J's A-N-E-S-T-H-E-S-I-A

Front 1

What are 12 characteristics of an ideal volatile anesthetic?

Back 1

1. Abscence of airway irritant effect.
2. Abscence of cerebral vasodilation.
3. Absence of hepatic/renal toxicity.
4. Abscence of flammability
5. Easily vaporized.
6. Low blood solubility to ensure rapid induction and recovery.
7. Minimal metabolism.
8. Compatible with epinephrine.
9. Skeletal muscle relaxation.
10. Suppression of excess sympathetic nervous system activity.
11. Bronchodilation.
12. Abscence of excessive myocardial depression.

Front 2

What are two defects of inhaled anesthetics prior to the mid 20th century?

(Give an example of each)

Back 2

1. Explosive
- Ether is explosive in oxygen.

2. Flammable
- Cyclopropane is toxic and flammable.

Front 3

Who was William Morton?

Back 3

A dentist who used diethyl ether vapor instead of nitrous oxide in front of an audience.

Front 4

Who was Crawford Long?

Back 4

He used ether in 1842, but didn't publish until 1849.

Front 5

Who was Carl Koller?

Back 5

He used Cocaine for local anesthesia of the cornea in 1884.

Front 6

Who was James Simpson?

Back 6

He was an obstetrician who proposed chloroform as an alternative to ether, which was used in labor in 1847.

Front 7

Who was John Snow?

Back 7

He was the first anesthesiologist. He popularized Chloroform.

Front 8

What is Curare derived from and what is it used for?

Back 8

- It is derived from lianes (vines) growing in South America.

- It is used as a nueromuscular junction blocker.

Front 9

What is the mortality rate for anesthesia compared to motor vehicle accidents?

Back 9

Anesthesia - 1 in 250,000

Motor vehicle accidents - 41 in 250,000

Front 10

What are the 10 most important patient safety issues as identified by anesthesiologists?

Back 10

1. Difficult airway management.
2. Production pressures.
3. Anesthesia delvery outside the operating room or at remote sites in the hospital.
4. Anesthesia delivery in physician's offices.
5. Neurologic deficit attributed to the anesthetic technique
6. Presence of coronary artery disease in patient.
7. Occupational Stress
8. Fatigue
9. Medication errors
10. Time available for pre-operation evaluation.

Front 11

List 4 major questions in the preoperative interview.

Back 11

1. What is the indication for the proposed surgery? Is it elective or emergency?
2. What are the inherent risks of this surgery?
3. Coexisting medical problems? Does surgery or care plan need to be modified because of them?
4. Has patient had anesthesia before? Were there complications? Are there risk factors for difficult airway management?

Front 12

Describe the characteristics of ionized drug molecules.

Back 12

Inactive, water soluble, does not cross lipid barriers, renal excretion, no hepatic metabolism.

Front 13

Describe the characteristics of non-ionized drug molecules.

Back 13

Active, lipid soluble, crosses lipid membranes, no renal excretion, hepatic metabolism.

Front 14

What factors determine drug absorption?

Back 14

1. Lipid or water solubility
2. molecular weight.
3. Concentration of drug
4. Drug form

- Liquids/crystalloids are absorbed better than solids/colloids.

- Increased area of absorption

- Increased blood supply

- Heat/vasodilation leads to more absorption as compared to Shock/vasoconstriction.

- Degree of ionization of environmental pH

Front 15

What is the first pass hepatic effect?

Back 15

Drugs absorbed from the GI tract enter portal circulation and pass throught the liver before entering systemic circulation for delivery to its receptor. (during this time it is metabolized to some degree by the liver)

Front 16

What factors determine drug distribution?

Back 16

1. pH of the drug's environment.
2. Degree of ionization.
3. pKa of the drug (dissociation constant)
4. Protein binding
5. Molecular weight of the drug.
6. Lipid solubility

Front 17

What is drug redistribution?

Back 17

The transfer of drugs to inactive tissue sites.

Front 18

Describe how drug redistribution is important when comparing the duration of action of a single dose as compared to multiple doses of a drug.

Back 18

If given repeated doses, the recptor will be saturated at inactive tissue sites, thus leading to longer duration of action until metabolism can decrease plasma concentration.

