Neuro Flashcards
1
Q
What anesthesia would you give to pts with MS?
A
- Avoid Succ!
- May have resistance OR prolonged response to NDMR
- No IV or inhaled anesthetic is superior
*
2
Q
What are you monitoring for in a pt with MS?
What should you consider with emergence?
A
- ANS dysfunction- lower threshold for arterial line
- Consider baseline muscle weakness during emergence; extubate wide awake with full NMB reversal
3
Q
Would you use regional anesthesia for a pt with MS?
A
- Best to avoid; may be considered in OB
- spinal anesthetics have been associated with post-op exacerbations
- because of damage to nerves, regional anesthesia may cause injury, especially if directly applied as in Spinal
- epidural anesthetics and peripheral nerve blocks have no reports of exacerbations
4
Q
Guillian barre expectations during surgery
A
- 60% have ANS dysfunction- pt does not compensate for physiological stressors normally
- will need positive pressure ventilation d/t muscle weakness
-
hypotension:
- positive pressure vent settings
- blood loss
- position change
-
hypertension:
- DVL
- pain
- with indirect acting vasopressors and sympathomimetics (fluids first)
- art line mandatory
- maintain preload with fluids
- altered temperature regulation
5
Q
How would you muscle relax a pt with Guillian-Barre?
A
- Avoid succ!
- Use a NDMR with minimal CV effects (vecuronium)
- monitor carefully for increased sensitivity or resistnace
- avoid NDMR with histamine release
6
Q
What should you consider regarding extubation for a pt with Guillian Barre?
A
- Monitor vigilantly because they are high risk for respiratory failure!
7
Q
Would you use regional anesthesia for a pt with guillian Barre?
A
- Epidural opioids can be beneficial for pain and discomfort
- Regional can be used with caution
- pts are sensitive to LAs (because of the Na channel blocking factor?)
- Epidural with slower onset preferred to rapid bolus of spinal
8
Q
What’s the deal with Levodopa in a pt with parkinson’s?
A
- Remember E1/2t is short
- withdrawal effects after 6 hours
- give levodopa 20 minutes before induction and repeat prn via OG tube and post op
- If oral dose cannot be given, apomorphine SQ is a dopamine agonist that can be given
9
Q
What should you consider regarding GA for a Parkinson’s pt?
A
- Aspiration risk- because of salivation, dysphagia, esophageal dysfunction
- RSI
- Avoid dopamine antagonists
- butyrophenones (droperidol)
- phenothiazines
- metoclopramide
- (unless you are treating L-dopa CV SE at the vasal ganglie)
- Alfentanil and fentanyl reported to cause an acute dystonic reaction
10
Q
What medications can you use for your GA for a pt with Parkinsons?
inhaled agents?
NMB?
A
- Ketamine can be used, but can be an issue because it causes SNS/psychosis and so can dopamine
- Plan for pt to be volume depleted; have aggressive fluid plan
-
Iso, Sevo, and Des acceptable
- may experience exaggerated BP decrease
- All types of muscle relaxant acceptable
11
Q
Do you extubate a parkinson’s pt awake or deeply sedated?
A
Wide awake after full reversal criteria is met because they are likely to have respiratory complications
12
Q
What drugs do you avoid during deep brain stimulation surgery?
What drugs are best?
A
- Avoid:
- L-dopa might be held in advance
- drugs that enhance GABA
- Best
- Opioids
- dexmedetomidine
- Avoid excessive sedation for neurologic assessment and airway management
- Communicate about any drug you are giving to the surgeon
13
Q
How will you intubate a patient with a spinal cord injury?
What if they are awake and alert?
A
- DVL with in-line stabilization for emergency or unstable/uncertain C-spine stability
- If awake, alert, and cooperative:
- Awake fiberoptic intubation
- blind nasal intubation
- transillumination with lighted stylet
- LMA or Bullard laryngoscope
14
Q
With what kind of spinal injuries would you expect more blood loss?
A
- Blood loss not large unless harvesting the iliac crest bone graft or vertebral body corpectomy
- Thoracic and lumbar regions have more blood loss than cervical
- expect hemodynamic instability from spinal shock
15
Q
How would you expect to treat hemodynamic instability in a pt with a spinal cord injury?
A
- Art line required
- Elderly pts or those with significant hemodynamic lability may require PAC
- Treat with:
- aggressive fluids
- blood replacement
- continue pre-op vasopressors
- keep BP robust!
16
Q
What drugs would you use for GA of a spinal cord injury?
A
-
All inhaled and IV agents acceptable
- N2O if closed air spaces have been ruled out
- NDMR- all acceptable
- Pancuronium SNS stimulation desireable
- Succinylcholine- OK for first few hours after injury but then should be avoided forever
17
Q
What are some GA concerns for a pt with a chronic spinal cord injury?
