Neurosurgery

Question 1

Cushing Response of ICP

Answer 1

Hypertension
Bradycardia
Kussmaul Respirations

Question 2

Cerebral Edema from BBB disruption

Answer 2

Vasogenic Edema

• most common
• exacerbated in setting of HTN

*tumors, infarct, trauma

Question 3

Cerebral Edema from cytotoxic edema

Answer 3

Metabolic Causes

• hypoxia, ischemia
• neurons actively extrude Na+

Question 4

Corticosteroids in edema?

Answer 4

Vasogenic edema from tumors responds well to steroids –> upregulation of tight junctions of BBB

Question 5

Steroids outside tumors for edema?

Answer 5

worse outcomes

Question 6

Mannitol in aneurysm cases?

Answer 6

don’t use, it could reduce CSF and cause hematoma or increased transmural pressure and aneurysmal rupture

Question 7

Posterior Fossa Surgery considerations

Answer 7

1. Obstructive Hydrocephalus
2. Brain Stem Injury
3. Positioning
4. Pneumocephalus
5. VAE

Question 8

Monitoring for brain stem injury?

Answer 8

auditory evoked potentials

Question 9

Venous Air Embolism

Answer 9

occurs when pressure w/i open vein is subatmospheric (usually when incision is above heart)
- entrainment of air can travel to heart and cause CV collpase

Question 10

When is VAE significant

Answer 10

depends on rate and amount of air entrainment, presence of R->L shunt
*most air is absorbed by lungs, but large air can cause problems

Question 11

Pathophys of significan VAE

Answer 11

air lock in RV or pulmonary circulation leads to decreased R-side CO and subsequent L-side CO

Question 12

Signs of VAE

Answer 12

1. drop in EtCO2
2. increase PaCO2
3. hypotension
4. tachycardia
5. stroke

Question 13

Monitors of VAE

Answer 13

1. TEE - best
2. Precordial doppler
3. EKG
4. Capnography

Question 14

Treatment of VAE

Answer 14

1. Notify surgeons -> flood field (ID entry site)
2. FiO2 100%
3. Head down (if possible)
4. Vasopressors + fluid
5. Aspirate CVC
6. Bilateral jugular compression
7. +/- PEEP
8. ACLS

Question 15

Goals in head trauma

Answer 15

Avoid hypoxia, hypercapnia and hypotension at all costs

• ICP concerns
• maintain cerebral perfusion
• NO STEROIDS*
• NO ALBUMIN*

Question 16

Neurogenic pulmonary edema

Answer 16

massive sympathetic discharge from increased ICP –> Severe pulmonary vascular congestion and alveolar hemorrhage

Question 17

Ruptured Cerebral Aneurysm timeline

Answer 17

sudden, severe WHOL

• rebleed w/i 24-48 hrs
• vasospasm w/i 72 hrs - 5 days

Question 18

Vasospasm treatment

Answer 18

Nimodipine ppx

• hydrate, ensure blood pressure
• intraarterial vasospastic agents

Question 19

What to do if aneursym ruptures in OR?

Answer 19

• adenosine or propofol bolus
• cooling the patient
• resuscitating the patient

Question 20

Acute Spinal Cord Injury

Answer 20

can cause sympathectomy with unopposed parasympathetic activity leading to drastically hemodynamic derangements during stimulating parts (laryngoscopy, suction, extubation)

Question 21

how long post-stroke should you wait for surgery?

Answer 21

Atleast 2 weeks –> altered blood flow and metabolic rate

- altered responsiveness to CO2 and BBB

Question 22

fluid disorders s/p neurosurgery

Answer 22

SIADH
Cerebral Salt Wasting
Diabetes Insipidus

Question 23

SIADH exam

Answer 23

hyponatremic
euvolemic
lots of urine sodium

Question 24

CSW exam

Answer 24

hyponatremic
hypovolemic
high urine sodium

Question 25

DI exam

Answer 25

hypernatremic hypovolemic Dilute urine - LOTS of urine

Question 26

Common anesthetic drugs that lower seizure threshold?

Answer 26

ketamine, methohexital, atra and cisatracurium

Question 27

Hematologic effect of antiepileptics?

Answer 27

MOST AED alter coagulation factors....watch for bleeding

Question 28

Parkinson Disease

Answer 28

progressive loss of DA neurons in nigrostriatum increase in GABA in basal ganglia --> inhibits thalamic nuclei and blocks the motor cortex

Question 29

Parkinson symptoms

Answer 29

bradykinesia, rigidity, postural hypotension, sensitivity to anesthetics

Question 30

Anesthetic concerns w/ Parkinson

Answer 30

continue med pre and intraop! | - avoid anti-dopamine meds --> worsen rigidity (droperidol and metocloperamide)

Question 31

Multiple Sclerosis

Answer 31

reversible demyelination of brain and SC (random)

Question 32

Anesthetic concerns w/ MS

Answer 32

- avoid elective surgery during flare - stress of surgery can flare - peripheral nerve blocks ok, neuraxial less so - avoid sux - maintain good room temp

Question 33

Amyotropic Lateral Sclerosis

Answer 33

disease of upper and lower motor neurons | super-oxide dismutase 1

Question 34

ALS anesthetic concerns

Answer 34

affects all muscles!!! - respiratory and swallowing - avoid sux - no neuraxial

Question 35

Guillan Barre

Answer 35

sudden ascending motor paralysis and areflexia w/ variable paresthesias - immune disease of myelin sheath

Question 36

Levels of acute spinal cord injury and complications

Answer 36

``` T1 = quadriplegia L4 = paraplegia ```