Inhalational Induction Agents Flashcards
(29 cards)
The stages of anaesthesia are:
i) Analgesia
ii) Disinhibition
iii) Surgical Anaesthesia
iv) Medullary depression
All inhalation induction agents are naturally in a liquid form except?
Nitrous Oxide (N₂O)
Properties of an ideal inhalation agent include:
- Rapid onset of action
- Rapid onset of recovery
- Rapid emergence
- Cheap
- Non-combustible
- Should have limited emetic effects
- Should not undergo biotransformation in the body
- Should cause reversible CNS effects.
What is MAC?
MAC is the minimum concentration of a drug in the alveolar at standard condition (i.e. 1 atmosphere) required to put 50% of patients to sleep.
Group these factors that affect MAC by their resultant action. Whether they decrease or increase MAC.
Thyrotoxicosis, Myxoedema, Hypertension, Hypothermia, Hypotension, Hyperthermia, Chronic opiod abuse, sedatives, Acute alcohol intoxication.
I) Increases MAC
- Thyrotoxicosis
- Hypertension
- Hyperthermia
- Chronic opoid abuse
II) Decreases MAC
- Myxoedema
- Hypotension
- Hypothermia
- Sedatives
- Acute alcohol intoxication
The measure of solubility of a gas in blood is known as?
Blood Gas Coefficient.
What is the relationship Blood Gas Coefficient and the onset of action on inhalation induction agents?
BCG is INVERSELY proportional to the onset of action of inhalation induction agents.
What is the mathematical relationship between MAC and potency of an inhalation induction agent?
MAC is INVERSELY proportional to the potency of an inhalational induction agent.
What is the mathematical relationship between the rate of inhalation/ventilation of an inhalational induction agent to its rate of onset.
The rate of inhalation is DIRECTLY proportional to the rate of onset.
What is the mathematical relationship between the arteriovenous concentration gradient of a drug to it’s onset of action?
AVG is DIRECTLY proportional to the onset of action
The common inhalational induction agents are:
- Desflurane
- Isoflurane
- Halothane
- Ether
- Nitrous Oxide (N₂O)
- Servoflurane
- Enflurane
What is the MAC of Isoflurane?
1.2
What is the MAC of Desflurane?
6.0
What is the MAC of Servoflurane?
1.7
What is the MAC of Enflurane?
1.7
What is the MAC of N₂O?
104
What is the MAC of Halothane?
0.75
What is the MAC value of Ether?
1.92
A pungent and easily flammable induction agent with a MAC value of 1.92 which is obsolete now is?
Ether
The effects if Ether on the GI system are:
i. Ether causes increased salivation and GI atony
ii. Ether cause nausea and vomiting
The inhalation induction agent associated with coronary steal syndrome is?
Isoflurane
The inhalation induction agent with the least amount being metabolised is?
Isoflurane (0.2%)
Halothane Hepatoxicity presents as:
- Mild liver dysfunction and deranged liver function test
2. Jaundice leading to fulminating liver necrosis
Risk factors for Halothane Helatotoxicity are:
- Female sex
- Obesity and middle age
- Multiple exposure to halothane ina 28 day span
