neurocritical care Flashcards
what type of edema is involved in obstructive hydrocephalus?
interstitial
what type of edema is associated with brain tumors?
vasogenic
what type of edema is associated with hypoxic ischemic injury?
cytotoxic.
what symptoms does and uncal herniation cause?
ipsilateral dilated pupil, contralateral hemiparesis.
what is the normal range of ICP?
5-15 cm H2O
When using hyperventilation to treat increased ICP, what is the goal pCO2?
30 mm Hg
When using Mannitol to treat increased ICP, what is the goal serum osmolality?
320 mOsm/L
what are some associated complications to using mannitol?
wasting of Potassium, magnesium and phosphorus. Should not be used if there is significant disruption of the BBB.
stupor
pathologically reduced consciousness but arousable with vigorous external stimulation.
Coma
patient is unarousable. May grimace or have stereotyped withdrawal to noxious stim, but does not localize.
vegitative state
unresponsive patient with an apparent sleep-wake cycle. Persistent if lasts > 30 days.
under what circumstances is surgical evacuation of SDH indicated?
when it is larger than 1cm or of there is midline shift.
what are 3 complications of SAH?
- vasospasm 2. acute hydrocephalus 3. rebleeding
what foramina does the middle meningeal artery pass through?
foramen spinosum.
sensitivity of CT in SAH
95% in the first 48 hours.
rate of sodium correction in hyponatremia to avoid CPM.
no more than 12 mEq/L/day or 0.5mEQ/L/hr
what is the Ca channel blocker of choice to prevent vasospasm after SAH.
Nimodipine.
What is the “triple H” treatment of vasospasm after SAH?
Hypertension, hypervolemia (with isotonic fluids) and hemodilution.
what is apneustic breathing and in what lesions is it seen?
pause at the end of full inspiration. Seen with bilateral pontine lesions.
what is Cheyne Stokes breathing and in what lesion is it seen?
alternating apnea and hyperpnea and variation in the depth of breathing. seen in forebrain lesions with intact brainstem.
What is ataxic breathing and in what lesions is it seen?
irregular and gasping respirations seen in medullary lesions.
what are treatments for Warfarin related ICH?
IV vit K, FFP, recombinant factor VII
in what location does injury cause decorticate posture.
Decorticate = upper extremity flexion. Caused by injury above the red nucleus.
in what location does injury cause decerebrate posture.
lesions below red nucleus but above vestibular nucleus.
what is the treatment of malignant hyperthermia?
Dantrolene
What is the treatment of neuroleptic malignant syndrome?
Dantrolene and bromocriptine
what is the treatment of seratonin syndrome?
supportive and benzos
What breathing pattern is seen with pontine pupils in a comatose patient? Would they have decerebrate or decorticate posturing?
Apneustic, decerebrate
In descending order from cortical to medullary. What are the breathing patterns associated with coma.
Cheyne Stokes (forebrain), hyperventilation (midbrain), Apneustic (pontine), Ataxic (upper medullary)
What are the two most important risk factors for aneurysmal SAH?
Hypertension and smoking. Also, FH, Etoh, atherosclerosis, OCPS
What are the Hunt and Hess grades? What is the survival of a Grade 3 post-operatively.
Grade 1- Asymptomatic or minimal headache and slight neck stiffness -70% survival
Grade 2- Moderate to severe headache; neck stiffness; no neurologic deficit except cranial nerve palsy -60% survival
Grade 3- Drowsy; minimal neurologic deficit -50% survival
Grade 4- Stuporous; moderate to severe hemiparesis; possibly early decerebrate rigidity and vegetative disturbances -20% survival
Grade 5- Deep coma; decerebrate rigidity; moribund -10% survival
What are the Fischer Grades of SAH?
Grade 1: No blood
Grade 2: Diffuse or thin layer of blood less than 1 mm thick (interhemispheric, insular, or ambient cisterns)
Grade 3: Localized clots and/or layers of blood greater than 1 mm thick in the vertical plane
Grade 4: Intracerebral or intraventricular clots with diffuse or absent blood in basal cisterns
Cytotoxic Edema is due to failure of what pump? Where does the fluid accumulate?
Na+/K+ ATPase, intracellularly. Causes restricted diffusion on MRI.
A trauma patient presents comatose with multiple fractures and on autospy is found to have multiple petechial hemorrhages on autopsy of this brain and more diffusely on skin. What is the cause?
Fat embolism from long bone fracture.
How long can hyperventilation assist with ICP control? How does it work?
10-20 hours, decrease pCO2 leading to decreased cerebral blood flow and decreased intracranial blood volume. Though likely leads to decreased CPP.
What is the target serum sodium for hypertonic sodium therapy?
~150mmol/L
PRES is thought to be a disruption of what mechanism?
Posterior circulation autoregulation causing vasogenic edema. Endothelial injury and dysfunction are also implicated.
What complication is associated with use of recombinant Factor VIIa?
Increased risk of thromboembolic events.
What is the most effective agent for reversal of vitamin k antagonists (warfarin)?
Four Factor Prothrombin Complex Concentrate (PCC) or FEIBA (Factor Eight Inhibitory Bypassing Activity). Rapid correction of INR, small volume compared to FFP, may have lower risk of thromboembolism.
What is the goal temperature for therapeutic hypothermia for post-cardiac arrest (if you believe in it :))
32-34C
What are the risks of intraventricular drainage devices?
Hemorrhage 1-6%. Infection 2-22%
Patient can be aroused with strong tactile stimulation only and when aroused has impaired consciousness. What would P&P say?
Stupor. Peds resident: minimally responsive :)
What are predictors of Malignant MCA syndrome?
NIHSS of >15, early hypodensity of >50% MCA territory, younger age, hypertension. Consider hemicraniectomy
Corticosteroids are useful in what type of edema? What is the usual cause?
Vasogenic Edema. CNS tumors.
When does vasospasm occur and when is the peak post SAH?
Risk days 3-15. Peak 6-8.
A patient with myasthenia presents with small pupils, secretions, diarrhea, sweating, bradycardia, weakness and fasciculations. What is the likely cause?
Cholinergic crisis from increasing mestinon use.
For patient with AIDP what is the lower limit of FVC to indicate intubation?
15-20ml/kg or
What findings are associated with critical care myopathy? Neuropathy?
Myopathy: increased CK, EMG with myopathic motor unit potentials (trains of fibrillations and positive sharp waves), biopsy with myosin loss.
Neuropathy: Normal velocity and latency, decreased CMAP and SNAP.
