Case 1 Traumatic Brain Injury : Review, Update, and Controversies Shirley I. Stiver MD, PhD 32 year old male s/p high speed MVA Difficult extrication Intubated at scene Case BP 75 systolic / palp GCS 3 (2T) Pupils 4 mm bilateral, reactive Motor nil Open femur fracture First Management Steps? A) Give Mannitol 0.5 g/kg iv bolus B) GCS 3 - donor? C) Get stat CT scan D) Elevate sys BP > 90 mmhg 1
Intracranial Pressure (ICP) Compliance V/ P Pressure Volume Curve ICP = Brain + CSF + Blood vascular volume + Mass Lesion High Low Small increase in the intracranial volume significantly increase the ICP and ppt herniation Raised Intracranial Pressure Indications for Mannitol Cerebral Herniation Signs of impending cerebral herniation (Level III) 2
Motor Treatment Raised ICP Motor Score 1 Nil 2 Decerebrate posturing 3 Decorticate posturing 4 Withdrawal 5 Localizes 6 Obeys commands Mannitol Osmotic diuresis Reduces blood viscosity Watch for hypotension 1-1.4gm/kg, bolus Glasgow Coma Scale Poor GCS check Brainstem reflexes GCS Eyes 4 Verbal 5 Motor 6 Perform after resuscitation & before sedation or paralytics Importance of testing Pupils Corneals, Cough and gag Motor component of the GCS is most predictive of outcome Before Paralytics Often determines whether to take patient to OR 3
Differentiating primary versus secondary injury Guidelines Blood Pressure Level II Early GCS in the field gives you the closest assessment of the severity of the primary impact Resuscitated evaluation ; hypoxia / hypotension false positive No drugs / alcohol on board Importance of the reports from the emergency response team Importance of serial GCS & neurological testing Avoid hypotension sys BP < 90 mmhg Isotonic saline Fluid resuscitation a balance: Maintain cerebral perfusion avoid fluid overload, osmotic shifts, brain edema Hypotension strong predictor of outcome Single episode sys BP<90 doubles mortality Case Non Contrast CT scan Next? A) OR for decompressive craniectomy B) ICU observation C) ICU and ICP monitoring D) Ortho to OR femur repair 4
Guideline for ICP Monitoring GCS < 8 With Abnormal CT scan Unresponsive with absence of a neurological exam that can be followed Normal CT scan with -age > 40 -unilateral or bilateral posturing -systolic pressure < 90 mmhg -ethanol intoxication ICP Monitoring Guideline ICP Treat for threshold > 20mmHg Tiers of Therapy Cerebral Perfusion Management CPP = Mean arterial blood pressure ICP Tier 1 EVD drainage ; Sedation (Mannitol x 1) Tier 2 Osmotic therapy; Mannitol or Hypertonic N/S ; pco2 30-35 mmhg; paralysis Tier 3 Decompressive craniectomy ; Induced Barbiturate or propofol coma CPP goal > 60 mmhg Lund Therapy 5
Advanced Monitoring? What advanced monitoring might best help you manage this patient? A) Cerebral blood flow probe B) Brain tissue oxygen monitor C) SjVO2 jugular venous saturation Brain Tissue Oxygen Brain O2 probes placed in white matter Normal values for white matter 20-30mmHg Brain Tissue Oxygenation Jugular Venous Saturation O2 content of blood Normal values 20-30 (white matter) mmhg Critical values < 15 Cerebral blood flow BBB Dissociation & Diffusion of O2 SjvO2 Normal values 50-75% Critical values < 50 Global measure of cerebral metabolism: Measures total venous brain tissue oxygen in jugular bulb Oxygen extraction by the brain 6
