Chapter 8 - Anesthesia

Question 2

MAC (minimum alveolar concentration) equals what?

Answer 2

Smallest concentration of inhalation agent at which 50% of patients will not move with incision

Question 3

Small MAC means what?

Answer 3

More lipid soluble = more potent = slow speed of induction

Question 4

Effects of inhalational agents?

Answer 4

Unconsciousness, amnesia, some degree of analgesia

Question 5

Side effects of inhalational agents?

Answer 5

Blunted hypoxic drive, myocardial depression, increased cerebral blood flow, decreased renal blood flow

Question 6

Characteristics of NO2?

Answer 6

Fast, minimal myocardial depression

Question 7

Characteristics of halothane?

Answer 7

Slow, highest degree of cardiac depression and arrhythmias, least pungent (good for kiddies)

Question 8

What is halothane hepatitis?

Answer 8

Fever, eosinophilia, jaundice, increased LFTs

Question 9

Side effect of enflurane?

Answer 9

Seizures

Question 10

Characteristics of sevoflurane?

Answer 10

Less myocardial depression, fast on/off, less laryngospasm, higher cost

Question 11

Side effects of sodium thiopental (barbiturate)?

Answer 11

Decreased cerebral blood flow and metabolic rate, decreased blood pressure

Question 12

Characteristics of propofol?

Answer 12

Very rapid distribution and on/off, amnesia, sedative; NOT an analgesic

Question 13

Side effects of propafol?

Answer 13

Hypotension, respiratory depression; do not sure in pts with egg allergy

Question 14

Characteristics of ketamine?

Answer 14

Dissociation of thalamic/limbic systems, places pts in cataleptic state (amnesia, analgesia); no respiratory depression

Question 15

Side effects of ketamine?

Answer 15

Hallucinations, catecholamine release (inc. CO and tachycardia), inc. airway secretions, inc. cerebral blood flow (contraindicated in head injuries)

Question 16

Characteristics of etomidate?

Answer 16

Fewer hemodynamic changes, fast acting

Question 17

Side effect of etomidate?

Answer 17

Continuous infusions can lead to adrenocortical suppression

Question 18

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

Answer 18

Diaphragm

Question 19

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

Answer 19

Neck and face muscles

Question 20

What is the only depolarizing agent?

Answer 20

Succinylcholine

Question 21

Characteristics of succinylcholine?

Answer 21

Fast, short acting; causes fasciculations

Question 22

Side effects of succinylcholine?

Answer 22

Malignant hyperthermia, inc. ICP, incraed end-tidal CO2 then fever, tachycardia, rigidity, acidosis, hyperkalemia

Question 23

Treatment of malignant hyperthermia?

Answer 23

Dantrolene: inhibits Ca release and decouples excitation complex; cooling blankets, HCO3, glucose, supportive care

Question 24

What patients do you NOT use succinycholine in?

Answer 24

Burn patients, neurologic injury, neuromuscular disorders, spinal cord injury, massive trauma, acute renal failure

Question 25

Nondepolarizing agents MOA?

Answer 25

Inhibit neuromuscular junction by competing with ACh

Question 26

What can cause prolongation of nondepolarizing agents?

Answer 26

Hypothermia, hypercarbia, certain abx, electrolyte abnormalities, myasthenia gravis

Question 27

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

Answer 27

Cis-atracurium (because it undergoes Hoffman degradation)

Question 28

Where is rocuronium metabolised?

Answer 28

Liver

Question 29

How does neostigmine reverse nondepolarizing agents?

Answer 29

Blocks AChE, increasing ACh

Question 30

How does edrophonium reverse nondepolarizing agents?

Answer 30

Blocks AChe, increasing ACh

Question 31

What should be given with nondepolarizing reveral agents to counteract effects of generalized ACh overdose?

Answer 31

Atropine or glycopyrrolate

Question 32

How do local anesthetics work?

Answer 32

By increasing action potential threshold, preventing Na influx

Question 33

What is the max dose of 1% lidocaine?

Answer 33

0.5cc/kg

Question 34

Why are infected tissues hard to anesthetize?

Answer 34

Acidosis

Question 35

When should you not use epinephrine with local anesthetics?

Answer 35

Patients with arrhythmias, unstable angina, uncontrolled hypertension, poor collaterals, uteroplacental insufficiency

Question 36

What type of local anesthetic has a higher rate of allergic reaction?

Answer 36

Esters (secondary to PABA analogue)

Question 37

Narcotic receptor?

Answer 37

Mu

Question 38

What happens when you mix narcotics in patients on MAOIs?

Answer 38

Can cause hyperpyrexic coma

Question 39

Effects of narcotics?

Answer 39

Profound analgesia, respiratory depression (dec. CO2 drive), no cardiac effects, blunted sympathetic response

Question 40

Unique side effects of morphine?

Answer 40

Decreased cough, constipation, histamine release

Question 41

Unique side effects of demerol?

Answer 41

Tremors, fasciculations, convulsions, NO histamine release

Question 42

In which patients should you avoid the use of demerol?

Answer 42

Renal failure - can get buildup of normeperidine analogue and result in seizures

Question 43

Morphine in epidural can cause what?

Answer 43

Respiratory depression

Question 44

Lidocaine in epidural can cause what?

Answer 44

Decreased heart rate and blood pressure

Question 45

Treatment for acute hypotension and bradycardia in patient with epidural?

Answer 45

Turn epidural down, fluids, phenylephrine, atropine

Question 46

Treatment for spinal headaches?

Answer 46

Rest, increased fluids, caffeine, analgesics; blood patch if persists >24h

Question 47

Contraindications for spinal anesthesia?

Answer 47

Hypertrophic cardiomyopathy, cyanotic heart disease

Question 48

What two conditions are associated with the most postoperative hospital mortality?

Answer 48

CHF and renal failure

Question 49

Presentation of post-op MI?

Answer 49

May have no pain or EKG changes; hypotension, arrhythmias, increased filling pressures, oliguria, bradycardia

Question 50

Which patients need a cardiology workup?

Answer 50

Angina, previous MI, SOB, CHF, FEV1 5/min, age >70, patients undergoing major vascular surgery

Question 51

Biggest risk factors for postop MI?

Answer 51

Age >70, DM, previous MI, CHF, unstable angina

Question 52

What is the best determinant of esophageal vs. tracheal intubation?

Answer 52

End tidal CO2

Question 53

What causes an intubated patient to have sudden transient rise in ETCO2?

Answer 53

Alveolar hypoventilation; increase TV or RR

Question 54

What causes an intubated patient to have a sudden drop in ETCO2?

Answer 54

Disconnected from the vent; PE or significant hypotension