ANESTHETICS

ANESTHETICS

Anesthetics drug image

ANESTHESIA: It is a way of control of pain during a surgery or procedures by using medicine called anesthetics.

HISTORY OF ANESTHESIA  

• Before middle of 19^th century a no. of agents like – alchohol opium ,cannabis

• 18^th century by using volatile liquids – diethylether , chloroform

• In 1844 Horace wall was 1^st used nirousoxide

• Later on cyclopropane, thiopental, D-tubacurin introduced as anesthetics

GOALS OF ANESTHESIA:

  

•  Analgesia

• Loss of reflexes- to minimize response

•  Loss of consciousness- patient don’t know what happening outside

• Provide skeletal muscle relaxation

 

THEORIES INVOLVED IN ANESTHESIA:

• Surface tension theory

• Lipid/water partition theory
•   Membrane expansion theory
•   Clathrates formation theory
•  Inhibition of energy production / utilization
•  Membrane fluidsation theory

PRINCIPLE OF ANESTHESIA:

• The basic concept of anesthesia is to prevent pain of patient

 The main thing is “the higher function loss first then lower areas of function in brain and spinal cord it’s opposite lower areas stop functioning first then higher function”

STAGES OF ANESTHESIA:

• THE satges of anesthesia discovered by “guedec”

• The anesthesia has four stages as given below—

1. analgesia
2. delirium
3. surgical anesthesia
4. medullary paralysis

STAGE 1: ANALGESIA

•  Start from anesthetic inhalation to loss consciousness
•   Patient can hear see fell like dream   
•   Minor operation carried out in this stage
• Limited to start procedure

STAGE 2  : DELIRIUM STAGE

• Start from loss consciousness’ to end with regular respiration
• In this stage patient shout struggle , hold breath, jaws closed , heart rate increase , blood pressure increases, muscle tone increases, cough vomit may lead to aspirational pneumonia to death
• Operative procedure carried out in this stage

 STAGE 3: SURGICAL STAGE

•  START with regular respiration to end spontaneous breathing (apnoea )
• It consist of 4 stages  plane ( 1, 2, 3 ,4 ) respectively

• Plane 1 –start regular respiration
• Plane 2 –ceation of eye movement ,paralysis start
• Plane 3 –increase abdominal extrusion; end with paralysis, except diaphragm
• Plane 4 –ceasion of intercostal muscle , Diaphragm paralysis

STAGE 4 : MEDULLARY PARALYSIS (APONEA)

•  Also called over dose stage
• Complete Respiration paralysis  lead to failure of circulation to death

IDEAL PROPERTIES OF ANESTHETICS AGENT

• Should be high potent
• Should be easy to administered (apt not required)
• Should have rapid induction and recovery without any unwanted symptoms
• Non inflammable , non-toxic
• Not irritant to mucosa
• Should be cheap , stable ,easily stored