECG) abnormalities and clinical outcomes of patients with all types of intracranial hemorrhage (ICH).

METHODS

A retrospective cohort study was conducted in a tertiary healthcare hospital on patients with ICH without cardiac disease or renal disease requiring dialysis. Demographic and clinical data were collected from hospital records. ECG record were obtained within 24 hours of presentation and prior to treatment. Records were interpreted for this study by a cardiologist blinded to other data.

RESULTS

Assessment of 291 patients (228 adults and 63 children) showed that subdural hemorrhage was the most common type of ICH (31.6%) followed by intraparenchymal hemorrhage (23.0%). ECG records were available for 98 patients. ECG abnormalities were most commonly nonspecific ST-segment changes (32.6%). In adults, history of neurological disease was associated with atrioventricular block (p=.004) and QTc prolongation (p=.041). Pediatric patients exhibited associations between ST-segment changes (p=.045) and sinus tachycardia (p=.027) and type of ICH. However, ECG changes were not statistically associated with clinical outcomes in adults or children.

CONCLUSION

Significant ECG changes frequently occurred in patients with all types of ICH but did not consistently predict the outcome in this study. Close observation of patients is still recommended to detect ECG changes that could affect the treatment.

Beta-Blockade in Aneurysmal Subarachnoid Hemorrhage: a Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVE

Sympathetic nervous system activation after aneurysmal subarachnoid hemorrhage (aSAH) is associated with complications and poor outcome. In this systematic review and meta-analysis, we investigate the effect of beta-blockers on outcome after aSAH.

METHODS

The review was prospectively registered with PROSPERO (CRD42019111784). We performed a systematic literature search of MEDLINE, EMBASE, the Cochrane Library, published conference proceedings, and abstracts. Eligible studies included both randomized controlled trials and observational studies up to October 2018, reporting the effect of beta-blocker therapy on the following outcomes in aSAH: mortality, vasospasm, delayed cerebral ischemia, infarction or stroke, cardiac dysfunction, and functional outcomes. Studies involving traumatic SAH were excluded. Citations were reviewed, and data extracted independently by two investigators using a standardized proforma.

RESULTS

We identified 819 records with 16 studies (four were randomized controlled trials) including 6702 patients selected for analysis. Exposure to beta-blockade either before or after aSAH was associated with a significant reduction in unadjusted mortality (RR 0.63, 95% CI 0.42-0.93, p = 0.02). A significant reduction in unadjusted mortality was also seen in prospective trials of post-event beta-blockade (RR 0.51, 95% CI 0.28-0.93, p = 0.03). Statistically significant differences were not seen for other outcomes investigated.

CONCLUSIONS

In adult patients with aSAH, beta-blocker therapy is associated with a mortality benefit. Studies are generally of a low quality with considerable clinical heterogeneity. Prospective large interventional trials with patient centered outcomes are required to validate this finding.

White Blood Cell Count Improves Prediction of Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Immune dysregulation has long been implicated in the development of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH).

OBJECTIVE

To determine the relationship of inflammatory cell biomarkers with DCI.

METHODS

We evaluated 849 aSAH patients who were enrolled into a prospective observational cohort study and had a white blood cell (WBC) differential obtained within 72 h of bleed onset.

RESULTS

WBC count > 12.1 × 109/L (odds ratio 4.6; 95% confidence interval [CI]: 1.9-11, P < 0.001) was the strongest Complete Blood Count (CBC) predictor of DCI after controlling for clinical grade (P < .001), thickness of SAH blood on admission computed tomography (P = .002), and clipping aneurysm repair (P < .001). A significant interaction between clinical grade and WBC count (odds ratio 0.8, 95% CI: 0.6-1.0, P = .02) revealed that good-grade patients with elevated WBC counts (49%: 273/558) had increased odds for DCI indistinguishable from poor-grade patients. Multivariable Cox regression also showed that elevated WBC counts in good-grade patients increased the hazard for DCI to that of poor-grade patients (hazard ratio 2.1, 95% CI 1.3-3.2, P < .001). Receiver operating characteristic curve analysis of good-grade patients revealed that WBC count (area under the curve [AUC]: 0.63) is a stronger DCI predictor than the modified Fisher score (AUC: 0.57) and significantly improves multivariable DCI prediction models (Z = 2.0, P = .02, AUC: 0.73; PPV: 34%; NPV: 92%).

