General anaesthesia

                                                                                       M.Fencl M.D.
                                                                                       L.Dadák M.D.



                            http://www.virtual-anaesthesia-textbook.com

Definition

4 loss of consciousness, felling, pain. No reaction to stimuli



4 allow therapy (surgery, electroshock)

4 allow diagnostic method (CT, MRI)



History

4  Opium (Egypt, Syria)

–        Hippokrates 400 BC     ease pain

4  1555  Andreas Vesalius - arteficial ventilation through tube between vocal cords, ventricular
fibrilation (animals)

4  Valerius Cordus (1546) ether – oleum vitreolum dulce

4  Paracelsus (1547) - analgetic účinky effect of ether

4  Severino (1646)  - kryoanaesthesia – např. v napoleonských válkách - Larey)

4  1773 N2O      Joseph Priestley (1733-1804)

4  1774 oxygen

4  1779 Humphry Davy  - anaesthetic effect of N2O

Beginning of GA

4 October 16th  1846 ether general anaesthesia Boston  dentist   William Thomas Green Morton to
Gilbert Abbott (tumor of mandibule)

4 February 6th 1847  Prague - first  czech ether anaesthesia  - Celestýn Opitz

4 1895 direct laryngoscopy Alfred Kirstein in Berlin.

–       1920 direct laryngoskopy to clinical praxis  Magill and Rowbotham

Patient + GA

4     preoperative anaest. visit

4     premedication

4     venous line

4     monitoring

4     induction

4     (airway protection)

4     maintenance

4     (extubation)

4     treatment of postoperative pain



record of GA

Preoperative examination

4 history (GA, RA, complications)

4 physical examination (neck, back)

4 laboratory: blood cells, ionts, urea, creatinin, glucose, AST, ALT, GMT, bilirubin, AB0.

4 EKG (older  45).

4 Xray  (older 60 let).

4 function exam

–      cardiological, lung, nephro, hemato

ASA Physical Status  = risk

I   Healthy patient

II Mild systemic disease, no functional limitations                   hypertension, smoker, mild
asthma

III Severe systemic disease- definite functional limitation              coronary disease, COPD,
DM, CHF, renal failure

IV Severe systemic disease that is a constant threat to life               unstable angina, burn
with septic shock

V  Moribund patient not expected to survive 24 hours with or without operation
        patient with extensive bowel infarction, polytrauma



Premedication

usually p.os  - evening + morning

4 sedation/anxiolysis (Benzodiazepines)

4 analgesia only if pain (opioids)

4 reduce airway secretions + heart rate control + hemodynamic stability

4 prevent bronchospasm

4 prevent and/or minimize the impact of aspiration

4 decrease post-op nausea/vomiting

Conversation before GA or RA

4 empty stomach - last food, fluid

4 tooth (artificial, free)

4 weight

4 allergy

4 complication of CA in his/family history



4 check-up questionnaire

4 agreement with anaesthesia

ORoom

Monitoring

4 basic: auscultation, NIBP, EKG- monitor, POX, Temperature

4 extend: CVP, IAP, diuresis, Swan-Ganz

4 peroperative laboratory exams

General anaesthesia

Anaesthesia machine

4  mix gases, ventilate



High pressure - central gas / cylinder

Low pressure system

4  flowmeters

4  vaporiser of volatile anaesthetic

4  circuit:

–        bag  + tubes

–        valves (one direction)

–        CO2 absorber

4  ventilator  (humidisator)



Intravenous  anaesthetics

4 Propofol

4 Barbiturate: Thiopental, Metohexital

4 Etomidate



4 Ketamin

4 Narcotics = Opioids: Fentanyl, Alfentanyl, Sufentanyl Remifentynyl, Morphin

4 Benzodiazepines: Diazepam, Flunitrazepam, Midazolam,

4 Neuroleptics: Dehydrobenzperidol

Volatile anaesthetics

4  Halotan, Izofluran, Sevofluran, Desfluran,



4  Vaporiser (liquid --> gas)



4  Lungs = gate to the body

4  Brain = place of effect



Run of anaesthesia

4 Induction:  i.v. /  inhalation   /+ airways

4 Maintenance: inhalation,  TIVA, add

4 end of A: extubation or  analgosedation + arteficial ventilation - transport to
ICU.

Airways

Indication for intubation:

4 need of relaxation  or  artificial ventilation

4 full stomach



4 Orotracheal intubation,  nasotracheal  intubation  with direct laryngoscopy

4 Tracheotomy

4 Laryngeal masks

4 Cricothyreotomy



Laryngeal Mask

Infusion therapy

4 see summer semester

Complications of GA

!!! No risk = no anaesthesia  !!!

4 difficult intubation, ventilation … asfyxia

4 aspiration of stomach fluid … pneumonia

4 overdose anaesthetic … cardiovascular, respiratory colaps

4 misfunction of  monitor, machines

4 organ failure (AIM, dekompensation COPD, hepatitis, ...)

4 malignant hyperthermia

4 anaphylactic reaction / shock

Mortality of anaesthesia (ASA I)

4 0,008-0,009% primary connected with A

4 0,01-0,02% partially connected with A

4 0,6%  6 day mortality after operation



4 3 times danger than flying



Postoperative care

4 ICU or standard department

4 monitoring according to type of OP + health

4 control laboratory

4 treatment of acute pain

4 infusion therapy, blood loss