general anesthesia methods definition and goal definition: a state where the patient a state where...
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General anesthesiaGeneral anesthesia
MethodsMethods
Definition and goalDefinition and goalDefinition:Definition: A state where the patientA state where the patient
does not respond to painful stimulidoes not respond to painful stimuli does not recall these stimulidoes not recall these stimuli
responsesresponses:: somaticsomatic vegetativevegetative control of anaesthesiacontrol of anaesthesia emotional/behaviouralemotional/behavioural
Main goals:Main goals: total total abolitabolition ion of of painpain suppression of harmful suppression of harmful reflexesreflexes relaxationrelaxation of striated muscles of striated muscles (body cavity or extremities) (body cavity or extremities)
Modes of general anaesthesiaModes of general anaesthesia
Main components: Main components: analgesiaanalgesia--amnesiaamnesia--unconsciousnessunconsciousness((hypnosishypnosis) – attenuation of ) – attenuation of
unwanted (harmful) vegetatív unwanted (harmful) vegetatív reflexesreflexes – immobility (muscle – immobility (muscle relaxationrelaxation).).
Main types of anaesthesia: Main types of anaesthesia: mono-anaesthesia:mono-anaesthesia:
single agent (e.g. aether) in high doses =single agent (e.g. aether) in high doses =overdosing of the agent to achieve certain special goals by side-effects of overdosing of the agent to achieve certain special goals by side-effects of
the drug (eg. muscle relaxation by high doses of aether)the drug (eg. muscle relaxation by high doses of aether) combined combined general general anaesthesiaanaesthesia: all desired effects achieved : all desired effects achieved
with appropriate doses of specific agents ( balanced with appropriate doses of specific agents ( balanced anaesthesia)anaesthesia)
side-effects avoided or diminished side-effects avoided or diminished proper management of anaesthesiaproper management of anaesthesia accommodation to individual needsaccommodation to individual needs accommodation to actual extent of variable intra-operative painaccommodation to actual extent of variable intra-operative pain
Stages of general anaesthesia Stages of general anaesthesia with ether with ether according to Guedelaccording to Guedel
I. Stadium analgesiaeI. Stadium analgesiae
II. Stadium excitationisII. Stadium excitationis
III. Stadium tolerantiaeIII. Stadium tolerantiae III/1-2-3-III/1-2-3-4.4.
IV. Stadium asphyxiaeIV. Stadium asphyxiae
Basics of classification:Basics of classification: consciousnessconsciousness ocular signs (pupilla)ocular signs (pupilla) breathing patternbreathing pattern vegetative signs (pulse)vegetative signs (pulse) muscle tonemuscle tone
StádiumStádium Conscious- ness
Br.
pupilla eyelid cornea secret. light gag vomit str. abd. smooth
I. I. 1.
Anal- 2. gesia 3.
II.II.excitaton
III. III. 1.1.
Tole- 2.2.
rance 3.3.
4.4.
IV.IV.As- phyxia
ReflexesMuscle tone
How can we get the anesthestics to How can we get the anesthestics to the place of their actionthe place of their action??
To the receptors and structions of the CNS peripheric receptors (e.g. neuromuscular junction)
It is always the blood circulation the anesthetics are transported by
Ways to the blood streem: GI system (intestinal capillary-portal vene – VCI- RA-RV-
lungs – LA – LV – arterial system) Mucous membranes (capillaries-venes-RA-RV-lungs – LA
– LV – arterial system) Injection into periferic tissues → capillaries…..