A
- Renal failure common
- High DVT risk
- position carefully- increased risk for fracture/skin break down
- chronic pain common
- spacsticity in skeletal muscle, often treated with baclofen
- can cause sz if interrupted
18
Q
What are some medication/anesthetic agent considerations to make regarding a pt with a chronic spinal cord injury?
A
- Surgery may cause AD even if they have never experienced it before
- VA, epidural or intrathecal anesthesia are effective in prevention
- have vasodilator available
- No Succ! >24 hours after injury
- use NDMR
- Pts should be monitored post op for AD
- can develop after anesthetic wears off
19
Q
What dose of Nitroprusside would you administer for AD?
A
1-2 mcg/kg
20
Q
Anesthetic considerations for pts with seizures
A
- Consider additive effect of anticonvulsants and sedative/anesthetic drugs (both use GABA)
- Consider how anti-epileptic meds may affect organs
- coagulation, CYP450 induction
- Give anticonvulsant meds morning of surgery, intra-op, and post op
21
Q
What medications must you avoid when caring for a pt with seizures?
A
- Methohexital
- ketamine
- etomidate
- meperidine
- atracurium and Cisatracurium (Laudanosine)
- Enflurane
- Alfentanil
22
Q
How will you notice an intraoperative seizure?
What will you do?
A
- BP and HR changes, maybe clonic movement depending on NMB
- IV TPL, propofol or benzos
- direct application of cold saline to the surface of brain
- ABG and temp monitoring
- adjust ventilation to blow off high CO2
23
Q
What are the 5 determinants of CBF?
A
- PaCO2
- our bes option for affecting CBF, at least for 6 hrs
- PaO2
- the hail mary
- Arterial pressure, autoregulation- btween 50-150
- Venous pressure
- head position
- Anesthetic drugs and techniques
24
Q
Describe the difference in CBF between a person with normal autoregulation and one without.
(graph)
A
25
What is the affect of volatile agents CBF?
* All volatile agents 0.6-1.0 MAC "uncouple" CMRO2 and cerebral blood flow
* vasodilation in the face of decreased metabolic need
* the greater the concentration, the more pronounced the uncoupling
* us IV agents (propofol) and hypocapnia to help compensate
* N2O has less interference with autoregulation compared with sevo/des/iso
* pt should have no recall with anything above 0.5 MAC
26
What is the affect of IV anesthetics on CBF and ICP?
What is the exception to the general rule?
* General rule: IV anesthetics are vasoconstrictors and will decrease CBF and ICP in general
* **Ketamine** is exception- DO NOT use in the face of inceased ICP
* Propofol and barbs are best
* Midaz, opioids and etomidate OK
* watch for resp. depression
27
What are the important principles about managing the anesthetic of a patient with increased ICP?
* Reduce ICP
* posture, hyperventilation, CSF drainage, hyperosmotics, Diuresis, Corticosteroids, barbs
* reduce CMRO2
* premedication
* smooth induction, maintenance, and emergence
* Venous air embolism detection
28
What are some ways to achieve a smooth emergence?
* Give large bolus of opioids at beginning of surgery
* pre inject lidocaine directly onto vocal cords (LTA)
29
How will you care for patients with intracranial tumors?
monitors, etc
non anesthetic medications/fluids
* Monitors/IV
* 2 large bore IV- expect lots of bleeding
* PRBC available
* Use Normasol or plasmalite (if unavailable, alternate LR and NS)
* Standard monitors
* Art line, temp, and PNS mandatory
* zero the art line at the circle of Willis
* Consider CVP or PA- depending on pt baseline status
* Meds- careful with sedative pre-medication
* corticosteroids!
30
How would you induce a pt with an intracranial tumor?
* Goal is to blunt the hemodynamic changes caused by DVL
* Optimize ICP pre-induction with osmotherapy, etc
* pre oxygenate pt fully
* TPL or propofol- deep!
* opioid
* NDMR
* Lidocaine
* consider extra TPL after twitch response disappears and before intubation
* esmolol infusions are also recommended for HR and BP control
31
What are the dosed you would give during induction of pts with intracranial tumors?
TPL
propofol
fentanyl
lidocaine
* TPL: 3-5 mg.kg
* Propofol: 1.25-2.5 mg/kg
* Fentanyl: 3-5 mcg/kg
* Lidocaine 1.5 mg/kg
32
What should you consider during maintenance of a pt with an intracranial tumor?
* Ventilation controlled PaCO2 between 30-35 mmHg
* Consider baseline intracranial compliance when determining how much VA to use
* 0.6-1.0 MAC
* if low compliance consider TIVA + low dose iso for amnesia
* Avoid pt movement
33
Why is it important to have a smooth emergence for a pt with an intracranial tumor?
