The ABCs of Statistics Anatomy TBI Classification of TBI Rachel - PDF document

3/10/2012 Outline The ABCs of  Statistics  Anatomy TBI  Classification of TBI Rachel Garvin, MD  Pathophysiology behind increased ICP Assistant Professor, Emergency Medicine Fellow, Neurocritical Care University of Cincinnati  PBtO2  Management Strategies 6 th Annual Northern Kentucky TBI Conference March 23, 2012 www.bridgesnky.org  Mild TBI TBI stats Classification of TBI  2 million TBI’s treated each year in US, one every 15  Pathoanatomic seconds  Leading cause of M&M in young adults  Physical Mechanism  Single severe TBI victim can generate 4 million dollars  Pathophysiologic in lifetime costs  Falls are leading cause of TBI in adults >65  Injury Severity  Adults ages >75 have highest rates of TBI related hospitalization and death  70- 90% of TBI worldwide are considered “mild,” 1% of those require a surgical intervention Pathophysiologic Pathoanatomic Epidural  Primary Injury Subdural  Immediate damage done Subarachnoid  Secondary Injury Contusion  Potentially avoidable factors Axonal injury  Hypoxia, hypotension, hypercarbia, hyponatremia, seizures 1

3/10/2012 Injury Severity Predicting Outcomes  GCS  Study using data from CRASH trial looked at predicting outcomes (death at 14 days  13-15  Mild TBI and death/disability at 6 months)  9-12  Moderate TBI  Best predictors: age (>40), low GCS,  <8  Severe TBI obliteration of basal cisterns/third ventricle, pupillary response, other extracranial injuries Rotterdam CT scoring Imaging  Basal Cisterns: open, compressed, absent  Noncon Head CT  Midline Shift: < or > 5mm  MRI  Epidural Mass Lesion  CTA  IVH or Traumatic SAH  Other trauma imaging ICP Cerebral Perfusion Pressure (CPP)  Monroe-Kellie Hypothesis: Blood, brain,  CPP = MAP-ICP CSF  Normal CPP >50mmHg  Normal ICP  5-15mmHg (3-7mmHg young  CBF: children)  Directly proportional to CPP and vessel radius  In TBI, the balance gets disrupted  Inversely proportional to blood viscosity and vessel length 2

3/10/2012 Causes of Increased ICP Monitoring in TBI  Intracranial  Extracranial  ICP  Hematomas/Contusio  Hypoxia ns  Hypercarbia  Brain tissue oxygen  Ischemia  Hyper/Hypotension  Hydrocephalus  Head rotation  Microdialysis  Increased CBF  Fever  Seizure  Jugular venous saturation  Increased intraabdominal  Cerebral blood flow pressure How do we treat low PBtO2? What about brain tissue oxygen?  Secondary brain injury not always associated with increased ICP  Increase oxygenation  Study by Spiotta et al looked at conventional ICP/CPP management vs PbtO2-based therapy  Increase MAP  70 pts with severe TBI managed with Licox to keep PbtO2  Change PCO2 > 20mmHg as well as ICP/CPP  Compared with 53 historical controls with goal of ICP <20 and CPP >60  Lower mortality and more favorable short term outcomes Early Management of TBI ABC’s  Airway  ABC’s  Avoiding hypoxia  RSI  Imaging  Post-intubation sedation  Emergent treatment  Breathing  Normocarbia  Circulation  Avoiding hypotension 3

3/10/2012 Treating ICP Mannitol vs Hypertonic Saline  Mannitol  HTS  Keeping things “normal”  Rheologic effects  Osmotic effect  Osmotic effects  Can be used in  Sedation hypovolemic pts  Crosses BBB  Can cause  Contraindicated in  Positioning hyperchloremic hypovolemic pts acidosis,  Mannitol/Hypertonic saline decreased platelet aggregation Emergent Treatment Hyperventilation  Decreased PaCO2  alkalinizing CSF   Hyperventilation cerebral vasoconstriction  Decompressive  Decreased CBV  decreased ICP, BUT……… Hemicraniectomy  Effects last around 6 hours until CSF pH equilibrates  Then there is re-dilation of cerebral arteries  rebound ICP Decompressive Hemicraniectomy Outcomes  Most often a rescue procedure  Difficult to make early predictions on outcome  Initial GCS  Data equivocal on whether  Pupils/Motor Score outcomes improved  Other injuries  MR spectroscopy  Specialty care in neuro- ICU’s improve outcomes 4

3/10/2012 Mild TBI Mild TBI  Study by Sterr et al looked at long term effects of Study by Bazarian et al looked at mild TBI in the ED MTBI  Used the NHAMCS for isolated mild TBI  29% of MTBI patients had symptoms of PCS at least 12 months post injury (as compared with  Less than ½ of patients were asked about pain matched controls)  Only half of those were treated  Problems mostly stemmed from issues in  Only 34% of those discharged from level I trauma cognitive function centers were referred for further follow-up  Loss of consciousness at time of injury was not predictive of PCS Help for Mild TBI Summary  TBI is a serious healthcare issue,  Educate patients on the possible especially in the elderly symptoms from mild TBI  There are many different ways to  Ensure follow-up classify TBI  Prevention of secondary injury is key  Educate patients with mild TBI References  Bazarian JJ, McClung J, Cheng YT, Flesher W, Schneider SM. Emergency department management of mild traumatic brain injury in the USA. Emerg Med J 2005; 22:473-477  Marguiles S, Hicks R. Combination therapies for traumatic brain injury: Prospective considerations. Journal of Neurotrauma 2009; 26:925-939  Meixensberger J, Jaeger M, Vath A, Dings J, Kunze E, Roosen K. Brain tissue oxygen guided treatment supplementing ICP/CPP therapy after traumatic brain injury. J Neurol Neuroaurg Psychiatry 2003; 74:760-764.  Rangel-Castillo L, Gopinath S, Robertson C. Management of intracranial hypertension. Neurol Clin 2008 May; 26(2): 521-541  Saatman KE, Duhaime AC, Bullock R, Maas A, Valadka A, Manley GT. Classification of traumatic brain injury for targeted therapies. Journal of Neurotrauma 2008; 25: 719-738.  Sterr A, Herron K, Hayward C, Montaldi D. Are mild head injuries as mild as we think? Neurobehavioral concomittants of chronic post-concussion syndrome. BMC Neurology 2006: 1471-2377  Spiotta AM, Stiefel MF, Gracias VH, Garuffe AM, Kofke WA, Maloney-Wilensky E, Troxel AB, Levine JM, Le Roux PD. Brain tissue oxygen-directed management and outcome in patients with severe traumatic brain injury. J Neurosurg 2010: 113: 571-580  Thompson HJ, McCormick WC, Kagan SH. Traumatic brain injury in older adults: Epidemiology, outcomes, and future implications. 5