Anaesthesia

Question 1

What is Anaesthesia ?

Answer 1

These are medications that are used to block pain for patients undergoing surgical or other medical procedure.

Question 2

Benefit of anaesthesia ?

5

Answer 2

* Sedation and
 anxiety reduction 
*Lack of awareness 
* Skeletal muscle relaxation
* Suppression of undesirable reflexes 
*Analgesia

Question 3

Note :

Answer 3

Anaesthesia being used alone cannot perform sufficiently but being combined or used with pre anaesthesia can bring 100% performance

Question 4

What are pre-anaesthetic medications?

Answer 4

They serve to calm the patient , relieve the pain and protect against the undesirable effect of anaesthesia or surgical procedure examples of pre anaesthetics 
Antacids , 
benzodiazipine , 
diazepam,
Antiemetics
Anticholinergic
Opioids 
Phenylthaline

Question 5

Stages of anaesthesia

Answer 5

1) induction : this is the period of time from the onset of administration of anaesthetics to the development of effective surgical anaesthesia in the patient . It depends on how fast the drugs gets to the brain.
2. ) Maintenance: this is providing a sustained stage of surgical Anaesthesia..
3. ) Recovery : this is the time from discontinuation of the administration of anaesthesia until consciousness and protective physiological response are regained.

Question 6

Types of anaesthesia ?

Answer 6

General

Local

Question 7

What is General anaesthesia?

Answer 7

These agents are used to produce unconsciousness immediately prior to and during surgical procedure

Note: potent general anaesthesia are administered via inhalational or intravenous injection.

Question 8

Inhalational Anaesthesia types

Answer 8

Halothane
Isofluorane 
Nitrous oxide 
Sevfluorane 
Desfluorane

Question 9

Note on inhalational Anaesthesia :

Answer 9

They are absorbed by the lungs where they get through systemic circulation and they get through to the brain where they exert CNS depression

They are used for the maintenance of anaesthesia after the administration of an IV agent
I.e
IV is used for induction while inhalational is used for maintenance.

The depth of anaesthesia is altered rapidly by changing the inhaled drug concentration.

Depth of anaesthesia: is the degree to which the CNS is depressed .

Question 10

The depth of anaesthesia are in

4 stages :

Answer 10

1) Analgesia (loss of pain sensation)
2) Excitement ( combative behaviour )
3) surgical anaesthesia (loss of muscle tone and reflexes )
4) medullary paralysis (it could lead to death)

Question 11

Note on MAC

Answer 11

The smaller the MAC the more potent the drug

The more the blood solubility the more the anaesthesia dissolve In the blood

If the drug is more soluble the faster it will get to depress the CNS.

Halothane > isofluorane > sevfluorane > nitrous oxide > desfluorane
(Range of solubility and potency of drug)

Question 12

MOA of Inhalational Anaesthesia

Answer 12

inhaled anesthetics work within the CNS by augmenting signals to chloride channels (GABA receptors) and potassium channels while depressing neurotransmission pathways.

Question 13

Side effect of Inhalational Anaesthesia

Answer 13

Halothane :
-It increases cardiac arrhythmias

(It is now replaced with other agents due to it adverse effect)

Isofluorane :
-It produces dose dependent hypotension

Sevfluorane :
It is suitable for paediatric patients
It has rapid induction
-Inflates the airway - chest pain - dizziness - confusion

Nitrous oxide :
It is non irritating to the airways
- It cannot provide surgical anaesthesia alone so it must be combined for more potency

Desfluorane:
It is popular for heart patient surgery due to rapid onset & recovery ..
It irritates airways and can cause cough and excessive secretion..