GENERAL ANESTHESIADr. Emilzon Taslim, Sp. An. M.KesMedical Faculty University of AndalasM. Djamil Hospital

ANESTHESIAGENERALIntravenousInhalationIntramuscularLOCALTopicalInfiltrationBlock peripheral nerveSpinalEpiduralCaudalIVRACOMBINATIONSpinal + propofol

General anesthesiaA reversible state of unconsciousness produced by anesthetic agent, with loss of sensation of pain over the whole body.Reversible irregular CNS depression. General anesthetic drugs are administered by inhalation, intravenously, intramuscularly, orally, rectally.

The order of descending depression of the CNSCortical and psychic centersBasal ganglia and cerebellumSpinal cordMedullary centers

GENERAL ANESTHESIATRIAS ANESTHESIAHypnoticAnalgesicRelaxationBALANCED ANESTHESIA

Balance anesthesia

Anesthesia componentDrugsHypnoticPentothal, Propofol, Enflurane, Isoflurane, SevofluraneAnalgesicPethidine, Morphine, Fentanyl, Sufentanil, RemifentanilRelaxationSucc choline, Atracurium, Cisatracurium, Pancuronium

Anesthetic drugsVolatile anesthetic inhalation : Halogen hydrocarbon (halothane) Halogen ether: enflurane, isoflurane, desflurane, sevofluraneGas anesthetic inhalation : cyclopropane, N2O, ethylene.Intravenous : thiopental, propofol, ketamine, etomidate, diazepam, midazolam

Concept balanced anesthesia

Component anesthesiaVIMATIVAHypnoticSevo, Iso, Enf, Hal, DesfluranPropofol, Pento, Ket, MidAnalgesicFentanyl, alf, suf ,Mo, pethidine, remifentanil Fentanyl, alf, suf ,Mo, pethidine, remifentanilRelaxationDepol & non depolDepol & non depol

Indication general anesthesiaInfant and young children.Adult who prefer general anesthesia.Extensive surgical proceduresPatient with mental diseaseProlonged surgeryPatient with a history of toxic or allergic reaction to local anesthetic drugsPatient on anticoagulant treatment

General anesthesiaInduction inhalation, maintenance anesthesia with inhalation anesthetic (VIMA)Induction intravenous , maintenance anesthesia with intravenous anesthetic (TIVA)Induction intravenous, maintenance anesthesia with inhalation anesthetic

General anesthesia techniqueSpontaneous breathingControlled ventilation

Face maskIntubationLMA (Laryngeal Mask Airway)COPA (Cuffed Oro Pharyngeal Airway)LSA (Laryngeal Seal Airway)

ConcentrationofAnestheticAgent

Techniques of general inhalation anesthesiaOpen-drop techniqueInsufflationAyre T-piece systemSystem with non-rebreathing valveSemiclosed Closed

Breathing circuit systemOpen systemSemi open systemSemi closed systemClosed system

Flow Rate Definition :Metabolic-flow: 250 ml/minuteMinimal-flow : 250 - 500 ml/minuteLow-flow : 500 - 1000 ml/minuteMedium-flow : 1-2 liter/minuteHigh-flow: 2-4 liter/minute

Advantageous Low-flow anesthesiaLess of anesthesia gas consumptionLess of pollutionHeat loss decreaseCost effective

THE EQUIPMENT

Component anesthesia machineGas sources : Oxygen, N2OReducing valve or pressure regulatorFlow meter Vaporizer for halothane, enflurane, isoflurane, desflurane or sevoflurane.CO2 absorption system (soda lime or bara lime)

SEE THE MOVIE

L.Heart

R.Heart

FA

Circulation

V.R.G.BrainHeartSplancKidney

M.G.

V.P.G.