CONCLUSION

Good-grade patients with early elevations in WBC count have a similar risk and hazard for DCI as poor-grade patients. Good-grade patients without elevated WBC may be candidates to be safely downgraded from the intensive care unit, leading to cost savings for both patient families and hospitals.

Assessment of the ECG T-Wave in Patients With Subarachnoid Hemorrhage

BACKGROUND

Prolongation of the interval from the peak to the end of the T wave (Tp-Te) on a 12-lead electrocardiogram (ECG) is associated with ventricular arrhythmias. The aim of this study was to clarify associations between Tp-Te, Tp-Te/QT, and Tp-Te/rate-corrected QT (QTc) with clinical severity of subarachnoid hemorrhage (SAH) and clinical outcomes.

METHODS

This retrospective study included 222 patients with acute SAH (group S) and 306 patients with unruptured cerebral aneurysms (group U). Tp-Te, Tp-Te/QT, and Tp-Te/QTc were manually measured in standard 12-lead ECG recordings on admission and comparisons made between patients in groups S and U. The relationships of these ECG parameters with Hunt and Hess grade and Glasgow outcome scale were analyzed using multiple logistic regression analysis after adjustment for confounding factors.

RESULTS

Tp-Te, Tp-Te/QT, and Tp-Te/QTc were significantly greater in group S than in group U (group S: 109±30, 0.26±0.07, and 0.24±0.06 ms; group U: 84±12, 0.22±0.03, and 0.21±0.03 ms, respectively; P < 0.0001). In addition, in the multiple logistic regression analyses these variables were positively correlated with the Hunt and Hess grade (Tp-Te odds ratio [95% confidence interval], 2.414 [1.375-4.238], P=0.002; Tp-Te/QT, 1.886 [1.085-3.277], P = 0.024; Tp-Te/QTc, 1.873 [1.07-3.278], P=0.028, and negatively correlated with Glasgow outcome scale Tp-Te odds ratio [95% confidence interval], 4.168 [2.409-7.209], P<0.001; Tp-Te/QT, 2.434 [1.413-4.192], P=0.001; Tp-Te/QTc 2.953 [1.703-5.123], P<0.001).

CONCLUSIONS

Tp-Te, Tp-Te/QT, and Tp-Te/QTc are associated with disease severity and clinical outcome in patients with SAH.

Heart rate variability after endovascular coiling is associated with short-term outcomes in patients with subarachnoid hemorrhage

OBJECTIVE

to evaluate whether postoperative heart rate variability (HRV) predicts short-term outcomes in patients undergoing coil embolization of ruptured aneurysms.

METHODS

Consecutive patients receiving endovascular coiling to treat aneurysmal subarachnoid hemorrhage (SAH) were retrospectively reviewed between November 2011 and December 2014 in the authors' institution. Heart rate (HR) and blood pressure (BP) recorded in the initial 24 h after endovascular treatment were extracted along with other clinical data. HR variability (HRV) and BP variability (BPV) were determined as standard deviation (SD) and successive variation (SV) of every 2-h HR and BP. The correlation between HRV and clinical outcomes as assessed by Glasgow Outcome Scale (GOS) scores at discharge were analyzed statistically.

RESULTS

Compared to the 310 patients with favorable outcomes (GOS 4-5), the 35 with unfavorable outcomes (GOS 1-3) had significantly higher HR, HRV, and BPV in the first postoperative day. Furthermore, HRV-SD remained to be an independent predictor of unfavorable recovery in multivariate logistic analysis (OR = 1.14; 95% CI, 1.02-1.29; P = 0.026) after adjusting for age, postoperative fever, and Glasgow Coma Scale scores on admission, which have been identified as predictors of poor prognosis. The area under the receiver operating characteristic curves for HRV-SD and BPV-SV were found to be 0.745 (95% CI, 0.658-0.833) and 0.633 (95% CI, 0.524-0.741), respectively (P < 0.05).

