LOGO

TCI : Target Controlled Infusion

Basic knowledge & Clinical experience

on

นพ.วิโรจน เพง ผล โรงพยาบาลราชบุรี

LOGO

TIVA : Why ? What ?1

Basic principle of TIVA & TCI2

TCI : Pharmacokinetics & Model 3

Induction, maintenance & emergence4

TCI : Advantage & clinical application5

TCI: Precaution & pitfalls6

LOGODisadvantage of InhalationsDisadvantage of Inhalations

1

Global warming

Work place pollution

3

•Nausea-vomiting •Emergence dysphoria•↑ICP, ↑IOP•Inhibit autoregulation

& HPV(hypoxic pul vasoconstriction)

•Trigger MH

2

Specific equipment anesthetic machine + vaporizer

Special ventilatory technique &compromised airway seals : bronchoscopy,

Environment Environment TechniqueTechnique InhalationsInhalations

LOGO

TTIVAIVA ::Total Intravenous anesthesia

the use of IV agentsexclusively to provide

a complete anesthetic condition

ImmobilityAnalgesia

opioids –

Morphine, fentanyl, remifentanil

dexmedetomidine, ketamine, NSAID

propofol, thiopentone,

midazolam dexmedetomidine,

non-depolarize muscle relaxant

Balancedanesthesia

DefinitionDefinition

Hypnosis

LOGODevelopment of delivery systems

Single injection, Intermittent injection,

Continuous iv. drip

Infusion pumpSyringe pump

Control rate

1st 2nd

AIMAIM maintenance of optimum & stable anesthetic condition

stable

plasmaconcentration

Bolus + elimination

Elimination

LOGODevelopment of delivery systemsDevelopment of delivery systems

22ndnd Infusion pumpSyringe pump : control rate

Controllable infusion rate

Intermediate blood supply

: muscle

Poor bl.supply

:fat

Rich blood supply

LOGOTIVATIVA--MCI: manually controlled infusionMCI: manually controlled infusion

LessPain

With N2

OWithout

N2

O

Start 8 10 12>10 mins. 5 7 9

>2 hrs. 3 5 7

Initial infusion rate 10 minSubsequence adjustmentso as to maintain a stable level of anesthesia

Not easy to control Not easy to control TimeTime--consuming calculationconsuming calculation

No compensate for interrupted infusionNo compensate for interrupted infusion

Delayed emergence !!!Delayed emergence !!!Require skill & experienceRequire skill & experience

““are used to designate

manual adjustment of infusion rates for anesthesia syringe pumps”

duration stop1 ชม. 10

นาที

3 ชม. 15 นาที4 ชม. 20 นาที

mg/kg/hr

LOGODevelopment of delivery systemsDevelopment of delivery systems

Single injection, intermittent injection,

Continuous iv. drip

Infusion pumpSyringe pump

TIVA:MCI

Target controlled Infusion

TIVA: TCI

1st 2nd 3rd

AIMAIM maintenance of optimum & stable anesthetic condition

LOGOTarget controlled infusion : TCITarget controlled infusion : TCIis an infusion system which allows the anaesthetist to

select the target blood concentrationrequired for a particular effect,

and then to control depth of anaesthesia by adjusting the requested target concentration

LOGOOpen, threeOpen, three--compartment modelcompartment model

Cet : effect targetSchneider model

Cp : plasmaMarsh model

Variable rate

LOGOTCI: basic principleTCI: basic principle

infusion rates are altered automatically according to a validated pharmacokinetic model

(Propofol :Marsh, Schnider, Remifentanil : Minto model)

Anesthesiologist selects

and inputs targets

blood concentration

TCI SubsystemMicroprocessor

+pharmacokinetic program

Patient

Infusion pump incorporating

1.Age 2.BW3.Height 4.Sex

LOGOTCI: pharmacokinetic modelTCI: pharmacokinetic model

Model

Drug specific : Remifentanil : Minto modelPropofol : Schneider model

A drug : different PKPropofol : Marsh model

Schneider model

LOGOB.E.T.schemeB.E.T.scheme

Targetconcentration

TransferCompensate for peripheral distribution

Decreasing infusion rate= Ct x V1

(k12

e(-k21

t)+k13

e(-k31

t))

Bolus

Fill central compartment

Bolus dose = Ct x V1

EliminationCompensate for

metabolism & elimination

= Ct x CL=Ct x K10

x V1

AIMAIMTo achieve a chosen concentration

LOGODrug for TCI : hypnoticsDrug for TCI : hypnotics

2 hrs.infusion→100 mins

3 hrs.infusion →25 mins

LOGODrug for TCI : analgesicsDrug for TCI : analgesics

Ideal for TCI

LOGOOpen loopTCI: propofol Open loopTCI: propofol

Fresofol in Syringe 50 ml Extension , 3-way

Syringe TCISchneider modelKey patient data

selectTarget Cet

1st 2nd 3rd

LOGO

Target = ?