How can this be done?
* Bucking can cause HTN and ICP elevation = cerebral edema and hemorrhage
* No reversal until head dressing applied
* IV lidocaine 1.5 mg/kg
* antihypertensives
* extubate when fully reversed and responsive
* leave ETT in place until following commands
* HOV 30 degrees
* warm pt to comfortable temp to avoid shivering
34
Which procedures have higher risk of Venous air embolism?
* posterior fossa
* upper c-spine procedures
* supratentorial procedures
* parasagittal or meningiomas near sagittal sinus, craniosynestosis
35
Describe the Venous air embolism monitoring chart
36
How are acute VAEs managed?
* Prevent further air entry
* notify surgeon- flood or pack surgical field
* jugular compression
* lower head
* Treat intravascular air
* aspirate via right heart catheter
* discontinue N2O
* FiO2 100%
* turn lateral with right side up
* pressors/inotropes/CPR
37
How should you manage the anesthesia for Head trauma?
BP
ventilation
fluids
* Maintain CPP 50-70 mmHg
* Hyperventilation
* used for acute ICP management
* Fluids to maintain intravascular volume
* prevent reduced serum osmolarity (NS, Normosol/plasmalyte, 5% albumin, blood all better than LR)
* avoid dextrose (keep glucose \<180)
38
What monitors are needed for pts with head trauma?
* Standard
* Art line- pre induction is best, but do not delay an emergency craniotomy for a line placement
* +/- R heart catheter (manage hemodynamics and VAE risk)
39
How should you induce a pt with head trauma?
* lidocaine 1-1.5 mg/kg
* IV anesthetics EXCEPT Ketamine
* consider hemodynamic stability needs
* opioids are a good choice
* NDMR- avoid histamine, avoid Succ if non-emergent
* succ will increase ICP
40
How should you emerge a patient with head trauma?
* transport intubated to ICU because max swelling is 12-72 hours post injury
* avoid HTN, coughing
* labetalol, esmolol, TPL or propofol helpful
41
What do you need to ask of a pt with a history of CVA?
* How long ago?
* any deficits?
* increased risk of adverse outcomes within **first 9 months** of CVA
* What meds do they take?
* BP, anti-thrombotic, anticoagulant, anti-platelet
42
What anesthetic technique is contraindicated in pts who have had a CVA?
PNS?
* neuraxial in para/hemiplegia or active anticoagulant use
* Do not monitor neuromuscular blockade on affected extremity
43
What are the important aspects of BP management in a pt who has had an intracranial aneurysm or sub arachnoid hemorrhage?
What is the major complication?
* Acute hypertension causes risk of rerupture which is often FATAL
* Brain relaxation will help make surgery easier
* mannitol or hyperventilate
* High-normal MAP to prevent critical reduction of CBF to ischemic area
* tight control of MAP as the surgeon clips the aneurysm and/or controls bleeding
* major intraoperative complication is **hemorrhage**, rebleeding kills!
44
How would you monitor a pt with intracranial aneurism/ SAH?
* Art line pre-induction
* +/- CVP, depending on amt of mannitol, fluid replacement, vasospasm
* +/- EEG or SSEP/MEP
45
How would you induce a pt with Intracranial aneurysm or SAH?
* Smooth induction CRITICAL
* prevent hypertension and hypotension and maintain good ICP control
* lidocaine + esmolol/labetalol + opioids + high dose TPL or propofol
46
If your pt with an intracranial aneurysm or SAH has a high ICP, what would you use for their maintenance anesthesia?
* propofol gtt- 100-300 mcg/kg/hr after bolus
* Fentanyl- 1-4 mcg/kg/hr
* \<10 mcg/kg if extubation planned
* 0.5 MAC Iso and O2
* All of the above meds together
47
How long can a clamp remain on the parent artey that supplies the aneurism?
\<10 minutes
48
How should you administer fluids to a pt with intracranial hemorrhage and SAH?
* prior to clipping, only administer maintenance and deficit
* PRBC should be immediately available
* after clipping, CVP can increase to 10-12 mmHg
49
How should you plan to emerge a pt with intracranial aneurism or SAH?
* avoid coughing, straining, hypercarbia, and HTN
* grade 1-2 with no intra-op complications can be extubated in OR
* Grades 3-5 or intraop complications should remain intubated on mechanical ventilation
50
What are important post op considerations for the pt with intracranial aneurysms or SAH?
* **control HTN** to avoid cerebral edema and hematoma
* control pain
* avoid increased PaCO2
* antihypertensive drugs
* vasospasm remains a threat
* high-normal intravascular volume, avoid hypotension