CONCLUSIONS

Higher HRV in the first day after coil embolization was associated with unfavorable outcomes in patients with SAH. Early detection and appropriate treatment of the overactive sympathetic activity might promote functional recovery after SAH. Abbreviation: BP: Blood pressure; CI: Confidence interval; DBP: Diastolic blood pressure; GCS: Glasgow coma scale; GOS: Glasgow outcome scale; HR: Heart rate; HRV: Heart rate variability; OR: Odds ratio; ROC: Receiver operating characteristics; SD: Standard deviation; SAH: Subarachnoid hemorrhage; SV: Successive variation; SBP: Systolic blood pressure.

Intradialytic blood pressure pattern recognition based on density peak clustering

End-stage renal disease (ESRD) is the final stage of chronic kidney disease (CKD) and requires hemodialysis (HD) for survival. Intradialytic blood pressure (IBP) measurements are necessary to ensure patient safety during HD treatments and have critical clinical and prognostic significance. Studies on IBP measurements, especially IBP patterns, are limited. All related studies have been based on a priori knowledge and artificially classified IBP patterns. Therefore, the results were influenced by subjective concepts. In this study, we proposed a new approach to identify IBP patterns to classify ESRD patients. We used the dynamic time warping (DTW) algorithm to measure the similarity between two series of IBP data. Five blood pressure (BP) patterns were identified by applying the density peak clustering algorithm (DPCA) to the IBP data. To illustrate the association between BP patterns and prognosis, we constructed three random survival forest (RSF) models with different covariates. Model accuracy was improved 3.7-6.3% by the inclusion of BP patterns. The results suggest that BP patterns have critical clinical and prognostic significance regarding the risk of cerebrovascular events. We can also apply this clustering approach to other time series data from electronic health records (EHRs). This work is generalizable to analyses of dense EHR data.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Beta-blocker therapy is not associated with mortality after intracerebral hemorrhage

BACKGROUND

Beta-blocker therapy has been suggested to have neuroprotective properties in the setting of acute stroke; however, the evidence is weak and contradictory. We aimed to examine the effects of pre-admission therapy with beta-blockers (BB) on the mortality following spontaneous intracerebral hemorrhage (ICH).

METHODS

Retrospective analysis of the Helsinki ICH Study database.

RESULTS

A total of 1013 patients with ICH were included in the analysis. Patients taking BB were significantly older, had a higher premorbid mRS score, had more DNR orders, and more comorbidities as atrial fibrillation, hypertension, diabetes mellitus, ischemic heart disease, and heart failure. After adjustment for age, pre-existing comorbidities, and prior use of antithrombotic and antihypertensive medications, no differences in in-hospital mortality (OR 1.1, 95% CI 0.8-1.7), 12-month mortality (OR 1.3, 95% CI 0.9-1.9), and 3-month mortality (OR 1.2, 95% CI 0.8-1.7) emerged.

CONCLUSION

Pre-admission use of BB was not associated with mortality after ICH.

The Extracranial Consequences of Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is managed across the full spectrum of healthcare, from clinical diagnosis to management of the hemorrhage and associated complications. Knowledge of the pathogenesis and pathophysiology of SAH is widely known; however, a full understanding of the underlying molecular, cellular, and circulatory dynamics has still to be achieved. Intracranial complications including delayed ischemic neurologic deficit (vasospasm), rebleed, and hydrocephalus form the targets for initial management. However, the extracranial consequences including hypertension, hyponatremia, and cardiopulmonary abnormalities can frequently arise during the management phase and have shown to directly affect clinical outcome. This review will provide an update on the pathophysiology of SAH, including the intra- and extracranial consequences, with a particular focus on the extracranial consequences of SAH.

METHODS

We review the literature and provide a comprehensive update on the extracranial consequences of SAH that we hope will help the management of these cohort of patients.

