Publications by authors named "Barnett R Nathan"

14 Publications

  • Page 1 of 1

The Insertion and Management of External Ventricular Drains: An Evidence-Based Consensus Statement : A Statement for Healthcare Professionals from the Neurocritical Care Society.

Neurocrit Care 2016 Feb;24(1):61-81

Department of Medicine, University of Toronto and Krembil Neuroscience Centre, Toronto Western Hospital, Toronto, Canada.

External ventricular drains (EVDs) are commonly placed to monitor intracranial pressure and manage acute hydrocephalus in patients with a variety of intracranial pathologies. The indications for EVD insertion and their efficacy in the management of these various conditions have been previously addressed in guidelines published by the Brain Trauma Foundation, American Heart Association and combined committees of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons. While it is well recognized that placement of an EVD may be a lifesaving intervention, the benefits can be offset by procedural and catheter-related complications, such as hemorrhage along the catheter tract, catheter malposition, and CSF infection. Despite their widespread use, there are a lack of high-quality data regarding the best methods for placement and management of EVDs to minimize these risks. Existing recommendations are frequently based on observational data from a single center and may be biased to the authors' view. To address the need for a comprehensive set of evidence-based guidelines for EVD management, the Neurocritical Care Society organized a committee of experts in the fields of neurosurgery, neurology, neuroinfectious disease, critical care, pharmacotherapy, and nursing. The Committee generated clinical questions relevant to EVD placement and management. They developed recommendations based on a thorough literature review using the Grading of Recommendations Assessment, Development, and Evaluation system, with emphasis placed not only on the quality of the evidence, but also on the balance of benefits versus risks, patient values and preferences, and resource considerations.
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http://dx.doi.org/10.1007/s12028-015-0224-8DOI Listing
February 2016

Emergency Neurologic Life Support: Meningitis and Encephalitis.

Neurocrit Care 2015 Dec;23 Suppl 2:S110-8

Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA.

Bacterial meningitis and viral encephalitis, particularly herpes simplex encephalitis, are severe neurological infections that, if not treated promptly and effectively, lead to poor neurological outcome or death. Because treatment is more effective if given early, the topic of meningitis and encephalitis was chosen as an Emergency Neurological Life Support protocol. This protocol provides a practical approach to recognition and urgent treatment of bacterial meningitis and encephalitis. Appropriate imaging, spinal fluid analysis, and early empiric treatment is discussed. Though uncommon in its full form, the typical clinical triad of headache, fever, and neck stiffness should alert the clinical practitioner to the possibility of a central nervous system infection. Early attention to the airway and maintaining normotension is crucial in treatment of these patients, as is rapid treatment with anti-infectives and, in some cases, corticosteroids.
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http://dx.doi.org/10.1007/s12028-015-0165-2DOI Listing
December 2015

Reversible posterior leukoencephalopathy syndrome during regorafenib treatment: a case report and literature review of reversible posterior leukoencephalopathy syndrome associated with multikinase inhibitors.

Clin Colorectal Cancer 2014 Jun 27;13(2):127-30. Epub 2013 Dec 27.

Division of Hematology/Oncology, Department of Medicine and the UVA Cancer Center, University of Virginia Health System, Charlottesville, VA.

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http://dx.doi.org/10.1016/j.clcc.2013.12.003DOI Listing
June 2014

Intravenous ketamine for the treatment of refractory status epilepticus: a retrospective multicenter study.

Epilepsia 2013 Aug 12;54(8):1498-503. Epub 2013 Jun 12.

Comprehensive Epilepsy Center, Department of Neurology, School of Medicine, Yale-New Haven Hospital, Yale University, New Haven, Connecticut 06520, USA.

Purpose: To examine patterns of use, efficacy, and safety of intravenous ketamine for the treatment of refractory status epilepticus (RSE).

Methods: Multicenter retrospective review of medical records and electroencephalography (EEG) reports in 10 academic medical centers in North America and Europe, including 58 subjects, representing 60 episodes of RSE that were identified between 1999 and 2012. Seven episodes occurred after anoxic brain injury.