(i.c., s.c., i.m. application) Intravenous injection
(v.cava-RA-RV-lungs-LA-LV-arteries)
Inhalation (lung capillaries-v.pulm.-LA-LV-arteries)
General anaesthesiaGeneral anaesthesia Cannot be deCannot be desscribed by a simple and single cribed by a simple and single
processprocess - - at least two fundamental processes: at least two fundamental processes: inhibition of painful stimuliinhibition of painful stimuli andand loss of consciousness loss of consciousness
Loss of consiousness is Loss of consiousness is achievedachieved by hypnotics by hypnotics Pain inhibition is Pain inhibition is achievedachieved by analgetics by analgetics
(opioids)(opioids) ThTheseese two different effects are closely related, two different effects are closely related,
the relation is continuous: the relation is continuous: very high dose of a hypnotic produces anti-very high dose of a hypnotic produces anti-
nociception,nociception, very high dose of an analgetic (opioid) produces very high dose of an analgetic (opioid) produces
unconsciousnessunconsciousness
Preparation before anesthesiaPreparation before anesthesiaBefore the patient arrives
Preparation and check of the equipment (e.g. suction, monitors, infusion, intubation, airway
maintenance equipment)
Check up: anesthesia machine, gas supply
Preparation of medicaments
After arrival of the patient
Greeting of patient, documentation checkup, anesthesia sheet
Monitors, registration of starting values
Venous access
Parts of general anesthesiaParts of general anesthesia Induction
From the start of the induction agent to the point when the patient is ready for the operation
MaintenanceMaintenance of the necessary depth of
anesthesia during operation and continuous control of the vital functions of the patient (values, tendencies, correction as necessary)
End (arousal) and recovery On the operating table Delayed– complete arousal later in the RR or
ICU
Drugs for general anaesthesiaDrugs for general anaesthesia Drugs for preoperative Drugs for preoperative preparationpreparation
sedatives, analgesics, vegetative (parasympatholytic) drugssedatives, analgesics, vegetative (parasympatholytic) drugs drugs for drugs for inductioninduction of anaesthesia of anaesthesia
short acting iv. short acting iv. aanaestheticsnaesthetics, inhalation agent(s), inhalation agent(s) maintenancemaintenance of anaesthesia of anaesthesia
intravenous intravenous oror/and /and volatile anaesthetics volatile anaesthetics + + supplementary drugssupplementary drugs
analgesics, vegetative stabilizing drugs, additives, analgesics, vegetative stabilizing drugs, additives, potentiating agents and other drugspotentiating agents and other drugs
drugs fordrugs for aawakeningwakening antagonists: antagonists: ((opioids, benzodiazepinesopioids, benzodiazepines), antidote of muscle ), antidote of muscle
relaxantsrelaxants
Decision influenced by:Decision influenced by: Patient’sPatient’s demands demands
Condition of the patient (hypCondition of the patient (hyperertension, cardiac failuretension, cardiac failure, …, …)) Circumstances of treatment (emergencyCircumstances of treatment (emergency or elective or elective situations) situations)
SurgicalSurgical aspects aspects type of surgerytype of surgery (e.g. dental-, dento-alveolar-, maxillo-facial (e.g. dental-, dento-alveolar-, maxillo-facial
surgery) surgery) region of procedureregion of procedure (intraoral, extraoral…) (intraoral, extraoral…) length of procedurelength of procedure special requirements (special requirements (e.g. controlled e.g. controlled hypotension needed)hypotension needed)
PPersonal ersonal experienceexperience of anaesthesiologist of anaesthesiologist Available circumstancesAvailable circumstances
Which method of anaesthesia?Which method of anaesthesia?
Intravenous anesthesiaIntravenous anesthesia
Bolus administrationBolus administration Continuous infusion (pump)Continuous infusion (pump)
Advantages Drawbacks•Easy, quick administration•Known dose•Does not depend on breathing•Combination of different agents possible•No pollution
•Once given, the dose can not be reduced
•Elimination depends on organ function/enzymes
•Allergy - more often
IV bolus administrationIV bolus administration
effective concentration
concentration
First dose Second dose
MethodsMethods• Total IntraVenous Anesthesia (TIVA)
Intravenous induction and maintenance Intravenous induction and maintenance (infusion pump) VentilationVentilation: oxygen – air mixture: oxygen – air mixture
• IntraVenous Anesthesia (IVA) – e.g. NLAII! Intravenous induction and mainetnance Intravenous induction and mainetnance (continuous or bolus) Ventilation: oxygen – nitrous oxide
• Inhalation anesthesia anesthesia Induction can be IV (adults), maintenance by inhalationInduction can be IV (adults), maintenance by inhalation VIMA: Volatile Induction and Maintenance of Anaesthesia: Volatile Induction and Maintenance of Anaesthesia
• Balanced anesthesia anesthesia Combination of intravenous and inhalational method Combination of intravenous and inhalational method (in a broader (in a broader
concept combination of more thasn one methods – e.g. GA + regional anesth.)concept combination of more thasn one methods – e.g. GA + regional anesth.)