% %

20 55

75

7

5

38

Pa

Uptake and distributionRespiration factorCirculation factorAnesthetic gas factorTissue factor

Respiration factorInspiration concentrationVentilation effect

Circulation FactorSolubility (partition coefficient)Cardiac outputThe difference of gas partial pressure alveoli and vein

Partition coefficient of anesthetic

AnestheticBlood/gasBrain/bloodTissue/bloodEtherHalothaneEnfluraneIsofluraneN2O12.12.31.81.40.471.12.62.63.71.10.92.51.74.01.2

Anesthetic gas factorMAC (Minimal Alveolar concentration)MAC 50, MAC 95MAC Ei 50, MAC Ei 95MAC BAR 50, MAC BAR 95

MAC inhalation anestheticMAC =minimal alveolar concentration, in 1 atmosphere, 50% patient without movement in noxious stimuli MAC Ei = concentration of volatile agent permitting laryngoscopy and intubation without untoward movement.MAC BAR = concentration of volatile agent required to block adrenergic response to skin incision

MAC inhalation anesthetic, 40 years old.

Volatile anestheticMACHalothaneEnfluraneIsofluraneDesfluraneSevofluraneN2O0,721.681.126.02.05105.2

Factors influencing or not influencing MAC

MAC decreasedMAC unchangedMAC increasedIncreasing ageCNS depressant: alcohol, barbiturate, lidocaine, benzodiazepine, narcoticDuration of anesthesiaGenderSpeciesHypertensionHypocarbiaAlcoholism chronicHyperthermia > 42HypercarbiaAnemia

Tissue factorTissue rich vessel : brain, heart, endocrine, kidney.Intermediate : muscle, skin. Fat.Tissue poor vessel : ligament, tendon.

General anesthesia planningPre operative visitPremedicationAnesthesia technique : General, RegionalIntraoperativePostoperative

Anesthesia technique :General anesthesiaAirway controlledInductionMaintenance anesthesiaAnalgesiaMuscle relaxation

IntraoperativeMonitoringPatient positionCrystalloid and colloidSpecial technique

PostoperativePost operative pain treatmentSend patient to Ward or ICU

INTRAVENOUS ANESTHETIC

Intravenous anestheticPentothalPropofol EtomidateMidazolamDiazepam

Ideal intravenous anestheticWater solubleNon irritationNo anta analgesic effectRapid and smooth InductionCardiovascular stable in clinically dose

ThiopentoneBlood pressure decreaseHeart rate increase or decreasePeripheral vasodilatationHeart contraction depressedLarynx spasm, bronchus spasmRespiratory depression until apnoeaDose 4-6 mg/kg BW

Relative contraindication thiopentoneAsthma bronchialeSevere liver diseaseSevere kidney diseaseSevere anemiaHypotensionShock

KetamineDissociative anestheticDeliriumHallucinationIncrease blood pressure : systolic 23% from base lineIncrease heart rateArrhythmiasHypersecretionDose 1-3 mg/kg I.v or 9-11 mg/kg I.m

Indication and Contraindication KetamineIndication : short surgeryContraindication : Hypertension systolic > 160 mmHgArrhythmiasHeart failurePharynx and larynx surgery without intubation.

PropofolNew intravenous anestheticFast onset, short duration of actionAccumulation minimalFast recoveryRapid metabolismNo complication at site of injection Dose 2-2.5 mg/kg BW

Pharmacology PropofolNo histamine release/reaction anaphylactoid (chremophor El change with soya bean oil).Perivascular injection, tissue necrosis negative. Injection intra artery : tissue necrosis negative.

