Salah G Keyrouz

Clinical review: Prevention and therapy of vasospasm in subarachnoid hemorrhage

Vasospasm is one of the leading causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). Radiographic vasospasm usually develops between 5 and 15 days after the initial hemorrhage, and is associated with clinically apparent delayed ischemic neurological deficits (DID) in one-third of patients. The pathophysiology of this reversible vasculopathy is not fully understood but appears to involve structural changes and biochemical alterations at the levels of the vascular endothelium and smooth muscle cells. Blood in the subarachnoid space is believed to trigger these changes. In addition, cerebral perfusion may be concurrently impaired by hypovolemia and impaired cerebral autoregulatory function. The combined effects of these processes can lead to reduction in cerebral blood flow so severe as to cause ischemia leading to infarction. Diagnosis is made by some combination of clinical, cerebral angiographic, and transcranial doppler ultrasonographic factors. Nimodipine, a calcium channel antagonist, is so far the only available therapy with proven benefit for reducing the impact of DID. Aggressive therapy combining hemodynamic augmentation, transluminal balloon angioplasty, and intra-arterial infusion of vasodilator drugs is, to varying degrees, usually implemented. A panoply of drugs, with different mechanisms of action, has been studied in SAH related vasospasm. Currently, the most promising are magnesium sulfate, 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, nitric oxide donors and endothelin-1 antagonists. This paper reviews established and emerging therapies for vasospasm.

Predictors of tracheostomy in patients with spontaneous intracerebral hemorrhage

BACKGROUNDnOne third of patients with intracerebral hemorrhage (ICH) require mechanical ventilation; in most, tracheostomy may be necessary. Limited data exist about predictors of tracheostomy in ICH. The aim of our study is to identify predictors of tracheostomy in ICH.nnnMETHODSnWe reviewed medical records of patients seen in our institution between 2005 and 2009, using ICD-9 codes for ICH, for admission clinical and radiological parameters. A stepwise logistic regression model was used to identify tracheostomy predictors.nnnRESULTSnNinety patients with ICH were included in the analysis, eleven of which required tracheostomy. Patients requiring a tracheostomy were more likely to have a large hematoma volume (≥30mL) (63.4% vs. 29.1%, p=0.037), intraventricular hemorrhage (81.8% vs. 27.8%, p<0.0001), hydrocephalus (81.8% vs. 8.8%, p<0.0001), admission GCS<8 (81.8% vs. 5.1%, p<0.0001), intubation≥14 days (54.5% vs. 1.27%, p<0.0001) and pneumonia (63.6% vs. 17.7%, p=0.003). Stepwise logistic regression yielded admission GCS (OR=80.55, p=0.0003) and intubation days (OR=87.49, p<0.006) as most important predictors.nnnCONCLUSIONnWe could potentially predict the need for tracheostomy early in the course of ICH based on the admission GCS score; duration of intubation is another predictor for tracheostomy. Early tracheostomy could decrease the time, and therefore risks of prolonged endotracheal intubation and length of hospital stay.

Management of anticoagulant-related intracranial hemorrhage: an evidence-based review

The increased use of anticoagulants for the prevention and treatment of thromboembolic diseases has led to a rising incidence of anticoagulant-related intracranial hemorrhage (AICH) in the aging western population. High mortality accompanies this form of hemorrhagic stroke, and significant and debilitating long-term consequences plague survivors. Although management guidelines for such hemorrhages are available for the older generation anticoagulants, they are still lacking for newer agents, which are becoming popular among physicians. Supportive care, including blood pressure control, and reversal of anticoagulation remain the cornerstone of acute management of AICH. Prothrombin complex concentrates are gaining popularity over fresh frozen plasma, and reversal agents for newer anticoagulation agents are being developed. Surgical interventions are options fraught with complications, and are decided on a case-by-case basis. Our current state of understanding of this condition and its management is insufficient. This deficit calls for more population-based studies and therapeutic trials to better evaluate risk factors for, and to prevent and treat AICH.

