Neuro Emergencies 2 Flashcards
1
Q
Management of Increased Intra-Cranial Pressure
BRAIN CODE
Cerebral Blood Flow and Perfusion
- Blood supplied from where? 2
- Drains via? 3
- Recieves how much CO?
- CPP=?
- Normal CPP?
- CPP over what indicates brain ischemia?
A
- Supplied from
- internal carotid and
- vertebral arteries - Drains via
- cerebral veins and
- dural venous sinuses into the -internal jugular veins - Receives 10-15% of CO
- CPP = MAP – ICP
- Normal CPP = 70-90 in adults
- CPP > 50 indicated brain ischemia
2
Q
Monroe-Kellie Concept
- What is ICP?/
- Volume of brain and constituents inside the cranium is fixed and cannot be compressed. Which parts make this up and what percent do they account for? 3
A
- ICP is a function of the volume and compliance of each compartment
- Brain volume = 85%
- Cerebrospinal fluid = 10%
- Blood = 5%
3
Q
Intracranial Compliance
- What kind of compliance?
- What are the initial compensatory mechanisms? 2
- Once compensatory mechanisms are exhausted what happens to volume and pressure?
A
- Nonlinear compliance
- Initial compensatory mechanisms
- Displacement of CSF into thecal sac
- Decrease in cerebral venous blood - Once compensatory mechanisms are exhausted, small increases in volume produce large increases in pressure
4
Q
Causes of Increased ICP
7
A
- Intracranial mass
- Cerebral edema
- Increased CSF production (choroid plexus lesion)
- Decreased CSF absorption (adhesions)
- Obstructive hydrocephalus
- Obstruction in venous outflow (venous sinus thrombosis)
- Idiopathic (pseudotumor cerebri)
5
Q
Signs and Symptoms: increased ICP
8
A
- Headache
- Vomiting
- Altered consciousness
- Seizures
- Papilledema
- Unequal and/or unreactive pupils
- Cushing’s triad: bradycardia, hypertension and abnormal respirations
- Impending herniation
6
Q
ICP Monitoring Indications
3
A
- Abnormal CT showing mass effect and/or midline shift
- GCS less than 8
- High risk for increased ICP (closed head injury)
7
Q
Non-invasive techniques
for ICP measurement?
4
A
- Ocular sonography – measures optic nerve sheath diameter
- Transcranial doppler – measures velocity of blood flow in proximal cerebral vasculature
- Intra occular pressure measurement
- Tympanic membrane displacement
8
Q
Management of ICP
1. Optimize Cerebral Venous OUtflow by
A
- Promote displacement of CSF from intracranial compartment to spinal compartment
- Elevate head of bed to 30°
- Line placement (subclavian vs IJ)
9
Q
- How can a fever cause increased ICP?
- Tx for this?
- If conventional efforts fail?
- core temp of?
A
- Elevated metabolic demand results in increased cerebral blood flow and elevated ICP
- Acetaminophen and cooling blankets
- Therapeutic hypothermia can be effective in lowering ICP with conventional efforts failed
- Goal core temperature between 32 and 34°
10
Q
Hyperventilation-ish
- PaCO2 of?
- Considered what kind of measure?
- Minimize in pts with what? 2
- (Why?)
A
- PaCO2 of 35-38
- Hyperventilation to lower PaCo2 levels: Considered an urgent measure, but should not be chronic
- Minimize in pts with
-TBI or
-acute stroke
(Vasoconstriction causes decrease in cerebral perfusion and can worsen outcome)
11
Q
Intubation
- hypoxia and hypercapnea increase ICP how?
- Why should you use PEEP with caution? 3
- Pre-medicate with what to prevent ICP surge?
A
- Hypoxia and hypercapnea can increase ICP
- Use PEEP with caution
- Impedes venous return,
- decreases blood pressure
- leading to reflex increase in cerebral blood flow - Pre-medicate w/ Lidocaine to prevent increased ICP surge
12
Q
What is the most commonly used osmotic diurectic?
A
Mannitol
13
Q
- Mannitol MOA?
- Dose?
- Can be given through what?
- Good option if also interested in doing what?
- Monitoring parameters?
3
A
- Draws free water out of brain and into circulation
- Dose: 20% solution given as 1g/kg bolus, repeat dosing q6-8 hrs as needed
- Can be given through peripheral line
- Good option if also interested in lowering BP
- Monitoring parameters:
- serum Na+,
- serum osmolality and
- renal function
14
Q
Varying volume and tonicity either as bolus or infusion
- Which fluid?
- Which fluid for an ICU or actively herniating pt?
- What kind of line preferred?
- Goal serum?
A
- 3%
- 23% (ICU or actively herniating patients only)
- Administration via central line preferred, but 3% okay peripherally
- Goal serum Na+ less than 155
15
Q
Sedation
- Decreases ICP by what?
- What has good effect since it is easily titratable and has a short half life?
A
- Decreases ICP by reducing metabolic demand
2. Propofol