This document discusses different types of anesthesia. It begins by defining anesthesia and its etymology. It then discusses four main types: general anesthesia, which causes loss of sensation; regional anesthesia, which inhibits sensation in a specific part of the body; local anesthesia, which causes loss of sensation locally; and conscious sedation, which reduces the level of consciousness while allowing purposeful response. For each type, it provides brief descriptions and examples of techniques. It also outlines some common side effects of general anesthesia and spinal anesthesia.

1. Anesthesia
Types
Dr. Sajith
Senior Resident

2. Greek an- without and aesthesia – sensation refers to the
inhibition of sensation
Origin of word anesthesia :
Oliver Wendell Holmes Sr 1846

3. OLIVERWENDELLHOLMES

4. • Anesthesia is essential for the practice of surgery.
• Since its beginning in1842 it has evolved into a recognized
specialty providing continuous improvement in patient care
• Anesthetists receive lives of patients in her/ his hands.
• It is a duty to administer the safest anesthetic possible, to
protect the patient and to give full attention for the
anesthetized patient.

5. Definitions
“Anaesthesia is a medical procedure
which is deliberately produced to make a
patient insensible to pain either in a part or
in the whole of the body by which diagnostic
and surgical procedure are done while the
patient safety and comforts are maintained.”

6. Definitions
Anesthesiology : The art and science of rendering a patient
insensible to pain by the administration of anesthetic agents
and related drugs and procedures.
An anesthetist : A qualified HCP who administers anesthetics
to produce total or partial loss of sensation in patients during
surgical or diagnostic procedures.
Nurse anesthetist : A nurse who specializes in administration
of anesthesia

7. WHY ANESTHESIA ??
 Loss of awareness/Amnesia
 Analgesia
 Reduce the movement in response to stimuli
 Minimize the autonomic response to surgical
stimuli
 Muscle relaxant
 Autonomic regulation

8. HISTORY OF ANESTHESIA
 Pre- 1846: – The foundation of anesthesia
 1846-1900: Establishment of anesthesia
 20th century: Consolidation and growth
 21stcentury: – The future

9. PRE- 1846
THE FOUNDATION OF ANESTHESIA

10. METHOD OF ANESTHESIA
 Drug method
 Non-drug method

11. DRUG
METHOD
 Alcohol
 Opium
 Hyoscine
 Cannabis
 Cocaine

12. N ON D RU G
M E T HOD
 Cold
 Concussion
 Carotid compression
 Nerve compression
 Mesmeric Magnetism
 Hypnosis
 Blood letting

13. Genesis
• Before the discovery of inhalational agent pain was
considered or believed to be an inevitable outcome of
surgery.
• Today, major surgery without adequate anesthesia would be
unthinkable and probably constitute grounds for malpractice
litigation.
• Recent development dating back only 160 years.

14. • Early Analgesia: Dioscorides, a Greek physician from the
first century AD, commented on the analgesia of
mandragora, a drug prepared from the bark and leaves of
the mandrake plant.
• He stated that the plant substance could be boiled in wine,
strained, and used when they wish to produce anesthesia.
• Alcohol was another element of the pre-ether
armamentarium because it was thought to induce stupor
and blunt the impact of pain.

15. Inhaled anesthetics
• Prior to the hypodermic syringe & needle (1855) and
routine venous access, ingestion and inhalation were
the only known routes of administering medicines to
gain systemic effects.
• Ether (1540): Ether was prepared by Valerius Cordus,
and called "sweet oil of vitriol". It was not used as an
anesthetic until 19th C when William Morton (1846), a
Boston dentist, used it.
• Halothane (developed in 1951; released in 1956),
methoxyflurane (developed in 1958; released in 1960),
enflurane (developed in 1963; released in 1973), and
isoflurane (developed in 1965; released in 1981).

16. Nitrous oxide (1772)
• Joseph Priestley in England prepared nitrous oxide but it
was not used as an anesthetic until about 1870.
• Humphrey Davy first noted its analgesic properties in 1800
• Gardner Colton and Horace Wells are credited with having
first used nitrous oxide as an anesthetic

17. Chloroform (1847):
 James Simpson, a Scottish obstetrician, used chloroform
as an anesthetic agent.
 Gained considerable notoriety after John Snow used it
during the deliveries of Queen Victoria (1853) for the birth
of Prince Leopold, thus giving the royal stamp of approval.
 For the next 50 years ether and chloroform dominated the
anesthetic scene.

18. ANCIENT ANESTHESIA
 Status of surgery
– Barber shop surgery
 Type of surgery
–
–
Amputation and dental
extraction
No antiseptic
Appalling mortality
 Indication
Unbearable pain
Crippling deformity
Imminent death

19. WILLIAM T G
MORTON
 First GA was given by
use diethyl ether
 Inventor and Revealer
of inhalational
anesthesia : Before
whom ,in all time
surgery was agony.

