3. The word anesthesia is derived from the Greek:
meaning insensible or without feeling.
ANESTHESIA IS BROKEN DOWN INTO 3 MAIN CATEGORIES
LOCAL AND GENERAL. REGIONAL, ALL OF WHICH AFFECT THE
NERVOUS SYSTEM IN SOME WAYAND CAN BE ADMINISTERED
USING VARIOUS METHODS AND DIFFERENT MEDICATION.
ANAESTHESIAARE AGENT THAT BRIING ABOUT REVERSIBLE
LOSS OF SENSATION .
4. (from Greek αν-, an-, "without"; and, aisthēsis, "sensation"),
traditionally meant the condition of having sensation (including the
feeling of pain) blocked or temporarily taken away.
It is a pharmacologically induced and reversible state of amnesia,
analgesia, loss of responsiveness, loss of skeletal muscle reflexes or
decreased stress response, or all simultaneously. These effects can
be obtained from a single drug which alone provides the correct
combination of effects, or occasionally a combination of drugs (such
as hypnotics, sedatives, paralytics and analgesics) to achieve very
specific combinations of results.
This allows patients to undergo surgery and other procedures
without the distress and pain they would otherwise experience.
5. An alternative definition is a "reversible lack of
awareness," including a total lack of awareness
(e.g. a general anesthetic) or a lack of awareness
of a part of the body such as a spinal anesthetic.
The pre-existing word anesthesia was suggested
by Oliver Wendell Holmes, Sr. in 1846 as a word
to use to describe this state.
Anaesthesiology is a special branch of
medicine. Nurses working in this area need to
have knowledge and skill to care for the
patient who is being given
premedication, under anaesthesia and
recovering.
6. ACCORDING TO willims
Loss of feeling in all or part of body with or without loss of
consciousness .the patient was given an injection before
surgery
According to lippen cott
Genral loss of the sense of feeling ,as pain ,heat ,cold,
touch,and other less common varieties of sensation .
According to devis
It is a reversible blocking of pain feeling in whole body or in
a part of it using pharmacology or other methods
10. •REGIONAL ANESTHESIA : Regional anesthesia renders a
larger area of the body insensate by blocking
transmission of nerve impulses between a part of the
body and the spinal cord. Two frequently used types of
regional anesthesia are spinal anesthesia and epidural
anesthesia.
•
11.
12.
13. LOCAL ANESTHESIA :
Local anesthesia inhibits sensory perception within a specific
location on the body, such as a tooth or the urinary bladder
14.
15. •SPINAL ANESTHESIA:
•it is achieved by injection 1.8 ml of 5%
lignocaine solution into the subarechnoid apece
through a lumber puncture.other drugs which
can be used are cinchocaine, procaine and
amethocaine. It can cause serious hypotension.
16.
17. •EPIDURAL ANESTHESIA: It is achieved by
injection 1 to 2 % of lignocaine solution in the
epidural space. It blocks the nerves
traverse the epidural space. It can
which
cause
hypotension, which is less severe than with
spinal analgesia. For prolonged operations, a
catheter may be passed into the epidural space
for intermittent administration of local
anaesthesia.
18.
19. GENERAL ANESTHESIA : General anesthesia
refers to inhibition of sensory, motor and
sympathetic nerve transmission at the level of the
brain, resulting in unconsciousness and lack of
sensation. There are three types of general
anaesthesia- spontaneous, controled and
assisted.
These types are based on whether the
patient breathes himself under anaeasthesia, is
ventilated artificially, or breathes himself but needs
assistance periodically.
20.
21. Induction:
Anaesthesia may be indused by one of the following techniques-
•Intravenouos injection of the following:-
•Thiopentone(2.5%:) short acting(15 to 30 minutes).
•Methohexitone (1%): ultra-short acting(15 to 30) minutes.
•Hexobarbitone(10%) : long acting (30 to 45 minutes).
•Inhalation agents:-
•Nitrous oxide.
•Cyclopropane*
•Halothane
•Ether*
•Trichlorethylene
•Ethyl ghloride
•Rectal instillation:- thiopentone or paraldehyde is instilled into the
rectum through a catheter, as a warmed solution. Alternatively, a
rectal suppository may be used. This method of induction is used in
children.
22.
23. DISSOCIATIVE ANESTHESIA:
Dissociative anesthesia uses agents that
inhibit transmission of nerve impulses
between higher centers of the brain (such as
the cerebral cortex) and the lower centers,
such as those found within the limbic
system.
24. GENERALANESTHESIAARE DRUGS THAT BRING ABOUT REVERSIBLE LOSS
OF SENSATIONAND CONSCIOUSNESS.
PURPOSES OF ANESTHESIA
1. ANALGESIA( LOSS OF RESPONSE TO PAIN )
2. AMNESIA ( LOSS OF MEMORY )
3. IMMOBILITY ( LOSS OF MOTOR REFLEXES )
4. HYPNOSIS ( UNCONSCIOUSNESS)
5. PARALYSIS ( SKELETAL MUSCLE RELAXATION )
25. INHALATIONAL ANAESTHESIA
Inhalational anesthesia is achieved through
airway tract by facemask, laryngeal mask or
endotracheal tube
agent used is a gas like nitrous oxide or volatile vapor
like chloroform, ether, or flothane.
