Treatment of hypertension in acute ischemic stroke

Systolic blood pressure in acute ischemic stroke and impact on clinical outcomes

CONTEXT

Stroke is one of the largest healthcare burdens in the United States and globally. It continues to be one of the leading causes of morbidity and mortality. Patients with acute ischemic stroke (AIS) often present with elevated blood pressure (BP).

OBJECTIVES

The objective of our study was to evaluate the association of systolic blood pressure (SBP) in the emergency department (ED) with stroke severity in patients with AIS.

METHODS

This observational study was conducted at an ED with an annual census of 80,000 visits, approximately half (400) of which are for AIS. The cohort consisted of adult patients who presented to the ED within 24 h of stroke symptom onset. BP was measured at triage by a nurse blinded to the study. Stroke severity was measured utilizing the National Institutes of Health Stroke Scale (NIHSS). Statistical analyses were performed utilizing JMP 14.0. This study was approved by our medical school's institutional review board.

RESULTS

Patients with higher SBP had significantly lower NIHSS scores (p=0.0038). This association was significant even after adjusting for age and gender. By contrast, diastolic blood pressure (DBP) did not appear to impact stroke severity. There was no difference in the DBP values between men and women. Higher SBP was also significantly associated with being discharged home as well as being less likely to die in the hospital or discharged to hospice. The DBP did not demonstrate this association. Neither the SDP nor the DBP were significantly associated with the hospital length of stay (LOS). In multivariate models that included age, gender, basal metabolic index (BMI), comorbidities, and ED presentation, elevated SBP was associated with better prognosis.

CONCLUSIONS

In this cohort of patients presenting with stroke-like symptoms to the ED, higher SBP was associated with lower stroke severity and higher rates of being discharged to home rather than hospice or death.

Tenecteplase vs. alteplase for acute ischemic stroke: a systematic review

INTRODUCTION

Thrombolysis for acute ischemic stroke (AIS) with alteplase is the currently approved therapy for patients who present within 4.5 h of symptom onset and meet criteria. Recently, there has been interest in the thrombolytic tenecteplase, a modified version of alteplase, due to its lower cost, ease of administration, and studies reporting better outcomes when compared to alteplase. This systematic review compares the efficacy of tenecteplase vs. alteplase with regard to three outcomes: (1) rate of symptomatic hemorrhage, (2) functional outcome at 90 days, and (3) reperfusion grade after thrombectomy to compare the efficacy of both thrombolytics in AIS METHODS: The search was conducted in August 2021 in PubMed, filtered for randomized controlled trials, and studies in English. The main search term was "tenecteplase for acute stroke."

RESULTS

A total of 6 randomized clinical trials including 1675 patients with AIS was included. No one's study compared alteplase to tenecteplase with all three outcomes after acute ischemic stroke; however, by using a combination of the results, this systematic review summarizes whether tenecteplase outperforms alteplase.

CONCLUSIONS

The available evidence suggests that tenecteplase appears to be a better thrombolytic agent for acute ischemic stroke when compared to alteplase.

Calcium-dependent blood-brain barrier breakdown by NOX5 limits postreperfusion benefit in stroke

Ischemic stroke is a predominant cause of disability worldwide, with thrombolytic or mechanical removal of the occlusion being the only therapeutic option. Reperfusion bears the risk of an acute deleterious calcium-dependent breakdown of the blood-brain barrier. Its mechanism, however, is unknown. Here, we identified type 5 NADPH oxidase (NOX5), a calcium-activated, ROS-forming enzyme, as the missing link. Using a humanized knockin (KI) mouse model and in vitro organotypic cultures, we found that reoxygenation or calcium overload increased brain ROS levels in a NOX5-dependent manner. In vivo, postischemic ROS formation, infarct volume, and functional outcomes were worsened in NOX5-KI mice. Of clinical and therapeutic relevance, in a human blood-barrier model, pharmacological NOX inhibition also prevented acute reoxygenation-induced leakage. Our data support further evaluation of poststroke recanalization in the presence of NOX inhibition for limiting stroke-induced damage.

