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Monitoring of muscle relaxation is most easily provided by means of a
peripheral nerve stimulator.
This device intermittently sends short electrical pulses through the skin over
a peripheral nerve while the contraction of a muscle supplied by that nerve is
observed. The effects of muscle relaxants are commonly reversed at the
termination of surgery by anticholinesterase drugs.
Intubation is the placement of a tube into an external or internal orifice
of the body.
In tracheal intubation, an endotracheal tube is passed through the nose
or mouth, through the larynx, and into the trachea.
In anesthetized patients spontaneous respiration may be decreased or
absent due to the effect of anesthetics, opioids, or muscle relaxants.
To enable mechanical ventilation, an endotracheal tube is often used,
although there are alternative devices such as face masks or
laryngeal mask airways.
In comatose or intoxicated patients
 Diagnostic manipulations of the airways such as bronchoscopy
Endoscopic operative procedures to the airways such as
laser therapy or stenting of the bronchi
Intensive care medicine for patients who require respiratory support
Emergency medicine, particularly for cardiopulmonary resuscitation
patient is comatose (unconscious)
or under general anesthesia.
 tube is then inserted under
Direct observation
when there is a risk of aspiration.
short acting narcotic is
administered
Thereafter by a paralytic such as
succinylcholine.
Another alternative is intubation of the awake patient under
local anesthesia using a flexible endoscope.
This technique is preferred if difficulties are anticipated,
as it allows the patient to breathe spontaneously throughout the
procedure, thus securing oxygenation even in the event of a
failed intubation.
Typically for patients who require long-term respiratory support
An emergency technique used when intubation is unsuccessful and
tracheotomy is not an option.
This is a last resort procedure that can only provide a minimum of oxygen
to the patient; therefore intubation or tracheotomy must subsequently
be performed.
 Free from toxic effects.
 Non irritant & Free from unpleasant taste and smell
 Act rapidly & produce smooth induction and recovery and rapid
excretion.
 High Potency.
 Produce complete muscle relaxation and not increase capillary
bleeding time.
 Cheap and Stable on storage
Delivered using an anaesthesia machine.
Machine allows composing a mixture of oxygen,
anaesthetics and ambient air, delivering it to the patient and
monitoring patient and machine parameters
 Liquid anaesthetics are vaporized in the machine
Desflurane
Often combined with nitrous oxide
Sevoflurane
Isoflurane
Halothane
Enflurane
 Inorganic General anaesthetic,
 Used as a component of “Balanced Anaesthesia”
 Non explosive inert gas
 Rapid onset and short duration of action
 Poor muscle relaxant
 Causes Hypoxia if concentrations greater than 80% used
USES
Induction of Anaesthesia.
Supplemental maintenance.
Production of Analgesia.
ADMINISTRATION
 By Inhalation in Oxygen mixture.
 FOR ANALGESIA 20-50% Used in brief surgical or Dental
procedures or Obstetrics
 FOR BALANCED ANAESTHESIA 50-70% used to prolong the
Anaesthetic state
 FOR RAPID INDUCTION 80% or occasionally higher for short
durations
 Dizziness , vivid dreams and hallucinations.
 Hypoxia, Cyanosis
 Convulsions,
 Bone marrow depression.
 Myocardial and Respiratory depression.
 Diffusion Hypoxia caused by the rapid outward diffusion of
N2O from tissues into the blood stream, then into the alveoli in
turn lowering arterial oxygen levels.
 High Partial pressure in blood and low blood gas partition
coefficient causes diffusion into air containing body cavities.
Administered by inhalation of the vapors
along with adequate amounts of Oxygen.
Depth of Anaesthesia can be controlled
fairly well
Recovery begins as soon as the drug is
stopped as most drugs are excreted by the
lungs.
 Good safety margin.
Excellent skeletal muscle relaxant.
Minimal effects on C.V.S.
Substantial analgesic effect.
DISADVANTAGES
 Noxious odour
 Slow and unpleasant induction.
 Respiratory irritation.
 Prolonged emergence.
 Increased salivary and bronchial secretions.
 Post-operative nausea and vomiting.
• DISADVANTAGES
ADVANTAGES
• Hence rarely used Nowadays
 Volatile liquid anaesthetic.
 Potent, Non-Flammable, pleasant smelling.
 Non irritating to the lungs, Dilates the
bronchioles.
 Does not increase Salivary and bronchial
secretion.
 Used with Nitrous Oxide to reduce the
concentration of Halothane needed.
Is a Myocardial depressant
Cardiac output, contractile force and blood
pressure are decreased.
Sensitizes the Myocardium
USES
 Induction and Maintenance of anaesthesia
DOSAGE
 FOR INDUCTION—
1-4%
 FOR MAINTAINENCE— 0.5-1.5%
ADVERE REACTIONS
 Rapid shallow respiration, slight fall in Blood
Pressure, Transient Bradycardia.
 Cardiac arrhythmias.
 Hepatitis
 Malignant hyperthermia.
PRECAUTIONS
 Potent uterine relaxant ,hence, not used for Obstetrical
anaesthesia.
 Contraindicated in active Hepatitis and Biliary Diseases.
INTERACTIONS
 Potentiates action of non-depolarizing skeletal muscle
relaxants(Gallamine,Pancuronium) and ganglionic blockers
Widely used
Rapid induction and recovery.
Non-Flammable.
Better Muscle relaxation.
 Increases salivary and Bronchial secretions.
 Profound respiratory depression.
 Seizures in children.
 Liver damage.
USES
Induction and Maintenance of anaesthesia
DOSAGE
FOR INDUCTION—
2-- 4.5 %
FOR MAINTAINENCE— 0.5--3%
85—90% Excreted through Lungs, rest via
Kidneys
ADVERSE REACTIONS
Slight Hypotension
Spasms, Tremors and Convulsions
with prolonged use.
