Types of Anaesthesia

PPT PREPARED BYDR RAJESH T EAPEN

ATLAS HOSPITALRUWI

Sushruta 800B.C. wrote first Surgery textbook

Anesthesiology

Making SurgeryPainless

Anesthesia From Greek anaisthesis

means not sensation Listed in Bailey´s English

Dictionary 1721. When the effect of ether was

discovered anesthesia” used as a name for the new phenomenon.

Oxford dictionary definition

insensitivity to pain, especially as artificially induced by the administration of gases or the injection of drugs before surgical operations

World Anesthesia Day 16th Oct

HISTORY OF ANESTHESIA• General anesthesia was absent until the

mid-1800s.• Ether synthesized in 1540 by Cordus• Ether used as anesthetic in 1842 by Dr.

Crawford W.Long• Ether publicized as anesthetic in 1846 by

Dr. William Morton. • Ether is no longer used in modern

practice, yet considered to be the first ‘ideal’ anesthetic

• Chloroform used as anesthetic in 1853 by Dr. John Snow

• Endotracheal tube discovered in 1878• Thiopental first used in 1934

Pre 1846 - The Foundations of Anaesthesia

……..so the Lord God caused him to fall into a deep sleep. While the man was sleeping, the Lord God took out one of his ribs. He closed up the opening that was in his side……...

Genesis 2:21 NIrV

Primitive Anesthesia

Ancient civilizations- opium poppy, coca leaves, mandrake root, alcohol

Regional anesthesia in ancient times- compression of nerve trunks or the application of cold (cryoanalgesia)

World Anaesthesia Day On 16 October 1846,

John Collins Warren removed a tumor from the neck of a local printer,Edward Gilbert Abbott. Warren reportedly quipped, "Gentlemen, this is no humbug.

MGH Boston

Regional Anaesthesia

1884 Sigmund Freud physiology actions cocaine

Carl Koller cocaine ophthalmological surgery

Birth of modern Anaesthesia 1913,Chevalier Jackson-use of

direct laryngoscopy as a means to intubate the trachea

Sodium Pentathal - first used in humans on 8 March 1934 by Ralph M. Waters

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History 1845- Horace Wells- N2O 1846- William Morton-

Ether 1847- Simpson-

Chloroform 1853-John Snow 1878- ETT 1884- Cocaine 1895-98- Spinal

analgesia/anaesthesia

Types Of Anesthesia

Types

.

Triad of General anaesthesia

Hypnosis

Analgesia Muscle relaxation

CLASSIFICATION:

18

General anaesthetics

Inhalational Intravenous

INTRODUCTION• General anaesthetics (GAs) are drugs which

produce reversible loss of all sensations and consciousness. It usually involves a loss of memory and awareness with insensitivity to painful stimuli, during a surgical procedure

General anesthesia

need for unconsciousness‘Amnesia-hypnosis’

need for analgesia‘Loss of sensory and autonomic reflexes’

need for muscle relaxation

General anesthetics

Amnesiasedation

Hypnosis

Coma

Death

Awake

Hypnosis

Hypnotic drugs-intravenous

Gold standard- thiopentone Propofol others Etomidate Benzodiazepines Ketamine

Inhalational anaesthetics

Nitrous oxide-weak Isoflurane Sevoflurane Desflurane Halothane

Analgesia Good analgesia= good

anaesthesia Hypnotic sparing effect Opiates Local anaesthetics NSAIDS Paracetamol

Analgesia-Opiates Gold standard – morphine Derivatives- diamorphine,

codeine Synthetic agents- Pethidine- Fentanyl/Alfentanil-short

acting- Remifentanil-ultra short

acting

Analgesia-NSAIDS Gold standard- aspirin Ibuprofen Diclofenac Cox-2 inhibitors

Muscle relaxation Aids intubation Helps surgeon/surgery Surgery of long duration Reduces maintenance dose

of anaesthetics agents

Muscle relaxants

Two types Depolarising-short acting e.g.; suxmethonium Non-depolarising-

medium/long acting- Tracurium- Vecuronium- Rocuronium- Cisatracurium (NIMBEX)

Prerequisites Oxygen Suction Tilting trolley Resuscitation drugs Monitoring Anaesthetist Skilled assistance Drugs and machine

The 21 st century-digital revolution

Phases of general anaesthesia

Induction Maintenance Recovery

Induction Intravenous- majority Inhalational- children, needle

phobics Monitoring Preoxygenation Hypnotic/analgesic and or

relaxant Mask/LMA/ET tube

Maintenance Intravenous or inhalational Oxygen –40%-100% Nitrous oxide Muscle relaxant Analgesia

Recovery Turn off agent Reverse relaxation Cough reflex Extubate when awake Recovery position Monitor until discharge

Advantages No absolute contraindications Quick to establish Never fails to work

Disadvantages Poly-pharmacy Effects on various systems Allergic reactions Recovery profile Post operative Nausea

&Vomiting Awareness

Providing operative conditions

Regional anaesthesia Spinal/epidural- surgery below umbilicus- Provides analgesia/muscle

relaxation Plexus blocks eg brachial

plexus Intravenous- Bier’s block

40

Spinal Block - Position

Regional anaesthesia

Analgesia Muscle relaxation

Local anaesthetics Lignocaine- quick/short

acting Bupivacaine/

levobupicvacaine- slow and long action

Ropivacaine- as above Amethocaine- topical Prilocaine- intravenous

Advantages Effective alternative to GA Avoids polypharmacy Allergic reactions Extended analgesia Patient can remain awake Early drink/feed

Disadvantages Limited scope Higher failure rate Time constraints Anticoagulants/Bleeding

diathesis Risk of neural injury

Patient is more important than our ego; call for help, whenever patient is in dangerYour Text here

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Choice of anesthesia The patient´s understanding and wishes regarding the

type of anesthesia that could be used The type and duration of the surgical procedure The patients´s physiologic status and stability The presence and severity of coexisting disease The patient´s mental and psychologic status The postoperative recovery from various kinds of

anesthesia Options for management of postoperative pain Any particular requiremets of the surgeon There is major and minor surgery but only major

anesthesia

Types of anesthesia careGeneral Anesthesia

Reversible, unconscious state is characterised by amnesia (sleep, hypnosis or basal narcosis), analgesia (freedom from pain) depression of reflexes, muscle relaxation

Put to sleep

Types of anesthesia care Regional Anesthesia

A local anethetic is injected to block or ansthetize a nerve or nerve fibers

Implies a major nerve block administered by an anesthesiologist (such as spinal, epidural, caudal, or major peripheral block)

Types of anesthesia careMonitored anesthesia care

Infiltration of the surgical site with a local anesthesia is performed by the surgeon

The anasthesiologist may supplement the local anesthesia with intravenous drugs that provide systemic analgesia and sedation and depress the response of the patient´s autonomic nervous system

Types of anesthesia carelocal anesthesia

Employed for minor procedures in which the surgical site is infiltrated with a local anesthetic vital signs

May injsuch as lidocaine or bupivacaine A perioperative nurse usually monitors

the patient´s ect intravenous sedatives or analgesic drugs

Thank you

Macintosh noted: “for the surgeon the spinal ends with the injection of the agent; for the anesthetist it begins with the injection of the agent.”