Neurology Literature Summaries
HYPOXIC ENCEPHALOPATHY
Zandbergen, E.G., et al (1998) “Systematic review of early prediction of poor outcome in anoxic-ischaemic coma” Lancet 352:1808-1812
- 33 studies
- 14 prognostic variables looked at
- 3 variable had a specificity of 100% for poor outcome:
1. absent pupillary reflexes @ day 3
2. absent motor response to pain (worse than withdrawal) on day 3
3. bilateral absence of early cortical SSEP within the first week - other poor prognostic factors = an isoelectric EEG, burst suppression, myoclonus on stimulation.
SEDATION IN ICU
Kress, J.P., et al (2000) “Daily interruption of sedative infusions in critically ill patients undergoing mechanical ventilation” N Engl J Med 342:1471-1477
- single centre RCT
- n = 128
- sedative infusions interrupted daily until patient awake VS at discretion of treating clinicians
-> reduction in the duration of MV
-> reduction in length of stay in ICU
-> decrease investigation for coma (CT, MRI, LP)
-> significant increase in days awake
Kress, J.P., et al (2003) – Am J Respir Crit Care Med 168:1457-1461
- daily interruption of sedative infusions
-> does not result in adverse psychological sequalae
-> reduces PTSD
other studies:
-> reduced vasoactive drug therapy
-> reduced fluid administration
-> reduced duration of MV
-> reduced stay in ICU
-> reduced stay in hospital
Girard, T. D., et al (2008)– “The Awake and Breathing Controlled Trial” Lancet; 371:126-134
- 4 Centers is North American
- RCT – 2003-2006
- inclusion criteria: > 18 years, on MV for > 12 hours
- exclusion criteria: post cardiac arrest, moribund, > 2 weeks ventilatory support, severe dementia, co-enrolled in another trial
- intervention = SBT vs SAT -> SBT
- primary end points = ventilator free days
- secondary end points = delirium, 28 day -> 1 year mortality, length of stay in ICU and hospital
- n = 334 (powered of 80%)
- intention to treat analysis
RESULTS
-> reduction in ventilator free days
-> reduced mortality at 1 year
-> similar delirium rates but less coma
-> increased risk of extubation -> however, risk of re-intubation same in control arm
-> higher rate of successful extubation
-> lower trachestomy rate
STRENGTHS
- protocolised
- multi-centre
WEAKNESSES
- not blinded
- not generalisable to Australasia (North America has Ventilator Technician)
- surgical patients not enrolled
- sedation time and practice not recorded
ISCHAEMIC STROKE
Chen, Z.M., et al (2000) “Indications for early aspirin use in acute ischemic stroke: a combined analysis of 40,000 randomized patients from the Chinese acute stroke trial and the international stroke trial.” On behalf of the CAST and IST Collaborative Group. Stroke 31:1240-1249
- combined results of two large RCT
- n = 40,000
-> starting aspirin promptly in patients with suspected acute ischaemic stroke -> reduces immediate risk of further stroke in hospital + in hospital death.
-> no significant increase in haemorrhage in patients given aspirin prior to CT
-> no increase in mortality or further strokes in those who were given aspirin inadvertently after a haemorrhage stroke.
The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. (1995) “Tissue plasminogen activator for acute ischemic stroke” N Engl J Med 333:1581-1587
- RCT (double-blind)
- n = 624
- rt-PA for ischaemic stoke delivered within 3 hours of onset of signs
-> lack of early benefit but significant improvement in functional status @ 3 months
-> significant increase in intracranial haemorrhage in the rtPA group (6.4% vs 0.6%)
-> other studies in the 90’s carried out: no benefit and increased risk of bleeding
Vahedi, K. et al (2007) “Early decompressive surgery in malignant infarction of the middle cerebral artery: a pooled analysis of three randomised controlled trials” Lancet 6:215-22
- 3 European MRCT’s (DECIMAL, DESTINY, HAMLET) looking at decompressive craniectomy for malignant infarction of MCA vs conservative management.
- mortality = 80% with medical treatment
- aim = to assess wheter decompressive surgery reduces mortality without an increase in the number of severely disabled survivors (mRS score of 5)
- inclusion criteria: age 18-60, treated within 48 hours, decreased LOC, signs on CT of an infarct of atleast 50% of MCA territory +/- anterior or posterior artery involvement on the same side, consent
- exclusion criteria: prestroke score of mRS > 2, fixed dilated pupils, contralateral ischaemia or brain lesion, space occupying haemorrhagic transformation, life expectancy < 3 years, other serious illnesses that could effect outcome, coagulopathy, contraindication to anaesthesia, pregnancy
- primary outcomes = modified Rankin scale @ 1 year (favourable or unfavourable)
- secondary outcomes = case fatality @ 1 year, dichotomisation of modified Rankin scale mRS 0 = no symptoms 3 = moderate disability (requiring some help, walk without assistance) 6 = death – n = 93 – base line characteristics similar
- NNT for survival = 2!