RESULTS

In addition to the pathophysiology of SAH, the following complications were examined and discussed: vasospasm, seizures, rebleed, hydrocephalus, fever, anemia, hypertension, hypotension, hyperglycemia, hyponatremia, hypernatremia, cardiac abnormalities, pulmonary edema, venous thromboembolism, gastric ulceration, nosocomial infection, bloodstream infection/sepsis, and iatrogenic complications.

CONCLUSIONS

Although the intracranial complications of SAH can take priority in the initial management, the extracranial complications should be monitored for and recognized as early as possible because these complications can develop at varying times throughout the course of the condition. Therefore, a variety of investigations, as described by this article, should be undertaken on admission to maximize early recognition of any of the extracranial consequences. Furthermore, because the extracranial complications have a direct effect on clinical outcome and can lead to and exacerbate the intracranial complications, monitoring, recognizing, and managing these complications in parallel with the intracranial complications is important and would allow optimization of the patient's management and thus help improve their overall outcome.

Emerging Markers of Early Brain Injury and Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage is characterized by a highly complex pathophysiology and results in neurologic deterioration after the inciting bleed. Despite its significant consequences, prompt diagnosis can be elusive and treatment is often administered too late. Early brain injury, which occurs within the first 72 hours after ictus, may be an important factor for delayed cerebral ischemia and poor overall outcome. Here, we explore the purported clinical and pathologic manifestations of early brain injury to identify biomarkers that could have prognostic value.

METHODS

We review the literature and discuss potential emerging markers of delayed cerebral ischemia in the context of early brain injury.

RESULTS

The following clinical features and biomarkers were examined: global cerebral edema, ictal loss of consciousness, ultra early angiographic vasospasm, continuous electroencephalogram monitoring, systemic inflammatory response syndrome, cellular mediators of the inflammatory response, and hematologic derangements.

CONCLUSIONS

Some of these markers possess independent value for determining the risk of complications after aneurysmal subarachnoid hemorrhage. However, their use is limited because of a variety of factors, but they do provide an avenue of further study to aid in diagnosis and management.

Clinical Presentation to the Emergency Department Predicts Subarachnoid Hemorrhage-Associated Myocardial Injury

INTRODUCTION

Aneurysmal subarachnoid hemorrhage (aSAH) is frequently seen in emergency departments. Secondary injury, such as subarachnoid hemorrhage-associated myocardial injury (SAHMI), affects one third of survivors and contributes to poor outcomes. SAHMI is not attributed to ischemia from myocardial disease but can result in hypotension and arrhythmias. It is important that emergency nurses recognize which clinical presentation characteristics are predictive of SAHMI to initiate proper interventions. The aim of this study was to determine whether patients who present to the emergency department with clinical aSAH are likely to develop SAHMI, as defined by troponin I ≥0.3 ng/mL.

METHODS

This was a prospective descriptive study. SAHMI was defined as troponin I ≥0.3 ng/mL. Predictors included demographics and clinical characteristics, severity of injury, admission 12-lead electrogardiogram (ECG), initial emergency department vital signs, and pre-hospital symptoms at time of aneurysm rupture.

RESULTS

Of 449 patients, 126 (28%) had SAHMI. Patients with SAHMI were more likely to report seizures and unresponsiveness with significantly lower Glasgow coma score and higher proportion of Hunt and Hess grades 3 to 5 and Fisher grades III and IV (all P < .05). Patients with SAHMI had higher atrial and ventricular rates and longer QTc intervals on initial ECG (P < .05). On multivariable logistic regression, poor Hunt and Hess grade, report of prehospital unresponsiveness, lower admission Glasgow coma score, and longer QTc interval were significantly and independently predictive of SAHMI (P < .05).

DISCUSSION

Components of the clinical presentation of subarachnoid hemorrhage to the emergency department predict SAHMI. Identifying patients with SAHMI in the emergency department can be helpful in determining surveillance and care needs and informing transfer unit care. Contribution to Emergency Nursing Practice.