CP50 2.7–3.4 µg/ml loss of response to verbal or tactile stimuli*

Cet 2-3 µg/ml loss of eyelash reflexCet 4-8 µg/ml for

anesthetic procedureIntubation, LMA

* : Vuyk J et al.

Anesthesiology 1992;

77:

3.

Crankshaw DP et al.

Anaesth Intensive Care 1994;

22:

481.

Smith C et al.

Anesthesiology 1994;

81:

820.

TCITCI--propofol concentrationpropofol concentration

Target concn based on•Level of stimulation•Drug interaction•Desired clinical endpoint•Individual variability

LOGOTCI for induction & intubationTCI for induction & intubation

Premedication : MO 5-10 mg, midazolam 1-2 mgInduction : propofol Cet 2-3 µg/ml

Check for loss of consciousness : eyelash reflex

Check for ventilation if OK muscle relaxationIntubation : Non-depolarize muscle relaxant 90-180 sec

Propofol Cet 4-8 µg/ml 45-60 sec

After taping endotracheal tube : no stimuli ↓Cet 2-3 µg/ml next painful stimuli : before skin incision ↑Cet 4-6 µg/ml

LOGO

titratetitrateUse TCI syringe as a iv. vaporizer for Fresofol Titrate depth of anesthesia to optimum level

bybyseverity of stimuli : more severe↑Cet, less severe:↓Cet clinical signs : HR, BP, movement, sweating, pupil sizedepth monitor: BIS, CSI

tricktrick ↑Propofol Cet before noxious stimuli↓Propofol Cet after a period of infusionTo achieve hemodynamic stability

rememberrememberAdequate analgesics & muscle relaxant supplementBlood & Volume replacementCheck for signs of awareness

TCI for maintenanceTCI for maintenance

LOGOPrepare for emergencePrepare for emergence

• Propofol Cet maintenance 3-5 µg/ml → 4 µg/ml • Set wake up concn 1.5-2.0 µg/ml → 2 µg/ml

• wake up time = time from 4→2 µg/ml = X min• X min to end of operation→ Stop or Cet 0.01 µg/ml• Observe Propofol Cet & clinical, BIS

• Usually wake up < 1.5-2.0 µg/ml →later than wake up time• Reverse MR → extubation

Rescue dose for unexpected event !!

LOGOCheck TCI advantage : post op.Check TCI advantage : post op.

non-idealenvironment

Not inhibit HPV

↓IOP

Clear headedrecovery ↓ICP ↓CMR

↓emesis

Do not prescribe prophylaxis for

PONVDate of BirthOrientation

Emergence delirium

LOGO

LOGO

LOGOTCI advantages & clinical applicationTCI advantages & clinical application

non-idealenvironment

Not inhibit HPV

↓IOP

Clear headed recovery without delirium ↓ICP ↓

CBF↓CMR

↓emesis

Laporoscopic Sx.ObstetricsGI surgeryEye, ENT

Hx of PONVneurosurgery

Day case surgeryNeuro exam

X-rays ER

MilitaryDeveloping

country

Open eye injury

One lung ventilation

LOGOTCI for neuroanesthesiaTCI for neuroanesthesia

Goal : : Not only an adequate anesthetic condition (amnesia/sedation, analgesia, immobility & hemodynamic stability)

..BUT..