Inhalation anesthesiaInhalation anesthesia
ProPro
Easy continuous administration
Easy modulation of blood concentration
Elimination through the lungs
Allergy rate low
ContraContra
Needs specific vaporizers
Induction can be slow, unpleasant
Pollution
Price?
InductionInduction Venous access, documentation, monitoring Medical preparation Preoxigenation Hypnosis/narcosis (Muscle relaxation) Securing of the airways: endotracheal intubation,
laryngeal mask,… Attachment of special equipment,… (+extra IV
access?) invasive monitoring? (Bladder catheter, CVC…) Positioning of the patient, stabilization Deepening of anesthesia, analgesia
Induction IIInduction II Medical preparation (coinduction)
E.g. Fentanyl + Midazolam (Earlier: Fentanyl + DHBP – NLA)
Intravenous induction – („falling asleep”) Bolus injection
eg. Thiopenthal, Propofol, Ethomidate,(Ketamin) + relaxant
Continuous administration by infusion pump
Inhalation induction Quick technique – (single breath method – a total vital
capacity breath after filling up of the system) Continuous inhalation (children)
Intravenous induction agents I. Intravenous induction agents I. Intravenous barbiturates
methohexital, thiopenthal, thiobutabarbitalmethohexital, thiopenthal, thiobutabarbital• Only for single induction or short IV anesthesia!Only for single induction or short IV anesthesia! • Quick action, redistribution, tendence to accumulationQuick action, redistribution, tendence to accumulation
Velocity of the injection influences the actionVelocity of the injection influences the action
• Negative inotropy + vasodilationNegative inotropy + vasodilationReduced cerebral metabolism and oxygen consumptionReduced cerebral metabolism and oxygen consumptionTissue damage!Tissue damage!
• Dose depends on the ageDose depends on the age, general state, previous medication , general state, previous medication (DHBP or Midazolam, Fentanyl reduce the dose)(DHBP or Midazolam, Fentanyl reduce the dose)
(1)-3-5 mg/kg diluted (1-2.5%), according to the effect!(1)-3-5 mg/kg diluted (1-2.5%), according to the effect!Slow injection until the eyelid reflex disappeares!Slow injection until the eyelid reflex disappeares!
• Contraindication:Contraindication: porphyria, lack of good veins, porphyria, lack of good veins, ventilation difficulties, circulatory insufficiency ventilation difficulties, circulatory insufficiency
Intravenous induction agents II.Intravenous induction agents II. EthomidateEthomidate
Only for induction (single dose) – short actionOnly for induction (single dose) – short action DoseDose: 0.15-0.3 mg/kg of the 0.2% solution (10 ml=20 mg): 0.15-0.3 mg/kg of the 0.2% solution (10 ml=20 mg) Circulatory effects less than with other agents Circulatory effects less than with other agents (for high risk cardiovascular for high risk cardiovascular
patients). Spontaneous twiching possiblepatients). Spontaneous twiching possible Adrenal depression!Adrenal depression!
Ketamine (S+ Ketamine)Ketamine (S+ Ketamine) „„Dissociative anesthesia”, hallucinogenic effects, Dissociative anesthesia”, hallucinogenic effects, analgesiaanalgesia DoseDose: 1-2 mg/kg IV (3-4 mg/kg IM), for repetition or sedation 0.1-1 mg/kg: 1-2 mg/kg IV (3-4 mg/kg IM), for repetition or sedation 0.1-1 mg/kg Good for: children, combinations - hypotensive patientsGood for: children, combinations - hypotensive patients Elevates the BP, intracranial pressure, intraocular pressure, blood Elevates the BP, intracranial pressure, intraocular pressure, blood
concentrastions of catehcolamines! Reflex sensitivity elevatedconcentrastions of catehcolamines! Reflex sensitivity elevated
PropofolPropofol Other agents for Other agents for IV induction or coinduction: IV induction or coinduction:
Midazolam Opioids ….