ADARRI: a novel method to detect spurious R-peaks in the electrocardiogram for heart rate variability analysis in the intensive care unit

We developed a simple and fully automated method for detecting artifacts in the R-R interval (RRI) time series of the ECG that is tailored to the intensive care unit (ICU) setting. From ECG recordings of 50 adult ICU-subjects we selected 60 epochs with valid R-peak detections and 60 epochs containing artifacts leading to missed or false positive R-peak detections. Next, we calculated the absolute value of the difference between two adjacent RRIs (adRRI), and obtained the empirical probability distributions of adRRI values for valid R-peaks and artifacts. From these, we calculated an optimal threshold for separating adRRI values arising from artifact versus non-artefactual data. We compared the performance of our method with the methods of Berntson and Clifford on the same data. We identified 257,458 R-peak detections, of which 235,644 (91.5%) were true detections and 21,814 (8.5%) arose from artifacts. Our method showed superior performance for detecting artifacts with sensitivity 100%, specificity 99%, precision 99%, positive likelihood ratio of 100 and negative likelihood ratio <0.001 compared to Berntson's and Clifford's method with a sensitivity, specificity, precision and positive and negative likelihood ratio of 99%, 78%, 82%, 4.5, 0.013 for Berntson's method and 55%, 98%, 96%, 27.5, 0.460 for Clifford's method, respectively. A novel algorithm using a patient-independent threshold derived from the distribution of adRRI values in ICU ECG data identifies artifacts accurately, and outperforms two other methods in common use. Furthermore, the threshold was calculated based on real data from critically ill patients and the algorithm is easy to implement.

Heart Rate Variability for the Early Detection of Delayed Cerebral Ischemia

Delayed cerebral ischemia is considered the leading cause of death or major disability in subarachnoid hemorrhage after the impact of the initial event and rebleeding. Waiting to treat patients until they exhibit clinical symptoms of ischemia is too late to prevent cerebral infarction for more than 60% of patients, and transcranial Doppler ultrasonography has not proven to be a reliable screening tool to identify high-risk patients. Continuous heart rate variability monitoring may provide an alternative screening strategy to identify patients at high risk for delayed cerebral ischemia. Heart rate variability is a composite reflection of autonomic outflow, neuroendocrine influences, and autonomic responsiveness. Most importantly, heart rate variability is responsive to changes in systemic inflammation, which evidence suggests is important to the causal pathway of delayed cerebral ischemia. The clinical application of continuous heart rate variability monitoring in critical care is relatively recent despite its existence for more than 50 years. Initial studies suggest promise for heart rate variability monitoring as a delayed cerebral ischemia screening tool, but significant research is still required before this approach may achieve clinical applicability and bring benefit to patients.

Early Circulating Lactate and Glucose Levels After Aneurysmal Subarachnoid Hemorrhage Correlate With Poor Outcome and Delayed Cerebral Ischemia: A Two-Center Cohort Study

OBJECTIVE

In critically ill patients, elevated blood lactate at admission is associated with poor outcome, but after aneurysmal subarachnoid hemorrhage, this has not been investigated. We studied the association between early circulating lactate and glucose with delayed cerebral ischemia and poor outcome. Lactate and glucose were both studied, hypothesizing that both may be increased due to sympathetic activation after subarachnoid hemorrhage similar to critically ill patients.

DESIGN

Retrospective cohort study.

SETTING

ICUs of two academic hospitals in the Netherlands.

PATIENTS

Patients with aneurysmal subarachnoid hemorrhage admitted to the ICU within 24 hours after the bleed surviving beyond 48 hours after ICU admission and who had at least one lactate measurement within 24 hours after admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In 285 patients, maximal lactate and glucose levels within the first 24 hours after admission were determined. Early lactate and glucose were related with delayed cerebral ischemia-related infarction and poor outcome (a modified Rankin Scale score of 4, 5, or death at 3 mo). Delayed cerebral ischemia occurred in 84 patients (29%), and 106 patients (39%) had poor outcome. Multivariable analyses were performed with adjustment of established predictors for delayed cerebral ischemia and outcome: age, sex, World Federation of Neurological Surgeons grade at admission and Hijdra sum scores. Early lactate and glucose were strongly related (Spearman ρ = 0.55; p < 0.001). Lactate and glucose were both independently associated with delayed cerebral ischemia and poor outcome in multivariable analyses with either lactate or glucose as covariates. When both lactate and glucose were included, only glucose showed an independent association with delayed cerebral ischemia (odds ratio, 1.14; 95% CI, 1.01-1.28) and only lactate showed an independent association with poor outcome (odds ratio, 1.42; 95% CI, 1.11-1.81).

