general anesthetics and local anaesthetics

2. General anaesthetics (GAs) are drugs
which produce reversible loss of all
sensations and consciousness.
Features of GA are :
1.Reversible loss of consciousness
2.Reversible loss of sensations
3.Analgesia & amnesia
4.Muscle relaxation & abolition of
reflexes

3. Classification
1. Inhalational GA –
a) Volatile liquids : Ether
Halothane
Enflurane
Isoflurane
Desflurane
b) Gas : Nitrous oxide

4. 2. Parenteral GA –
a) Inducing drugs – Thiopentone sodium
Propofol
Etomidate
b) Slow-acting drugs –
BZDs : Diazepam, lorazepam
Ketamine : Dissociative anesthesia
Opioids : Fentanyl, alfentanil

5. Therapeutic uses :
 For operations on head, neck & face
 For induction and maintenance of
anaesthesia – cardiac catheterization,
bronchoscopy
 Short procedures – dressing of burns
 As an adjuvant to anaesthetics for effective
analgesia
 Postoperative pain

6. Complications of GA –
A. During anaesthesia :
 respiratory depression
 salivation, respiratory secretions
 cardiac arrhythmias, asystole
 fall in BP
 aspiration of gastric contents
 laryngospasm & asphyxia
 delirium, convulsions

7. B. After anaesthesia :
 nausea & vomiting
 persisting sedation
 pneumonia
 organ toxicities – liver & kidney damage
 nerve palsies
 cognitive defects

8. LocaL anaestheticsLocaL anaesthetics

9. LAs are drugs which when applied
topically or injected locally, block nerve
conduction & cause reversible loss of all
sensations in the part supplied by the
nerve.

10. 
Cocaine
 Lignocaine
 Benzocaine
 Tetracaine

Procaine

Prilocaine

Bupivacaine

Ropivacaine

11. Mechanism of action -
Local anaesthetics
Block voltage-gated Na+
channels
No entry of Na+
ions into the cell – no
depolarization
No generation of action potential
No generation and conduction of impulse to CNS
Local anaesthesia

12. Therapeutic uses :
 Anaesthetize mucous membrane of the
eyes, nose, mouth, cornea, urinary & upper
respiratory tracts
 Abscess drainage
 Surgery – lower & upper limbs, lower abdomen,
perineum, caesarean section
 Excision of small swellings, suturing of
cut wounds, dental procedures

13. Thank youThank you