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					Title: Care of Central Nervous System Injuries
Author: Chesnut RM
Journal: Surgical Clinics of North America 87(2007) 119-156

Key Points
         •     Primary brain injury occurs at the time of the initial trauma and cannot be treated so efforts should focus or monitoring and
               aggressively treating the cause of secondary brain injury.
          •    Careful monitoring of neurologic status, intracranial pressure, and CT scan is critical to detect decline and guide urgent treatment
          •    Surgery may be necessary in cases where there is mass effect, sudden neurologic decline, or refractory intracranial hypertension.

Clinical Conclusions
           •   Careful patient monitoring is the key to the prevention, detection, and management of those critical factors that can lead to poor
               outcome after traumatic brain injury.

Section Highlights
Primary and secondary brain injury
           •    Primary brain injury is the damage to the brain that occurs or is initiated at the time of trauma and may include direct force,
                contrecoup injury, rotational forces, or penetrating trauma.
           •    Secondary brain injury occurs from processes that take place after the initial injury and either worsen that injury or negatively
                influence recovery with the most common secondary insult being hypotension but others include hypoxia and pyrexia.
Intracranial pressure and cerebral perfusion pressure
           •    Intracranial hypertension can produce two deleterious consequences: herniation and ischemia.
                      o Herniation occurs when a pressure gradient across a fixed anatomic barrier causes a shift of brain matter.
                      o Ischemia develops when intracranial hypertension lowers the cerebral perfusion pressure (CPP) Figure 1-2
Targeted therapy
           •    The old linear algorithms to treat TBI are currently being replaced with targeted therapy which supports a physiology-based, parallel
                processing approach.
Clinical care
           •    Patient assessment should evaluate critically for possible brain injury even in patients with a Glasgow Coma Score (GCS) of > 8, and
                the clinician must remember never to attribute neurological deficits to intoxication without imaging.
           •    Patient assessment should evaluate critically for possible brain injury even in patients with a Glasgow Coma Score (GCS) of > 8, and
                the clinician must remember never to attribute neurological deficits to intoxication without imaging.
           •    Imaging includes the most important tool in neurotrauma which is the CT scan which have largely replaced conventional skull
                radiographs and should be done in any case of suspected TBI to expedite diagnosis and treatment.
                      o Epidural hematoma (blood collection between the dura mater and the skull), subdural hematomas (below the dura mater),
                           and acute intracerebral hematomas all have unique appearances on CT scan. Figures 3-5
                      o Subarachnoid hemorrhage, cerebral edema and shear injury can also all be visualized on CT scan. Figures 7-9
           •    Treatment of patients with traumatic brain injury begins with the basic principles of trauma resuscitation.
                      o Patients with GCS < or equal to 8 require airway control, adequate oxygenation, and controlled or assisted ventilation.
                           Figure 10
                      o Hypoventilation before implantation of an ICP monitor should be limited to a PaCo2 range of 30-35 mm Hg and only used
                           when there are clinical signs of intracranial hypertension (papillary changes, motor posturing, or neurologic deterioration.
                           Figure 11
                      o Hypotension in an independent predictor of morbidity and mortality in TBI and should be aggressively treated with volume
                           resuscitation with isotonic solution and temporary pressors if needed.
           •    Disability from TBI needs to be limited by obtaining a baseline neurologic status that is frequently rechecked to provide immediate
                treatment for deterioration. Figure 11
           •    Monitoring ICP is indicated with cases of severe TBI, moderate TBI thought to be at risk of intracranial hypertension, or those who
                cannot be evaluated with serial examination (e.g. sedated patients).
                      o Pre-ICU care should begin with rapid and vigorous resuscitation of all TBI patients, early CT imaging, neurosurgical
                           consultation, placement of an ICP monitor, and transport to the ICU. Figure 10-11
           •    Initial ICU care should continue resuscitation and monitoring according to the treatment algorithms established in the Guidelines for
                the Management of Severe Traumatic Brain Injury and the Guidelines for the Acute Medical Management of Severe Traumatic Brain
                                                                              1, 4
                Injury in Infants, Children, and Adolescents. Figures 12-14
     Special considerations may be necessary in individual cases.
           •    Early decompressive craniectomy has been experiencing a growing role in TBI management and should be considered in cases where
                ICP control is difficult.
           •    Burr holes have two roles in the treatment of TBI: exploration when imaging has not yet or cannot be done and temporizing where
                herniation from an epidural hematoma occurs.
           •    Intracranial pressure monitoring is mandated in cases of severe TBI with intraparenchymal and intraventricular monitoring devices
                                                                               4, 5
                preferable to subdural, subarachnoid, or epidural monitors.
           •    Cerebral spinal fluid rhinorrhea and otorrhea that persists beyond the first several days should be an indication to consider surgical
                closure to reduce the risk of infection.
         •     Observation of TBI patients should be done in an ICU rather than a general floor bed to allow for close observation and hourly
               neurosurgical checks.
•    Surgical issues arise for certain types of TBI with evacuation of hematomas indicated when the hematoma is large, exhibit mass effect, or
     patient GCS scores are low or deteriorating with time.

                                                                   Key References

1.       Bullock R., Chesnut R.M., Clifton G., Ghajar J., Marion D.W., Narayan R.K., Newell D.W., Pitts L.H., Rosner M.J., and Wilberger J.W.,
         Guidelines for the management of severe head injury. Brain Trauma Foundation. Eur J Emerg Med, 1996. 3(2): p. 109-27.
2.       Chesnut R.M., Marshall L.F., Klauber M.R., Blunt B.A., Baldwin N., Eisenberg H.M., Jane J.A., Marmarou A., and Foulkes M.A., The role of
         secondary brain injury in determining outcome from severe head injury. J Trauma, 1993. 34(2): p. 216-22.
3.       Jones P.A., Andrews P.J., Midgley S., Anderson S.I., Piper I.R., Tocher J.L., Housley A.M., Corrie J.A., Slattery J., Dearden N.M., and et al.,
         Measuring the burden of secondary insults in head-injured patients during intensive care. J Neurosurg Anesthesiol, 1994. 6(1): p. 4-14.
4.       Adelson P.D., Bratton S.L., Carney N.A., Chesnut R.M., du Coudray H.E., Goldstein B., Kochanek P.M., Miller H.C., Partington M.D., Selden
         N.R., Warden C.R., and Wright D.W., Guidelines for the acute medical management of severe traumatic brain injury in infants, children,
         and adolescents. Chapter 1: Introduction. Pediatr Crit Care Med, 2003. 4(3 Suppl): p. S2-4.
5.       Aarabi B A.T., Chestnut RMD, et al., Part 1: Guidelines for the management of penetrating brain injury. Introduction and methodology. J
         Trauma, 2001. 51(2 Suppl): p. S3-6.

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