Key Findings: Permanent control of RSE was achieved in 57% (34 of 60) of episodes. Ketamine was felt to have contributed to permanent control ("possible" or "likely" responses) in 32% (19 of 60) including seven (12%) in which ketamine was the last drug added (likely responses). Four of the seven likely responses, but none of the 12 possible ones, occurred in patients with postanoxic brain injury. No likely responses were observed when infusion rates were lower than 0.9 mg/kg/h, when ketamine was introduced at least 8 days after SE onset, or after failure of seven or more drugs. Ketamine was discontinued due to possible adverse events in five patients. Complications were mostly attributed to concurrent drugs, especially other anesthetics. Mortality rate was 43% (26 of 60), but was lower when SE was controlled within 24 h of ketamine initiation (16% vs. 56%, p = 0.0047).

Significance: Ketamine appears to be a relatively effective and safe drug for the treatment of RSE. This retrospective series provides preliminary data on effective dose and appropriate time of intervention to aid in the design of a prospective trial to further define the role of ketamine in the treatment of RSE.
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http://dx.doi.org/10.1111/epi.12247DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3731413PMC
August 2013

Emergency neurologic life support: meningitis and encephalitis.

Neurocrit Care 2012 Sep;17 Suppl 1:S66-72

Department of Emergency Medicine and Center for Resuscitation Science, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA, USA.

Bacterial meningitis and viral encephalitis, particularly herpes simplex encephalitis (HSE), are severe neurological infections that, if not treated promptly and effectively, lead to poor neurological outcome or death. Because treatment is more effective if given early, the topic of meningitis and encephalitis was chosen as an Emergency Neurological Life Support protocol. This protocol provides a practical approach to recognition of and urgent treatment for bacterial meningitis and HSE, including imaging and spinal fluid analysis, and discusses the choice of empirical treatments until the cause of infection is determined. Though uncommon in its full form, the typical clinical triad of headache, fever, and neck stiffness should alert the clinical practitioner to the syndromes. Early attention to the airway and maintaining normotension is crucial in treatment of these patients, as is rapid treatment with anti-infectives and, in some cases, corticosteroids.
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http://dx.doi.org/10.1007/s12028-012-9751-8DOI Listing
September 2012

Does experience doing lumbar punctures result in expertise? A medical maxim bites the dust.

Neurology 2012 Jul 6;79(2):115-6. Epub 2012 Jun 6.

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http://dx.doi.org/10.1212/WNL.0b013e31825dd3b0DOI Listing
July 2012

Ondine's curse with accompanying trigeminal and glossopharyngeal neuralgia secondary to medullary telangiectasia.

Neurocrit Care 2010 Jun;12(3):395-9

University of Virginia, Charlottesville, VA, USA.

Background: Central hypoventilation syndrome ("Ondine's Curse") is an infrequent disorder that can lead to serious acute or chronic health consequences. This syndrome, especially in adults, is rare, and even less frequent in the absence of clear pathogenic lesions on MRI. In addition, we are not aware of any previously reported cases with associated cranial nerve neuralgias.

Methods: We describe a patient with baseline trigeminal and glossopharyngeal neuralgia, admitted with episodes of severe hypoventilatory failure of central origin, consistent with "Ondine's Curse". After evaluation, she was found to have a medullary capillary telangiectasia, thought to be the causative lesion, and which could explain her complete neurologic and hypoventilatory syndrome. The patient was treated with placement of a diaphragmatic pacing system, which has been effective thus far.

Results: This case illustrates the need for investigation of centrally mediated apnea, especially when co-occurring cranial nerve neuralgia is present and cardiopulmonary evaluation is negative. It provides an example of capillary telangiectasia as the causative lesion, one that to our knowledge has not been reported before.

Conclusions: Placement of a diaphragmatic pacing system was warranted and became lifesaving as the patient was deemed to be severely incapacitated by chronic ventilatory insufficiency.
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http://dx.doi.org/10.1007/s12028-009-9321-xDOI Listing
June 2010

Intravascular temperature control system to maintain normothermia in organ donors.

Neurocrit Care 2008 ;8(1):31-5

Davee Department of Neurology and Clinical Neurological Sciences, Northwestern Memorial Hospital, Northwestern University, Feinberg School of Medicine, 710 N. Lake Shore Dr. Abbott Hall, Room 1123, Chicago, IL, 60611, USA.