- Inhalational anesthesia depresses the brain from up
[cortex] to down [the medulla] by increasing dose.
26. 1. INHALATIONAL
( A ) GASES
NITROUS OXIDE
A colorless gas with a slightly sweetish odor prepared by heating
ammonium nitrate . It produce light anesthesia without significant
depression of respiration or vasomotor center .
It has the dis advantage that it produces light anesthesia and therefore can
only be used along anesthesia .long term exposure ( like in staff of
operation theater ) to low dose can impair DNA synthesis which may
result in fetal abnormalities when such staff become pregnant.
( B ) LIQUIDS
ETHER-
1. Is a colorless volatile liquid .
2. It is a potent and reliable anesthetic ,good analgesic ,muscle relaxant and
does not depress cardiovascular and respiratory function in therapeutic
doses.
27. HALOTHANE
Is colorless volatile liquid with a sweet odor .
It is non irritant and non inflammable
Induction is smooth and rapid in 2-5 min surgical anesthesia can be produced
ENFLURANE AND ISOFLURANE
safer
They are metabolized to a lesser extent then halothane - therefore
regarding the liver toxicity
They do not sensitize the heart to adrenaline
DESFLURANE AND SEVOFLURANE
Are newer agent which bring about very rapid induction and recovery because
of low solubility in blood but they too have some disadvantages desflurane is
pregnant -may induce coughing and some times laryngospasm .
28. OXYGEN IN ANESTHESIA
`oxygen should be added routinely to inhalation agents to protect against
hypoxia ( especially when halothane is used ) when O2 is not available
,ether is the safer agent for maintenance of anesthesia.
INTRAVENOUS ANESTHESIA
Iv anesthesia allow an extremely rapid induction because the blood
concentration be raised rapidly -in few second there is loss of consciousness
1.Inducing agents
Thiopentone sodium
Proprofol
2.Dissociative anesthesia
ketamine
3.Neuroleptanalgesia
fentanyl + droperidol
4. Benzodiazepines
diazepam , lorazepam , midazolam
29. THIOPENTONE SODIUM is used for induction of anesthesia prior to
administration of inhalation anesthesia .
A .PROPOFOL
Is an oily liquid . It is used for induction and maintenance of anesthesia for
short procedures of up to 1 hours duration.
B. DISSOCIATIVE ANESTHESIA
KETAMINE
Ketamine hydrochloride given slow iv produces dissociative anesthesia within
3-5 min which lasts for 10-15 min after a single injection .premedication with
atropine is needed .
C. NEUROLEPT ANALGESIA
FENTANYLE + DROPERIDOL
A combination of a neuroleptic ( droperidol ) with an analgesia ( fentanyl )
it last s for 30-40 min .
It is employed for endoscopies , burn dressing , angiographies ,and other
diagnostic and minor surgical procedures .
30. STAGE OF GERNAL ANESTHESIA
1. Stage of analgesia
Is from the beginning of inhalation of the anesthetic to consciousness .
2. Stage of delirium
the stage is from loss of consciousness to beginning of surgical anesthesia . It
may be associated with excitement shouting ( speak with very loud voice ) crying
and violent behavior.
3. Stage of surgical anesthesia
the has 4 planes .as anesthesia passes to deeper planes , respiratory depression is
seen ,there is gradual loss of reflexes and relaxation of skeletal muscle .
depression – cessation of
4. Stage of medularly paralysis
is seen only with overdose . It is the stage of medullary
breathing circulatory failure and death may follow.
31. I. Analgesia stage
• Patient conscious
• Spontaneous respiration
• Reflexes present
• Possible small surgery procedures like
dressing change in burns
II. Excitation stage
•Possible uncontrolled movements,
vomiting
• Increase in respiratory rate
III. Anesthesia for surgery
• It begins with lack of lid reflex
• 4 sub stages
• Airway opening necessary
•Possible surgery except for abdominal
opening if no relaxants are used
• Possible end tracheal intubation
IV. intoxication, overdosing
• Respiratory arrest
• If anesthesia not discontinued
possible
cardiac arrest
32.
33. Local anesthesia are drug s are used that the block nerve conduction when
applied locally to nerve tissue in appropriate concentration . There action is
completely reversible
Local anesthesia –
the administration of an anesthetic agent to one part of the body by local
infiltration or topical application. It is usually administered by the surgeon.
Used for minor procedures if the patient’s cooperation and the
condition warrants
its use.
Local anaesthetic agents can be defined as drugs which are used clinically to
produce reversible loss of sensation in a circumscribed area of the body.
Drugs include Beta-adrenoceptor antagonists, opioid analgesics, anticonvulsants
and antihistamines.
Local anaesthetics can be divided into two groups on the basis of their chemical
structure:
- amides: Lignocaine, prilocaine and bupivacaine
- esters: Amethocaine, benzocaine, cocaine
e.g., amethocaine lozenges for the oropharynx, cocaine for nasal surgery.
