Anesthesia as a specialty Past, present and future

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

www.katedraanest.cm-uj.krakow.pl Prof. Janusz Andres (Head of the Chair and Department) email: msandres@cyf-kr.edu.pl Agnieszka Frączek (Secretary) email: agafrk@cm-uj.krakow.pl Katarzyna Lepszy-Muszyńska (Coordinator, email:muszynscy.brzozowka@neostrada.pl

Pain as a part of surgery Hypnosis Alkohol Botanical preparation Superficial surgery Galenic concept: body humors: blood, phlegm, yellow and black bile

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”

Local anesthesia Ancient Incas: coca leaf as a gift to the Incas from the sun of God: destruction of Incas culture slaves payment

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)

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

American and British Origin 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

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

Important steps in development of anesthesia Ether (Morton) Regional (spinal, epidural) end of XIX century Thiopental 1934 Curara 1942 Halotane 1956

Anesthesia analgesia reversible anesthetic effect amnesia areflexia sleep supression of the vegetative response

Is anesthesia safe? Like airplane? Anesthesia related deaths: 1940 1/1000 1970 1/10 000 1995 1/250 000 2005 ?

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

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

Present status of anesthesiology Anesthesia Pain management Intensive Care Medicine Emergency Medicine Operative Medicine Education Research

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

Progress in anesthesia 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

Future of anesthesiology 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

General anaesthesia and Preoperative evaluation

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

An anaesthetic plan Patient’s baseline condition with medical record and previous anaesthesia and surgery Planned procedure Drug sensitivities Psychological makeup

The anesthetic plan ASA physical status scale General versus regional Airway Induction Monitoring Intraoperative management Postoperative management

ASA and perioperative mortality rate 1 0.07% 2 0.3% 3 2% 4 7-23% 5 9-51%

Documentation Informed consent Preoperative note Intraoperative anesthesia record patient status review of anesthesia and surgery laboratory drugs dosage and time of administration

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

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

Ventilation management Breathing systems Open drop anesthesia Mapleson circuits Anesthesia machines

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,

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

Airway management

Airway management

Airway management

Airway management

Airway management

Airway management

Mask ventilation

Mask ventilation

Edotracheal intubation Most common and safe protection of aiways during anaesthesia and intensive care But Need skills and permament training

AIRWAY Difficulty in managing the airway Difficult intubation Traumatic intubation Esophageal intubation Bronchial intubation Laryngospasm Bronchospasm

Special airway techniques Fiberoptic intubation Retrograde (wire) intubation Transtracheal jet ventilation Lighted stylets Laryngeal mask Combitube Surgical airway

Patient monitors Arterial blood pressure ECG CVP, PAC Capnometry Pulsoxymetry EEG, BIS Temperature Nerve stimulation

Inhalation anesthetic agents Nitrous oxide Halothane (Fluothane) Methoxyflurane (Penthrane) Enflurane (Ethrane) Isoflurane (Forane) Desflurane (Suprane) Sevoflurane (Ultane) MAC concept

Pharmacokinetics and pharmacodymanics Pharmacokinetics: how the body affects the drug Pharmacodymanics: how the drugs affects the body

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

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

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)

Inhalation anesthetic agents Nitrous oxide Halothane (Fluothane) Methoxyflurane (Penthrane) Enflurane (Ethrane) Isoflurane (Forane) Desflurane (Suprane) Sevoflurane (Ultane)

Intravenous induction and anesthestic agents Thiopental Metohexital Benzodiazepins (Midazolam) Propofol Etomidate Ketamine Opioids Droperidol

Intravenous anaesthesia Changes in plasma concentration Absorption Distribution (Vd= Dose/Concentration) Biotransformation Excretion Compartment model of distribution and elimination

Muscle relaxants Neuromuscular transmission Depolarizing agents (Ach rec. agonists) Nondepolarizing agents (Ach rec. antagonists) Cholinesterase inhibitors (edrofonium, neostigmine, pyridostigmine)

Anticholinergic drugs Antimuscarinic effect Atropine Scopolamine Glycopyrrolate

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

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

Anesthesia and perioperative complications Airway Circulation Central and peripheral nervous system Pain therapy Drugs used in anesthesia Equipment failure