Clonidin
Intravenous induction agents III. Intravenous induction agents III. Anesthesia indction (and maintenance) withAnesthesia indction (and maintenance) with
Propofol Propofol (Diprivan)Characteristic: Quick and short action, easy control of anesthesia depth Reduces BP (cardiodepressive, vasodilatative) Venous irritation
Bolus-administration: Sleep dose: 2 mg/kg (slowly), repeated dose: 0.5-1 mg/kgSleep dose: 2 mg/kg (slowly), repeated dose: 0.5-1 mg/kg
Continuous administration With infusion pump 4-12 mg/kg/hourWith infusion pump 4-12 mg/kg/hour TCI („Target Controlled Infusion”) TCI („Target Controlled Infusion”) ––
(target concentration 3-5 (target concentration 3-5 g/ml)g/ml)
Typical coinduction methodTypical coinduction method
IV IV MidazolamMidazolam ( (Dormicum) 0.1-(0.2) mg/kg) 0.1-(0.2) mg/kg IV IV Fentanyl Fentanyl 1-1.5 g/kg Oxygen inhalation IV induction (Thiopenthal or Propofol or
Ethomidate) Muscle relaxant (if mask ventilation easy) Endotracheal intubation Arteficial ventilation
Inhalational anesthesiaInhalational anesthesia
Inhalation anesthetics are gases (NInhalation anesthetics are gases (N22O) or vaporsO) or vapors::
Halothan, Enfluran, Isofluran, Sevofluran, DesfluranHalothan, Enfluran, Isofluran, Sevofluran, Desfluran
Inhaled anesthestics get into the alveoli of the Inhaled anesthestics get into the alveoli of the lung and according to the concentration gradient lung and according to the concentration gradient to the capillaries. The blood stream takes them to the capillaries. The blood stream takes them through the left heart to the brain.through the left heart to the brain.
Factors influencing the effectFactors influencing the effect
Concentration of the inhalation agent in the Concentration of the inhalation agent in the inhaled mixtureinhaled mixture
BreathingBreathing: minute ventillation, FRC: minute ventillation, FRC LungsLungs: diffusion, perfusion: diffusion, perfusion Solubility in blood, Solubility in blood, blood/gasblood/gas coefficient coefficient HeartHeart: cardiac output: cardiac output CerebralCerebral circulation circulation Oil/waterOil/water coefficient, boiling point coefficient, boiling point
Important valuesImportant values
Blood/gas coefficientBlood/gas coefficient::
Halothan:2.4 Isofluran 1.4 Sevofluran 0.6 Desfluran 0.4Halothan:2.4 Isofluran 1.4 Sevofluran 0.6 Desfluran 0.4
MACMAC= Minimal Alveolar Concentration= Minimal Alveolar Concentration
Concentration of an inhalation anesthestic which Concentration of an inhalation anesthestic which prevents movements at surgical incision in 50% of prevents movements at surgical incision in 50% of the patients.the patients.
1 MAC 1 MAC isofluranisofluran = = 1.15 volume%1.15 volume%
1 MAC 1 MAC sevofluransevofluran== 2 volume% 2 volume%
1 MAC 1 MAC desflurandesfluran = = 7.3 volume% 7.3 volume%
MAC reduced: by premedication, sedato-hypnotics, age, pregnancy, alcohol, hypthermia, hyponatremia, N2O co-administration
Inhalation anesthesia Inhalation anesthesia
Induction: Induction: High starting flow, relatively high concentrationHigh starting flow, relatively high concentration
filling up the system with the anestheticfilling up the system with the anesthetic„„Vital capacity rapid inhalation induction” (VCRII)Vital capacity rapid inhalation induction” (VCRII)
Maintenance: Maintenance: Gradually reduced concentration, reduced gas flow (at low Gradually reduced concentration, reduced gas flow (at low
flow the inhaled concentration is entirely different from the flow the inhaled concentration is entirely different from the concentration delivered by the vaporizer!)concentration delivered by the vaporizer!)
End of anesthesia: End of anesthesia: Closing the vaporizer depending on the type of agent, flow Closing the vaporizer depending on the type of agent, flow
and actual concentration.and actual concentration.
