2. Learning Objectives
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• Differentiate among local, Regional and general anesthesia.
• Mention the routes of administering local anesthesia.
• Identify two methods of administering general anesthesia.
• Manage the adverse effects of local anesthesia.
• Identify the stages of general anesthesia.
3. Principles of anesthesia
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⦁ AnesthesiaIs the absence of sensationwhich may be produced
in Specific body area or systemically.
⦁ Anesthesiology –Branch of medicine concerned with the
administration of anesthetic agent to relieve pain and support
physiologic function during a surgical procedure.
4. Principles of anesthesia…
Common terms in anaesthesia
Analgesia- lessening sensitivity to pain (Pain relief without loss
of feeling or movement)
Anastasia – loss of feeling or sensation of pain
Anaesthetic- drug that induce loss of sensitivity
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5. Common terms…
Anaesthetist- person who trained to administer anaesthesia
Anaesthesiologist- medical doctor who trained to administer
anaesthesia
Anoxia –absence of oxygen
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6. Common terms…
• Hypnosis - a state of altered consciousness
• Hypnotic – a drug that induces sleep
• Assisted respiration - the maintenance of adequate
alveolar ventilation by supplementing the patients
respiration by manual or mechanical means.
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7. Common terms…
• Apnea - cessation of breathing
• Induction - period from administration up to loss of
pain
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9. A) Local anesthesia
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• Used to numb a small site for minor procedures
• They act on afferent nerve fibers –more on nociceptors
• Prevents generation and conduction of action potential
• It acts on a single nerve, a group of nerves or on superficial
nerve endings and blocks the conduction of pain.
• During all types of local anesthesia, the patient remains conscious
10. A) Local anesthesia
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⦁ Examples of local anesthesia
⦁ Lidocaine –Has rapid induction, good penetration
⦁ Bupivacaine –has slow onset, long duration,
commonly used in long surgeries,
medium tissue
has high cardio
penetration,
toxicity.
11. A) Local anesthesia
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⦁ Advantages:
⦁ It needs minimal and simple equipment
⦁ Loss of consciousness doesn’t occur
⦁ It doesn’t need fasting/NPO
⦁ Surgeon can administer with out anesthesiologist
12. A) Local anesthesia…
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⦁ Contra indication to local anesthesia
⦁ Allergic sensitivity
⦁ Local infection
⦁ Septicemia
⦁ Hypertension
13. A) Local anesthesia…
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⦁ Local anesthesia can be given in different ways
⦁ Local infiltration
⦁ Nerve block
⦁ Topical
14. 1) Local infiltration
The agent is injected intracutaneously and subcutaneously into
tissues at and around the incisional site to block peripheral
sensory nerve stimuli at their origin.
The surgery should not be extensive
• It is used to suture superficial lacerations or for excision of
minor lesions
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15. Local infiltration…
Adrenaline is added to prolong anesthesia & minimize local
bleeding
Addition of Adrenaline (Epinephrine) to the anesthetic agent
causes vasoconstriction to slow circulatory uptake and
absorption, thus prolonging anesthesia
Use a calibrated syringe to avoid over dosage
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16. Local infiltration…
• The patient receiving Adrenaline should be well oxygenated
• Agents with Adrenaline are contraindicated for operative
procedures involving fingers and penis
• High levels of local anesthetic are toxic
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17. Local infiltration…
Administration of it takes place as part of the sterile
procedure - use sterile needle and syringe.
When highly vascularized areas are to be injected,
epinephrine is sometimes added to the anesthetic (to
minimize local bleeding, prolong the effect of the agent).
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19. A) Local anesthesia…
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2) Nerve block
• Anesthesia of a large single nerve or nerves
• Injection is done not necessarily at the immediate surgical
site.
• The nerve supplying body part is anesthetized
• Commonly used in surgery that is performed on fingers and
toes.
21. A) Local anesthesia…
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3) Topical
• Used to numb superficial nerve endings particularly those of the
mucous membranes
• The agent may be swabbed, sprayed or applied in drops as for eye
surgery
• Useful in preparing the patient for endoscopic procedures, such as
bronchoscopy and esophagoscopy.
22. B) Regional Anesthesia
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Is use of local anesthetics to block sensations of pain from large
area of the body like arm, leg or abdomen
It is Method of blocking of nerve impulses before they reach the
central nervous system in order to induce analgesia.
Before performing conduction block, full facilities for
resuscitation should be available
23. Cheap
High Patient Satisfaction
Maintain Patent Airway
Decreased blood Loss
Selective Muscle Relaxation
Decreased Incidence of DVT & PE
B) Advantage of regional Anesthesia
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24. Hypotension
Risk of toxicity
Many patients prefer to be asleep
Skills are required
Patient Can talk
Patient Anxiety
Not Reliable for Surgery > 2 hours
B) Dis adv. of regional Anesthesia
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25. Regional Anesthesia…
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between spinal fluid and anesthetic).