Neuroprotective and neuroregenerative potential of pharmacologically-induced hypothermia with D-alanine D-leucine enkephalin in brain injury

Neurovascular disorders, such as traumatic brain injury and stroke, persist as leading causes of death and disability - thus, the search for novel therapeutic approaches for these disorders continues. Many hurdles have hindered the translation of effective therapies for traumatic brain injury and stroke primarily because of the inherent complexity of neuropathologies and an inability of current treatment approaches to adapt to the unique cell death pathways that accompany the disorder symptoms. Indeed, developing potent treatments for brain injury that incorporate dynamic and multiple disorder-engaging therapeutic targets are likely to produce more effective outcomes than traditional drugs. The therapeutic use of hypothermia presents a promising option which may fit these criteria. While regulated temperature reduction has displayed great promise in preclinical studies of brain injury, clinical trials have been far less consistent and associated with adverse effects, especially when hypothermia is pursued via systemic cooling. Accordingly, devising better methods of inducing hypothermia may facilitate the entry of this treatment modality into the clinic. The use of the delta opioid peptide D-alanine D-leucine enkephalin (DADLE) to pharmacologically induce temperature reduction may offer a potent alternative, as DADLE displays both the ability to cause temperature reduction and to confer a broad profile of other neuroprotective and neuroregenerative processes. This review explores the prospect of DADLE-mediated hypothermia to treat neurovascular brain injuries, emphasizing the translational steps necessary for its clinical translation.

The safety of post-operative elevation of mean arterial blood pressure following brain tumor resection

We demonstrate the safety of artificially elevating the mean arterial blood pressure (MAP) greater than 85 mmHg or 10% above the mean MAP in patients with underlying hypertension during the acute post-operative period in patients undergoing surgery for resection of brain tumors. A retrospective review was undertaken of all patients undergoing surgery by the senior author between 2013 and 2018. Patients who underwent MAP therapy were analyzed for hemorrhagic and cardiac complications. A total of 1162 of 2270 post-operative brain tumor patients underwent MAP therapy after surgery for a minimum of 24 h post-operatively. Of these, 7/1162 (0.6%) patients experienced intra-cavitary hemorrhage within 5 days of surgery. Two of 7 (29%) patients were diagnosed with venous infarction. One of 7 (14%) patients experienced post-operative, intra-cavitary hemorrhage prior to the initiation of MAP therapy. The remaining 4/1162 (0.35%) patients experienced intra-cavitary hemorrhage post-operatively without clear etiology. In assessing cardiac outcomes, 2/1162 patients (0.2%) experienced elevated troponin levels. No patient demonstrated significant cardiac related morbidity or mortality within this cohort. Post-operative MAP therapy with a goal of maintaining MAP greater than 85 mmHg or 10% above the mean MAP in patients with underlying hypertension appears to be a safe intervention in brain tumor patients for at least 24 h in the post-operative period.

Management of the Pediatric Neurocritical Care Patient

Pediatric neurocritical care is a growing subspecialty of pediatric intensive care that focuses on the management of acute neurological diseases in children. A brief history of the field of pediatric neurocritical care is provided. Neuromonitoring strategies for children are reviewed. Management of major categories of acute childhood central neurologic diseases are reviewed, including treatment of diseases associated with intracranial hypertension, seizures and status epilepticus, stroke, central nervous system infection and inflammation, and hypoxic-ischemic injury.

The Role of Circulating Platelets Microparticles and Platelet Parameters in Acute Ischemic Stroke Patients

BACKGROUND

Platelet activation and aggregation are critical in the pathogenesis of acute ischemic stroke (AIS). Circulating platelet microparticles (PMPs) and platelet parameters are biologic markers of platelet function in AIS patients; however, their associations with stroke subtypes and infarct volume remain unknown.

METHODS

We recruited 112 AIS patients including large-artery atherosclerosis (LAA) and small-artery occlusion [SAO] subtypes and 35 controls in this study. Blood samples were collected at admission and after antiplatelet therapy. The levels of circulating PMPs and platelet parameters (mean platelet volume [MPV], platelet count, plateletocrit, and platelet distribution width) were determined by flow cytometry and hematology analysis, respectively. Infarct volume was examined at admission by magnetic resonance imaging.

RESULTS

(1) The levels of circulating PMPs and MPV were significantly elevated in AIS patients compared with healthy controls; (2) the level of circulating PMPs, but not platelet parameters, was decreased after antiplatelet therapy in AIS patients; (3) the infarct volume in LAA subtype was larger than that in SAO subtype. Notably, circulating PMP level was positively correlated with the infarct volume in LAA subtype. No association with infarct volume in either AIS subtype was observed for platelet parameters; and (4) according to the regression analysis, circulating PMP was an independent risk factor for the infarct volume in pooled AIS patients after adjustments of other impact factors (hypertension and diabetes).