Introduction: Temperature regulation in humans is controlled by the hypothalamus. After death by neurological criteria, the hypothalamus ceases to function and poikilothermia ensues. Preservation of normothermia in those patients destined to become organ donors is an important part of maintaining the normal physiology of the organs and organ systems. Typical means of achieving normothermia include increasing the temperature of the ambient air, infrared warming lights, instillation of warmed intravenous fluids, and warm air or water blankets.

Methods: In this prospective case series of five organ donors, we used an intravascular temperature modulation catheter (Alsius, Irvine, CA) to maintain normothermia in organ donors declared dead by neurological criteria. Data on accuracy of temperature maintenance at 37 degrees C and nursing ease of use were collected.

Results: This intravascular temperature modulation catheter provided an accurate method of temperature regulation in brain death donor and easier to use from a nursing workload perspective.

Conclusions: Intravascular warming is a viable method for the maintenance of normothermia in organ donors. The experience here provides some insight into the ability of these devices to warm patients in other clinical situations.
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http://dx.doi.org/10.1007/s12028-007-9008-0DOI Listing
April 2008

Cerebral correlates of hyponatremia.

Authors:
Barnett R Nathan

Neurocrit Care 2007 ;6(1):72-8

Department of Neurology, University of Virginia, Charlottesville, VA 22908, USA.

Hyponatremia, defined as a serum sodium concentration ([Na+]) less than 135 mEq/L, is commonly caused by elevated levels of the hormone arginine vasopressin (AVP), which causes water retention. The principal organ affected by disease-related morbidity is the brain. The neurologic complications associated with hyponatremia are attributable to cerebral edema and increased intracranial pressure, caused by the osmotically driven movement of water from the extracellular compartment into brain cells. Although neurologic symptoms induced by hyponatremia are limited by an adaptive brain mechanism known as "regulatory volume decrease," an overly rapid correction of serum [Na+] before the reversal of this adaptive response can also produce neurologic damage. The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a frequent cause of hyponatremia related to central nervous system disorders, neurosurgery, or the use of psychoactive drugs. Fluid restriction is the standard of care for patients with SIADH who are asymptomatic or who have only mild symptoms, but patients with severe or symptomatic hyponatremia require more aggressive therapy. Infusion of hypertonic saline is the usual approach to the treatment of symptomatic hyponatremia, but patients require frequent monitoring. Pharmacologic agents such as demeclocycline and lithium may be effective in some patients but are associated with undesirable adverse events. The AVPreceptor antagonists are a new therapeutic class for the treatment of hyponatremia. The first agent in this class approved for the treatment of euvolemic hyponatremia in hospitalized patients is conivaptan. Two other agents, tolvaptan and lixivaptan, are being evaluated in patients with euvolemic and hypervolemic hyponatremia. The AVP-receptor antagonists block the effects of elevated AVP and promote aquaresis, the electrolyte-sparing excretion of water, resulting in the correction of serum [Na+]. These agents may also have intrinsic neuroprotective effects.
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http://dx.doi.org/10.1385/NCC:6:1:72DOI Listing
September 2007

Cardiopulmonary complications of brain injury.

Curr Neurol Neurosci Rep 2005 Nov;5(6):488-93

Department of Neurology, Box 800394, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.

Cardiac and pulmonary complications following acute neurologic injury are common and may be a cause of morbidity and mortality in this population. Examples include hypertension, arrhythmias, ventricular dysfunction, pulmonary edema, shock, and sudden death. Primary neurologic events are represented by stroke, subarachnoid hemorrhage, traumatic brain injury, epilepsy, and encephalitis and have been frequently reported. Given the high frequency of these conditions, it is important for physicians to become familiar with their pathophysiology, allowing for more prompt and appropriate treatment.
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http://dx.doi.org/10.1007/s11910-005-0039-7DOI Listing
November 2005

A new method for measuring blood-brain barrier permeability demonstrated with Europium-bound albumin during experimental lipopolysaccharide (LPS) induced meningitis in the rat.

J Neurosci Methods 2005 Mar;142(1):91-5

Department of Infectious Diseases, University of Virginia, Charlottesville, VA 22908, USA.