• The patient should be closely watched
C
1
N
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S,CVS,RS…
1) Epidural
• The agent is Introduced into the epidural space of the spine
• The agent baths the nerve roots of the spinal cord and the area supplied
by these nerves is anesthetized
• The anesthetic is injected outside the spinal canal (no direct contact
because anesthetics affect
27. 2) Spinal anesthesia
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• Anesthetic agent is injected into the subarachnoid space at the 4th or
5th lumbar interspace.
• Anesthetic agent does come into contact with the spinal fluid
⦁ Used for surgery of the lower pelvis, such as cesarean section
or hernia repair; lower extremities.
• It has risk of infection in the spinal canal if the puncture site
is contaminated.
30. 2)Spinal anesthesia…
1. Common position for spinal anaesthesia
• Lateral position- the most common
• Prone position
• Sitting position
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31. Anesthetic agent Uses Duration of
action
Dosage
Bupivacaine hydrochloride Local
Regional block
epidural
2-3hr 400mg
Procaine hydrochloride Infiltration
Spinal nerves
¼- ½ hr. 100mg or
14mg/kg)
Cocaine hydrochloride Topical ½ hr. 200mg(4mg/kg)
Lidocaine
hydrochloride(xylocaine)
Topical
Infiltration,
peripheral nerve,
nerve block,
spinal, epidural
½- 2hr 200mg
500mg or
7mg/kg
Tetra Caine hydrochloride Topical
Spinal
2-4 hr 20mg
Common Local and regional Anesthetic Agents
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32. Adverse reactions to local anesthesia
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⦁ Stimulation: patient may become very talkative or anxious, signs
of tachycardia, thready pulse, convulsion.
⦁ Depression: patient may appear sleepy and unresponsive,
bradycardia, hypotension.
⦁ Other signs: patient may develop cyanosis, sweating, feel cold,
restless (signs of shock),dizzness,headaches, blurred vision etc..
33. Treatment of the Reaction
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• Discontinue the anesthetic immediately
• Oxygen administration may be needed
• Cardiopulmonary resuscitation is initiated, if necessary.
34. C) General Anesthesia
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• Causes unconsciousness, provides analgesia and muscle
relaxation
• A combination of different anesthetic agents is frequently used
to achieve the desired level of muscle relaxation and analgesia.
• Intravenous and inhaled gases may be used
• It is medically induced coma
36. 1) Induction
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• Is a period when the patient goes from consciousness to
unconsciousness.
• Lasts until the patient is unconscious
• During this phase, the patient retains an exaggerated sense of hearing
⦁ so it is mandatory to remain as quiet as possible during induction.
37. 2) Excitement
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• During this phase, the patient is deliriousand sensitive to
external stimuli
• Involuntary muscle activity and struggle may be seen
• The critical phase for different adverse events
• Thrashing, vomiting, laryngospasms and dysrhythmias
• Patient is physiologically unstable
38. 3) Relaxation(surgical phase)
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• In this stage there is gradual loss of muscle tone and reflex.
• This phase is the level at which surgery may be performed safely.
⦁ The patient is relaxed, unconscious of pain and is
physiologically stable
• Breathing is steady and automatic
• This phase ends at its deepest level with respiratory paralysis.
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4) Danger
⦁ This stage begins when the amount of
depression of the central nervous system
immediate danger of cardiopulmonary arrest.
agent causes severe
that the patient is in
40. Methods of Administering General Anesthesia
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⦁ 1) Inhalation
• In this case the anesthetic agent is administered by
anesthesia machine
• The most controllable method in the up take and elimination
of anesthetic agent
• Are mainly accomplished by pulmonary ventilation
• The blood and lungs functioning as the transporting system
41. Inhalation…
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⦁ The techniques of inhalation anesthetic used are:
⦁ A) Mask inhalation: in closed system of anesthetic machine. Excess
carbon dioxide is absorbed by soda lime.
⦁ B) Endotracheal administration: inhaled in the trachea through nasal or
oral tube insertion
⦁ Intubation: insertion of tube directly in to the trachea
42. Inhalation anesthetic agents
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• Few side effect except headache, Vertigo and drowsiness
• Excellent analgesia for minor operation
⦁ Disadvantage
• Poor relaxation, excitement, laryngospasm and hypoxia
⦁ Nitrous oxide(N2O)
• Comfortable, rapid
irritating
induction and recovery, non toxic and non
43. Inhalation anesthetic agents …
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⦁ Cyclo propane
⦁ Very potent gas very seldom used, highly explosive
⦁ Advantage
⦁ Pleasant, rapid induction, moderate relaxation, support circulation
⦁ Disadvantage:
⦁ Flammable, explosive
44. Inhalation anesthetic agents …
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⦁ Halothane (fluothane)
⦁ Volatile liquids ,very widely used, Has a pleasant odor
⦁ Advantages:
⦁ Non flammable, potent ,chemically stable, rapid induction
⦁ Non-irritating for respiratory tract, doesn’t stimulate
respiratory secretion
⦁ Useful for patients with bronchial asthma
46. 2) Intravenous (IV) and intramuscular (IM) administrations
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• Injections are also used in general anesthesia.