CONCLUSIONS

Our results suggest that circulating PMP level is associated with cerebral injury of AIS, which offers a novel evaluation parameter for AIS patients.

Republished: Society for Neuroscience in Anesthesiology and Critical Care expert consensus statement: Anesthetic management of endovascular treatment for acute ischemic stroke

Literature on the anesthetic management of endovascular treatment of acute ischemic stroke (AIS) is limited. Anesthetic management during these procedures is still mostly dependent on individual or institutional preferences. Thus, the Society of Neuroscience in Anesthesiology and Critical Care (SNACC) created a task force to provide expert consensus recommendations on anesthetic management of endovascular treatment of AIS. The task force conducted a systematic literature review (up to August 2012). Because of the limited number of research articles relating to this subject, the task force solicited opinions from experts in this area. The task force created a draft consensus statement based on the available data. Classes of recommendations and levels of evidence were assigned to articles specifically addressing anesthetic management during endovascular treatment of stroke using the standard American Heart Association evidence rating scheme. The draft consensus statement was reviewed by the Task Force, SNACC Executive Committee and representatives of Society of NeuroInterventional Surgery (SNIS) and Neurocritical Care Society (NCS) reaching consensus on the final document. For this consensus statement the anesthetic management of endovascular treatment of AIS was subdivided into 12 topics. Each topic includes a summary of available data followed by recommendations. This consensus statement is intended for use by individuals involved in the care of patients with acute ischemic stroke, such as anesthesiologists, interventional neuroradiologists, neurologists, neurointensivists and neurosurgeons.

Benefits of using dexmedetomidine during carotid endarterectomy: A review

As per current recommendation, patients with acute ischemic stroke should be offered carotid endarterectomy (CEA) within 24-72 hours. The same applies to patients with recurrent transient ischemic attacks (TIA). This time is usually less for hemodynamic optimization of patients who’ve suffered acute ischemic stroke. Hence’ they are hemodynamically labile and can have accelerated hypertension on induction/extubation. This can have disastrous outcomes. It is a common practice among anesthesiologists to avoid angiotensin converting enzyme(ACE) inhibitors or angiotensin receptor blockers on the day of surgery. This also adds to hypertensive issues perioperatively. Dexmedetomidine is a wonderful drug which can be used during CEA. Due to its centrally mediated sympatholytic effect, it confers good hemodynamic control during induction, intraoperatively, and during extubation. We did a search on PubMed and Google for carotid endarterectomies done under general and locoregional anesthesia during which dexmedetomidine was used. The keywords used by us during the search were as follows: anesthesia, carotid endarterectomy, anesthesia. We also searched for use of dexmedetomidine infusion to attenuate hypertensive response to intubation and for providing stability in major surgeries like CABG, craniotomies, bariatric surgeries, and valve replacements.

Management of acute ischemic stroke

Stroke is one of the most common causes of morbidity and mortality in hospitalized patients in the United States. A proper understanding of stroke mechanisms helps to guide specific case management. The only therapy approved by the US Food and Drug Administration for the management of acute ischemic stroke is initiation of intravenous recombinant tissue plasminogen activator within 3 hours of symptom onset. Other treatment options include intra-arterial recombinant tissue plasminogen activator, mechanical thrombectomy, clot retrieval, or a combination of these approaches. In this article, we provide an evidence-based review of the diagnostic approach for acute ischemic stroke, including recognizing common stroke mimics. We detail the initial medical management of acute stroke and the medical and surgical therapeutic interventions for patients who have sustained acute ischemic stroke.

Predictors of short-term improvement of ischemic stroke

OBJECTIVES

Several studies have sought factors predictive of early neurological deterioration during acute stroke; however, no study carried out a systematic search for factors capable of predicting early improvement. This investigation is aimed at identifying the variables associated with short-term neurological improvement in patients with ischemic stroke not undergoing thrombolysis.

METHODS

Two-hundred and fifty-two patients with ischemic stroke were retrospectively examined (mean age: 76.7 ± 10.6 years, 120 males, median delay of admission 8 hours). Stroke severity was assessed both on admission and at discharge (median stay: 4 days) by the National Institutes of Health Stroke Scale (NIHSS). Improvement was defined as a difference between initial and final assessment (ΔNIHSS) ≥ the median value (2 points). Thus, 127 patients improved (mean change: +3.8 points) and 125 did not (mean change: -1.4 points).

