definition of anesthesia, history , general anesthesia, spinal anesthesia, epidural anesthesia, uses, drug agents, complications and management.

1. Dr. Poonam arya
BAMS ,MS 2nd year
(shalya tantra deptt.)
skgac kurukshetra

2. Anesthesia : defination
 . Anesthetic, also spelled anaesthetic, any agent that
produces a local or general loss of sensation,
including pain. Anesthetics achieve this effect by acting on
the brain or peripheral nervous system to suppress
responses to sensory stimulation. The unresponsive state
thus induced is known as anesthesia. General
anesthesia involves loss of consciousness, usually for the
purpose of relieving the pain of surgery. Local anesthesia
involves loss of sensation in one area of the body by the
blockage of conduction in nerves.

3. HISTORY OF ANESTHESIA
 The Wood Library-Museum of Anesthesiology (WLM)
presents an interactive timeline of the history of anesthesia
and the profession of anesthesiology through important
milestone people, places, dates and developments.
 While the use of opium poppy, moha churna , alcohol
and other herbal remedies as anesthetics date back to early
civilization(described in sushruta samhita) , the first public
demonstration of modern anesthesia was on October 16,
1846 ("Ether Day"). William T. G. Morton and surgeon John
Collins Warren made anesthesia history at Massachusetts
General Hospital with the successful use of diethyl ether
"anaesthesia" to prevent pain during surgery. Since this
historic milestone, advancements in anesthesia
administration and newer anesthetics led to the medical
specialty of anesthesiology in the early 20th century.

4. ANESTHESIA
10 golden rules
 Mnemonic: ANESTHESIA
 A: Assessment and preparation of patient.
 N: Nil per oral.
 E: Equipment and drugs checked.
 S: Suction working.
 T: Tipping table.
 H: Have a vein open.
 E: Evaluate vitals.
 S: Somebody to help.

5. Examination
Investigations & Assessment
 Examination
 General
 A general systems examination should identify obvious
abnormalities:
 Cardiovascular system - heart murmur. With the exception of
emergency surgery, patients should be haemodynamically stable
and their vital signs normal before starting anaesthesia.
 Respiratory system - abnormal breath sounds.
 Gastrointestinal system - abdominal masses, previous scars.
 Musculoskeletal system - skeletal malformations such as
kyphoscoliosis.
 General - local skin infection

6. Airway assessment
How easy or difficult it will be to intubate a patient depends on
the following points:
Are they obese?
Do they have a short neck and small mouth?
To what extent can they open their mouth?
Is there anft tissue swelling at the back of the mouth or are there
any limitations in neck flexion or extension?y so
 Investigations
 Cbc, blood sugar , blood urea. Serum creatinine,
electrolytes, chest x ray , ecg , blood grouping , BT, CT,
blood gas analysis, cardic assessment , lft , kft, cross match
,ecg, spirometry , pregnancy test .

7. Scoring to assess intubation:
Mallampati scoring :

8. Preoperative treatment:
 Control of respiratory and cardiac disease.
 Improvement of hb% , if anaemia is present .
 Preoperative antibiotics are given .
 Blood should be kept ready for major cases.
 Starvation for 4 hours for liquids and six hours for solids.
 Bladder and bowel should be empited to prevent soiling on
the operation table . Urinary catheter may be passed and
enema may be given .
 Dantures , jewellery, contact lenses must be removed .
 Analgesic, anti-emetic , sedative should be given as per
requirements.

9. Genral anaethesia
 It means abolition of all sensation, i.e. Touch, pain ,
posture and temperature with a state of reversible loss of
consciousness. It has got three components ; analgesia ,
hypnosis , muscle relaxation.
Instruments used in GA:
 The respirator bag valve mask.
 Anesthesia machine.
 Oxygen mask.
 Laryngoscope.
 Tracheostomy tube.
 Tuohy needle.
 Flexible Endoscope.
 Syringe.

10. 1 Intravenous anaesthetics
2 gaseous anaesthetics
-etomidate-lipura (Anaesthetics only)
-ketamine (Anaesthetics, A&E,
Palliative Care Team and Acute Pain
Team only)
-propofol (Anaesthetics and ICU only)
-propofol-lipura , thiopental sodium
and desflurane .
Nitrous oxide and cyclopropane .
Anaesthetic agents :
3 Inhalational anaesthetics enflurane (Anaesthetics only)
halothane (Anaesthetics only)
isoflurane (Anaesthetics only)
sevoflurane (Anaesthetics only)
4 Muscle relaxants -rocuronium
- suxamethonium (Anaesthetics, ICU and
Neonatal directorate only)
-vecuronium (Anaesthetics, ICU and
Neonatal directorate only)
-edrophonium ,neostigmine, doxapram

11.  Stages of anaesthesia:
Guedel's classification, introduced by Arthur Ernest
Guedel in 1937,[22] describes four stages of anaesthesia. Despite
newer anaesthetic agents and delivery techniques, which have led
to more rapid onset of—and recovery from—anaesthesia.
 Stage 1, called Induction, is the period between the
administration of induction agents and loss of consciousness.
Patients can carry on a conversation at this time.
Stage 2 called Excitement stage, is the period following loss of
consciousness and marked by excited and delirious activity.
During this stage, the patient's respiration and heart rate may
become irregular. In addition, there may be uncontrolled
movements, vomiting, suspension of breathing, and pupillary
dilation. Because the combination of spastic movements,
vomiting, and irregular respiration may compromise the patient's
airway, rapidly acting drugs are used to minimize time in this stage
and reach Stage 3 as fast as possible.