Effect Propofol to CNSHypnotic effect 1,8 time pentothalAirway depression > pentothalAnti emetic effectNo anti convulsant effect

Comparative properties of intravenous anesthetics

ThiopenKetaminPropofDiazepMidazAqueous solutionAvailable in solutionPain on injectionVenous thrombosis+

-

-

-+

+

-

--

+

+

--

+

+

++

+

-

-

Comparative properties of intravenous anesthetics

ThiopenKetaminPropofDiazepMidazRapidly actingSmooth inductionRespiratory depressionCardiovascular depression+

++

+

++-

+

-

-+

+

+

++-

+

-

+/--

+

+/-

+/-

Comparative properties of intravenous anesthetics

ThiopenKetaminPropofDiazepMidazRapid recoverySmooth recoverySuitable for infusionInteraction with relaxant-

+

-

--

-

+/-

-+

+

+/-

--

-

-

--

-

-

-

Resume: Effect anesthetic non volatile to organ system

DrugHRMAPVent BdilThiopentoneDiazepamMidazolamMeperidineMorphineFentanylKetaminePropofol0/ 0**00**0 0

Resume: Effect anesthetic non volatile to CNS

DrugCBFCMRO2ICPThiopentoneDiazepamMidazolamMeperidineMorphineFentanylKetaminePropofol

INHALATION ANESTHETIC

Choice of anesthetic inhalationCardio pulmonal effectProduct degradation with soda limeWhat metabolites ?How much metabolism?

Ideal anesthetic inhalationPleasant odor and non irritationLow solubilityNo organ toxicSide effect cardiovascular and respiration minimalCNS effect reversible without stimulant activityEffective in high O2 concentration Boiling pressure and boiling point can delivered by vaporizer standard

New Trend in General AnesthesiaVIMA Fast-Track AnesthesiaLow-flow AnesthesiaLow-cost AnesthesiaSingle-breath induction (Rapid induction)

Physicochemical propertiesHalothaneEnflIsofl Desfl SevoOdor + - - - +Irritating to Resp system - + + + -Solubility2,351,91 1,40,42 0,63MAC0,761,68 19156,0 2,05Metabolism17-20%2,4%

Interaction with Sodalime

Anestheticdegradation Product organ Toxicityclinical RelevancyHalothaneBCDFENephrotoxicNon identified to dataEnfluraneCO--IsofluraneCO--DesfluraneCO--SevofluraneCompound ACompound BNephrotoxicNon identified to date

WHY VIMA???intravenous induction, ex: Propofol : rapid and smooth induction, but need vein access first, hypotension, apnoe.Pediatric anesthesia commonly by VIMA.More advantages than intravenous induction, maintenance inhalation.

Cardiovascular effect of Volatile inhalational anesthetics

VariableHalothaneEnfluraneIsofluraneBlood pressureVascular resistanceCardiac outputCardiac contractionCVPHeart rateSensitization of the heart to epinephrine 0 0 0000?0 = No change (

Clinical pharmacology of Inhalational anesthetics : Respiratory

N2OHaloEnflurIsoflu SevofluTidal volumeResp ratePaCO2 resting

Clinical pharmacology of Inhalational anesthetics : CNS

N2OHaloEnflurIsoflu SevofluCBFICPCMRO2Seizure

Clinical pharmacology of Inhalational anesthetics

N2OHaloEnflurIsoflu SevofluHBF Nondep blockadeMetabolism

0.004

15-20

2.5

0.2

2-3

N2O1.5 time heavier than airMust be give with O2 100%Weak anestheticAnalgesic N2O 20% equal with 15 mg morphineDont use in closed systemAt the end of anesthesia, to prevent diffusion hypoxia O2 100%

Advantages N2ORapid induction and recoveryNo sensitized myocardium with catecholamineNo irritation respiratory tractOdor pleasantStrong analgesic

Disadvantages N2OWeak anestheticNo muscle relaxation effectNeed high concentration oxygenPossibility aplasia bone marrow

HalothaneA clear, colorless, potent volatile liquid.Metabolism 17-20%

Advantages HalothaneRapid, smooth induction and recovery.PleasantNon irritating, no secretionBronchodilatorNonemeticNon flammable and non explosive

Disadvantages HalothaneMyocardial depressantAn arrhythmia producing drugSensitizes the myocardial conduction system to the action of catecholaminesA potent uterine relaxantPossible toxic to the liverShivering during recovery period.

EnfluraneA clear, colorless, stable volatile liquid with a pleasant ether-like odor.A potent inhalation anesthetic CNS excitationUse of epinephrine : saver than halothane.

