Bb Scoliosis

Front 1

What degree of scoliosis causes severe cardiac and respiratory dysfunction?

Back 1

>100 degrees
-if <65 degrees respiratory impairment is minimal

Front 2

In a scoliosis patient what vital capacity should concern you for possible need for postop ventilation?

Back 2

VC < 40% predicted
-if >70% patient should be fine postop

Front 3

What are the pulmonary problems encountered in severe scoliotic patients?

Back 3

1. restrictive lung disease - decreased VC, TLC, RV, FRC, increased VD/Vt which causes increased A-a gradient, alveolar hypoventilation, hypoxemia, nml PaCO2
2. chronic hypoxia - can lead to pulm htn and cor pulmonale (RVH, RAD, RBBB)

Front 4

What cardiac valvular problem is often seen in patients with scoliosis?

Back 4

mitral valve prolapse (25%)

Front 5

What are frequent findings in CXR in patients with severe scoliosis?

Back 5

chronic aspiration pna

Front 6

What inhaled agent should you avoid in patients with severe scoliosis?

Back 6

N2O bc it can worsen pulm htn (as do acidosis, hypoxemia, and hypercarbia)

Front 7

What lung complication is more common in patients with severe scoliosis compared to normal patients?

Back 7

pneumothorax - increased airway pressure, tracheal deviation, dilated neck veins

Front 8

How can you tell if an injury occurs by SSEP monitoring?

Back 8

P1 component increases in latency and decreases in amplitude

Front 9

What disturbs SSEP monitoring?

Back 9

1. hypoxia
2. hypercarbia
3. hypothermia,
4. hypotension,
5. drugs - diazepam, volatiles, N2O

Front 10

What should you do if SSEP trace changes?

Back 10

stop surgery and raise blood pressure
-it may be due to stretching of the spinal cord, a bone chip, or direct cord trauma

Front 11

Pertaining to SSEP monitoring what instrument rejects random waves and produces P1, N1, P2, N2?

Back 11

amplifier averager

Front 12

What is the cause of paralysis during harrington rod surgery?

Back 12

anterior spinal artery ischemia

Front 13

What are complications of harrington rod surgeries?

Back 13

1. paralysis,
2. hemorrhage,
3. fat and air embolism,
4. ptx

Front 14

What hypotensive agent is preferrable for hypotensive anesthesia in adolescents and children?

Back 14

sodium nitroprusside for reliable and sustained induction of hypotension

Front 15

What is the benefit of using labetalol for inducing hypotension compared with SNP?

Back 15

effective
-not associated with some of the side effects such as tachycardia, intrapulmonary shunt or increased CO

Front 16

what is a wake-up test?

Back 16

-after narcotic base is established, small increments of narcan are given until the patient responds to verbal commands and moves lower extremities
-assistant holds the head of ETT

Front 17

What is the benefit of autologous blood for scoliosis surgery?

Back 17

minimizes the need for donor blood

Front 18

When should you begin collecting autologous blood before surgery?

Back 18

3 weeks before the operation with 4-7 days between collections to allow for readjustment of the blood volume
-don't collect within 7 days of surgery

Front 19

How much blood is typically taken from patients for autologous donation base on their weight?

Back 19

->50kg and hgb 11 full units
-25-50kg and hgb 11 half units

Front 20

What preop evaluation is important in pt with scoliosis?

Back 20

1. PFTs
2. ABGs - hypoxemia, hypercarbia, acidosis exacerbate pulm htn
3. CXR

Front 21

What lines should be placed intraop?

Back 21

Foley, arterial, and CVP
-CVP reasonable to assess fluid status
-If cor pulmonale is advanced, PA catheter is indicated

Front 22

What is the postoperative course for pts with scoliosis?

Back 22

Ventilatory weaning postop should be slow and cautious
-if VC is <40%, postop ventilation is necessary

Front 23

Does nitrous effect SSEP monitoring? Do volatiles?

Back 23

Yes, nitrous has a depressant effect on SSEPs
-Volatiles do as well
-nitrous effects SSEPs more than low concentrations of enflurane and isoflurane

Front 24

What 2 medications can decrease the total dose of SNP?

Back 24

1. propranolol
2. captopril

Front 25

Explain the differences in sensitivity of brain stem responses vs cortical responses with SSEP monitoring.

Back 25

-Brain stem responses much more resistant to volatile anesthetic than are cortical responses
-Clinical concentrations tend to increase the latency of BAEP but do not have much effect upon amplitude

Front 26

What are the physical characteristics of the scoliotic curve?

Back 26

-usually right sided curve
-involves 7-10 vertebrae

Front 27

What happens to FEV1/FVC in restrictive lung disease?

Back 27

both FEV1 and FVC are decreased, but the percentage is not

Front 28

What is the major pulmonary defect in severe scoliosis?

Back 28

Alveolar hypoventilation secondary to V/Q mismatch
-typically rapid, shallow breathing develops bc of the restrictive nature of the dz leading to increased dead space
-both A-a gradient and dead space are increased

Front 29

Is hypercapnia seen in scoliosis?

Back 29

Usually only in very severe cases bc of the high solubility of CO2

Front 30

What neuropathic diseases can cause scoliosis?

Back 30

1. meningomyelocele
2. poliomyelitis
3. cerebral palsy
4. muscular dystrophy

Front 31

Which scoliotics may be at an increased risk for malignant hyperthermia?

Back 31

Those with mytonic dystrophy