Endovascular management of symptomatic vertebral artery origin stenosis in the presence of an acute thrombus

A woman in her early 60s with hypertension and hyperlipidemia was undergoing investigations for anemia of unknown etiology. She developed a sudden reduction in visual acuity and bilateral visual field impairment. MRI and angiography revealed acute infarcts in the posterior circulation and severe narrowing of the left vertebral artery origin. Digital subtraction angiography demonstrated a high-grade stenosis of the left vertebral artery origin with a thrombus just distal to the stenosis. The patient developed recurrent infarcts while on antithrombotic therapy. The lesion was successfully treated by vertebral artery origin angioplasty and stenting (VOAS) using a flow reversal technique and distal embolic protection. She was discharged to a rehabilitation facility 4u2005days later without worsening or new neurological deficits. A search of the literature yielded a similar report managed with anticoagulation and subsequent VOAS after complete lysis of the thrombus. Our report highlights the technique, safety and feasibility of VOAS in the presence of a thrombus using a flow reversal technique and distal protection.

Comparing External Ventricular Drains-Related Ventriculitis Surveillance Definitions

OBJECTIVE To evaluate the agreement between the current National Healthcare Safety Network (NHSN) definition for ventriculitis and others found in the literature among patients with an external ventricular drain (EVD) DESIGN Retrospective cohort study from January 2009 to December 2014 SETTING Neurology and neurosurgery intensive care unit of a large tertiary-care center PATIENTS Patients with an EVD were included. Patients with an infection prior to EVD placement or a permanent ventricular shunt were excluded. METHODS We reviewed the charts of patients with positive cerebrospinal fluid (CSF) cultures and/or abnormal CSF results while they had an EVD in place and applied various ventriculitis definitions. RESULTS We identified 48 patients with a total of 52 cases of ventriculitis (41 CSF culture-positive cases and 11 cases based on abnormal CSF test results) using the NHSN definition. The most common organisms causing ventriculitis were gram-positive commensals (79.2%); however, 45% showed growth of only 1 colony on 1 piece of media. Approximately 60% of the ventriculitis cases by the NHSN definition met the Honda criteria, approximately 56% met the Gozal criteria, and 23% met Citerios definition. Cases defined using Honda versus Gozal definitions had a moderate agreement (κ=0.528; P<.05) whereas comparisons of Honda versus Citerio definitions (κ=0.338; P<.05) and Citerio versus Gozal definitions (κ=0.384; P<.05) had only fair agreements. CONCLUSIONS The agreement between published ventriculostomy-associated infection (VAI) definitions in this cohort was moderate to fair. A VAI surveillance definition that better defines contaminants is needed for more homogenous application of surveillance definitions between institutions and better comparison of rates. Infect Control Hosp Epidemiol 2017;38:574-579.

Neurologic manifestations of intravascular large B-cell lymphoma

PURPOSE OF REVIEWnIntravascular large B-cell lymphoma is a rare subtype of large B-cell lymphoma that affects various organs including the nervous system. The diagnosis is challenging and frequently made at autopsy.nnnRECENT FINDINGSnWe report 5 cases with an array of neurologic manifestations. All patients were initially evaluated for alternative diagnoses. Three patients were diagnosed at autopsy, one with brain biopsy, and another with muscle biopsy. Muscle was involved in all 3 patients who had muscle tissue available for analysis.nnnSUMMARYnOur observations suggest that random open muscle biopsy may present a high-yield, less invasive option for the diagnosis of this disorder.

The Role of Osmotic Therapy in Hemispheric Stroke

BackgroundDecompressive hemicraniectomy (DHC) can be lifesaving in hemispheric stroke complicated by cerebral edema. Conversely, osmotic agents have not been shown to improve survival, despite their widespread use. It is unknown whether medical measures can similarly confer survival in certain patient subgroups. We hypothesized that osmotic therapy (OT) without DHC may be associated with a greater likelihood of survival in particular populations depending on demographic, radiologic, or treatment characteristics.MethodsWe performed a retrospective cohort analysis of patients with large anterior circulation strokes with an NIH stroke scale (NIHSS) ≥10 who received OT. We compared clinical, radiologic, and treatment characteristics between two groups: (1) those who survived until discharge with only OT (medical management success) and (2) those who required either DHC or died (medical management failure).ResultsThirty patients met eligibility criteria. Median NIHSS was 19 [interquartile range (IQR) 13–24], and median GCS was 10 [IQR 8–14]. Forty-seven percent of the medical management cohort survived to discharge. Demographic characteristics associated with medical management success included NIHSS (pxa0=xa00.009) and non-black race (pxa0=xa00.003). Of the various interventions, the administration of OT after 24xa0hours and a smaller hypertonic saline dose was also associated with survival to discharge (pxa0=xa00.038 and 0.031 respectively).ConclusionOur results suggest that patients with moderate size hemispheric infarcts on presentation and those who do not require OT within the first 24xa0h of stroke may survive until discharge with medical management alone. Black race was also associated with conservative management failure, a finding that may reflect a cultural preference toward aggressive management. Further prospective studies are needed to better establish the utility of medical management of hemispheric edema in the setting of moderate size hemispheric infarcts.