Advantages EnfluranePleasantRapid induction and recoveryNon-irritating : no secretionBronchodilatorGood muscle relaxationNonemeticNon flammable and non explosiveCompatible with epinephrine

Disadvantages EnfluraneMyocardial depressantShivering on emergenceCSF production increaseCNS excitation, in high dose and hypocarbia.

IsofluraneA stabe, volatile liquidA isomer enfluraneInhalation anesthetic choice for neurosurgical patient, kidney, liver.

Advantages IsofluraneRapid induction of anesthesia and swift recoveryNonirritating : no secretionBlood pressure remain stableIndicated in poor-risk patient

Disadvantages IsofluraneLess than halothane and enflurane

SevofluraneInhalation anesthetic with low solubility (0,63), low MAC (2,05), pleasant odor, no airway irritation, rapid uptake and elimination , cardio vascular stable.Rapid induction, with technique single breath induction, induction time 23 seconds.

SevofluraneDrugs of choice for Neuro anesthesia : WCA 2000 Montreal, Canada.Drugs of choice for Pediatric Anesthesia : ESA Barcelona, 1998. ASPA, Singapore, 2000., ESA Sweden 2001.In Sectio Caesarea equal with Isoflurane and spinal anesthesiaReduce sphlannic blood flow, hepatic blood flow lesser than other anesthetic inhalation.

NARCOTIC ANALGESIC

Narcotic analgesic ideal :

Wide margin of safetyFast onset of actionShort duration of actionEasier analgesia controlledStrong analgesic no histamine releaseNon active metabolite

Opiate in Anesthesia

1. Premedication2. Induction Anesthesia3. Narcotic anesthesia4. A part of balanced anesthesia5. Adjuvant in regional anesthesia6. Neurolept anesthesia7. Post operative pain relief

Drugs Protein binding Lipid solubility

Morphine ++ +Pethidine +++ ++Fentanyl +++ ++++Sufentanil ++++ ++++Alfentanil ++++ +++

Note : + = very low; ++ = low; +++ = high ++++ = very high

Morgan GE. Clinical Anesthesiology, 1996.

Narcotic effect :

Bradycardia : central vagotonic effect & SA & AV node depression Respiratory depression : respiratory rate, rhythm, Response CO2, Minute Volume, Tidal VolumeMuscle stiffnessNausea vomiting cause by stimulation CTZ, GIT mobility, decrease gastric mobility, increased gastric volume

Clinical Doses of Narcotics

Drugi.v doseOnset (min)Approximate durationMorphineMeperidineFentanylSufentanilAlfentanil0.05-0.3 mg/kg0.5-1 mg/kg1-5 ug/kg10-40 ug/kg30-80 ug/kg5-105-102

MUSCLE RELAXANT

Muscle relaxantVery useful in general anesthesia.laryngoscopy and intubation more easier and avoid injuryMuscle relaxation very useful during surgery and controlled ventilation

Ideal muscle relaxantNon depolarizationRapid onset, short duration of actionRapid recovery, high potencynon cumulative, metabolite non activeNo cardiovascular effectNo histamine releaseCounteract with anticholinesterase

Mechanism neuromuscular blockadeCompetitive block : non-depol, avoid AcCh access to receptor.Depolarization block : depol, depolarization as AcCh but permanentDeficiency block: influence syntesis and release AcCh: Procaine, toxin botulinus, Ca decrease, Mg increase. Morgan GE, Mikhail MS. Clinical Anesth, 1996

Terminology in muscle relaxantED 50 : dose what can paralyzed 50% muscle strengthED 90 : dose what can paralyzed 90% muscle strength.Onset : interval between start of injection until maximal effect

Table 9 - 1. Depolarizing and nondepolarizing muscle relaxants.

