General anesthetics are drugs that produce reversible loss of consciousness and sensations. They have four main features: reversible loss of consciousness, reversible loss of sensations, analgesia and amnesia, and muscle relaxation and abolition of reflexes. There are two main classifications of general anesthetics - inhalational anesthetics which are volatile liquids or gases administered via inhalation, and parenteral anesthetics which are intravenous inducing drugs or slower-acting drugs. General anesthetics are used for operations on the head, neck and face, for induction and maintenance of anesthesia for procedures like cardiac catheterization and bronchoscopy, and for short procedures and postoperative pain management. Complications can occur during or after anesthesia and include respiratory depression, cardiac issues, falling

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

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