NUR 265 Exam 3 Study Guide & Exam Questions and Answers

NUR 265 Exam 3 Study Guide & Exam Questions and Answers Increased ICP (939-940, chart 941) • Normal ICP 10-15 mmHg, pressures 20 mmHg impair cerebral circulation • IICP is leading cause of death from head trauma in pts who reach the hospital alive. • Cerebral Perfusion Pressure (CPP) o Blood flow required to provide adequate oxygenation & glucose for brain metabolism o Maintenance above 70 mmHg o CPP= MAP-ICP ▪ MAP= (2xD) + S MAP NEEDS TO BE ATLEAST 80 3 • Compensation o First Response – CSF is shunted or displaced into the spine (compliance) o Next – Reduction of blood volume in the brain (autoregulation) o As ICP continues to increase cerebral perfusion decreases leading to brain tissue ischemia, edema, vasodilation then acidosis which causes further increases ICP o In edema remains untreated the brain may herniate into spinal canal – death from brain stem compression • Assessment Findings o Changes in LOC – First sign of IICP is declining LOC & includes restlessness or confusion to Stuporous ▪ W/o glucose & 02, brain shuts down. Ex. Pt knew who you were in am & now don’t remember o Headache – Quite environment may have photophobia so keep room lights very low. o Change in speech pattern – Aphasia, Slurred Speech o Changes in pupil size – 2 cm change in either direction is significant, dilated or constricted, Notify Dr ▪ Normal is 6 mm. Getting better if going back toward normal from dilated or constricted ▪ Uneven pupils tx as IICP until proven otherwise; pinpoint - brain stem (pons) dysfunction o Abnormal Posturing – Decorticate (flexion) or Decerebrate (extensor) ▪ Decorticate – arms drawn to core, legs straight ▪ Decerebrate – arms straight and stiff, pts rarely survive o Hyperthermia – followed later by hypothermia ▪ When hypothermic – BE CONCERNED, pressure on hypothalamus located next to brain stem o Cardiac & respiratory rate/rhythm changes ▪ Tachy first – Increased HR & RR before brady HR & RR o N/V – Common in IICP o Cushing’s Triad – Severe HTN, Widened Pulse Pressure, Bradycardia ▪ Late response & indicates severe IICP w/loss of autoregulation, Imminent death ▪ Systolic BP increases bc decreased blood flow to brain ▪ Pressure on Vagus nerve and brainstem = bradycardia • Managing IICP o Elevate HOB 30-45 degrees (unless contraindicated) ▪ If hypotension, elevate HOB where CPP 70 o Maintain head in a midline neutral position o Avoid sudden and acute hip or neck flexion during positioning – Log roll pt o Avoid clustering of care (bath followed by linen change) o Coughing and suctioning increase ICP o Decrease cerebral edema – osmotic diuretics (mannitol) & fluid restriction ▪ Mannitol is hypertonic- pulling fluid into vascular space- will inc. fluid output & monitor BP for HTN ▪ Furosemide used in adjunct to reduce incidence of rebound from mannitol. Helps reduce edema & blood volume, decrease Na uptake by the brain, & decrease production of CSF at choroid plexus. o LOW CSF using intraventricular drain system o Control fever w/antipyretics or cooling blanket – do not allow pt to shiver as will increase ICP ▪ When febrile every cell in body needs more 02 and glucose o Oxygenation – Hyperventilate on a vent to decrease CO2 which causes vasodilation o Reduce cellular metabolic demands – barbiturates (-bital, -barbital) and/or sedation (coma) Traumatic Brain Injury (946-957) • Primary Brain Injury o Occurs at time of injury o Open – Head fractured or penetrated; Closed – Blunt trauma, shaken baby o Open Head Injuries ▪ Skull Fractures • Linear Fx – thin line on x-ray, no tx unless underlying brain tissue damaged • Depressed Fx – Brain damage from bruising (contusion), laceration from bone fragments • Basilar skull Fx – Fx of bones of the base of skull & results in CSF leak from nose & ears. o May not be seen on plain x-ray, R/F Infection w/ CSF leak o Manifested by bruises around eyes(raccoon eyes) or behind ears (Battle’s sign) o Has potential for hemorrhage if it damages the internal carotid o Closed Head Injuries ▪ Caused by blunt force trauma ▪ Contusion – Bruising to brain tissue @ site of impact (coup) or opposite (contercoup) ▪ Laceration – tearing of the cortical surface vessels, lead to secondary hemorrhage, cerebral edema and inflammation ▪ Diffuse Axonal Injury (DAI) – Tissue of entire brain from high speed acel/decel MVC • Impaired cognitive functioning, results in disorganization, impaired memory • Severe will present with immediate coma, survivors require lone-term care o Classified as ▪ Mild – GCS 13-15 (concussion) • Blow to head, transient confusion, or feeling dazed or disoriented • Loss of consciousness for up to 30 min, loss of memory before and after accident • No evidence of brain damage, sx resolve w/i 72 hrs • Sx: HA, N/V, Fatigue, Foggy, Balance off, Irritable, Sad, Nervous, Emotional, Visual probs ▪ Moderate – GCS 9-12 • Loss of consciousness 30 min – 6 hrs w/ memory loss up to 24 hrs. • Short hospital stay to prevent secondary injury