anesthesia or anaesthesia (from Greek "without sensation") is a state of controlled, temporary loss of sensation or awareness that is induced for medical purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), amnesia (loss of memory), and unconsciousness

1. LOCAL AND GENERAL
ANAESTHESIA
Mohd asad farooqi
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2. INTRODUCTION
ANAESTHESIA :
GENERAL
ANAESTHESIA
LOCAL
ANAESTHESIA
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3. What is Anaesthesia ???
 Anesthesia – is a reversible condition of comfort and quiescence for a
patient within the physiological limit before, during and after
performance of a procedure.
 General anesthesia – for surgical procedure to render the patient
unaware/unresponsive to the painful stimuli.
 Drugs producing General Anaesthesia – are called General Anaesthetics.
 Local anesthesia - reversible inhibition of impulse generation and
propagation in nerves. In sensory nerves, such an effect is desired
when painful procedures must be performed, e.g., surgical or dental
operations.
 Drugs producing Local Anaesthesia – are called Local Anaesthetics e.g.
Procaine, Lidocaine and Bupivacaine etc.
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4. LOCAL ANAESTHETICS
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5. DIFFERENCE BETWEEN GENERAL ANAESTHESIA &
LOCAL ANAESTHESIA
Gen.Anaesthsia Local AnaesthsiaFEATURES
Site of action
Area of body involved
Consciousness
Care of vital functions
CNS
Whole body
Lost Essential
Peripheral nerves
Restricted area
Unaltered
Usually not needed
Risky
Possible
Safer
Not possible
Poor health patients
Use in non cooperative
patients
Major surgery
Minor surgery
Preferred
Not preferred
Cannot be preferred
preferred
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6. LOCAL ANAESTHETICS
 DEFINITION: are drugs which, when applied directly to
peripheral nervous tissue, block the nerve conduction and
abolish all sensations in the part supplied by the nerve
without loss of consciousness.
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7. FEATURES OF LOCAL
ANAESTHETICS
 Should have quick onset of action
 Should not be irritating to skin & mucous membranes
 Duration of action must be long enough to allow desired surgery to be
completed
 Should be effective on both injection & local application
 Should have low Systemic toxicity
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8.  Should not cause any permanent damage on any tissue.
 Should be relatively free from producing allergic reaction.
 Should be stable in solution and readily undergo
biotransformation.
Contd…
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9. CLASSIFICATION
1. INJECTABLE ANAESTHETIC:
 SHORT DURATIONLOW POTENCY,
procaine
chloroprocaine


INTERMEDIATE POTENCY AND DURATION
Lidocaine prilocaine
HIGH POTENCY, LONG DURATION
tetracaine bupivacaine
ropivacaine dibucaine
EFFICACY-
maximum effect that a drug can
produce regardless of dose.
POTENCY -
amount of a drug that is needed to
produce a given effect
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10. 2. SURFACE ANAESTHETIC:
INSOLUBLE
benzocaine
butylaminobenzoate
oxethazaine
SOLUBLE
cocaine
lidocaine
tetracaine
benoxinate
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11. MECHANISM OF ACTION OF LAs

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12. MECHANISM OF ACTION OF LAs
 LA blocks the nerve conduction by reducing entry of Na+ through
the voltage gated channels
 Due to this, they block the initiation & propagation of nerve impulse.
 At higher doses it also blocks
1. Voltage gated Ca2+ channels
2. K+channels
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13. GENERAL
ANAESTHESIA
Mohd asad farooqi
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