Indications for general anesthesia in Indications for general anesthesia in dentistrydentistry
Maxillofacial surgery Maxillofacial surgery Abscesses, other situations Abscesses, other situations
where local anesthesia is not effectivewhere local anesthesia is not effective Long, unpleasant dentoalveolar interventionsLong, unpleasant dentoalveolar interventions Dental treatment : patient comfortDental treatment : patient comfort
Goal of sedation for dental interventionsGoal of sedation for dental interventions
Easier tolerance of unpleasant interventions
Reduction of anxiety and connected risks and dangers
Prevention of pain and unpleasant experiences
Facilitate medical work
Very Very anxiousanxious patient patient Patients with Patients with elevated riskelevated risk of a exaggerated of a exaggerated
sympathoadrenal reaction sympathoadrenal reaction (hypertension, cardiac failure, (hypertension, cardiac failure, hyperthyreosis, paroxysmal tachycardia, etc.)hyperthyreosis, paroxysmal tachycardia, etc.)
All problem patients All problem patients (psychologic or medical risk)(psychologic or medical risk) Imbecile, demented patientsImbecile, demented patients Not cooperativeNot cooperative children children
Indication for sedation for dental Indication for sedation for dental interventionsinterventions
Grades of sedation - the transition from one to the other is contunuous!
Grade
Consciousness CNS Airways
Spontaneous breathing
Cardiovasc.sytem
Minimal monitorin
g
I. I. anxiolysianxiolysiss
Clear, reactions OK
Free OK OK inspection
II. II. „conscio„consciousus
sedationsedation””
Reacion t stimuli, lightly influenced
Free Usually satisfactor
y
Slightly affected
NIBP, HR, Sat O2 - - also post-sedation
III. Deep III. Deep
sedationsedation
Consciousness partly lost, falls asleep, reaction only to strong stimuli
Intervention often necessary
Usually ↓ assisted
ventillation necessary
Usually influence
d↓
As above + ECG
IV. IV. General General anesthesianesthesiaa
Loss of consciousnessno reaction to painful stimuli
Professionalairway
management
necessaryl!
Assisted or controlled ventilation necessary
Usually influence
d
Total anesthesio-logic equipment!!
Methods of sedationMethods of sedation
Verbal, psychologic methods - straightforward behaviour suggesting security, empathy, information and asking for consent!
Medical sedation Oral / rectal Intramuscular –rarely, for children (Ketamine 3-6 mg/kg) Intravenous Inhalation – only N2O/O2
- + vaporised inhalational anesthetics
Az oral (GI) sedation One hour before the intervention in adults
(½ hour in children) Prolonged action (sedation grade I. ) Drawbacks:
Not always practicable Diverse modes action in individual patients Inability ti drive afterwards (reaction-time ↑!) Synergistic action with other drugs (alcohol!)
Advantages: Simple, no need for numerous personal, usually no circulatory depression, can be administered by the doctor resposible for the intervention
Recommanded medication: Midazolam (7,5-15 mg) - for children0,3-0,4 mg/kg
(in Panadol syrup) Alprazolam (0,25-0,5 mg), (Diazepam)
Old patients are especially sensitive – administer with care!
Az inhalational sedation N2O/O2 for dental interventions Maximal concentration without the
danger of hypoxia (60%) causes superficial conscious sedation
(grade II.) Special equipment necessary Requires an extra doctor, expert in
airway management, mechanical ventilation and emergency techniques (anesthesiologist) , who is not involved in the dental intervention!
• Sedation with vaporized inhalation-anesthetics is already GA with the same objetive and
subjective conditions
Intravenous sedation
Opioids -Antidot: naloxone (0,l mg –repeated if necessary.)
For painful inteventions it is the first drug eg. fentanyl (1g/kg), alfentanil, sufentanil, remifentanil, pethidin
Danger: respiratory depression, synergism - administration is the task of an anesthesiologist!
Benzodiazepins - titrated administration, until we reach the intended grade of sedation
Midazolam: 0,03-0,05 mg/kg – 0,1-(0,15)mg/kgPrepare for airway management + mechanical ventilation! be careful in older patients – reduce doses!
Ketamine Propofol
TCI sedation: 2-2,5 g/ml as a target concentration
Használatuk aneszteziológus orvosi feladat!
Possible complication of Possible complication of sedationsedation
Apnoea, airway obstractionApnoea, airway obstraction Vomiting, aspirationVomiting, aspiration Circulatory depression, fall in BPCirculatory depression, fall in BP Allergic reaction, anaphylaxis, anaphylactoidAllergic reaction, anaphylaxis, anaphylactoid
Be allways prepared for all possible complications!