CONCLUSIONS

Early lactate and glucose levels after aneurysmal subarachnoid hemorrhage are associated with delayed cerebral ischemia and poor outcome, suggesting that they may be considered in conjunction with other parameters for future prognostic models.

A Partial Least-Squares Analysis of Health-Related Quality-of-Life Outcomes After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Individuals who have aneurysmal subarachnoid hemorrhages (SAHs) experience decreased health-related qualities of life (HRQoLs) that persist after the primary insult.

OBJECTIVE

To identify clinical variables that concurrently associate with HRQoL outcomes by using a partial least-squares approach, which has the distinct advantage of explaining multidimensional variance where predictor variables may be highly collinear.

METHODS

Data collected from the CONSCIOUS-1 trial was used to extract 29 clinical variables including SAH presentation, hospital procedures, and demographic information in addition to 5 HRQoL outcome variables for 256 individuals. A partial least-squares analysis was performed by calculating a heterogeneous correlation matrix and applying singular value decomposition to determine components that best represent the correlations between the 2 sets of variables. Bootstrapping was used to estimate statistical significance.

RESULTS

The first 2 components accounting for 81.6% and 7.8% of the total variance revealed significant associations between clinical predictors and HRQoL outcomes. The first component identified associations between disability in self-care with longer durations of critical care stay, invasive intracranial monitoring, ventricular drain time, poorer clinical grade on presentation, greater amounts of cerebral spinal fluid drainage, and a history of hypertension. The second component identified associations between disability due to pain and discomfort as well as anxiety and depression with greater body mass index, abnormal heart rate, longer durations of deep sedation and critical care, and higher World Federation of Neurosurgical Societies and Hijdra scores.

CONCLUSION

By applying a data-driven, multivariate approach, we identified robust associations between SAH clinical presentations and HRQoL outcomes.

ABBREVIATIONS

EQ-VAS, EuroQoL visual analog scaleHRQoL, health-related quality of lifeICU, intensive care unitIVH, intraventricular hemorrhagePLS, partial least squaresSAH, subarachnoid hemorrhageSVD, singular value decompositionWFNS, World Federation of Neurosurgical Societies.

Isoflurane postconditioning with cardiac support promotes recovery from early brain injury in mice after severe subarachnoid hemorrhage

AIMS

Neurocardiac dysfunction is a life-threatening systemic consequence of subarachnoid hemorrhage (SAH) that contributes to triggering delayed cerebral ischemia (DCI). This study aimed to determine the impact of dobutamine cardiac support during isoflurane postconditioning on post-SAH DCI.

MAIN METHODS

Male C57BL/6 mice were subjected to SAH, SAH plus isoflurane postconditioning, or SAH plus isoflurane postconditioning with dobutamine. Severity of SAH was graded from 1 to 4 (mild, 1-2; severe, 3-4) based on T2*-weighted magnetic resonance imaging (MRI). Cardiac output (CO) measured by transthoracic pulsed wave Doppler-echocardiography was titrated at a supra-normal level with intravenous dobutamine infusion. Neurological function was examined daily by neurological score and Rotarod tests. DCI was analyzed 3days later by determining new infarction on diffusion-weighted MRI. In a separate experiment, mice were pretreated with hypoxia-inducible factor (HIF) inhibitor 2-methoxyestradiol (2ME2).

KEY FINDINGS

Clinically relevant CO depression was notable in severe SAH grade mice, in which dobutamine CO management combined with isoflurane postconditioning showed earlier and improved functional recovery than postconditioning with single isoflurane inhalation. Incidence of infarction and volumes on day 3 reduced significantly in this subgroup. All of the effects during preconditioning were attenuated by 2ME2 pretreatment.