• Liquid agents may be administered directly into the blood stream.
• A continuous intravenous drip is maintained throughout surgery.
47. Intravenous agents
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⦁ Thiopental sodium (pentothel sodium)
• Short acting in small doses and used for induction
⦁ Advantage
• Pleasant rapid induction
• Non flammable and non irritating
• Nausea and vomiting are rare
⦁ Large dose causes rapid; prolonged respiratory
depression Coughing, laryngospasm
and circulatory
48. Intravenous agents
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⦁ Ketamine hydrochloride
⦁ Can be administered IV or IM
⦁ Produces rapid induction (30 seconds IV and 2-4 minutes IM)
⦁ Advantage:
⦁ Used for short procedure-in children (age 2-10 yrs.) for plastic and
eye procedure
49. Intravenous agents
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⦁ Disadvantage:
⦁ Emergence reactions with psychologic manifestations in recovery
periods like delirium ,hallucination , increase B/P
50. Choice of Anesthesia
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• Choice of anesthesia is made by anesthesiologist or surgeon
• Anesthetic drugs depress activities of all cells. So the primary
consideration with any anesthetics is that it should be associated with low
morbidity and mortality
51. Choice of Anesthesia…
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⦁ The one who select the anesthetic agent should include some or all of
the following:
• Provide maximum safety and comfort for the patient
• Provide optimum operating condition
• Have a low index of toxicity
• Provide potent, predictable analgesia extending to post operative
period
52. The factors to consider during anesthesia
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⦁ Age of the patient
⦁ Physical and mental status of the patient
⦁ Presence of complicating systemic disease
⦁ Previous anesthesia experience
⦁ Position required for operation
53. The factors to consider …
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• Type and expected length procedure
• Local and systemic toxicity of the agent
• Expertise of the anesthesiologist
• Presence of infection at the site of operation
• Preference of the patient
54. Pre-medication
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⦁ It is the type of medication given to the client prior to operation in order
to alleviate anxiety.
⦁ It is usually given 45-60 minutes prior to induction.
⦁ Purposes of premedication
To alley pre-operative anxiety
T4
o3have dull awareness of the OR environment
55. Pre-medication…
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⦁ Purposes of premedication…
It decreases secretion in the respiratory tract
It counter act undesirable side effect of anesthesia
Prolong the effect of the anesthetic and
increase a respiratory depressant effect
56. Pre-medication…
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⦁ The 4 common classes of pre medications are;
1) Barbiturates (Nembutal, Secobarbital)
⦁ Produces a hypnotic effect as sedatives
2) Opiates (Metapon, Demerol, Morphine)
⦁ Act as analgesia
⦁ Produces narcosis (unconsciousness)
57. Pre-medication…
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3) Belladonna Derivatives (Atropine, scopolamine)
⦁ Inhibit mucus secretion
4) Tranquilizers (valium, vistaril, chlorpromazine)
⦁ These relax and allay apprehension and allow for smooth
induction.
⦁ Reduce anxiety, fear and tension
58. Special considerations in pre-medication
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• Hypnotics: is valuable as a premedicant - in children
• Heavy smokers, alcoholics hyper thyroid, toxic, emotional, high fever
patients require more medication.
59. The nurses role in anesthetized patient
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• The patient position
• Patient’s ability to
tolerate stress
detoxify, anesthetic agents(liver function) and
• Patient’s respiratory and circulatory care
• T
eam members must be constantly aware of potential trauma to the
patient
Fasciculation- it coordinates skeletal muscle contraction
Through the direct action of epinephrine-greater probability of acute hypertensive crisis (dangerously high blood pressure), angina pectoris and myocardial infarction, as well as cardiac arrthymias
Hypotension is occurred in Regional Anesthesia due to a decrease in systemic vascular resistance (SVR) and/or cardiac output (CO)
Epidural needs high doses because does not make direct contact with the cord or nerve roots.
Identification of needle entry into the epidural space (EDS) is performed most commonly using a loss of resistance (LOR) technique,
Excitement phase/delirium phase
The patient may stop breathing without the help of machines. The anesthesiologist will keep you at this stage until the procedure is over.
The brain will stop telling your heart and lungs to work. It’s rare with modern technology, but it can be fatal
