Transcript Anesthesia as a specialty - Katedra Anestezjologii i

Anesthesia as a specialty
Past, present and future
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Reference book
• Clinical Anesthesiology,
G. Edward Morgan, Jr., Maged S.
Mikhail, Michael J. Murray
Fourt Edition by the McGraw-Hill
Companies 2006 a LANGE
Medical Book
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www.katedraanest.cm-uj.krakow.pl
• Prof. Janusz Andres (Head of the Chair and
Department)
email: [email protected]
• Agnieszka Frączek (Secretary)
email: [email protected]
• Katarzyna Lepszy-Muszyńska (Coordinator,
email:[email protected]
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Pain as a part of surgery
• Hypnosis
• Alkohol
• Botanical preparation
• Superficial surgery
• Galenic concept: body humors: blood,
phlegm, yellow and black bile
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Inhalation Anesthesia
• 1540 Paracelsus: oil of vitriol (prepared by
Valerius Cordus and named “Aether” by
Frobenius): used to feed fowl: “it was taken
even by chickens and they fall asleep from
it for a while but awaken later without
harm”
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Local anesthesia
• Ancient Incas: coca leaf as a gift to the
Incas from the sun of God:
• destruction of Incas culture
• slaves payment
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Important names in history of
anesthesia
• Humphry Davy: 1778 - 1829 (“laughing
gas”, N20)
• Horace Wells: January 1845, Harvard
Medical School, clinical use of N20
• William Morton: October 16,1846 ether for
the excision of the vascular lesion from the
neck (John Collin Warren: gentlemen this is
not a humbug)
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Important names in the history of
anesthesia
• Prof. Ludwik Bierkowski: February 1847
KRAKÓW ether in Poland
• anesthesia = temporary insensibility
• James Simpson: November 1847,
chloroform
• John Snow : 1813-1858, first
anesthesiologist, face mask, vaporizer,
clinical study
• Joseph T. Clover follows John Snow
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American and British Origin
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Mayo Clinic and Cleveland Clinic
Students and nurses as anaesthetists
Long Island Society of Anesthetist 1905
New York Society of Anaesthetist 1911 became in
1936 ASA (Anaesthetists) in 1945 ASA
(Anaesthesiologists)
• England: Sir Robert Macintosh in 1937 first Chair,
Faculty of Anaesthetists of the Royal College of
Surgeons was established in 1947
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Important names in the history of
anesthesia
• Carl Koller 1857-1944, cocaine in
ophthalmology
• Sir Magill (1888-1986)
• Arthur Guedel (1883-1956)
• Harold Griffith 1942 : curara
• Paul Janssen: intravenous anesthesia
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Important steps in development
of anesthesia
• Ether (Morton)
• Regional (spinal, epidural) end of XIX
century
• Thiopental 1934
• Curara 1942
• Halotane 1956
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Anesthesia
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analgesia
reversible anesthetic effect
amnesia
areflexia
sleep
supression of the vegetative response
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Is anesthesia safe?
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Like airplane?
Anesthesia related deaths:
1940 1/1000
1970 1/10 000
1995 1/250 000
2005 ?
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Safety of anesthesia
• 1950 - 25 000 deaths during 108 hours of
anesthesia
• 2000 - 500 deaths during 108 hours of
anesthesia
• Airplane risk (very low) - 5 deaths during
108 hours of flight
• Risk of anaesthesia: 100 x higher
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Receptor theory of anesthesia
• GABA: major inhibitory neurotransmitter
(point of action of anesthetic drugs)
• Membrane structure and function: future of
the anesthesiology
• Glutamate: major excitatory
neurotransmitter
• Endorphins: analgesia
• Unitary hypothesis of the inhalation agents
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Present status of anesthesiology
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Anesthesia
Pain management
Intensive Care Medicine
Emergency Medicine
Operative Medicine
Education
Research
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Practice of anaesthesiology is the
practice of medicine (ABA)
• Assesment of, consultation for, and preparation of
patients for anaesthesia
• Relief and prevention of pain
• Monitor and maintenance of the perioperative
period
• Management of critical ill patients
• Clinical management and teaching of the CPR
• Teaching, Research, Administration,
Transdisciplinary approach
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Progress in anesthesia
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New monitoring techniques and standards
New anesthetics (iv and inhalation)
New drugs (inotropic, NO)
New ways of drug delivery
New management techniques
Cost - effective
Fast truck
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Future of anesthesiology
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CNS and transdermal stimulation
Safe delivery of drugs
More specific drugs (membrane function)
Perfluorocarbons
Genetically focus therapy
Noninvasive monitoring
Visible pre- and postsynaptic area
Hibernation
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General anaesthesia and
Preoperative evaluation
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ASA scale
• 1 normal healthy patient
• 2 mild systemic disease (no limitation0
• 3 moderate to severe systemic disease with
limitation of function
• 4 severe systemic disease (threat to life)
• 5 moribund patient
• E emergency case
• 6 brain death patient
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An anaesthetic plan
• Patient’s baseline condition with medical
record and previous anaesthesia and surgery
• Planned procedure
• Drug sensitivities
• Psychological makeup
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The anesthetic plan
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ASA physical status scale
General versus regional
Airway
Induction
Monitoring
Intraoperative management
Postoperative management
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ASA and perioperative mortality
rate
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0.07%
0.3%
2%
7-23%
9-51%
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Documentation
• Informed consent
• Preoperative note
• Intraoperative anesthesia record
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patient status
