ABSITE Review - Anesthesia

Question 1

What is MAC?

Answer 1

Minimum alveolar concentration = smallest concentration of inhalational agent at which 50% of patients will not move with incision.

Question 2

Explain the potency of MAC vs solubility.

Answer 2

Small MAC –> more lipid soluble = more potent
Nitrous is fastest but has high MAC (low potency)
Speed of induction is inversely proportional to solubility

Question 3

Describe the potency and side effects of the following INHALATIONAL AGENTS: nitrous oxide, halothane, enflurane, isoflurane and sevoflurane.

Answer 3

Nitrous oxide - fast, minimal myocardial depression
Halothane - slow, highest degree of cardiac depression and arrhythmias
Enflurane - seizures
Isoflurane - good for NSG; higher cost
Sevoflurane - fast, less myocardial depression

Question 4

Which induction agent is contraindicated in patients with head injury?

Answer 4

Ketamine

Question 5

What are the side effects of sodium thiopental?

Answer 5

decrease cerebral blood flow and metabolic rate, decrease BP

Question 6

What are the side effects of propofol? When is this contraindicated?

Answer 6

SEs: hypotension, respiratory depression

Do not use in patients with egg allergy

Question 7

What are the side effects of ketamine?

Answer 7

SEs: hallucinations, catecholamines release (increase carbon monoxide, tachycardia), increase airway secretions and increase cerebral blood flow

Question 8

Mention the indication for a rapid sequence intubation.

Answer 8

Recent oral intake, GERD, delayed gastric emptying, pregnancy, bowel obstruction

Question 9

What is the last muscle to go down and 1st muscle to recover from paralytics?

Answer 9

Diaphragm

Question 10

What is the 1st muscle to go down and the last to recover from paralytics?

Answer 10

Neck muscles and face

Question 11

What is the only depolarizing agent? What are the side effects?

Answer 11

Succinylcholine

SEs: increase ICP, malignant hyperthermia

Question 12

What is the 1st sign of malignant hyperthermia?

Answer 12

Increase end tidal CO2 then fever, tachycardia, rigidity, acidosis, hyperkalemia

Question 13

Why malignant hyperthermia occurs?

Answer 13

Defect in calcium metabolism. Calcium released from sarcoplasmic reticulum causes muscle excitation –> contraction syndrome.

Question 14

What is the treatment of malignant hyperthermia?

Answer 14

Dantrolene (10mg/kg) inhibits Ca release and decouples excitation complex, cooling blankets, HCO3, glucose, supportive care

Question 15

In which patients, is succinylcholine contraindicated?

Answer 15

Do not use in burn patients, neurologic injury, neuromuscular disorders, spinal cord injury, massive trauma, acute renal failure

Question 16

What is the MOA of nondepolarizing agents?

Answer 16

Inhibit neuromuscular junction by competing with acetylcholine. Can get prolongation of these agents with hypothermia, hypercarbia, certain antibiotics, electrolyte abnormalities, myasthenia gravis.

Question 17

Which nondepolarizing agent can be used in liver and renal failure patients?

Answer 17

Cis-atracurium which undergoes Hoffman degradation

Question 18

Which nondepolarizing agents cause histamine release?

Answer 18

Cis-atracutium and Mivacurium

Question 19

Which nondepolarizing agent undergoes hepatic metabolism?

Answer 19

Rocuronium

Question 20

Which nondepolarizing agent undergoes renal metabolism?

Answer 20

Pancuronium

Question 21

Which nondepolarizing agent cause tachycardia?

Answer 21

Pancuronium

Question 22

What is the MOA of neostigmine and edrophonium?

Answer 22

Counters non-depolarizing agents. Blocks AchE, increased Ach

Question 23

Why atropine or glycopyrrolate should be given with neostigmine or edrophonium?

Answer 23

To counteract effects of generalized acetylcholine overdose

Question 24

What is the maximum dose of lidocaine?

Answer 24

0.5cc/kg

Question 25

What is the relation in lenght of action for lidocaine, bupivacaine and procaine?

Answer 25

bupivacaine > lidocaine > procaine

Question 26

Which patients cannot have epinephrine in their local anesthetics?

Answer 26

Arrhythmias, unstable angina, uncontrolled HTN, poor collaterals (penis and ear), uteroplacental insufficiency

Question 27

Mention the amides of local anesthetics.

Answer 27

Lidocaine, bupivacaine, mepivacaine (have "i" in first part of the name)

Question 28

Mention the esters of local anesthetics.

Answer 28

Tetracaine, procaine, cocaine

Question 29

What is the drug of choice for narcotic overdose?

Answer 29

Narcan

Question 30

What is the drug of choice for benzodiazepine overdose?

Answer 30

Flumazenil

Question 31

Which benzodiazepine is contrindicated in pregnancy because it cross the placenta?

Answer 31

Versed

Question 32

What is the treatment for acute hypotension and bradycardia cause by epidural anesthesia?

Answer 32

Turn epidural down, fluids, phenylephrine, atropine

Question 33

What is the treatment for spinal headaches?

Answer 33

Rest, increased fluids, caffeine, analgesics; blood patch to site if persists > 24 hrs.

Question 34

Which patients need cardiology work up prior to surgery?

Answer 34

Angina, previous MI, SOB, CHF, walks 5/min, age > 70, pts undergoing major vascular surgery

Question 35

Describe the ASA classes.

Answer 35

ASA I - Healthy ASA II - Mild disease without limitation (controlled HTN, obesity, DM, significant smoking history, older age) ASA III - Severe disease (angina, uncontrolled HTN, DM w complications, moderate COPD) ASA IV - Severe constant threat to life (unstable angina, CHF, renal failure, liver failure, severe COPD) ASA V - Moribund (ruptured AAA, saddle PE, ascending aortic dissection resulting in heart failure) ASA VI - Donor ASA E - Emergency

Question 36

What are the biggest risk factors for postop MI?

Answer 36

age > 70, DM, previous MI, CHF, and unstable angina

Question 37

What is the best determinant of esophageal vs tracheal intubation?

Answer 37

End tidal CO2

Question 38

What is the adequate position for ETT?

Answer 38

Should be placed 2cm above the carina.