TL Deck 3

Question 1

What is the typical presentation of anterior ischemic optic neuropathy postoperatively?

Answer 1

Unilateral painless visual loss after the first postoperative day, often with afferent pupillary defect; associated with hypoperfusion, common in cardiac surgery.

Question 2

What central brain structure is involved in dexamethasone’s antiemetic effect?

Answer 2

Nucleus tractus solitarii.

Question 3

How do opioids cause nausea?

Answer 3

By acting on the area postrema.

Question 4

What conditions make IPPV unreliable in some patients?

Answer 4

Cardiac arrhythmias, changes in chest wall/lung compliance (e.g. laparoscopic or open chest surgery)

Question 5

What shifts the oxyhemoglobin dissociation curve to the right?

Answer 5

Sulfhemoglobin and CADET: CO₂, Acidosis, 2,3-DPG, Exercise, Temperature.

Question 6

What nerves are involved in the oculocardiac reflex?

Answer 6

Afferent: CN V1 (ophthalmic); Efferent: CN X (vagus).

Question 7

What drugs are metabolized by CYP3A4?

Answer 7

Most anesthetics, lidocaine, dexamethasone.

Question 8

What drugs are metabolized by CYP2C19? (5)

Answer 8

Omeprazole, antidepressants, phenytoin, warfarin, ibuprofen.

Question 9

What drugs are metabolized by CYP2C9?

Answer 9

Phenytoin, warfarin, ibuprofen.

Question 10

What drugs are metabolized by CYP2D6?

Answer 10

Codeine, beta-blockers, diltiazem, tramadol.

Question 11

What does a high blood:gas partition coefficient indicate?

Answer 11

Greater solubility in blood → slower onset and offset.

Question 12

What does a high oil:gas partition coefficient indicate?

Answer 12

Greater lipid solubility → greater potency (Meyer-Overton correlation).

Question 13

What is the biphasic hemodynamic response to dexmedetomidine?

Answer 13

Loading dose: hypertension + bradycardia; Infusion: hypotension + bradycardia.

Question 14

How does dexmedetomidine affect BIS?

Answer 14

It lowers BIS.

Question 15

How is clopidogrel activated?

Answer 15

By hepatic CYP2C19. Prasugrel and ticlopidine are also prodrugs; cangrelor and ticagrelor are direct inhibitors.

Question 16

What is the cardiac mechanism of bupivacaine toxicity?

Answer 16

Blocks cardiac Na⁺ channels → delayed conduction → arrhythmias → CV collapse.

Question 17

Why is bupivacaine more cardiotoxic?

Answer 17

It has tighter binding and slower dissociation from cardiac Na⁺ channels and causes direct myocardial depression.

Question 18

Why is pulse oximetry a poor monitor of ventilation?

Answer 18

Because it measures oxygenation, not CO₂ levels; especially inaccurate when patient is on 100% FiO₂.

Question 19

What is the best monitor of ventilation?

Answer 19

Capnography (end-tidal CO₂).

Question 20

Which ECG leads are best for detecting right heart issues?

Answer 20

V1 and V2.

Question 21

Which ECG lead is best for detecting left ventricular ischemia?

Answer 21

V5.

Question 22

How do volatile anesthetics affect motor evoked potentials?

Answer 22

They depress motor evoked potentials.

Question 23

Which volatile anesthetic has the fastest onset and offset?

Answer 23

Desflurane.

Question 24

Why should N₂O be avoided in closed air spaces?

Answer 24

It diffuses into and expands air-filled cavities (e.g. bowel, middle ear, pneumothorax).

Question 25

What is the mechanism of succinylcholine?

Answer 25

Depolarizing neuromuscular blocker that mimics acetylcholine at the NMJ.

Question 26

What are common side effects of succinylcholine? (5)

Answer 26

Hyperkalemia, malignant hyperthermia, bradycardia, increased IOP and intragastric pressure.

Question 27

What happens to succinylcholine metabolism in pseudocholinesterase deficiency?

Answer 27

It is prolonged, leading to extended paralysis.

Question 28

What drugs trigger malignant hyperthermia?

Answer 28

Volatile anesthetics and succinylcholine.

Question 29

What is the treatment for malignant hyperthermia?

Answer 29

Dantrolene, cooling, hyperventilation, and supportive care.

Question 30

How does dantrolene work?

Answer 30

It inhibits calcium release from the sarcoplasmic reticulum.

Question 31

When is succinylcholine-induced hyperkalemia a concern?

Answer 31

In patients with burns, neuromuscular diseases, spinal cord injuries (after 24–48 hours).

Question 32

Which nerve is blocked in the TAP block?

Answer 32

Thoracolumbar nerves (T6–L1).

Question 33

Which area is targeted by the TAP block?

Answer 33

Anterior abdominal wall between the internal oblique and transversus abdominis.

Question 34

What does the BIS monitor measure?

Answer 34

It estimates the depth of anesthesia using EEG data; values <60 suggest adequate hypnosis.

Question 35

What are common BIS interferences? (5)

Answer 35

EMG activity, neuromuscular blockers, ketamine, nitrous oxide, and artifact.

Question 36

Which area of the brain does dexamethasone target for its antiemetic effect?

Answer 36

Nucleus tractus solitarius.

Question 37

Which area of the brain does opioid-induced nausea involve?

Answer 37

Area postrema in the medulla.

Question 38

What does CADET stand for in the oxyhemoglobin dissociation curve right shift?

Answer 38

CO₂, Acidosis, 2,3-DPG, Exercise, Temperature.

Question 39

What is the afferent limb of the oculocardiac reflex?

Answer 39

Cranial Nerve V1 (ophthalmic branch of trigeminal).

Question 40

What is the efferent limb of the oculocardiac reflex?

Answer 40

Cranial Nerve X (vagus).

Question 41

Which drugs are activated by CYP2C19?

Answer 41

Clopidogrel, prasugrel, and ticlopidine.

Question 42

Which P450 enzyme metabolizes most anesthetic drugs?

Answer 42

CYP3A4.

Question 43

What happens when a drug has a high blood:gas partition coefficient?

Answer 43

More soluble in blood → slower onset and recovery.

Question 44

What does a high oil:gas partition coefficient mean clinically?

Answer 44

Higher lipid solubility → higher potency.

Question 45

What is the clinical significance of dexmedetomidine's biphasic effect?

Answer 45

Hypertension and bradycardia during bolus; hypotension and bradycardia with continuous infusion.

Question 46

Which form of clopidogrel is pharmacologically active?

Answer 46

The metabolite generated by CYP2C19 activation.

Question 47

Why does succinylcholine cause hyperkalemia in some conditions?

Answer 47

Upregulates ACh receptors in burns, spinal cord injuries, and neuromuscular disorders.

Question 48

What is the physiological action of dantrolene in MH treatment?

Answer 48

Blocks ryanodine receptors → reduces intracellular calcium release.

Question 49

Why should succinylcholine be avoided in patients with denervation injuries?

Answer 49

Increased risk of hyperkalemia due to receptor upregulation.

Question 50

What causes increased intraocular pressure with succinylcholine?

Answer 50

Contraction of extraocular muscles and choroidal vascular congestion.

Question 51

What layer does the TAP block target for local anesthetic deposition?

Answer 51

Plane between internal oblique and transversus abdominis muscles.

Question 52

What does BIS <60 indicate?

Answer 52

Adequate hypnosis for general anesthesia.

Question 53

How can EMG activity affect BIS readings?

Answer 53

Increases BIS due to muscle signal interference.