review of anesthesia and surgery
laboratory
drugs dosage and time of administration
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Documentation 2
• Patient monitoring (intraoperative monitor, future
reference for the patient, tool for quality
assurance)
• fluid administration
• procedures (catheters, caniulas, tubes)
• time of important events
• unusual complication
• end of procedures
• state of consciousness
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Safety of working place
• gas systems (liquid oxygen, air, a pin index system
to avoid failure, Nitrous Oxide critical temperature
36,5 oC, different colours of the cylinders)
• electrical safety (leakage current on the OR less
than 10 uA)
• surgical diathermy (malfunction of the return
electrode may cause burns)
• fire and explosion (uncommon), temperature,
humidity, ventilation, noise)
• www.apsf.org
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Ventilation management
• Breathing systems
• Open drop anesthesia
• Mapleson circuits
• Anesthesia machines
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Breathing Systems
• Patient – breathing system – anaesthesia
machine
• Mapleson systems: Beathing tubes, fresh
gas inlets, adjustable pressure limiting
(APL) or pop-off valves, reservoir bags
• Carbon Dioxide Absorbent: CO2 + H2O =
H2CO3,
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The anesthesia machine
• Receive medical gases from gas supply
• Permits other gases (anaesthetics) only if there is
enough oxygen in the mixture
• Vaporizers are agent- specific
• Deliver and control tital volume
• Waste gas scavenger system
• Regulary inspections
• Failure of the machine is a significant percentage
of the mishaps in anaesthesia practice
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Airway management
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Airway management
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Airway management
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Airway management
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Airway management
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Airway management
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Mask ventilation
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Mask ventilation
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Edotracheal intubation
Most common and safe protection
of aiways during anaesthesia and
intensive care
But
Need skills and permament training
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AIRWAY
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Difficulty in managing the airway
Difficult intubation
Traumatic intubation
Esophageal intubation
Bronchial intubation
Laryngospasm
Bronchospasm
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Special airway techniques
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Fiberoptic intubation
Retrograde (wire) intubation
Transtracheal jet ventilation
Lighted stylets
Laryngeal mask
Combitube
Surgical airway
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Patient monitors
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Arterial blood pressure
ECG
CVP, PAC
Capnometry
Pulsoxymetry
EEG, BIS
Temperature
Nerve stimulation
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Inhalation anesthetic agents
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Nitrous oxide
Halothane (Fluothane)
Methoxyflurane (Penthrane)
Enflurane (Ethrane)
Isoflurane (Forane)
Desflurane (Suprane)
Sevoflurane (Ultane)
MAC concept
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Pharmacokinetics and
pharmacodymanics
• Pharmacokinetics: how the body affects the
drug
• Pharmacodymanics: how the drugs affects
the body
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Factors affecting anesthetic uptake
• Solubility in blood
• Alveolar blood flow
• Differences in partial pressure between
alveolar gas and venous blood
• Therefore: low output states predispose
patients to overdosage of the soluble agents
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Factors affecting elimination
• Biotransformation: cytochrome P-450
(specifically CYP 2EI)
• Transcutaneous loss or exhalation
• Alveolus is the most important in
elimination of the inhalation agents
• „Diffusion hypoxia” and the nitrous oxide
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Minimum alveolar concentration
• Is the concentration of inhaled
anaesthetics in the alveolar that
prevents movements in 50% of patients
in response to a standardized stimulus
(eg surgical incision)
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Inhalation anesthetic agents
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Nitrous oxide
Halothane (Fluothane)
Methoxyflurane (Penthrane)
Enflurane (Ethrane)
Isoflurane (Forane)
Desflurane (Suprane)
Sevoflurane (Ultane)
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Intravenous induction and
anesthestic agents
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Thiopental
Metohexital
Benzodiazepins (Midazolam)
Propofol
Etomidate
Ketamine
Opioids
Droperidol
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Intravenous anaesthesia
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Changes in plasma concentration
Absorption
Distribution (Vd= Dose/Concentration)
Biotransformation
Excretion
Compartment model of distribution and
elimination
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Muscle relaxants
• Neuromuscular transmission
• Depolarizing agents (Ach rec. agonists)
• Nondepolarizing agents (Ach rec.
antagonists)
• Cholinesterase inhibitors (edrofonium,
neostigmine, pyridostigmine)
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Anticholinergic drugs
• Antimuscarinic effect
• Atropine
• Scopolamine
• Glycopyrrolate
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Anesthesia complications
• Inadequate preoperative planning and errors
in patient preparation are the most commom
causes of anesthestic complications
• Anesthesia and elective operations should
not proceed until the patient is in optimal
medical condition
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Anesthetic complications
• Human error (technical problems, lack of
communication, experience, fatigue,)
• Ventilation (breathing circuit, defect of
monitoring equipment, anesthesia machine)
• Position (periferal nerve damage)
• Anaphylaxis
• Latex allergy
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Anesthesia and perioperative
complications
• Airway
• Circulation
• Central and peripheral nervous system
• Pain therapy
• Drugs used in anesthesia
• Equipment failure
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