Front 19

What is effect site equilibration? Why is it important?

Back 19

The time between IV administration of a drug and the onset of its clinical effects, or the time for equilibration between drug concentration in plasma and drug effect.

- It is important when determining dosage intervals.

Front 20

Define Pharmacodynamics.

Back 20

The responsiveness of receptors to drugs and to the mechanism by which these effects occur (i.e. what the drug does to the body)

Front 21

Define Pharmacokinetics.

Back 21

Absorption, distribution, metabolism, and excretion of inhaled or ingested drugs. (i.e. what the body does to the drug)

Front 22

Define Therapeutic index.

Back 22

LD50 / ED50 (the higher the therapeutic index, the safer the drug) (essentially you want a much higher LD50 than ED50)

Front 23

Define Competitive antagonism

Back 23

When a molecule competes for the same receptor as the agonist. This then can be displaced by increasing the concentration of the agonist.

- Is reversible
- Shifts dose response curve to the right.

Front 24

Describe non-competitive antagonism.

Back 24

Produces a conformational change of the receptor that results in diminished receptor response even at high doses of the agonist.

- Dose response curve is shifted to the right.
- Slope of the curve is decreased
- maximum pharmacological response is diminished
- Can be reversible or irreversible.

Front 25

Define Stereospecificity.

Back 25

How drugs interact with a receptor in a geometrically specific way.

- Two isomers of opposite shape have different pharmacokinetics/dynamics and side effects.

Front 26

Define Tachyphylaxis.

Back 26

Acute tolerance to effects of drugs when administered at short intervals.

- Occurs with ephedrine and amphetamine. It reflects depletion of norepinephrine stores or altered dissociation of drug from its receptor site.

Front 27

Define Drug dependence.

Back 27

Psychic or physical states characterized by behavioral responses including complusion to take drug on continuous or periodic basis to experience its effect or avoid discomfot of its abscence.

Front 28

How is mean arterial pressure related to systemic resistance and cardiac output?

Back 28

MAP = SVR x CO

Front 29

Describe the effects of anesthetics on blood pressure.

Back 29

All decrease blood pressure, except nitrous oxide (N2O)

Front 30

Describe the effects of anesthetics on systemic vascular resistance.

Back 30

All decrease systemic vascular resistance.

Front 31

Describe the effects of anesthetics on cardiac output.

Back 31

- Decreased with halothane and enflurane.

- Increased with nitrous oxied (N2O)

- No change with desflurane and isoflurane.

Front 32

Describe the effects of anesthetics on preload.

Back 32

It will be decreased due to venodilation that occurs with general anesthesia.

Front 33

Describe the effects of anesthetics on heart rate.

Back 33

- No change with halothane and N2o

- Increased with desflurane at high doses.

- Increased with enflurane.

Front 34

Define afterload.

Back 34

The resistance to ejection of blood from the left ventricle after each contraction.

- Determined by the systemic vascular resistance.

Front 35

Define contractility.

Back 35

The measure of force of contraction independent of preload and afterload.

Front 36

Define preload.

Back 36

The amount of cardiac muscle that is stretched before contraction or the end diastolic volume of the heart.

Front 37

What can cause a low preload?

Back 37

- Hypovolemia and venodilation.

- Tension pnuemothorax and pericardial tamponade. (prevent ventricular filling)

- Pulmonary embolism and pulmonary hypertension

Front 38

What is expected to happen to arterial CO2 during anesthesia? Why?

Back 38

Most anesthesia drugs suppress breathing. Sedative-hypnotics act on GABAa receptors that provide inhibitory input to neurons of the respiratory system.

- Volatile anesthetics decrease excitatory neuronal transmission.

- PaCO2 is lowered during anesthesia because of assisted ventilation, which may result in cessation of ventilation.

Front 39

What is the most practical perioperative test for autonomic nervous system dysfunction?

Back 39

Orthostasis.

- Dysfunction when decrease in systolic blood pressure is >30 mmHg and absence of increased heart rate on assuming upright position.

Front 40

What are the clinical uses for Dopamine?

Back 40

- Used for congestive heart failure, cardiogenic shock, and septic shock.