SIGNIFICANCE

Isoflurane postconditioning under dobutamine cardiac support improves recovery from SAH-induced early brain injury, leading to reduced DCI resultant from severe experimental SAH. These results indicate the importance of neuro-cardiac protection, in which HIF may be acting as a critical mediator, as a promising therapeutic approach to SAH.

Indicators of Subarachnoid Hemorrhage as a Cause of Sudden Cardiac Arrest

Subarachnoid hemorrhage (SAH) may present with cardiac arrest (SAH-CA). We report a case of SAH-CA to assist providers in distinguishing SAH as an etiology of cardiac arrest despite electrocardiogram findings that may be suggestive of a cardiac etiology. SAH-CA is associated with high rates of return of spontaneous circulation, but overall poor outcome. An initially non-shockable cardiac rhythm and the absence of brain stem reflexes are important clues in indentifying SAH-CA.

Tachycardia burden in stroke unit is associated with functional outcome after ischemic stroke

BACKGROUND

Stroke unit care is associated with decrease in mortality and improvement in neurological outcome in patients with acute stroke. Heart rate is a commonly monitored variable in the stroke unit. However, little is known about tachycardia burden in the stroke unit and its association with outcome.

AIMS

To investigate the effects of tachycardia burden in the stroke unit on functional outcome in patients with acute ischemic stroke.

METHODS

We collected data from 246 patients with acute ischemic stroke admitted to our stroke unit between July 2013 and June 2014. Tachycardia burden was defined as duration of heart rate over 95 per minute divided by the total monitoring time, using the heart rate data sampled every 1 min. We divided the study population into quartiles of tachycardia burden and analyzed their association with poor three-month functional outcome (modified Rankin Scale score of ≥3).

RESULTS

Among included patients (age, 67.4 ± 12.8; male, 53.7%), tachycardia burden was 0.7% (median, interquartile range [0.1-5.7%]). The patients with higher tachycardia burdens were older, more likely to have higher stroke severity, cardioembolic etiology, atrial fibrillation, fever, pneumonia, higher initial glucose level, and higher white blood cell count. As compared with the lowest quartile (<0.1%), the highest quartile of tachycardia burden (≥6.0%) was significantly associated with poor outcome (adjusted odds ratio, 5.10; 95% confidence interval, 1.38-18.90; p = 0.01) after adjustment for covariates.

CONCLUSIONS

Patients with increased tachycardia burden during stroke unit stay have poor functional outcome. Countermeasures against worsening factors might be utilized for patients with increased tachycardia burden.

Elevated high-sensitive troponin T on admission is an indicator of poor long-term outcome in patients with subarachnoid haemorrhage: a prospective observational study

BACKGROUND

Patients with subarachnoid haemorrhage (SAH) frequently develop cardiac complications in the acute phase after the bleeding. Although a number of studies have shown that increased levels of cardiac biomarkers after SAH are associated with a worse short-term prognosis, no prospective, consecutive study has assessed the association between biomarker release and long-term outcome. We aimed to evaluate whether the cardiac biomarkers, high-sensitive troponin T (hsTnT) and N-terminal pro B-type natriuretic peptide (NTproBNP), were associated with poor 1-year neurological outcome and cerebral infarction due to delayed cerebral ischaemia (CI-DCI).

METHODS

In this single-centre prospective observational study, all consecutive patients admitted to our neurointensive care unit from January 2012 to December 2013 with suspected/verified SAH with an onset of symptoms <72 hours were enrolled. Blood samples for hsTnT and NTproBNP were collected during three consecutive days following admission. Patients were followed-up after 1 year using the Glasgow Outcome Scale Extended (GOSE). Poor neurological outcome was defined as GOSE ≤ 4.

RESULTS

One hundred and seventy seven patients with suspected SAH were admitted during the study period; 143 fulfilled inclusion criteria and 126 fulfilled follow-up. Forty-one patients had poor 1-year outcome and 18 had CI-DCI. Levels of hsTnT and NTproBNP were higher in patients with poor outcome and CI-DCI. In multivariable logistic regression modelling age, poor neurological admission status, cerebral infarction of any cause and peak hsTnT were independently associated with poor late outcome. Both peak hsTnT and peak NTproBNP were independently associated with CI-DCI.