1. optimal operating conditions 2. neurological protection3. rapid emergence from anesthesia for

neurological examination

LOGOGoal I : optimal neurosurgical conditionGoal I : optimal neurosurgical condition

↓ICP

Low CBFAdequate

CPP

minimal brain bulk

↓

CMR O2

Optimal operating condition

LOGOspecific effects of IV. & inhalationsspecific effects of IV. & inhalations

Drug CBF CMR

ketamine Increase increase

nitrous oxide increase increase

halothane increase decrease

enflurane increase decrease

isoflurane increase decrease

desflurane increase decrease

sevoflurane increase decrease

thiopental decrease decrease

etomidate decrease decrease

propofol decrease decrease

LOGOTCI for neuroanesthesiaTCI for neuroanesthesia“Volatile anesthetics have been shown to affect

…cerebral autoregulation and intracranial pressure…which can make the surgery more difficult and dangerous, increasing the risk of …….ischemic cerebral insults”

“ the reduction in cerebral blood flow with ↑

in cerebral vascular resistance and ↓

CMRO2

seems to make TIVA ..the more advantages anesthesia technique ..

for patients with increased ICP ”

: :Todd MM et al: Anesthesiology 78:1005-1020,1993

: Neurosurgery 61[ONS suppl 2] : ONS369-ONS378,2007

LOGOGoal II : cerebral protection Goal II : cerebral protection

Pharmacologic technique

Non - pharmacologic

technique

↓O2 demand↑O2 supply

Avoid ischemia

LOGONonNon--pharmacologic techniquepharmacologic technique

Good venous returnUpright head

HemodilutionHct 30-34 %

euvolemia

Mild hypothermia1۫c ↓CMRO2

7% 32-35 ۫ ۫c protection

not recommendAvoid hyperthermia

Glusoce control< 150 mg/dl> 60 mg/dl

Avoid Hypoxia, Hypercarbia

PaCO2

28-32 mmHg

Avoid hypotensionMAP > 70 mmHgSAP > 90 mmHg

CPP = MAP-ICP = 60-70

Brain protection

LOGOPharmacologic techniquePharmacologic technique

↓Ca

++,↓Na+

influx

↓free radical

IV. Agent

•Thiopental•Propofol

•Local anesthetics

But not Ketamine

Inhalation

•Isoflurane•Sevorane

•Desflurane

But not halothane,

N2 O

Prevent apotosis

Block ischemic cascade

↑GABA,↓NMDA

LOGOGoal III : rapid emergence for neuroexam. Goal III : rapid emergence for neuroexam.

Isoflurane

Propofol

Sevoflurane

Desflurane

slow fast faster fastest

Clear headness dysphoria ?

LOGORatchaburiRatchaburi’’s experiences experience

Induction : TCI Propofol Cet 2-3 → 6-8 µg/ml → 2-3 µg/ml

Air:O2, Fentanyl, Midazolam, Muscle relaxants

Maintenance : TCI Propofol →Cet 4-6 µg/ml

(Cet 6.2 µg/ml burst suppression)

End point :

systemic hypotension is a major contributor to poor outcome –

avoid

SBP < 90 mmHg level II*

BP BIS

* www.braintrauma.org

ICP

40 -

50brain relaxation & surgical access

LOGOMost common pitfallsMost common pitfalls

Delayed awakening Movement Hypotension Not deep

enough

Unfamiliar

BIS,CSI

delayedmuscle relaxant

Supplement

Neuromuscular monitoring

Hypovolemia

Fluid statusevaluation

Unsecured iv. access

Always checked !!

LOGOOther problemsOther problems

Awareness Bradycardia agitationBIS diff.

from clinical

Unfamiliarlong dead space

Inadequateanalgesics

BIS,CSI

On ß-block ? judgement

LOGOprecaution

Not recommend for TCI-propofolNot recommend for TCINot recommend for TCI--propofolpropofol

No available model placental transfer Drug metabolite

Age <15 BW>150BW>150 C/SLiver

impairment

LOGOPropofolPropofol--related infusion syndromerelated infusion syndrome

High dose infusion >5 mg/kg/hr for > 48 hrs

Abrupt onset of profound bradycardia, metabolic acidosis , lipemic plasma,

renal failure, fatty liver, rhabdomyolysis or myoglobinuria

Risk factors

: poor oxygen delivery, sepsisserious cerebral injury

Monitor

: acidosis, K+, renal function

symptomssymptomssymptoms

LOGOTake home message :Take home message :

TCI

Simple…. to operateContinuous process…

from induction through to maintenance

Easy to titrate…

the level of anesthesiaGood control of depth…

of anesthesia

Improved control …of cardiovascular and respiratory parameters

Try it !!

LOGO