Most blocks take 5 – 20 minutes to work.
35. MECHENISM OF ACTION
PREVENT THE GENRATION AND THE
CONDUCTION OF NERVE IMPULSES .THE
PRIMARY MECHENISUM OF ACTION IS
BLOCKADE OF VOLTAGE -GATED SODIUM
CHANNELS .
36. Regional Anesthesia –
is broadly defined as a reversible loss of sensation in a specific area or region
of the body when a local anaesthetic is injected to purposefully block or
anaesthetize nerve fibres in and around the operative site.
Commonly R.A techniques include:
Spinals (subarachnoid block), epidurals (extradural space) , caudals,
and major peripheral nerve blocks.
-The subarachnoid, epidural or plexus block are called
REGIONALANAESTHESIA
- Some called it regional analgesia as patient is conscious.
-Some use sedative with regional analgesia to be
anaesthesia.
- Local anaesthesia means block of peripheral nerve or
tissue infiltration as in lipoma ( slow growing fat cell in a
thin fibrous capsule usually found just below the skin ),
circumcision, teeth, eye even craniotomy
37. 1. HYPERSENSITIVITY REACTION - INCLUDED SKIN RASHES
,DERMATITIS , ASTHAMA, OR RARELY ANAPHYLAXIS
2. C.N.S - DIZZINESS , AUDITORY AND VISIUAL DISTURBANCE ,
MENTAL CONFUSION , DISORIENTATION ,ANXIETY , MUSCLE
TREMORS, CONVULSIONS AND RESPIRATORY FAILURE CAN
RESULT FROM LARGE DOSES INTRAVENOUS DIZAPAM
CONTROLS CONVULSION .
3. C.V.S - HYPOTENTION , BRADYCARDIA , ANDARRHYMIAS MAY
BE ENCOUNTERED . RARELY CARDIAC ARREST CAN
OCCUR.
4. LOCAL IRRITATION - CAN BE SEEN WITH BUPIVACAINE .
WOUND HEALING MAY BE DELAYED
38. METHODS OF ANESTHESIA
1. Spinal cord: By injection of local drug in sub -
arachnoid space in CSF, this must be bellow L
2
2. Epidural: The drug is injected outside dura [no
puncture] to block the nerve roots at its exit
from spinal cord.
3. Nerve plexus: Cervical, brachial, lumbosacral
4. Peripheral nerve: Radial, ulna, median, sciatic,
femoral, popletial, facial, mandibular.
5. Injection into tissues, skin, subcutaneous.
39. Spinal anesthesia –
local anesthetic injected
into subarachnoid space at 3rd or 4th lumbar space
- Too high = affects resp. muscles
- Headaches - poss. d/t a in CSF pressure at site of
needle insertion
Spinal Block - subarachnoid membrane (2nd layer of cord)
Epidural Block - outer covering of spinal cord (dura mater)
Caudal Block - sacrum
Saddle Block - Lower end of spinal column - blocks peri area
- clients in labor
Monitor BP with all of the above
40. 1. Anaesthetic machine.
2. Monitoring system.
1. Oxygen gas supply.
2. Nitrous oxide gas supply.
3. Flow meter
4. Vaporizer specific for every agent
5. Mechanical ventilator
6. Tubes for connection.
1. Pulse, ECG
2. Blood pressure
3. Oxygen saturation.
4. End tidal CO2
5. Temperature
6. Urine output, CVP, EEG, bispectral
index, muscle tone, ECHO, drug
concentration
Need
for 2
impo
tools
Anesthetic
machine
monitoring
41. PREPERATION :
•the suction machine should be checked. Solution catheters and
tips are arranged for.
•The working of the operation table is checked, especially the
mechanism of lowering the head end.
•Nasogastric tubes are kept on the trolly.
•Resuscitation equipment is checked-
(a) O2 cylinder
(b) face mask, ambu valve, bag
(c) laryngoscope
(d) endotracheal tubes
(e)drugs: atropine, adrenaline, sodium bicarbonate,
mephentermine, dopamine, hydrocortisone, pronethazine.
(f) monitoring equipment is checked, e.g. cardioscope with
defibrillator, pulse oximiter, capnometer etc.
42. MAINTENANCE:
Components of the anaesthesia are anagesia and
amnesia.
The former is important, because the patient must not
feel any pain.
The later is important because the patient must not
recall any events at the time of the operation.
Analgesia is provided by nitrous oxide,
trichlorethylene, ether cyclopropane or pethidine.
Sleep is achieved with thiopentone, nitrous oxide
or cyclopropane.
Controlled general anaesthesia needs
endotracheal intubation.
43. The vocal cord are paralysed for intubation with
suxamethonium or d-tubocurarine.
Muscles relaxation for artificial ventilation is
achieved with intermitlent administration of
suxamethonium, or long acting muscle relaxants
like gallamine or d- tubocurarine. The action of
last two drugs are reversed at the end of the
operation with neostigmine. Atropine has to be
administered prior to neostigmine to reduce
cardiac slowing, and profuse bronchial and
salivary secretions produced by neostigmine as a
side effect