Therapies for Hemorrhagic Transformation in Acute Ischemic Stroke

Opinion statementHemorrhagic transformation occurs in about 10–15% of patients with acute ischemic stroke. The treatment of hemorrhagic conversion is complex and includes blood pressure management, reversing coagulopathy, and managing its complications including increased intracranial pressure. Future research should be directed on identifying indications to treat and use of appropriate homeostatic regimens to effectively reverse the different anticoagulants and thrombolytic agents in an attempt to improve outcomes of patients with hemorrhagic transformation.

Year in review 2011: Critical Care - neurocritical care

Contributions from the neurosciences to Critical Care in 2011 covered an array of topics. We learned about potential biomarkers for, and the effect of cerebral oxygen metabolism on, delirium, in addition to treatment of the latter. A group of investigators studied surface cooling in healthy awake volunteers, and incidence of infection associated with therapeutic hypothermia. The effects of statin and erythropoietin on stroke were revisited, and the role of adhesion molecule in the inflammatory reaction accompanying intracerebral hemorrhage was scrutinized. Biomarkers in subarachnoid hemorrhage and their relationship to vasospasm and outcome, and effect of daylight on outcome in this patient population, as well as a new meta-analysis of statin therapy were among the research in subarachnoid hemorrhage. Moreover, 2011 witnessed the publication of a multidisciplinary consensus conferences recommendations on the critical care management of subarachnoid hemorrhage. Results of studies regarding the diagnosis and vascular complications of meningitis were reported. Traumatic brain injury received its share of articles addressing therapy with hypertonic saline and surgical decompression, the development of coagulopathy, and biomarkers to help with prognostication. Finally, research on the treatment of Guillain-Barre syndrome in children, prediction of long-term need of ventilatory support, and pathophysiology of critical illness polyneuropathy and myopathy were reported.

Posterior Reversible Encephalopathy Syndrome as a Complication of Induced Hypertension in Subarachnoid Hemorrhage: A Case-Control Study

BACKGROUNDnInduced hypertension (IH) remains the mainstay of medical management for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH). However, raising blood pressure above normal levels may be associated with systemic and neurological complications, of which posterior reversible encephalopathy syndrome (PRES) has been increasingly recognized.nnnOBJECTIVEnTo ascertain the frequency and predisposing factors for PRES during IH therapy.nnnMETHODSnWe identified 68 patients treated with IH from 345 SAH patients over a 3-yr period. PRES was diagnosed based on clinical suspicion, confirmed by imaging. We extracted additional data on IH, including baseline and highest target mean arterial pressure (MAP), comparing PRES to IH-treated controls.nnnRESULTSnFive patients were diagnosed with PRES at median 6.6 d (range 1-8 d) from vasopressor initiation. All presented with lethargy, 3 had new focal deficits, and 1 had a seizure. Although baseline MAP (prior to DCI) did not differ between cases and controls, both MAP immediately prior to IH (112 vs 90) and highest MAP targeted were greater (140 vs 120 mm Hg, both Pxa0<xa0.01). Magnitude of MAP elevation was greater (54 vs 34 above baseline, Pxa0=xa0.004) while degree of IH was not (37 vs 38 above pre-IH MAP). All 4 surviving PRES patients had complete resolution with IH discontinuation.nnnCONCLUSIONnPRES was diagnosed in 7% of SAH patients undergoing IH therapy, most often when MAP was raised well above baseline to levels that exceed traditional autoregulatory thresholds. High suspicion for this reversible disorder appears warranted in the face of unexplained neurological deterioration during aggressive IH.