ICP 18 MAP 86 FiO2 50% 7.4/35/141 PBrO2 18 SjVO2 90 Case UpDATES 1. A Trial of Intracranial-Pressure Monitoring in TBI R. Chesnut et al. NEJM 367: 2471-81 (2012). Treatment based on ICP monitor vs Clinical Exam 2. Protect Study Methylprednisolone 3. Pharmacologic DVT Prophylaxis in TBI ICP versus Clinical Exam No randomized trial to show that treatment based on monitored ICP improves outcome 324 severe TBI patients Randomly assigned to 1. ICP monitor group 2. Clinical group Outcome measures : survival, functional and neuropsychological outcome at 6 months R. Chesnut NEJM 367: 2471-81 (2012) At 6mo ICP Clinical p value 1 Outcome score 56 53 0.5 Mortality 39% 44% 0.4 Favorable Outcome Unfavorable Outcome 44% 39% 17% 17% Conclusions Management guided by ICP Monitoring NOT > Clinical Exam ICP versus Clinical Results 7
DVT Prophylaxis after TBI The controversy : TBI : enoxaparin has the potential to iatrogenically exacerbate intracranial hemorrhage View that hemorrhage stabilizes with time Is there an early prohibitive period, but once hemorrhage stabilizes, anticoagulation is safe - - Timing? Recent Studies Pharmacologic DVT Prophylaxis in TBI Importance of hemorrhage stability before starting prophylaxis Worsening of hemorrhage between 1 st and 2 nd CT scan followed by enox 13-fold increase in rate of continued hemorrhage Stable scan no hemorrhage expansion A. Levy et al, J. Trauma 68: 886-94 (2010) Recent Studies Pharmacologic DVT Prophylaxis in TBI Parkland Model Risk Stratification for Starting Enoxaparin Risk stratification by injury patterns -different lesions have different risks of hemorrhage progression different time frames for stabilization, and different times for starting prophylaxis Low risk for enox at 24h : SDH < 9mm EDH < 9mm Contusion < 2cm Single contusion per lobe S. Norwood J Trauma 65: 1021-27 (2008) Low Risk Repeat CT at 24h Stable? yes Start Enox at 24 h no Moderate Risk Repeat CT at 72 h Stable? yes Start Enox at 72 h no High Risk Consider IVC filter H. Phelan, J Neurotrauma 29: 1821-28 (2012) 8
Controversy Decra: Study Methods Does Decompressive Craniectomy Improve Outcome? DECRA Study Severe TBI (GCS 3-8) with Diffuse injury Tier 1 therapy: osmotics, sedation, paralytics, EVD drainage Refractory ICP defined as >20mmHg for > 15min Bifrontal decompressive craniectomy Continued ICU Care Tier 2 & 3 therapy : mild hypothermia to 35 Barbiturate coma DECRA Study Results : GOSE @6mo Hemi- Craniectomy 25 20 15 10 5 0 Die Veg LS US LM UM LG DC shifted survivors from favorable unfavorable outcome (dependent for ADLs) UG DC DC MC RescueICP www.rescueicp.com 9
Conclusions Basic Principles Once ICP already used up compensatory reserves Mannitol for impending herniation Poor GCS brainstem exam Distinguish primary v secondary injury Hypoxia / hypotension / drugs & ethanol may mask GCS ICP monitoring for unresponsive without neuro exam DECRA: Study Design 155 adults, aged 15-59 yrs Severe TBI (GCS 3-8) with Diffuse injury Randomized Standard Care vs Bifrontal craniectomy for Refractory ICP Outcome : GOS-E @ 6mo Exclusions - Dilated, unreactive pupils - Mass lesions (unless small) - Cardiac arrest at scene History Pharmacologic DVT Prophylaxis in TBI History No role for pharmacologic prophylaxis in TBI before 2000 Gearhart 2000 DVT prophylaxis in 102 trauma patients 26 TBI with intracranial blood no instance of TBI worsening Kim 2002-76 severe TBI, unfrac heparin; groups <72 h and > 72 h ; no increase in intracranial bleeding between groups 10
Decra: Study Methods Severe TBI (GCS 3-8) with Diffuse injury Tier 1 therapy: osmotics, sedation, paralytics, EVD drainage Refractory ICP defined as >20mmHg for > 15min Icp control DECRA: Study Results Bifrontal decompressive craniectomy Continued ICU Care Tier 2 & 3 therapy : mild hypothermia to 35 Barbiturate coma Life saving DC >72 h after admission 11