20. 1846 (16T H O C T )
 Anesthetist
– William T G Morton
 Agent: Ether
 Patient
– Gilbert Abort
 Operation
– Excision of tumor
under jaw
 Surgeon
– John Collin Warren

21. JOHN SNOW
Use chloroform to deliver
the last two children of
Queen Victoria
First anesthesiologist
Describe the stage of
ether anesthesia
Improve the method of
administration of ether
and chloroform

23. The three components…..
1. Analgesia
2. Hypnosis (amnesia) and
3. Muscle relaxation.
 ???May be Prevention of undesirable autonomic reflex
 Drugs used in anesthesia have varying effect on these
three areas and to be combined to optimize the whole
process of anesthesia.
20

24. A. Hypnosis (amnesia):a state of sleep or unconsciousness
which enable the patient unaware any events
B. Analgesia: Insensitivity to pain + loss of
consciousness.
c. Muscle relaxation: aided by drugs which affect
skeletal muscle function and decrease the muscle tone
by which immobility and relaxation of the skeletal
muscle produced ….surgery will be proceeded at ease.
21

25.  Be Completely reversible.
 Be Safe!...
• Comfort- important
• Safety - essential and must come first.
 Provide good operating conditions.
• E.g. good relaxation for abdominal surgery.
 Be acceptable to the patient. 22
Features of a good anaesthetic

26. Anesthesia Types

27. Anesthesia Types
▸ Local Anesthesia
▸ GeneralAnesthesia
▸ RegionalAnesthesia
▸ Conscious sedation

28. General
Anesthesia

29. obsolete
Total inhalational
anesthesia

30. Total intravenous anesthesia (TIVA) is a
technique of general anesthesia which uses a
combination of agents given exclusively by the
intravenous route without the use of inhalation
agents (Gas Anesthesia)
TIVA

31. Balanced anesthesia
The concept of balanced anaesthesia was introduced by John
Lundy in 1926 and described a combination including
premedication, regional analgesia and general anaesthesia
utilizing one or more agents in order that pain relief was
obtained by a balance of both agents and techniques

32. A drug-induced reversible depression of the CNS
resulting in the loss of response to & perception of
all external stimuli.
Definition

34. First step of GA :Preop evaln, plan of anesthesia
and premedication
 Safe conduction of anesthesia depends on
o Preoperative evaluation,
o Anesthesia plan,
o Monitoring &
o Responding to homeostatic ∆ throughout anesthesia and operation.

35.  The fundamental purpose of preoperative evaluation is
o To obtain pertinent information regarding the patient's current
and past medical history and
o To formulate an assessment of the patient's intraoperative risk
and requisite clinical optimization.

36.  At a minimum, the preanesthesia visit should include
o An interview with the patient to review the medical history
(including medications, allergies, coexisting diseases, and previous
operations),
o An appropriate physical examination,
o Review of laboratory data,
o Consultation with the operating surgical team and/or involvement of
other specialties according the patient’s condition and need, and
o A formulation and discussion of the planned anesthetic with the
patient.

37. To be valuable, performing a preoperative test implies
that an increased perioperative risk exists when the
results are abnormal and a reduced risk exists when
the abnormality is corrected.

38. Following preoperative evaluation and obtaining informed consent an
anesthetic plan should be formulated that will optimally accommodate the
patient's baseline physiological state, including
• Any medical conditions
• Previous operations
• The planned procedure
• Drug sensitivities
• Previous anesthetic experiences, and
• Psychological makeup

39. •  Inadequate preoperative planning & errors in pt
preparation are the most common causes of anesthetic
complications.
 Anesthesia and elective operations should not
proceed until the patient is in optimal medical
condition.

40.  Anesthesia plan may include
o Premedication for anxiolysis (diazepam 5-10 mg orally/IV),
o Prophylaxis of aspiration (metoclopramide 10mg IV/orally,
Cimetidine 200-300mg orally or Ranitidine 150mg orally),
o Drying airway (Atropine 0.5 – 1mg), etc and
o Withholding some drugs like oral hypoglycemic agent

41.  Second step of general anesthesia: Induction and
securing the airway
Induction
 Process of initiating GA(unconsciousness) by
administration of drug or combination of drugs
 The most critical phase in the whole process.

42. Selection of drugs for induction and maintenance of anesthesia depends on
o The patient preexisting condition and
o Type of anesthetic planned.
 Before induction,
o Minimum basic standard monitor should be applied & base line
values are recorded
o Intravenous access should be opened always before anesthesia.

43.  Before administering anesthesia we have to administer 100%
oxygen for 3 to 5 minutes to replace the air which contains 78
% of nitrogen in the FRC of the lungs with oxygen.
 This practice should increase the margin of safety during
periods of UAW obstruction or apnea that may accompany
induction of anesthesia.

44.  Induction of GA can be achieved by
o IV induction agents (e.g., Ketamine 1-2 mg IV or 5- 10 mg IM,
Thiopentone 3-5mg IV & propofol 1-2.5 mg/kg) or
o Inhalation of VAA (e.g., halothane) or combination of both.
 In addition to the induction drug, most patients receive an injection
of narcotic analgesic (e.g., pethedine .5 to 1 mg/kg, Fentanyl1-2
µg/kg).

