TRAUMATIC BRAIN INJURYwith INITIAL MANAGEMENT IN ED

DR. MUNAWARUZZAMAN BIN ABDUL MANANPAKAR PERUBATAN KECEMASAN JABATAN KECEMASAN HOSP QUEEN ELIZABETHKOTA KINABALUSABAH

ClassificationTBI is classified based on the clinical assessment of a patient's level of consciousness with little or no regard to the actual underlying injurysevere (GCS score of 3 to 8)moderate (GCS score of 9 to 13)mild (GCS score of 14 or 15)

PathophysiologyBrain consumes 20% of the body's total oxygen requirementand 15% of total cardiac outputsensitive to ischemia and low-oxygen statesVasoconstriction occurs with HypertensionHypocarbiaalkalosis

CBFFlow = 750 mls/minCMRO2 = 50mls O2/minControlCBF = CPP/CVR

CBFCPPCPP = MAP ICPNormal ICP < 15 mmHgCVRMetabolic autoregulationPressure autoregulationChemical (pO2 & pCO2)Nervous system

Monro-Kellie DoctrineSkull is a rigid boxFluid is incompressibleAny increase in intracranial content will result in a large increase in pressureHowever, pressure does not rise initially because of translocation of csf into extracranial subarachnoid space

Primary brain injuryContusionHematoma (SDH, EDH, SAH, Intraparenchymal, Intraventricular)DAITearing, shearingirreversible

Secondary brain injurydamage caused by a series of deleterious cellular and subcellular events that follows the primary injury and leads to an expansion of the original injuryAKA Secondary cascadecalcium and ion shifts, mitochondrial damage, production of free radicals, and enzyme activity that lead to cell death

Secondary insulthypotension, hypoxemia, elevated ICPWorsen the outcome of TBI

ED ManagementHistoryMechanism of injuryFall from height, impact area, speed, seat belt, airbagPatient condition before and after injuryMedical cond on anticoagulationIntoxicationNausea, Vomitting, HeadacheThe goal of ED resuscitation is to prevent secondary insult and potentially slow the expansion of the underlying injury

Airway and BreathingHypoxia increases mortalityPatients with severe TBI (GCS score of 8) require prompt airway controlInductionEtomidate Favourable hemodynamic/ rapid onset/ short duration (0.3 mg/kg)Propofol rapid onset and recovery/ strong anti seizure/ cautious in labile BP (1-2mg/kg)Paralysis - Scoline

Circulationthe most important secondary insult is hypotensionHypotension and subsequent ischemia of vulnerable and injured neuronal tissue can dramatically exacerbate the underlying secondary cascade and lead to an expansion of the injury and worse outcomesIn severe TBI, a single episode of hypotension doubles mortalityaggressive fluid resuscitation may be required to prevent hypotension and secondary brain injuryDoes not increase ICPMaintain SBP >90 mmHg (BTF 3rd ed 2007)

DisabilityModerate and severe CTMild Head injuryCanadianNew Orlean

The Canadian CT Head RuleIan G Stiell, George A Wells, Katherine Vandemheen, Catherine Clement, Howard Lesiuk, Andreas Laupacis,R Douglas McKnight, Richard Verbeek, Robert Brison, Daniel Cass, Mary A Eisenhauer, Gary H Greenberg, JamesWorthington, for the CCC Study Group.Lancet 2001; 357: 1391961.GCS

The New Orleans CriteriaHaydel MJ et al. Indications for computed tomography in patients with minor head injury. N Engl J Med 2000 Jul 13 343 100-105.

GCS = 15 and require CT scanning if..HeadacheVomitingAge >60 years of ageDrug or alcohol intoxicationPersistent anterograde amnesiaVisible trauma above the clavicle

Extra/Epidural Hematoma (EDH)traumatic accumulation of blood between the inner table of the skull and the stripped-off dural membraneBlunt trauma to the temporal or temporoparietal area with an associated skull fracture and middle meningeal arterial disruption is the primary mechanism of injury

EDHprognosis is excellent if treated aggressivelyClassic history Lucid interval temporary improvement in a patient's condition after a traumatic brain injury, after which the condition deterioratesThe high-pressure arterial bleeding of an epidural hematoma can lead to herniation within hours after an injury1/3 venous bleed

EDHExpanding high-volume epidural hematomas can produce a midline shift and subfalcine herniation of the brain. Compressed cerebral tissue can impinge on the third cranial nerve, resulting in ipsilateral pupillary dilation and contralateral hemiparesis

MxResusRSI if necessaryReduce ICPElevate head 300Mannitol 0.25 1 g/kg200 cc of 20% over 20 min (40g of mannitol)HyperventilationPhenytoin - reduces the incidence of early posttraumatic seizures, not affect late-onset seizuresRefer for evacuation

Subdural Hematomacollection of blood below the inner layer of the dura but external to the brain and arachnoid membraneacute subdural hematomasare less than 72 hoursHyperdensesubacute phasebegins 3-7 days after acute injuryisodense or hypodenseChronic subdural hematomas21 days (3 wk) or olderHypodenseTinti acute 2/52

SDHcaused by sudden acceleration-deceleration of brain parenchyma with subsequent tearing of the bridging veinsBrains with extensive atrophy, as in the elderly and in alcoholics, are more susceptible to acute subdural hematoma

MxMedical management similar to EDHSurgical decompassociated with a midline shift greater than or equal to 5 mmexceeding 1 cm in thicknesscomatose patient with an acute subdural hematoma less than 1 cm in thickness causing a midline shift of less than 5 mm if any of the following criteria are metThe GCS score decreases by 2 or more points between the time of injury and hospital evaluationThe patient presents with fixed and dilated pupilsThe intracranial pressure (ICP) exceeds 20 mm Hg

Diffuse Axonal Injurydisruption of axonal fibers in the white matter and brainstemShearing forces on the neurons generated by sudden deceleration cause diffuse axonal injuryedema can develop rapidlyresult in devastating and often irreversible neurologic deficits

DAIA CT scan of a patient with diffuse axonal injury may show normal findings, but the classic CT demonstrates punctuate hemorrhagic injury along the grey-white junction of the cerebral cortex and within the deep structures of the brain

Subarachnoid hemorrhageextravasation of blood into the subarachnoid space between the pial and arachnoid membranesPatients with isolated traumatic subarachnoid hemorrhage may present with headache, photophobia, and meningeal signsPatients who show early development of traumatic subarachnoid hemorrhage have a threefold higher mortality risk than those without traumatic subarachnoid hemorrhage

SAHSome traumatic subarachnoid hemorrhages can be missed on early CT scans.Generally, CT scans performed 6 to 8 hours after injury are more sensitive for detecting traumatic subarachnoid hemorrhage

Hunt & Hess

Intraparenchymal hematoma / contussionbleeding into the tissue of the brain caused by trauma to the headmost commonly occur in the subfrontal cortex, in the frontal and temporal lobes, and, occasionally, in the occipital lobes Contusions may occur at the site of the blunt trauma or on the opposite site of the brain, known as a contrecoup injury

THANK YOU