Drugs in General Anesthesia Flashcards

1
Q

Drugs used in GA

A

IV induction agents
Inhalational induction agents
Muscle relaxants and reversals
Analgesics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

All the induction agents are _____ and act on _____ receptors which causes ______ and subsequently _______

A
  1. Depressants
  2. GABA receptors
  3. Increased chloride conductance
  4. membrane hyperpolarization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Examples of barbiturate induction agents

A

Thiopentone sodium
Methohexital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is arm brain circulation time?

A

Time taken for onset of induction agents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Onset of Thiopentone sodium

A

15 secs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

ph of Thiopentone sodium

A

10.5 (most alkaline)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Thiopentone sodium:
1. Smell
2. Termination of action is by ____ because the drug is highly ______
3. Dose
4. AOC in ________
5. Other use
6. Accidental intraarterial injection causes
7. Mx in case of intraarterial injection

A
  1. Garlic/ onion
  2. Redistribution, lipophillic
  3. 3-5mg/kg
  4. NeuroSx, Hyperthyroidism
  5. Truth serum
  6. pain, pallor, gangrene, edema
  7. Retain cannula (to prevent vasospasm), saline/ heparin flush, stellate ganglion block (lower cervical sympathetic ganglion)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why is Methohexital avoided in neuroSx?

A

Proconvulsant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Indication of Methohexital
Dose

A

ECT
1-1.5 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Examples of non barbiturate induction agents

A

Propofol
Etomidate
Ketamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Propofol
1. Form? This leads to? What is done to prevent this?
2. Made of?
3. Should be used within?
4. Properties
5. Dose:
6. Duration

A
  1. Oily–> painful–> add lignocaine
  2. Egg lecithin, soya bean oil
  3. 6 hrs
  4. Antipruritic, antiemetic
  5. 1-2.5 mg/kg
  6. 8-10 mins (w/o hangover)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Propofol
1. AOC in?
2. Side effects?

A
  1. Day care Sx and MAC Ophthalmic Sx bc dec IOP
    LMA insertion and in laryngospasm bc dec reflexes
    TIVA
    Endoscopy and colonoscopy
  2. Propofol infusion syndrome– on prolonged–
    green urine, severe metaolic Acidosis, asystole
    addictive d/t pleasant hallucinations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Etomidate
1. Form:
2. Properties
3. Dose
4. AOC in
5. Side effects

A
  1. oily– propylene glycol
  2. Most cardiostable
  3. 0.2-0.3 mg/kg
  4. DC cardioversion, cardiac aneurysm Sx
  5. myoclonus, emetic and epileptogenic, inhibits adrenocortical synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ketamine
1. Form
2. Properties
3. ___ receptor antagonist
4. DOse:
5. How to increase duration

A
  1. Phencyclidine derivative
  2. Dissociative anesthesia, depressant (in vivo)
  3. NMDA; increases catecholamine
  4. 1-2 mg/kg IV; 4-6 mg/kg IM
  5. intrathecal admin; used with LA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ketamine
1. AOC in
2. Side effects
3. C/I

A
  1. Shock ( to incr HR and BP)
    Asthma/ COPD (bronchodilator)
    TOF
    In low resource settings (burns, i and D)
    Pediatric Sx
  2. inc oral secretions (Tx: atropine/ glycopyrrolate), unpleasant hallucinations/ emergence (reduces with midazolam)
  3. HTN, cardiac conditions, ocular sx (inc IOP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Inhalational agents enter and exit circulation via?

A

lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Inhalational induction agents are used to _____

A

maintain depth of anesthesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Newer inhalational agents

A

Halothane, Isoflurane, Desflurane, Sevoflurane
They are non flammable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Older inhalational agents

A

Ether, chloroform, trilene, cyclopropane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Meyer overton rule

A

Potency proportional to lipid solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

MAC

A

min drug required to produce immobility to painful stimulus
potency inverse proportional to MAC values

22
Q

Arrange inhalational agents in order of least MAC to most MAC

A

Methoxyflurane
Halothane
Isoflurane
Sevoflurane
Desflurane
N2O

23
Q

MAC of N20

A

104

24
Q

MAC of Desflurane

A

6

25
Q

MAC of methoxyflurane

A

0.2

26
Q

Concentration effect

A

increased conc–> quicker induction

27
Q

Second gas effect

A

in presence of N2O, conc of other gas increases. d/t rapid movement of N2O into pulmonary circulation

28
Q

What effects are seen at start of surgery?

A

Conc effect and second gas effect seen simultaneously

29
Q

What effect is seen at the end of sx?

A

Diffusion hypoxia/ fink effect

30
Q

Diffusion hypoxia?

A

AKA Fink effect
Rapid diffusion of N2o from pulm circulation dilutes the o2 present– hypoxia
Mx: O2 supplementation

31
Q

Blood gas partition coefficient

A

Conc of agent in blood/ conc of agent in alveoli

32
Q

increased B/G ratio means?

A

delayed induction as it has more solubility in blood

33
Q

Order drugs on least to highest B/G

A

Xenon
Desflurane
N2O
Sevoflurane
Isoflurane
Halothane
Methoxyflurane

34
Q

Which new inhalational agents are avoided in asthmatics?

A

Isoflurane (pungent)
desflurane (irritant)

35
Q

AOC for asthmatics

A

Sevoflurane– sweet smell
Also used in Day care surgery and lung injury

36
Q

Effect of new inhalational agents on resp system

A

dec RR
dec pulm vascular resistance
mild hypoxic pulm vasoconstriction

37
Q

Effect of inhalational agents on CVS

A

Dec HR and BP

38
Q

AOC for cardiac patients

A

Sevoflurane > Isoflurane

39
Q

Which agent causes Coronary steal syndrome?

A

Isoflurane (only theoretically)

40
Q

Maximum HR dec is seen with

A

Halothane

41
Q

Which agent is avoided in cardiac patients?

A

Desflurane– increases HR temporarily and irritant

42
Q

Which agent sensitizes myocardium to adrenaline?

A

Halothane

43
Q

Effect of inhalational agents on CNS

A

Incr cerebral blood flow and ICP

44
Q

Which agent is c/i in neurosurgery?

A

Halothane (max increase in ICP)

45
Q

Enflurane causes ____

A

Seizures

46
Q

How is rise of ICP countered in inhalational agents?

A

by hyperventilation (dec EtCO2–> dec ICP)

47
Q

AOC in CNS surgery

A

Iso = Des = Sev

48
Q

Electrical silence

A

higher conc of inhalational agents causes flat lines on EEG

49
Q

At what level is electrical silence produced for isoflurane

A

1.5 MAC

50
Q

Main controller of ICP is ____ level

A

PaCO2

51
Q
A