TBI

what is a GCS of 13-15 considered?

mild → normal to slightly altered consciousness

what is a GCS of 9-12 considered?

moderate → significant impairment but not comatose

what is a GCS of less than or equal to 8 considered?

severe → comatose, requires aggressive intervention

characteristics of a concussion?

neurocellular injury from blunt force; not visible on imaging, considered a mild TBI → symptoms can last months to a year (headache, dizziness, memory issues, irritability, insomnia)

characteristics of a contusion?

superficial bleeding on the cortext, can expand into larger TBI → monitor for worsening symptoms

what is a big risk of penetrating injuries to the head?

high risk of infection and severe damage

what does a focal injury mean?

localized to one area → hematomas, contusions

what is a primary injury?

direct result of mechanical force → impact, shearing, rotational, penetrating

what is a secondary injury?

physiological reactions after initial injury → ischemia, swelling, inflammation, increased ICP

what is an acceleration injury?

moving object strikes head → bat/baseball

what is a deceleration injury?

head strikes immovable object → fall, car accident

what is a coup-contrecoup injury?

injury at a point of impact and opposite side → common in car accidents

what is a rotational injury?

head rotates on axis causing shearing of axons → boxing, falls from horses

what is a penetrating injury?

object enters brain → bullet, knife, crush injury

what is a linear skull fx?

simple, non-displaced, low-velocity trauma → usually no specific intervention needed

what is an open skull fx?

skull and scalp laceration with communication to environment → high risk of infection, requires sx repair and abx

what is a depressed skull fx?

high force, bone pressed inward, often w large hematoma → requires sx repair and evacuation

what is a basilar skull fx?

at base of skull (temporal/occipital) → can cause CSF leak, raccoon eyes, battle sign (bruising behind ear)

what is the halo sign?

testing clear fluid for glucose which causes a clear ring shape around a drop of blood

characteristics of subdural hematomas?

venous bleed between dura and arachnoid (slower onset) → can be acute (24-48 hrs with confusion, headache, neuro changes), subacute (2 days - 2 weeks post injury, may be subtle esp with elderly), or chronic (over weeks, often mistaken for dementia in elderly)

characteristics of epidural hematomas?

arterial bleed between dura and skull (often middle meningeal artery) → rapid onset, classic lucid interval with LOC then brief recovery then rapid decline

characteristics of intraparenchymal hematomas?

bleeding deep in brain tissue; often from hypertension, ruptured aneurysm, or high-impact trauma → hard to evacuate surgically, want to focus on managing ICP and cerebral perfusion pressure

what is a diffuse axonal injury?

shearing of axons from rotational forces; often not visible on imaging → high morbidity/mortality if severe, common in high-speed MVCs

what is an anoxic injury?

brain deprived of oxygen causing diffuse, severe deficits

characteristics of a subarachnoid hemorrhage?

blood between arachnoid and pia mater from aneurysm, trauma, arteriovenous malformation → can cause midline shift, herniation & the “worst headache of my life”

what is the monro-kellie hypothesis?

skull is a fixed box so brain, blood, and CSF must balance → if one increases, the others must decrease to fit

what is auto regulation relating to the brain and CSF levels?

brain adjusts vessel diameter to maintain constant cerebral blood flow → only works if cerebral perfusion pressure is 50-150 mmHg

what is the equation for cerebral perfusion pressure?

CPP = MAP - ICP → goal CPP is greater than 60 or ”65 to stay alive”

what is the goal for ICP?

less than 20-25 mmHg

what are some causes of increased ICP?

increased brain volume from edema, tumor or abscess, increased blood volume from hypoxemia, hypercapnia, outflow obstruction, and increased CSF d/t hydrocephalus and decr absorption

what are some signs of increased ICP?

decreased GCS, irregular breathing, cushing’s triad (HTN, bradycardia, irregular respirations), vomiting, unequal/sluggish pupils, headache, restlessness, temp changes, motor deficits, posturing

when do you typically see cushing’s triad?

late sign of herniation with increased ICP → emergency

what occurs in the tier 1 of management for increased ICP?

short-acting analgesics/sedatives like tylenol, opiates, and precedex, want to maintain normothermia with antipyretics and cooling blankets, maintain neutral head position at 30 degrees at the HOB with minimal stimulation, want paO2 > 100 and paCO2 30-35

what occurs in tier 2 of management for increased ICP?

hyperosmolar therapy (mannitol, hypertonic saline), external ventricular drain (EVD) to drain CSF, temporary hyperventilation to lower CO2 and ICP

what occurs in tier 3 of management for increased ICP?

medically-induced coma & decompressive craniectomy (bone flap removed to allow swelling)

how to do an assessment on a patient who is vented/trached?

need established baseline for comparison, use “T” for verbal (pt can’t respond so score is modified), PERRLA, motor/sensory by withdrawing from pain or posturing

what does high sodium to do a patient?

put them at risk for seizures

characteristics of diabetes insipidus?

low ADH, high urine output (300-600 mL/hr), hypernatremia, hypotension → tx with vasopressin/desmopressin and maintenance fluids

characteristics of SIADH?

water retention, hyponatremia, edema, low urine output → tx with fluid restriction, strict I&Os, and frequent neuro checks

what are signs of brain herniation?

cushing’s triad (HTN, bradycardia, irregular resps) & blown pupils → fatal

who are the highest risk individuals for TBIs?

males, elderly 85+, infants < 1 year, native americans, african americans