The blood-brain barrier (BBB) is a critical extrameningeal site of injury during bacterial meningitis, manifested by enhanced BBB permeability (BBBP). Previous methods to measure altered BBBP during meningitis involve radioactive materials, or are poorly quantified. Europium (EU) is a fluorescent, non-radioactive metal that is a sensitive and stable marker. Europium fluorescence can be measured with a spectrophotometer capable of time-resolved fluorescence (TRF). We used EU-albumin (EU-A) to examine BBBP in experimental lipopolysaccharide (LPS) induced meningitis. The results presented here introduce a simple and accurate method for measuring BBB permeability.
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http://dx.doi.org/10.1016/j.jneumeth.2004.07.015DOI Listing
March 2005

The efficacy of trovafloxacin versus ceftriaxone in the treatment of experimental brain abscess/cerebritis in the rat.

Life Sci 2003 Aug;73(14):1773-82

Departments of Neurology and Internal Medicine, University of Virginia, Box 800394, Charlottesville, VA 22908, USA.

Current estimates of the mortality associated with brain abscesses range from 0-24%, with neurological sequellae in 30-55% of survivors. Although the incidence of brain abscess appears to be increasing, likely due to an increase in the population of immunosuppressed patients, the condition is still sufficiently uncommon to make human clinical trials of therapy problematic. An animal model to study the efficacy of new treatment regimens, specifically, new antimicrobial agents is therefore necessary. This study uses a well-defined experimental paradigm as an inexpensive method of inducing and studying the efficacy of antibiotics in brain abscess. The rat model of brain abscess/cerebritis developed at this institution was used to determine the relative efficacy of trovafloxacin as compared to ceftriaxone in animals infected with Staphylococcus aureus. S. aureus ( approximately 10(5) CFU in 1 microliter) was injected with a Hamilton syringe, very slowly, over the course of 70 minutes after a two mm burr hole was created with a spherical carbide drill just posterior to the coronal suture and four mm lateral to the midline. Eighteen hours later treatment was begun; every 8 hours the rats were dosed with subcutaneous ceftriaxone (n = 10), trovafloxacin (n = 11) or 0.9% sterile pyogen-free saline (n = 10). After four days of treatment the brains were removed and sectioned with a scalpel. The entire injected hemisphere was homogenized and quantitative cultures performed. The mean +/- SEM log(10) colony forming units/ml S. aureus recovered from homogenized brain were as follows: controls 6.10 +/- 0.28; ceftriaxone 3.43 +/- 0.33; trovafloxacin 3.65 +/- 0.3. There was no significant difference in bacterial clearance between ceftriaxone versus trovafloxacin (p = 0.39). Trovafloxacin or other quinolones may provide a viable alternative to intravenous antibiotics in patients with brain abscess/cerebritis.
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http://dx.doi.org/10.1016/s0024-3205(03)00507-1DOI Listing
August 2003

The potential roles of C-reactive protein and procalcitonin concentrations in the serum and cerebrospinal fluid in the diagnosis of bacterial meningitis.

Curr Clin Top Infect Dis 2002 ;22:155-65

Departments of Neurology and Internal Medicine, University of Virginia, Charlottesville, Virginia, USA.

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February 2003

Central Nervous System Infections in the Immune-competent Adult.

Curr Treat Options Neurol 2002 Jul;4(4):323-332

*Department of Neurology, University of Virginia School of Medicine, Box 800394, Charlottesville, VA 22908, USA.

The clinician must maintain a high level of suspicion for central nervous system infections even if not all of the classic signs are present, because prompt treatment may make a difference in patient outcome. If bacterial meningitis is suspected, a CT scan of the head should be obtained prior to lumbar puncture if there is papilledema, a focal neurologic exam, or if the patient is comatose. In bacterial meningitis, empiric antibiotics should be chosen based on a patient's risk factors and should be started immediately. Depending on the resistance patterns of the institution, Streptococcus pneumoniae may be resistant to penicillins and cephalosporins. Corticosteroids are of uncertain benefit in bacterial meningitis and may decrease the penetration of antibiotics into the central nervous system. The dosage for acyclovir treatment in herpes simplex encephalitis is 10 to 15mg/kg every 8 hours. Subdural empyema is a neurosurgical emergency. Brain abscesses should be surgically drained if they exceed 2.5 centimeters.
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http://dx.doi.org/10.1007/s11940-002-0033-1DOI Listing
July 2002