Fluorinated congener of Isoflurane
Nonflammable
Stable in Carbon dioxide
Non corrosive to Metals.
Provides controlled anaesthesia.
Rapid onset and rapid recovery.
Lowers Blood Pressure in dose-dependant
manner
Specially useful in “ambulatory surgery”.
Ultra short
acting
Methohexital
Thiamylal
Thiopental
Rapid onset and
short duration of
action
15-30 minutes
Rapid-Acting
Dissociative
Ketamine
Droperidol
Etomidate (Amidate)
Onset is in 1 Minute
and persists for 3-5
minutes
ADVANTAGES
 Rapidity and smoothness of onset.
 Absence of salivation; greater patient acceptance.
 Short duration of action;
better control.
 Speedy recovery.
 Non-Flammability.
 Absence of bronchial irritation.
 Little danger of Cardiac Arrhythmias.
DISADVANTAGES
 Higher incidence of Respiratory & circulatory
depression.
 Laryngospasm.
 Bronchospasm.
 Tissue necrosis if leakage occurs.
 Cumulative toxicity on repeated administration.
 Depress the CNS producing hypnosis & anaesthesia without
analgesia.
 Muscle relaxation is inadequate.
 Dose dependant respiratory depression.
 Depression of Myocardium, decrease Cardiac output and lower
Blood pressure.
 Decrease the Hepatic blood flow and the GFR.
USES
 Induction of Anaesthesia.
 Supplementation of other Anaesthetics.
 Anaesthesia for Short duration procedures.
 Induction of Hypnosis.
 For Narcoanalysis & Narcosynthesis.
FATE
 Induction is smooth and rapid.
 Onset within 30 – 60 seconds.
 Quickly crosses the Blood-Brain barrier.
 Redistributed first to the highly vascular organs.
ADVERSE REACTIONS.
 Dose – dependant respiratory depression.
 Laryngospasm, coughing and Yawning.
 Myocardial and circulatory depression.
 Headache, delirium, allergic reactions.
 Nausea , vomiting, shivering.
PRECAUTIONS
 Absolutely contraindicated in Latent or manifest Porphyria.
 Absence of suitable vein for IV administration.
 Contraindicated in Status Asthamaticus.
 Additive CNS depressive effects can occur.
 Produces rapid hypnosis but is not an analgesic.
 No effect on Heart rate and Cardiac output.
 Cerebral blood flow slightly reduced.
 Respiratory depression is minimal.
USES
 Induction of General Anaesthesia.
 Supplemental Anaesthesia.
 Prolonged sedation of critically ill patients.
DOSAGE
 FOR INDUCTION: 0.2 – 0.6 Mg/Kg IV over 30 – 60 secs.
 FOR MAINTAINENCE: 0.1 - 0.3 Mg/Kg IV with Nitrous Oxide and
Oxygen.
FATE
 Onset within a minute.
 Effects persists for 3 – 5 mins.
 Rapidly metabolized in the Liver
 Primarily excreted by the Kidneys.
ADVERSE REACTIONS
 Hypotension, Tachycardia, Arrhythmias
 Laryngospasm.
 Hiccups, nausea, vomiting.
 Venous pain, Myoclonic skeletal muscle movements.
 Tonic muscle activity, Eye movements.
 Embryocidal activity.
 DISSOCIATIVE ANAESTHESIA IS A STATE IN WHICH
ANAESTHETISED PATIENT FEELS TOTALLY DISSOCIATED
FROM THE SURROUNDINGS
 Used in situations when an anesthesia-like
state is desired but not unconsciousness.
 Used alone or with other anesthetic or analgesic
 Examples are KETAMINE & FENTANYL.
 Rapid- acting producing a state of dissociation.
 Patient appears awake but does not respond to pain and has
amnesia on recovery.
 Actions presumed to be due to interruption of association
pathways.
 Has a wide margin of safety
 Emergence is prolonged and with psychological manifestations
ranging from pleasant to disagreeable
USES
 Procedures not requiring muscle relaxation like treatment of
burns.
 Induction of Anaesthesia.
 Supplementation of low potency agents like Nitrous Oxide.
DOSAGE
 Available in 3 strengths(10mgs,50mgs & 100 mgs)
 For Induction: 1 – 4.5 mgs/kg IV over 60 seconds or
6.5 – 13 mgs/kg IM
 To maintain: One half of the induction dose is repeated as
needed.
 Innovar is a drug combination of a narcotic analgesic Fentanyl
and a neuroleptic Droperidol.
 Produces Neuroleptanalgesia, a state in which conciousness
is not lost, but the anxiety of the patient is allayed.
 Ability to perceive pain is reduced or abolished.
 Addition of Nitrous Oxide to this combination produces
Neuroleptanaesthesia.
USES
 Production of Tranquilization and analgesia for diagnostic and
minor surgical procedures.
 Anaesthetic premedication & Induction of Anaesthesia.
 Adjunct of general anaesthesia.
DOSAGE
For Premedication: 0.5 – 2.0 ml 45 – 60 mins before surgery.
For Induction: 1 ml / 20-25 Lbs body weight by slow IV.
Diagnostic: 0.5 – 2.0 ml 45 – 60 mins before the procedure.
IT IS BETTER TO STAY HEALTHY AND AVOID
SURGERY THAN TO GO UNDER THE KNIFE
WITH ALL THE PROBLEMS WITH THE
ANAESTHESIA AND SURGERY.
HOPE YOUR ARAS IS
FUNCTIONING WELL BY NOW &
HAVE A GREAT DIWALI !!!!