Front 41

What are the clinical uses for Epinephrine?

Back 41

- Used as continuous infusions to treat decreased myocardial contractility.

- Decreases systemic absorption of local anesthetics and local hemostasis when used simultaneously.

- Used in life threatening allergic/hypersensitivity reactions.

- Restores cardiac rhythm in patients with cardiac arrest.

- Treats refractory bradycardia.

Front 42

What are the clinical uses of isoproterenol?

Back 42

- Used as a continuous infusion to increase heart rate after a heart transplant.

- Used as a chemical pace-maker in complete heart block.

- Used in patients with valvular heart disease to decrease pulmonary resistance of vasculature.

Front 43

Ephedrine and phenylephrine are what classes of drugs? How do they differ?

Back 43

- They are sympathomimetics

- Ephedrine is indirect because it stimulates release of norepinephrine with alpha and beta adrenergic activity.

- Phenylephrine is direct and selective for alpha-1 receptors that increase venous constriction > than arterial.

Front 44

Inhaled anesthetics, with the exception of halothane, are derivatives of what chemical compound?

Back 44

- Methyl ethyl ether.

- Halothane derives from alkane.

Front 45

Define contractility.

Back 45

The measure of force of contraction independent of preload and afterload.

Front 46

Define preload.

Back 46

The amount of cardiac muscle that is stretched before contraction or the end diastolic volume of the heart.

Front 47

What can cause a low preload?

Back 47

- Hypovolemia and venodilation.

- Tension pnuemothorax and pericardial tamponade. (prevent ventricular filling)

- Pulmonary embolism and pulmonary hypertension

Front 48

What is expected to happen to arterial CO2 during anesthesia? Why?

Back 48

Most anesthesia drugs suppress breathing. Sedative-hypnotics act on GABAa receptors that provide inhibitory input to neurons of the respiratory system.

- Volatile anesthetics decrease excitatory neuronal transmission.

- PaCO2 is lowered during anesthesia because of assisted ventilation, which may result in cessation of ventilation.

Front 49

What is the most practical perioperative test for autonomic nervous system dysfunction?

Back 49

Orthostasis.

- Dysfunction when decrease in systolic blood pressure is >30 mmHg and absence of increased heart rate on assuming upright position.

Front 50

When are beta blockers used for preoperative administration?

Who would likely benefit?

Back 50

They are recommended for patients that are at risk for myocardial ischemia. (coronary artery disease, positive stress test, diabetes mellitus type 2, and left ventricular hypertrophy)

- Also used during high risk surgeries (vascular, thoracic, intra-abdominal, and large blood loss)

Front 51

What class of drug is clonidine?

Back 51

Alpha-2 adrenergic agonist in the CNS.

Front 52

How is Clonidine used clinically?

Back 52

It is used to differentiate essential hypertension from pheochromocytoma. (Patients with essential hypertension have much decreased levels of norepinephrine).

- It ameliorates the signs/symptoms of opiod withdrawal and tobacco craving.

- Decreases the MAC of injected and inhaled drugs.

- Attenuates the sympathetic nervous system response evoked for larygnoscopy.

- Antihypertensive.

- Injection into epidural/subarachnoid space produces analgesia without causing hypoventilation/pruritis/nausea/vomiting.

Front 53

What were the main drawbacks of inhaled anesthetics between 1920 and 1940?

Back 53

- They were flammable (diethyl ether, divinyl ether, ethylene, cyclopropane)

- They were toxic (chloroform, ethyl chloride, trichlorethylene [all halogenated with chlorine which made them toxic])

Front 54

What major scientific advance led to the development of modern inhaled anesthetics?

Back 54

Fluorination increases stability and lessens toxicity.

- This was developed from effects to produce atomic weapons.

Front 55

What is the major advantage of sevoflurane and desflurane as compared to older inhaled anesthetics?

Back 55

Sevoflurane and desflurane are halogenated exclusively with fluorine and are less soluble in blood, therefore allowing faster awakening.

Front 56

What is MAC?

Back 56

Minimal alveolar concentration (partial pressure) of inhaled anesthetic dose required to suppress movement in 50% of patients in response to surgical incision.