RESULTS

During the first 48 hours of hospitalization, 263 clinical, laboratory, instrumental, and therapeutic variables were collected. These were preliminarily compared between two subgroups of patients, improved and non-improved, which were matched for initial NIHSS score, and 17 possible predictors of improvement were found. The subsequent multivariable analysis led to the identification of four factors independently associated with improvement (odds ratio, 95% confidence interval): total anterior circulation syndrome (TACS) (0.20, 0.10-0.39, P<0.0001), aphasia (3.58, 1.89-6.77, P = 0.0001), average systolic blood pressure (0.98 per mmHg, 0.96-0.99, P = 0.002), and age (0.97 per year, 0.94-0.99, P = 0.02).

CONCLUSIONS

The ischemic strokes that are not TACS, with aphasia, with normal/low blood pressure, or occurring in younger subjects, may have a significant tendency to short-term improvement.

The role of head computed tomography imaging in the evaluation of postoperative neurologic deficits in cardiac surgery patients

BACKGROUND

Computed tomography (CT) scans of the head without contrast are routinely obtained to evaluate neurologic deficits after cardiac surgery, but their utility is unknown. We evaluated our experience with this imaging modality to determine its value.

METHODS

We retrospectively identified cardiac surgery patients with postoperative neurologic deficits occurring during the first week after surgery between January 2000 and December 2012. Stroke was defined by neurologist's determination, whereas a nonfocal deficit (NFD) was defined by the presence of seizure, delirium, or cognitive impairment. We defined early noncontrast head CT as occurring within 7 days of surgery. Outcomes included positive findings on CT, in-hospital mortality, and length of stay. Multivariate logistic regression identified predictors of positive findings on head CT.

RESULTS

Within the population of 11,070 postoperative patients, 451 had early noncontrast head CT scans (4%). Two hundred two (44.7%) were associated with stroke, and 249 (55.2%) were associated with NFD. Among stroke patients, 40 of 202 (20%) showed acute infarction, 17 of 202 (8%) showed subacute infarction, and 5 of 202 (2%) showed hemorrhage. Among NFD patients, 1 of 248 (0.4%) showed acute infarction, 4 of 248 (1.6%) showed subacute infarction, and 1 of 248 (0.4%) showed hemorrhage. There was no difference in in-hospital mortality (stroke, 42 of 201 [21%] versus NFD, 41 of 248 [16%]; p = 0.2) or length of stay (stroke, 24 d versus NFD, 22 d; p = 0.5). On multivariable logistic regression, only focal deficits and aortic procedures predicted a positive finding on CT scan.

CONCLUSIONS

This study reviewed the utility of early postoperative noncontrast head CT in cardiac surgery patients. With focal neurologic deficits, this imaging modality was positive for approximately one third of patients, but rarely positive for NFD. Its use in this setting has limited utility.

The impact of blood pressure hemodynamics in acute ischemic stroke: a prospective cohort study

Objective

To assess relationships between blood pressure hemodynamic measures and outcomes after acute ischemic stroke, including stroke severity, disability and death.

Methods

The study cohort consisted of 189 patients who presented to our emergency department with ischemic stroke of less than 24 hours onset who had hemodynamic parameters recorded and available for review. Blood pressure (BP) was non-invasively measured at 5 minute intervals for the length of the patient's emergency department stay. Systolic BP (sBP) and diastolic BP (dBP) were measured for each patient and a differential (the maximum minus the minimum BP) calculated. Three outcomes were studied: stroke severity, disability at hospital discharge, and death at 90 days. Statistical tests used included Spearman correlations (for stroke severity), Wilcoxon test (for disability) and Cox models (for death).

Results

Larger differentials of either dBP (p = 0.003) or sBP (p < 0.001) were significantly associated with more severe strokes. A greater dBP (p = 0.019) or sBP (p = 0.036) differential was associated with a significantly worse functional outcome at hospital discharge. Those patients with larger differentials of either dBP (p = 0.008) or sBP (0.007) were also significantly more likely to be dead at 90 days, independently of the basal BP.

Conclusion

A large differential in either systolic or diastolic blood pressure within 24 hours of symptom onset in acute ischemic stroke appears to be associated with more severe strokes, worse functional outcome and early death