12. Stage 3, also known as surgical anaesthesia, the skeletal
muscles relax, vomiting stops, respiratory depression occurs,
and eye movements slow and then stop. The patient is
unconscious and ready for surgery. This stage is divided into
four planes: The eyes roll, then become fixed;
 Corneal and laryngeal reflexes are lost;
 The pupils dilate and light reflex is lost;
 Intercostal paralysis and shallow abdominal respiration occur.
Intercostal paralysis and shallow abdominal respiration occur.
Stage 4, also known as overdose, occurs when too much
anaesthetic medication is given relative to the amount of
surgical stimulation and the patient has
severe brainstem or medullary depression, resulting in a
cessation of respiration and potential cardiovascular collapse.
This stage is lethal without cardiovascular and respiratory
support.

13. Premedication : for reduce vomiting – promethazine 12.5mg.
for sedation& anxiety –pethidine 50mg/.
 Induction- Patient is preoxygenated with 100%
oxygen for 3 minutes then induced with Iv
thiopentone, given 4-5mg/kg. Patient loses
consciousness. Induction is maintained by 67%
nitrous oxide and 33% oxygen.
 Scoline is given IV relax muscles so as to facilitate
endotracheal intubation.
 Once intubated, ventilation can be either controlled
using one muscle relaxants or spontaneous using a
volatile anaesthetic agent.
 Reversal is done using neostigmine and atropine or
glycopyrrolate.

14. complications of
general anaesthesia
Post operative care
 Pain, hypoxia ,
pneumothorax.
 Nausea and vomiting - up to
30% of patients.
 Damage to teeth.
 Sore throat and laryngeal
damage.
 Anaphylaxis
to anaesthetic agents -
approximately 1 in 3,000.
 Cardiovascular collapse.
 Respiratory depression
 Mendel son's syndrome.
 Pulse, temp. ,Bp chart.
 Level of consciousness.
 Urine output.
 Care of respiratory system
 Oxygen therapy.
 Pulse oxymetry.
 Monitoring of the patient.
 Cardiac monitoring.
 Blood gas analysis in case of
patient on ventilator.
 Serum electrolyte
assessment.

15.  Regional anesthesia is the use of local anesthetics to block
sensations of pain from a large area of the body, such as an arm or
leg or the abdomen. Regional anaesthesia allows a procedure to be
done on a region of the body without your being unconscious.
 Advantages: technically simpler.
 GA is avoided & consciousness is retained.
 Drugs used- cocaine, procaine, lignocaine-amino esters.
 Lignocaine, prilocaine, bupivacaine ,ropivacaine-amino amides.
 Topical anasthesia: it is defined as superficial loss of sensation
in conjunctiva, mucous membranes, or skin, produced by direct
application of local anaesthetic solutions, ointments, gels or
sprays.
 Infiltration block- direct inj. of local anaesthetic under the skin
for small procedure.
 Field block: it is achieved by blocking the entire field of excision
where lesion is located.
 Nerve block, or neural blockade, is a method of producing
anesthesia — a loss of feeling used to prevent or control pain.
Nerve blocks can be surgical or nonsurgical.

16. Spinal anaesthesia (or spinal
anesthesia), also called spinal
block, subarachnoid
block, intradural
block and intrathecal block,[1] is
a form of neuraxial regional
anaesthesia involving
the injection of a local
anaesthetic or opioid into
the subarachnoid space, generally
through a fine needle, usually 9 cm
(3.5 in) long.
 Types-caudal (up to L5).
 Low spinal ( up to L1).
 Mid spinal(up to T10).
 High spinal( up to T6).
 Unilateral spinal.

17. Advantages: Disadvantages&
complications
 economical.
hypotension
reduces the
bleeding.
 Adequate
relaxation is
achieved.
 Respiratory
complications
are less.
 Failure of the spinal.
 Pain during the injection.
 Low blood pressure.
 Headaches.
 Itching.
 Difficultly passing urine.
 Backache
 Complication-meningism &
infection.
 Bradycardia.
 Nausea and vomiting.
 Transient
neurological symptoms (lower back
pain with pain in the legs).
 Post-dural-puncture headache.

18. Epidural anasthesia :
 It is a potential space between Dura anteriorly and
ligamentum flavum posteriorly which has got negative
pressure inside. It extends from foramen magnum to
sacral hiatus. Toughy needle is used for epidural
anaesthesia. Once the needle is in space there will be
sudden indrawing of air and saline drop.
 A epidural catheter is placed in the space and fixed . 2%
xylocaine with adrenaline or 0.5% bupivacaine is
injected into space to achieve anathesia up to desired
level.
 advantages : it can be used for continuous repeated
prolonged anaesthesia.
 It can be used for postoperative analgesia.
 It can be kept for several days.

19. Thankyou