Diagnostics Flashcards
Non contrast or plain
Looks at brain tissue and brain
Present with focal/neurologic sx
Rule out patho process in intracranial vault involving brain
Quick image to develop
CT
Contrast injected
Looking at arteries in the head rather than brain tissue
3D CT angiogram
Contrast - can point out ischemic stroke
Iodine based - check allergies!
CT angiogram
More detailed images of brain
Start with CT scan
Takes 1hr 15min
Nursing responsibility
Screen pt for metals: sheet where check off
Claustrophobia
Any hospital provided things (SCDS, IV pumps) leave
Let MRI suite know if cannot leave MRI pump - sits in MRI suite and 15 feet of tubing
MRI
Non-iodine based dye injected to visualize arteries in head and neck
More detailed than CTA
Nursing responsibility
Screen pt for metals: sheet where check off
Claustrophobia
Any hospital provided things (SCDS, IV pumps) leave
Let MRI suite know if cannot leave MRI pump - sits in MRI suite and 15 feet of tubing
MRA
Done in IR under fluoroscopy; insert need between two lumbar vertebral bodies and hand injects IV contrast - not into spinal column - contrast goes into subarachnoid space (spinal canal around SC) and spinal root nerves are imaged
Myelogram
Records electrical activity of brain
Electrodes adhered to head and forehead
Waveforms get bigger - onset of seizure
Nurses primary role - educate; tell fam and pt - noninvasive procedure; just lay there; no shaving or IV access; see what electrical activity is; video EEG - see seizure happen - subclin seizure - no outward seizure activity but in brain are electrical activity present
Electroencephalogram (EEG)
Performed get sample of CSF
Pts in sitting position or on side and knees tucked up
Need spine curved to open vertebral columns - needle between vertebral bodies
After LP, nurse to label and sent to lab to get diagnostic testing done
Clear: normal
Straw yellow but clear: little blood - subarachnoid hemorrhage
More yellow to red gets - more blood
Cloudy = bacteria = meningitis
Presence/absence of bacteria. Diagnosis: bacterial meningitis
Presence/absence of blood. Diagnosis: subarachnoid hemorrhage
Lumbar puncture
treat or Prevent seizures - after craniotomy or blood in brain - very irritating and cause seizures - dx of epilepsy can have these meds in hospital
Phenytoin
Fosphenytoin
Anticonvulsants
CNS depression
Phenobarbital – reduces spread of epileptic focus (given pentodiazepines to stop seizure, propofol to stop seizures and if break through seizures do drip of this)
Pentobarbital - barbiturate coma; not seen as common; very sick and need decrease all metabolic demand; given in status epilepticus - brain time to rest and stop seizure
Barbiturates –
Mannitol - Treats cerebral edema
Pull edema from intracellular to extracellular - takes up less space in intracranial space - pee it off
Osmotic Diuretics
Nimodipine – Decreases cerebral vasospasm in pt.’s with subarachnoid hemorrhage (SAH); oral; subarachnoid hemorrhage - originates from arteries in head - ruptured anyreursm - until blood out of head - artery irritable and get spasm - narrows - affects blood flow in head leading to ischemic event
Calcium Channel Blockers
Maintain euvolemia in pt.’s with ICP & CPP within defined limits.
Everything is normal after surgery and out on dry side; ICP and MAP and CPP fine - NS given still
0.9% Sodium Chloride/NS
Dependent on what used
ICP - most common
CPP - most common
Brain Oxygenation
CBF - cerebral blood flow
Cerebral metabolism
Brain function
What is being monitored? - ICP monitoring devices
Issues with increased ICP or increased metabolism in brain; device placement dependent on pt presentation
What patient populations require intracranial pressure monitoring? - ICP monitoring devices
Transcranial cranial dopplers (TCD), CT/MRI, pupillometry
Noninvasive intracranial monitoring - ICP monitoring devices
Transcranial cranial dopplers (TCD), CT/MRI, pupillometry
Noninvasive intracranial monitoring - ICP monitoring devices
Intracranial monitoring devices - neurosurgeon present - intraventricular catheter, subarachnoid screw, intraparechymal sensor, subdural bolt
intraventricular catheter - distal tip in ventricle of the brain
subarachnoid screw - screwed in subarachnoid space - indirectly get pressure of brain based on pressure pushed against tip screw
intraparechymal sensor - distal tip catheter in brain tissue - direct measurement of ICP
Subdural bolt - distal tip in subdural space
Invasive - ICP monitoring devices
Intracranial Pressure: Normal 5-15 mmHg
Normal range for ICP? - ICP monitoring devices
Intraventricular catheter with EVD - common set up
Intraventricular catheter - into head - feed catheter until in ventricles - get CSF flashback - out to EVD set up
Most used at SLH: External ventricular drain (EVD) AKA Intraventricular monitoring, intraventricular catheter device.
Continuously draining CSF to achieve a prescribed amount (usually 5, 10, or 15 ml/hour). - Drain off CSF to decrease ICP - done slowly
Do not drain the CSF too quickly.
External ventricular drain (EVD)
Normal range for Intracranial Pressure (ICP): 5 -15 mmHg
Know perfect wave form looks like (on slide)
Intracranial pressure waves
Not waveform
How is CPP calculated?
MAP - ICP
Normal: 50 - 70 mmHg = need for pressure gradient for blood to get from arteries into brain tissue
Cerebral perfusion pressure (CPP) (pg 570)
Depends on the numbers
MAP: 64 mmHg
ICP: 15
CPP: 49 mmHg
Consider giving phenoefran - raise BP to raise MAP or something decrease ICP - decrease external stimuli and metabolic demand of brain, increase head of bed, consider sedation (valium or ativan PRN orders), Sats low - give O2, mannitol to decrease cerebral edema
How does the nurse know if the intervention is effective?
Decrease ICP or raise MAP
The nurse is taking care of a patient who has a low CPP. What intervention(s) should be done to get the CPP in the normal range?
No because if MAP stays constant and ICP goes up the CPP goes down; MAP - ICP = CPP
The nurse is caring for a patient who’s ICP is trending up. Should the nurse expect the CPP to go up as well?
Objectively measures Pupil size and reactivity
Able Trend pupil size and reactivity based on device; take guesswork out
Takes away guesswork from pen light
Pupillometry
Measure velocity of cerebral blood flow
Measured through thinnest part of skull: windows - temple and eye socket and transoccipital
What is measured? - Transcranial doppler (TCD)
Velocities measured and trended to monitor for vasospasm - vessel narrowed at pt decreasing blood distal to spasm causing neuro decline
What information does the TCD monitoring collect?
Ordered for pts with a subarachnoid hemorrhage - caused by trauma/ruptured aneurysm - by intracerebral artery
What is the patient’s most likely diagnosis?