The intravenous and inhalational sedation requires the fulfillment of all subjective and objective conditions!!
Suitability for sedation/anesthesia in the dental practice
Anesthesiologic evaluation (preadmission Anesthesiologic evaluation (preadmission clinic!)clinic!) HistoryHistory Physical examinationPhysical examination Laboratory tests (?)Laboratory tests (?)
Preoperatice carency – NPO?Preoperatice carency – NPO? Bladder emptying, necessary preparationBladder emptying, necessary preparation
DocumentationDocumentation
Detailed petient information Signed „informed consent” Anesthesia sheet Post-sedation observation sheet Detailed operation instructions adapted to
the function of the ward (competencies, responsibilities,etc.)
Simplified discharge criteriaSimplified discharge criteria Stable vital functions for more than 1 hour The patient
Is well oriented in person, time, local conditions (mental state similar to the original)
can drink alone can urinate (regional anesthesia!) takes up cloths, walks without help
No PONV Serious pain (VAS <30) bleeding
Adult attendant Dentist and anesthesiologist agreed to discharge Home care arranged Written directions for the postoperative period
(name and telephone of the contact persons!)
CompetencyCompetencyGrade Doctor Nurse
I. anxiolysis doctor
responsible for the intervention
(dentist)
Dental nurse
II. „conscious sedation”+ independent
doctor with good knowledge in airway
management and emergency medical methods (specialist
anesthesist)!!!
?
III. Deep sedation Absolutly necessary the presence of a
specialist anesthesist!
The doctor, responsible for the intervention is not
allowed to make anesthesia or deep sedation even if he/she is specialized in
anesthesia as well!
Necessary/ recommended
IV. General anesthesia
Necessary
Objective conditionsObjective conditionsGrade
I. anxiolysis
II. „conscious sedation”
Easily accessible dental chair/operating table
O2 (cylinders, reductor, connectors, tubes, masks…) +airway management equipment, tools of mechanical
ventilation;Necessary equipment for intravenous access;
Strong suction-set, BLS accessorries, emergency medication and equipment
pulzoximeter, stetoscope, BP manometer
III. Deep sedation +
+ ECG, anesthesia machine, defibrillator, availability of quick medical help, ICU background, recovery room, supervising
stuff
IV. General anesthesia
Have a nice relaxed (but not sedated) afternoon!
General anaesthesiaGeneral anaesthesia
phases:phases: preparationpreparation induction maintenance emd of anesthesia (arousal) recoveryrecovery
pain relief!pain relief!
Old anesthesia methodsOld anesthesia methods Ether/chloroform… drip methodEther/chloroform… drip method Intravenous barbituratesIntravenous barbiturates
Gray method: intubation anesthesia (!) Gray method: intubation anesthesia (!) thiopenthal induction, thiopenthal induction,
maintenance: Nmaintenance: N22O/OO/O22, opioid, muscle relaxants, opioid, muscle relaxants
NLA type I. anesthesia:NLA type I. anesthesia:haloperidol + phenoperidin (N2O/O2)
NLA II.NLA II. anesthesia: anesthesia:dehydrobenzperidol (DHBP)+fentanyl
(N2O/O2)
DE CASTRO & MUNDELEER
Further modificationsFurther modifications TypeIITypeII. . neuroleptneurolept anesthesia anesthesia
Induction:Induction: DHBP 0,25-0,5 mg/kg Fentanyl 2-3g/kg + N2O/O2
Maintenance Fentanyl 1-1 g/kg, N2O/O2, muscle relaxants if necessary
ModifiedModified neuroleptneurolept anesthesia anesthesia Induction: Induction: DHBP 0,05-0,1 mg/kg
Fentanyl 1g/kg + N2O/O2
+ Thiopenthal –until the disapperance of the eyelid reflex
Maintenance: Maintenance: Fentanyl 1g/kg + N2O/O2, muscle relaxant
CoinductionCoinduction method method Induction: Induction: Midazolam 0,05 mg/kg, Fentanyl 1-2 Midazolam 0,05 mg/kg, Fentanyl 1-2 g/kgg/kg