- 95% of patients should not move at a dose of 1.2 x MAC

- 99% of patients should not move at a dose of 1.3 x MAC

- MAC allows for the potency of drugs to be compared.

Front 57

What factors decrease MAC?

Back 57

- Preoperative medications
- Hypothermia
- IV anesthesia
- Neonates
- Elderly
- Pregnancy
- alpha-2 agonists
- Acute EtOH ingestion
- Lithium
- Cardiovascular bypass
- Opiates
- PaO2 < 38 mmHG (hypoxia)
- Anemia
- Hyponatremia

Front 58

What factors increas the MAC?

Back 58

- Hyperthermia
- Increased CNS catecholamines (MAOI's, TCA'sacute use of amphetamines/cocaine)
- infants
- chronic EtOH use
- Red hair
- hypernatremia

Front 59

How does solubility of an inhaled anesthetic influence anesthetic induction and emergence?

Back 59

The more soluble a gas is in blood, the longer it is for both induction and emergence.

Front 60

What do inhaled anesthetics do to evoked potentials?

Back 60

All volatile anesthetics and N2O depress the amplitude and increase the latency of evoked potentials in a dose dependent manner.

Front 61

How might inhaled anesthetics effect the anesthetic management of a patient for spine surgery?

Back 61

It would decrease the reliability of motor evoked potential monitoring.

Front 62

What is the apneic threshold for pCO2?

Back 62

35 mmHG

Front 63

List 5 possible ways inhaled anesthetics can depress circulation.

Back 63

1. Lowered blood pressure
2. Lowered cardiac output
3. Skeletal muscle relaxation.
4. Blunts the cardiac reflexes
5. Vasodilation.

Front 64

What anesthetic has been implicated in spontaneous abortions?

Back 64

Nitrous Oxide (N2O)

- Not proven to be mutagenic

Front 65

What information should be relayed to the recovery room nurse post-operatively?

Back 65

- Pertinent history
- medical condition
- anesthetic used
- what surgery was performed

Front 66

Why do intravenous anesthetics act so rapidly?

Back 66

They are lipophilic and bind preferentially into highly perfused lipophilic tissues like the brain and spinal cord.

Front 67

Why do all anesthetic induction drugs have similar duration of action for a single dose despite different pharmacokinetic profiles?

Back 67

There is redistribution of the drugs into less perfused areas such as muscle and fat.

Front 68

What is the most common drug used for induction of anesthesia?

Back 68

Propofol.

Front 69

What food allergy influences the choice of propofol?

Back 69

Egg yolk.

Front 70

Why is propofol not associated with "hangover" effect and utilized effectively as a continuous infusion?

Back 70

It has rapid metabolism resulting in effecient plasma clearance in conjunction with slow redistribution.

Front 71

What effect does propofol have on blood pressure?

Back 71

- Causes arterial and venous vasodilation, thus causing a profound decrease in blood pressure.

- Inhibits the baroreceptor reflex

- Causes a very small increase in heart rate.

Front 72

What effect does propofol have on Ventilation?

Back 72

- It is a potent repiratory depressant and apnea after induction dose.

- Maintainance infusions reduce minute ventilation by reducing tidal volume and respiratory rate.

- Decreases the response to hypoxia and hypercapnia

- Decreases upper airway reflexes

- Decreases wheezing.

Front 73

What drugs are commonly used prior to induction of propofol?

Back 73

Barbiturates like thiopental and methohexital.

Front 74

What do barbiturates do to blood pressure?

Back 74

- Cause a modest decrease in blood pressure (less than propofol) by peripheral vasodilation and increased heart rate.

Front 75

What do barbiturates do to ventilation?

Back 75

- Depress the medullary respiratory center.

- Decrease cerebral requirements of O2 by decreasing cerebral blood flow by decreasing cerebral blood volume and intracranial pressure.

Front 76

What benzodiazepines are commonly used in the perioperative period?

Back 76

- Diazepam
- Midozolam
- Lorazepam

Front 77

What effect do benzodiazepines have on blood pressure?

Back 77

- Midazolam decreases blood pressure greater than diazepam due to peripheral vasodilation.