45. Third step: Maintenance
 It is the time from the end of induction to emergence phase in
which procedures are performed safely.
 Drugs used to initiate the anesthetic are beginning to wear off,
the pt must be kept anesthetized using a maintenance agent.
 For the most part, this refers to the delivery of anesthetic
gases into the patient's lungs.
 These may be inhaled as the patient breathes himself or
delivered under pressure by bagging manually, or each
mechanical breath of a ventilator.

46.  Usually the most stable part of the anesthesia.
 However, it is important to understand that anesthesia is
a continuum of different depths.
 A level of anesthesia and relaxation that is satisfactory
for surgery to the skin of an extremity may be inadequate
for manipulation of the bowel.
 Appropriate levels of anesthesia must be chosen both for
the planned procedure and for its various stages.

47.  If muscle relaxants have not been used, inadequate
anesthesia is easy to spot.
 The patient will move, cough, or obstruct his airway if the
anesthetic is too light for the stimulus being given.
 If muscle relaxants have been used, then clearly the patient is
unable to demonstrate any of these phenomena.
 In these pts, rely on observation of autonomic phenomena
such as HTN, tachycardia, sweating, and capillary dilation.
 Excessive anesthetic depth is associated with decreased HR
& BP, and can jeopardize perfusion of vital organs.

48. Emergence
 Phase of awakening
 Should ideally be smooth and gradual awakening in a controlled
env’t.
 Experience and close communication enable to predict the time at
which the application of dressings and casts will be complete.
 In advance of that time, anesthetic vapors have been decreased or
even switched off to allow time for them to be excreted by the lungs.
 Reverse residual MR using Neostigmine 0.2 – 0.5mg/kg
 Removal of ETT or other airway device when the pt has8s1ufficient

49. Recovery phase
 The patient recovering from anesthesia should be
monitored for common problems postop to ensure their
safety, providing for a smooth and uneventful recovery.
 Common complications may include, Hypoxemia related
to AWObsn or inadequate respn, hypoVx, HN,
hypothermia, pain, nausea and vomiting and ∆HR and
rhythm
 These should be addressed PACU until full recovery of
consciousness and complications are managed.

50.  Documentation
 written relevant information about the patient which contains
o An evidence of client findings,
o Detail of procedure and
o Events happened during the procedure.
 It is an indicator of quality care and is the responsibility of an
anesthetist to record throughout the procedure on time.
 While anesthesia care is a continuum, it is usually viewed as
consisting of preanesthesia, intraoperative/procedural anesthesia
and post anesthesia components.
 Anesthesia care should be documented to reflect these components
and to facilitate review.

51. Regional
Anesthesia

52. Regional anesthesia is an art of
making specific part of the body numb to
relieve pain or allow surgical procedures to
be done
Definition

53. Spinal
anesthesia
It is a massive & temporary interruption of nerve
transmission within the SAS produced by
injection of a LA solution into cerebrospinal fluid to
produce a reversible loss of sensation &
motor function

56. Epidural
anesthesia
It involves the use of LA injected into the epidural
space to produce a reversible loss of
sensation and motor function.

58. IV regional
anesthesia
It is an Injection of LA in to an exsanguinated limb to
produce anesthesia by direct diffusion of
the anesthetic from the vessels in to the nearby nerves.

61. Topical
anesthesia
Application of LA in the form of spray or jelly to the skin,
mucous membrane of the eye, ear, nose and mouth as well
as other mucous membranes to provide effective short term
analgesia.

63. Infiltration
anesthesia
Intradermal & or subcutaneous infiltration or injection
of LA to provide anesthesia for minor surgical
procedures.

65. Field block
anesthesia
Produced by subcutaneous injection of a solution of LA in
order to anesthetize the region distal to the injection. For
example, subcutaneous infiltration of the proximal portion of the
palmar surface of the forearm results in an extensive area of
cutaneous anesthesia that starts 2 to 3 cm distal to the site of
injection.

67. Peripheral
nerve block
Injection of a solution of a local anesthetic into or about
individual peripheral nerves or nerve plexuses produces greater
areas of anesthesia.
Blockade of mixed peripheral nerves and nerve plexuses also
usually anesthetizes somatic motor nerves, producing skeletal
muscle relaxation

70. Conscious
Sedation
Conscious sedation
reduces the
patient’s level of
consciousness. In
this sedation
patient may
response
purposefully to
verbal commands
or light commands.

71. Side Effects of GA
• Temporary confusion and memory loss, although this is more common in
the elderly
• Dizziness
• Difficulty passing urine
• Bruising or soreness from the IV drip
• Nausea and vomiting
• Shivering and feeling cold
• Sore throat, due to the breathing tube
• Unintended intraoperative awareness

72. Side Effects of SA
• Allergic reaction to the anesthesia used.
• Bleeding around the spinal column (hematoma)
• Difficulty urinating.
• Drop in blood pressure.
• Infection in your spine (meningitis or abscess)
• Nerve damage.
• Seizures (this is rare)
• Severe headache.

73. Conscious
Sedation
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