Traumatic Brain Injury Prepared by Shane Barclay MD

Objectives Develop a clinical approach to Traumatic Brain Injury (TBI) for both evaluation and ER management.

Prehospital Two major goals are to prevent hypotension and hypoxia, both of which are major causes of secondary injury. Clinical studies of prehospital intubation for hypoxia show conflicting results. Some had better outcomes but some had worse. The negative outcomes may be related to hyperventilation, transient hypoxia, longer time to transport and hemodynamic instability induced during intubation. If prehospital intubation is not done by experienced paramedics, bag-mask ventilation is the preferred treatment. ALL patients with TBI should be presumed to have a spinal fracture/injury.

Transfer Transfer to a tertiary care center should be initiated as soon as a traumatic brain injury is recognized.

Increased Intracranial Pressure (ICP) Although this presentation focuses on TBI as a cause of increased ICP there are many other causes: - Subarachnoid hemorrhage from aneurysm rupture - Brain tumor - Encephalitis - Hypertensive Brain Hemorrhage - Stroke Status epilepticus However, treatment principles remain the same.

ER Management of TBI Oxygenation. PaO2 should be kept greater than 60 mmHg MAP should ideally be maintained in the 100-110 mmHg range. GCS early on and repeated during the course in ER. Assess for other systemic trauma (ATLS protocol – ABCDE) Labs: CBC, creat., blood alcohol, urine drug screen, preg test in females, INR, ABG

ER Management of TBI If patient is hypotensive, search for other causes than brain injury, as TBI does not usually cause hypotension on it’s own.

Assessing for elevated Intra Cranial Pressure (ICP) Cushing Response: Increase in systolic and pulse pressure, reduction in heart rate and irregular respirations. Not very accurate. Patients with GCS < 8, unilateral or bilateral fixed pupils, decorticate/decerebrate posturing, bradycardia &/or respiratory depression should be suspected of having increased ICP.

ER Management of TBI and suspected increased ICP 1. Elevate head of the bed 30 degrees. If on clam shell may need to use reverse Trendelenburg. 2. If they become hyperthermic (‘brain fever’), which can be due to TBI, try cooling techniques/blankets etc. 3. Fluid resuscitation should be with normal saline. Try to avoid excessive hypervolemia. 4. Steroids? Discuss with neurosurgeon. NOT for intracranial bleeds. 5. Analgesia – adequate. Fentanyl drip is ideal. 6. Keep PaCO2 35-38 mmHg range. Use venous blood gases.

7. If patient is hypertensive and suspected of having increased ICP Mannitol (1 – 1.4 gm/kg IV) over 10 minutes. - Put in Foley, monitor output. - Replace urine output with normal saline. If output is not corrected patient may become hypotensive. (which is BAD) Or

7. If patient is hypotensive or normotensive and suspected of having increased ICP some have suggested ? 3% Hypertonic Saline. Give 250 ml over 15 minutes. - may be ? ‘as effective’ (sparse literature) as mannitol for treating ICP and also increases cardiac output. CJEM March 2016 “Hypertonic saline as a first line treatment for patients with severe traumatic brain injury cannot be recommended at this time”

Intubation of patients with increased ICP If the patient is hypotensive, hypoxic and ‘crashing’ don’t worry about cerebro-protective meds discussed in future slides. The crashing TBI patient needs fluids, ketamine, succinylcholine and intubation ASAP. For the non crashing, hypertensive/normotensive patient, you have some time to pre medicate and hopefully prevent ICP changes and further CNS damage.

Intubation of patients with increased ICP Cerebral blood flow can be regulated within a wide range of MAPs (from 60-160mmHg). However when severe IC hypertension develops, this autoregulation is lost. Also when systemic hypotension develops, this can result in decreased cerebral perfusion and hypoxemia which in turn causes cerebral edema and further increases in ICP. Therefore you want to avoid both hypotension and hypertension.

Intubation of patients with increased ICP Many airway management techniques can increase ICP. There is a reflex sympathetic response to glottic stimulation which releases catecholamines which in turn can increase ICP. Any manipulation of the glottic area can cause this reflex response. So OPA, LMA, suctioning, ETT etc can all be causes. Certain drugs for intubating ‘may’ blunt this response.

Steps for Intubation of patients with increased ICP 1. Do pre-neuro exam as baseline – GCS, pupillary reflexes. 2. Pre-oxygenate, ideally with nasal cannula or non-rebreather mask or if really necessary bag-mask x 3 minutes, but not LMA etc. 3. Set up EtCO2 (put it on the Ambu bag) 4. Try to minimize the time of intubation and the number of attempts, both of which are associated with increasing ICP.

Intubation of patients with increased ICP If Hypertensive : Give Labetaol 10- 20 mg IV or Hydralazine 10-20 mg IV to lower BP or at least prevent spikes in BP and concomitant increase ICP. If mildly Hypotensive (ie shock from other injuries) or concern of BP drop - Have vial of push dose Epinephrine, use to raise or maintain BP

Intubation of patients with increased ICP 5. Pretreatment with agents below ‘may’ blunt ICP response (1) Lidocaine 1.5 mg/kg IV 2-3 minutes prior to intubation. Very little evidence this drug has any benefit. (2)Fentanyl 4 - 5 mcg/kg IV giving 100 mcg per minute. Fentanyl is a sympatholytic. Yes a big dose, but this may blunt ICP spikes better than Lidocaine. If BP drops can give Epinephrine push.

Intubation of patients with increased ICP 5. Pretreatment with agents below ‘may’ blunt ICP response (3) 250 ml 3% Hypertonic saline. Can increase BP if hypotensive and can also blunt ICP spikes.

Intubation of patients with increased ICP 6. Induction agents: - Propofol 1.5 – 2 mg/kg - Ketamine 1-2 mg/kg IV if normotensive/hypertensive Always have a vial of push does Epinephrine on hand in case BP drops, and have Labetalol on hand in case BP jumps. Goal is to try and maintain Systolic BP 120 – 140 range. 7. Succinylcholine 1.5 mg/kg IV or Rocuronium 1.2 mg/kg IV.

Intubation of patients with increased ICP Once sedated and paralyzed, use video laryngoscope if you feel comfortable. Likely to cause less glottic manipulation.

Intubation of patients with increased ICP 7. Mechanical Ventilation - try to keep PaCO2 at 35 mmHg. Avoid hyperventilation. - maximize oxygenation (SpO2 95%), but avoid PEEP if possible or high inspiratory pressures. - FiO2 ~ 30-40% 8. Post intubation analgesia (Propofol drip) and sedation (Fentanyl). Watch the BP.

Transfer By the time you have done all the previous, transfer should be well under way.

Traumatic Brain Injury Clinical Case Scenario

Scenario 18 year old long board rider loses control and crashes on the pavement, hitting his head. Of course he isn’t wearing a helmet. EHS arrives. He is breathing on his own and responding to questions and commands, but is inappropriate. BP at scene is 135/60, HR 145, RR 18. He is put in neck collar, clam board, IV started in his hand and transported to the hospital. On route BP noted 160/90. Seems to be ‘babbling’. By the time he arrives in the ER, he is moaning and mumbling incoherent words occasionally, but not responding to commands or questions. He does moan and withdraws from pain and opens his eyes to pain. BP now is 175/100, HR 45, RR 20 and irregular. SpO2 91%.

What are you going to do?