Depolarizing

Nondepolarizing

Short-acting

Succinylcholine

Decamethonium

Long-acting

Tubocurarine

Metocurine

Doxacurium

Pancuronium

Pipecuronium

Gallamine

Intermediate-acting

Atracurium

Vecuronium

Rocuronium

Short-acting

Mivacurium

Nondepolarizing drugDo not produce muscular fasciculationEffect are decreased by anticholinesterase agent, depolarizing agent, lowered body temperature, epinephrine, acetylcholineEffect are increased by non-depolarizing drugs, volatile anesthetic .

Depolarizing drugsProduce muscular fasciculation .Effect are increased by anticholinesterase agent, Acetylcholine, hypothermiaEffect decrease with non-depolarizing relaxant drugs, anesthetic inhalationDose Succ choline : 1 mg/kg BW

Burn injuryMassive traumaSevere intra-abdominal infectionSpinal cord injuryEncephalitisStrokeGuillain-Barre syndromeSevere Parkinsons diseaseTetanusProlonged total body immobilizationRuptured cerebral aneurysmPolyneuropathyClosed head injuryNear drowningHemorrhagic shock with metabolic acidosisMyopathies ( eg, Duchenness dystrophy )Table 9 - 5. Conditions causing susceptibility to succiniylcholine-induced hyperkalemia.

Table 9 - 6. A summary of the pharmacology of nondepolarizing muscle relaxant

Sheet1

RelaxantMetabolismPrimaryOnsetDurationHistamineVagalRelativeRelative

ExcretionReleaseBlockadePotency1Cost2

TubocurarineInsignificantRenal++++++++01Low

MetocurineInsignificantRenal+++++++02Moderate

Atracurium+++Insignificant+++++01High

Mivacurium+++Insignificant++++02.5Moderate

DoxacuriumInsignificantRenal++++0012High

Pancuronium+Renal+++++0++5Low

Pipecuronium+Renal+++++006High

Vecuronium+Biliary++++005High

RocuroniumInsignificantBiliary+++++0+1High

1For example, pancuronium and vecuronium are five times more potent than tubocurarine or atracurium

2Based on average wholesale price per 10 mL; does not necessarily reflect duration and potency

Onset : + = slow; ++ = moderately rapid; +++ = rapid

Duration : + = short; ++ = intermediate; +++ = long

Histamine release : 0 = no effect; + = slight effect; ++ = moderate effect; +++ marked effect

Vagal blockade : 0 = no effect; + = slight effect; ++ = moderate effect

Sheet2

Sheet3

Relaxation

DrugED95 (mg/kg)Recommended intubating dose (mg/kg)Infusion rate for steady state blockade (mg/kg/h)AtracuriumPancuroniumVecuronium0.210.0670.0430.3-0.60.005-0.0080.08-0.10.250.0320.078

INDUCTION AND MAINTENANCE OF ANESTHESIA

Choice of anesthesia technique depend on:Patient conditionSkill anesthetistSkill surgeonHospital socioeconomi

Problem during induction of anesthesiaMain problem : airwaySign of partial obstruction : snoring, crowing, gargling, wheezing, chest retraction, cyanosisSign of total obstruction : air flow from nose/mouth negative, supraclavicular retraction, intercostal retraction, cyanosis

Other problem during inductionRespiratory depressionCoughLarynx spasmMucus and salivavomiting

Airway controlledWithout equipment : Triple mannuver SafarWith equipment: OPA (Oro Pharyngeal Airway) NPA (Naso Pharyngeal Airway) LMA ( Laryngeal Mask Airway) ETT (Endo Tracheal Tube)

Indication IntubationHead and neck surgeryDifficult airwayThoracotomyLaparotomyLateral positionProne positionControlled ventilation

Technique laryngoscopy Head positionInsertion laryngoscope bladeVisualization epiglottisLift epiglottisView larynx and surrounding structure

Advantages Endotracheal intubationEnsures a patent airwayNormal anatomic dead space (75 ml) is decreased to 25 ml.Ventilation can be assisted or controlledPossibility of aspiration diminished drasticallySuctioning of the lung is facilitated

Disadvantages endotracheal intubationIncreases resistance to respirationTrauma to the lips, teeth, nose, throat, larynx.