CONCLUSION

Increased serum levels of the myocardial damage biomarker hsTnT, when measured early after onset of SAH, are independently associated with poor 1-year outcome. Furthermore, release of both hsTnT and NTproBNP are independently associated with CI-DCI. These findings render further support to the notion that troponin release after SAH is an ominous finding. Future studies should evaluate whether there is a causal relationship between early release of biomarkers of myocardial injury after SAH and neurological sequelae.

Classifying individuals based on a densely captured sequence of vital signs: An example using repeated blood pressure measurements during hemodialysis treatment

Electronic Health Records (EHRs) present the opportunity to observe serial measurements on patients. While potentially informative, analyzing these data can be challenging. In this work we present a means to classify individuals based on a series of measurements collected by an EHR. Using patients undergoing hemodialysis, we categorized people based on their intradialytic blood pressure. Our primary criteria were that the classifications were time dependent and independent of other subjects. We fit a curve of intradialytic blood pressure using regression splines and then calculated first and second derivatives to come up with four mutually exclusive classifications at different time points. We show that these classifications relate to near term risk of cardiac events and are moderately stable over a succeeding two-week period. This work has general application for analyzing dense EHR data.

Ellagic acid improves electrocardiogram waves and blood pressure against global cerebral ischemia rat experimental models

BACKGROUND

Global cerebral ischemia (GCIR) arises in patients that are shown a variety of clinical difficulty including cardiac arrest, asphyxia, and shock. In spite of advances in understanding of the brain, ischemia and protective effects to improve ischemic injury still remain unknown. The aim of our study was to investigate the effect of ellagic acid (EA) pretreatment in the rat models of global cerebral ischemia reperfusion.

METHODS

This experimental study was conducted in 2014 at the Physiology Research Center of the Ahvaz Jundishapur University of Medical Sciences in Ahvaz, Iran. Adult male Wistar rats (250-300 g) were used in this study. GCIR was induced by bilateral vertebral and common carotid arteries occlusion (4-VO). 32 rats were divided randomly to four groups: 1) So (Sham) received normal saline as vehicle of EA, 2) EA, 3) normal saline + GCIR, and 4) EA + GCIR. After anesthesia (a mix of xylazine and ketamine), animal subjected to 20 minutes of ischemia followed by 30 minutes of reperfusion in related groups. EA (100 mg/kg, dissolved in normal saline) or 1.5 ml/kg normal saline was administered (gavage, 10 days) to the related groups. EEG was recorded from NTS in GCIR treated groups.

RESULTS

Present data showed that: 1) EEG in GCIR treated groups was flattened; 2) Blood pressure, voltage of QRS and P-R interval were reduced significantly in the ischemic groups compared to before ischemia, and pretreatment with EA prevented this reduction; and 3) MDA level and heart rate was increased by GCIR and pretreatment with EA reduced MDA level and restored the HR to normal level.

CONCLUSION

Results indicate that global cerebral ischemia-reperfusion impairs certain heart functions and ellagic acid as an antioxidant can restore these parameters. The results of this study suggest the possible utility of ellagic acid in patients with brain stroke.

The harmful effects of subarachnoid hemorrhage on extracerebral organs

Subarachnoid hemorrhage (SAH) is a devastating neurological disorder. Patients with aneurysmal SAH develop secondary complications that are important causes of morbidity and mortality. Aside from secondary neurological injuries, SAH has been associated with nonneurologic medical complications, such as neurocardiogenic injury, neurogenic pulmonary edema, hyperglycemia, and electrolyte imbalance, of which cardiac and pulmonary complications are most common. The related mechanisms include activation of the sympathetic nervous system, release of catecholamines and other hormones, and inflammatory responses. Extracerebral complications are directly related to the severity of SAH-induced brain injury and indicate the clinical outcome in patients. This review provides an overview of the extracerebral complications after SAH. We also aim to describe the manifestations, underlying mechanisms, and the effects of those extracerebral complications on outcome following SAH.