Thiopenthal Thiopenthal - - until the disapperance of the eyelid reflex Maintenance:Maintenance: Fentanyl, Fentanyl, N2O/O2, muscle relaxant, , muscle relaxant,
with supplementation as necessary („balanced”)with supplementation as necessary („balanced”)
neurolept analgézia
Neurolept anesthesia/analgesiaNeurolept anesthesia/analgesia
Advantages:Advantages: Cooperable but emotionally indifferent patientCooperable but emotionally indifferent patient „ „ mineralisation”, mineralisation”, antinociceptionantinociception Possibility of balanced maintenancePossibility of balanced maintenance
Disadvantages:Disadvantages: DHBP is an DHBP is an receptor blocking agent – BP fall receptor blocking agent – BP fall
possible, prolonged actionpossible, prolonged action Control of anesthesia depth not easy, slow actionsControl of anesthesia depth not easy, slow actions
Induction by continuous infusionInduction by continuous infusion
Oxigygen inhalationOxigygen inhalation PropofolPropofol - TCI – - TCI –5-6 5-6 g/mlg/ml continuously reduced continuously reduced Remifentanil Remifentanil or or SufentanilSufentanil or or Fentanyl,Fentanyl,
(Fentanyl Fentanyl bolus 1-2 mg/kg1-2 mg/kg))RemifentanilRemifentanil: 5mg in 50 ml: 1 : 5mg in 50 ml: 1 g/kg bolus 0.05-1 g/kg bolus 0.05-1 g/kg/ming/kg/minFentanylFentanyl: 500 : 500 g (10 ml) diluted to 50 ml,g (10 ml) diluted to 50 ml,
1-2 mg/kg bolus, 100-150 mg(5-7.5 ml)/hour1-2 mg/kg bolus, 100-150 mg(5-7.5 ml)/hourCumulation!Cumulation!
After the patient is asleep, mask ventilation, than muscle After the patient is asleep, mask ventilation, than muscle relaxationrelaxation
IntubationIntubation
Monitoring of anesthesia depthMonitoring of anesthesia depth Changes in the ventilation type and frequencyChanges in the ventilation type and frequency Autonomic nerve responses to stimuliAutonomic nerve responses to stimuli Mechanical methodsMechanical methods
„„isolated upper arm”isolated upper arm” Measurement of lower oesophagus contractions Measurement of lower oesophagus contractions
(Measurement of the concentration of anesthetics in (Measurement of the concentration of anesthetics in the blood)the blood)
Cerebral electric activity measurementsCerebral electric activity measurements Cerebral function monitorCerebral function monitor BISBIS monitoringmonitoring PSI (physical state index)PSI (physical state index) AEPAEP
Important valuesImportant values
Blood/gas coefficientBlood/gas coefficient::
Halothan:2.4 Isofluran 1.4 Sevofluran 0.6 Desfluran 0.4Halothan:2.4 Isofluran 1.4 Sevofluran 0.6 Desfluran 0.4
MACMAC= Minimal Alveolar Concentration= Minimal Alveolar Concentration
Concentration of an inhalation anesthestic which Concentration of an inhalation anesthestic which prevents movements at surgical incision in 50% of prevents movements at surgical incision in 50% of the patients.the patients.
1 MAC 1 MAC isofluranisofluran = = 1.15 volume%1.15 volume%
1 MAC 1 MAC sevofluransevofluran== 2 volume% 2 volume%
1 MAC 1 MAC desflurandesfluran = = 7.3 volume% 7.3 volume%
MAC reduced: by premedication, sedato-hypnotics, age, pregnancy, alcohol, hypthermia, hyponatremia, N2O co-administration
Factors influencing the uptake of the Factors influencing the uptake of the inhalational agentinhalational agent
Inspiration concentration Inspiration concentration (parcial pressure)(parcial pressure) Alveolar ventillationAlveolar ventillation Blood/gas coefficientBlood/gas coefficient
bad solubility bad solubility – early saturation– early saturation Tissue uptake, saturationTissue uptake, saturation
A concentration difference between the end tidal A concentration difference between the end tidal (alveolar) and inhaled concentration: alveolar) and inhaled concentration: FFAA/F/FII – – equilibrium after long continuous administrationequilibrium after long continuous administration