Complication IntubationTeeth ruptureMouth bleedingEndobronchial intubationOesophageal intubationSore throatHypertensionArrhythmias

Induction techniqueMask induction / inhalationIntravenousIntra muscularPer rectal

Mask Induction with SevofluraneGradual InductionSingle Breath InductionTriple Breath Induction (Multiple Breath Induction)

Fast technique with Single Breath Induction, without cough, breath holding, spasm larynx.

Gradual InductionClassic method for Mask Induction.To decrease respiratory tract irritation and non pungent odor no need for Sevoflurane.Combined with N2O or Oxygen 100%.Concentration Sevo increase 0.5-1,5 vol% every 2-3 breath until anesthesia adequate.Commonly reach in 60-90 seconds with Sevo 7%.

Single-Breath InductionPriming circuit with N2O 60% + Sevo 8% 30 seconds.Ask patient for maximal expiration (until residual volume) face mask .Ask patient inspiration maximal (vital capacity), keep 20 seconds, then normal breathing.After eyelash reflex negative, Sevo turn to 2%.

Triple Breath InductionA variation from Single Breath InductionAsk patient 3 times deep breath.Difference with Single Breath, no breath holding.Commonly patient sleep, in 2-3 breathing.

How to maintain anesthesia ?Maintenance anesthesia depend on deep of anesthesia to reach adequate anesthesia.Commonly with SEVO 1-1,5 vol% depend on type of surgery, spontaneous breathing or controlled.To reduce vol% (MAC) : add N2O or Fentanyl.

Sign of deep anesthesiaPRST Score (balanced anesthesia)Guedel sign (ether anesthesia)PRST Score (score 2-4: adequate anesthesia) P = Systolic arterial pressure (mmHg) R = rate (heart rate) S = sweat/ lacrimation T = tear

PRST Scoring indexes for Balanced anesthesia

IndexConditionScoreSystolic arterial pressure (mmHg)

Heart rate (beats/min)

Sweat

Tears or LacrimationLess than control + 15Less than control + 30More than control +30Less than control + 15Less than control + 30More than control +30NilSkin moist to touchVisible beads of sweatNo excess tears when eyelids openExcess teas visible when eyelids openTears overflow from closed eyelid012012012012

ExtubationAfter adequate ventilationIn deep anesthesia or after patient awakeClear airwayOxygen 100% after and before extubation

Factor which influence total anesthetic inhalation :

1. Constanta2. Fresh gas flow3. Volume % (MAC)4. Length of surgeryTotal anesthetic inhalation = constanta x fresh gas flow (ml) x vol % x time (minute)

If length of surgery 2 h, total Sevoflurane : Inductionfirst 30 secondFresh gas x 1/183x Vol % x timeflow (ml) (minute) 6000 x 1/183 x 8% x 0,5 = 1,33 minute for intubation : 6000x 1/183 x 2% x 3 = 1,93 minute start for low-flow : 3000x 1/183 x 3%x 3 = 1,4second 3 minute: 1000x 1/183 x 1%x 3 = 0,5Operation 2 hours : 1000x 1/183x 1% x 120 = 6,5Total Sevoflurane 11,6 ml

TIVA CONTINU

Propofol 6-10 mg/kg/h + Vecuronium 0.1 mg/kg/h + Fentanyl 2 ug/kgPentotal 1-3 mg/kg/h + Vecuronium 0.1 mg/kg/h + Fentanyl 2 ug/kgKetamine 2 mg/kg/h + Vecuronium 0.1 mg/kg/h + Diazepame 0.25 mg/kgMidazolam 50 ug/kg/h + Ketamine 2 mg/kg/h + Atracurium 0,25 mg/kg/h

POSTOPERATIVESee: Lecture of RR and ICU

Thank you for your kind attentionTatang BisriBandung, 2001

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