General Anaesthesia

Question 1

Triad of genreal anesthesia:

Answer 1

• 1 - Unconsciousness
• 2 - Analgesia
• 3 - Muscle relaxation

Question 2

1st of GA:

Answer 2

Analgesia and sedation

Question 3

Stage of GA no longer found in modern medicine:

Answer 3

Erratic breathing, heart rate, nausea, pupil dilation breath-holding
Choking can occur due to irregular breathing and a risk of vomiting

Question 4

3rd stage of anesthesia:

Answer 4

Surgical anesthesia
Begins with lackof lid reflex
4 substages:
- Roving eye balls
- Loss of corneal and laryngeal reflexes
- Pupil starts dilating and light reflex is lost
- Intercostal paralysis, shallow abdominal respiration, dilated pupils

Question 5

4th potential stage of GA:

Answer 5

Intoxication - resp. arrest, cardiac arrest, widely dilated pupils, muscles are flabby, low BP, no pulse

Question 6

Pharmacodynamics in GA is?

Answer 6

MAC value

Question 7

PA (alveolar partial pressure) is equal to?

Answer 7

Input into alveoli - loss of IA from alveoli into arterial blood

Question 8

Input is dependent on 3 factors:

Answer 8

PI (inspired partial pressure), alveolar ventilation, characteristics of anesthetic breathing system

Question 9

Alveolar uptake is dependent on 3 factors:

Answer 9

Solubility, CO, alveolar to venous pressure difference

Question 10

PA is determined by __ factors

Answer 10

6 (the factors affecting input and alveolar uptake

Question 11

Increased PI (partial pressure)

Answer 11

accelerates induction

Question 12

Second gas effect is typical for?

Answer 12

NO

Question 13

Increased alveolar ventilation…

Answer 13

For exmaple, hyperventialtion, increases induction

Question 14

Solubility:
lower blood-gas partition coefficient =

Answer 14

faster induction and recovery

Question 15

lower CO (shock) causes ____ induction

Answer 15

faster induction

Question 16

MAC definition:

Answer 16

Minimum concentration in lungs for more than 50% of people to not respond to pain

Question 17

high MAC = low _____

Answer 17

potency

Question 18

___MAC prevents movemtn in all patients

Answer 18

1.3

Question 19

Factors increasing MAC:

Answer 19

Hyperthermia
Hypernatremia
Hyperthyroidism
Drugs increasing catecholamine levels (Cocaine, trycyclics, MAOI’s)
Chronic alcohol abuse

Question 20

Factors decerasing MAC

Answer 20

Hypothermia
Hypoxia
Hyponatremia
Pregnancy
Lidocaine
Lithium
a2 agonsits
PaO2 < 38mmhg
BP <40mmhg
preoperative meds
Drugs decreasing catecholamines (clonidine, a-methyldopa, clonidine, chronic amphetamine ingestion)
Acute ethanol ingestion

Question 21

Nitrous oxide

Answer 21

Sweet, colorless odorless
Powerful analgesic, not potent anesthetic
low potency
non-flammable, non-irritating
Inhibits B12 metabolism
MAC value = 104%

Question 22

Halothane:

Answer 22

Halogenated alkane
Pungent odor
Thymol preservative and amber-colored bottles to retard spontaneous oxidative decomposition
Overall decrease in CVS
Rapid shallow breathing
Decreased renal blood flow
Potentiates NM relaxants
Myometrial relaxation
Decrease hepatic blood flow

Oxidative CYP450 metabolism
Halothane hepatitis (allergic rxn)

Question 23

Enflurane:

Answer 23

Colorless
Mild, sweet etheral odor
Decreases BP
Increased sensativity to epinephrine
Increased ICP
Seizures
Decreased renal output
Potentiates relaxants
Myometrial relaxation
Decreased hepatic blood flow

Elimination primarily by ventilation
Metabolite of fluoride
Fluoride-induceed nephrotoxicity

Question 24

Isoflurane

Answer 24

Mild, sweet, ethereal odor
Colorless
Least cardiac depression
IRRITANT TO UPPER AIRWAY
MAC value 1.3%

Question 25

Desflurane:

Answer 25

PUNGENT ODOR
Decfrease BP
Increase HR
Increase ICP
Irritates upper airways

Question 26

Sevoflurane:

Answer 26

Colorless
Pleasent odor
Smooth mask induction
Bronchodilator
Not irritating

Question 27

Malignant hyperthermia

Answer 27

Hypermetabolism of skeletal muscle
Large calcium release from SR
TRIGGERED BY IA AND SUCCINYLCHOLINE
Increased CO2
Metabolic and resp. acidosis
Accelerated O2 consumption
Increased heat production
SNS activation
Hyperkalemia
DIC
Multiple organ dys. and failure
Increased end-tidal CO2, tachycardia, muscle rigidity, tachypnea
Fever, myoglobinuria, multiple organ failure

Question 28

Ideal IA has ____ solubility in blood

Answer 28

low

Question 29

3321 measurement

Answer 29

3 interincisial
3 hyoid-mental
2 hyoid-thyroid
1 sublaxation of mandible

Question 30

Mallampati score

Answer 30

1 uvula fauces soft pallate pillars
2 uvula fauces soft palate
3 base of uvula, soft palate
4 hard palate

Question 31

Intubation equipment

Answer 31

Suction
Airway
Laryngoscope - adults macintosh, curved - children miller, straight
Tube (F is 7-8mm while M is 8-9mm)

Question 32

Physiological response to intubation:

Answer 32

HTN, tachcardia, intracranial HTN, laryngospasm

Question 33

Does not cause histamine release:

Answer 33

Etomidate

Question 34

_____ and _____ can cause histamine induced bronchospasm

Answer 34

Mopprhine
Meperidine

Question 35

Opioid indicated in asthma:

Answer 35

Fentanyl

Question 36

Factors not affecting MAC:

Answer 36

• Potassium disorders
• Duration of anesthesia
• Magnitude of anaesthetic metabolism
• Gender
• PaCO2 of 15-95mmHg
• PaO2 >38mmHg
• Blood pressure >40mmHg

Question 37

Main side effect of NO

Answer 37

Inhibition of vit b12 metbolism

Question 38

Inhlaed anesthetics basics, MAC value:

Answer 38

NO - MAC 104%
Halothane - Hepatitis - pungent odor
Enflurane - Sweet - Fluoride - induced nephrotoxicity
Isoflurane - sweet - IRRITANT- 1.3%
Desflurane - pungent odor - IRRITANT - 6.6%
Sevoflurane - sweet - 2%

Question 39

3321 locations:

Answer 39

3 - interincisor
3 - thyreomental
2 - hyoid-thyroid
1 - sublaxation of mandible

Question 40

Complications of endotracheal intubation:

Answer 40

• Trauma
• Hypoxia
• Dysrhythmias
• Aspiration
• Intubation of oesophagus or right mainstem bronchus
• Laryngospasm
• Bronchospasm