-> post decompression anti-oedema treatment rarely needed
-> increases survival and favourable outcome (mRS < 3 after 12 months)
OTHER
Plasma Exchange/Sandoglobulin Guillain-Barre Syndrom Trial Group. (1997) “Randomized trial of plasma exhange, intravenous immunoglobulin, and combined treatments in Guillian-Barre syndrome” Lancet 349:225-230
- MRCT
- n = 383
- plasma exchange VS IV IgG VS plasma exchange + IgG
-> no significant difference in disability
-> no significant difference in time to independent mobility
-> no significant difference in duration of MV
-> IgG is fine and simpler than plasma exchange
van de Beek D, de Gans J, McIntyre P, et al: Corticosteroids for acute bacterial meningitis. Cochrane Database Syst Rev 2007; 1
de Gans J, van de Beek D: European Dexamethasone in Adulthood Bacterial Meningitis Study Investigators: Dexamethasone in adults with bacterial meningitis. N Engl J Med 2002; 347:1549-1556
- systematic reviews
- dexamethasone with first antibiotics in community acquired bacterial meningitis
-> reduces mortality
-> reduces severe hearing loss
-> reduces neurological sequelae
References and Links
CCC Neurocritical Care Series
Emergencies: Brain Herniation, Eclampsia, Elevated ICP, Status Epilepticus, Status Epilepticus in Paeds
DDx: Acute Non-Traumatic Weakness, Bulbar Dysfunction, Coma, Coma-like Syndromes, Delayed Awakening, Hearing Loss in ICU, ICU acquired Weakness, Post-Op Confusion, Pseudocoma, Pupillary Abnormalities
Neurology: Anti-NMDA Encephalitis, Basilar Artery Occlusion, Central Diabetes Insipidus, Cerebral Oedema, Cerebral Venous Sinus Thrombosis, Cervical (Carotid / Vertebral) Artery Dissections, Delirium, GBS vs CIP, GBS vs MG vs MND, Guillain-Barre Syndrome, Horner’s Syndrome, Hypoxic Brain Injury, Intracerebral Haemorrhage (ICH), Myasthenia Gravis, Non-convulsive Status Epilepticus, Post-Hypoxic Myoclonus, PRES, Stroke Thrombolysis, Transverse Myelitis, Watershed Infarcts, Wernicke’s Encephalopathy
Neurosurgery: Cerebral Salt Wasting, Decompressive Craniectomy, Decompressive Craniectomy for Malignant MCA Syndrome, Intracerebral Haemorrhage (ICH)
— SCI: Anatomy and Syndromes, Acute Traumatic Spinal Cord Injury, C-Spine Assessment, C-Spine Fractures, Spinal Cord Infarction, Syndomes,
— SAH: Acute management, Coiling vs Clipping, Complications, Grading Systems, Literature Summaries, ICU Management, Monitoring, Overview, Prognostication, Vasospasm
— TBI: Assessment, Base of skull fracture, Brain Impact Apnoea, Cerebral Perfusion Pressure (CPP), DI in TBI, Elevated ICP, Limitations of CT, Lund Concept, Management, Moderate Head Injury, Monitoring, Overview, Paediatric TBI, Polyuria incl. CSW, Prognosis, Seizures, Temperature
ID in NeuroCrit. Care: Aseptic Meningitis, Bacterial Meningitis, Botulism, Cryptococcosis, Encephalitis, HSV Encephalitis, Meningococcaemia, Spinal Epidural Abscess
Equipment/Investigations: BIS Monitoring, Codman ICP Monitor, Continuous EEG, CSF Analysis, CT Head, CT Head Interpretation, EEG, Extradural ICP Monitors, External Ventricular Drain (EVD), Evoked Potentials, Jugular Bulb Oxygen Saturation, MRI Head, MRI and the Critically Ill, Train of Four (TOF), Transcranial Doppler
Pharmacology: Desmopressin, Hypertonic Saline, Levetiracetam (Keppra), Mannitol, Midazolam, Sedation in ICU, Thiopentone
MISC: Brainstem Rules of 4, Cognitive Impairment in Critically Ill, Eye Movements in Coma, Examination of the Unconscious Patient, Glasgow Coma Scale (GCS), Hiccoughs, Myopathy vs Neuropathy, Neurology Literature Summaries, NSx Literature Summaries, Occulocephalic and occulovestibular reflexes, Prognosis after Cardiac Arrest, SIADH vs Cerebral Salt Wasting, Sleep in ICU
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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