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Modern

Anesthesia Machine

ผศ. นพ. ธนิต วีรังคบุตร ภาควิชาวิสัญญีวิทยา รพ. รามาธิบด ี

Modern anesthesia machine

advanced ventilation feature

automated check out

low flow adaptation

depending upon electricity

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What is new ?

ventilator

: modes, accurate tidal volume

adaptation to low flow

automated control of end-tidal gas

concentrations

Anesthesia ventilator

bellow

piston

blower

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Advance ventilator feature

mode

: PCV, PS, SIMV, PCV-VG

: variable PEEP, sensitivity

accurate tidal volume

advance monitoring

Ventilator setting

modes

tidal volume

inspiratory flow

rate, I:E ratio

PEEP

sensitivity

rise time, end of breath

FIO2

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modes

1) CMV : VCV, PCV, PCV-VG

2) SIMV

3) PS

VCV (volume controlled ventilation)

TV constant

airway pressure : change

monitor : peak airway pressure

adequate flow ?

VCV

Vt

I:E, Flow

Pause

Rate

PEEP

FIO2

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PCV

(pressure controlled ventilation)

airway pressure limit

TV : variable

monitor : low tidal volume

decelerating flow pattern

flow automatic

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Why ? : PCV

: flow variable : airway pressure < VCV

: better alveolar recruitment,

gas exchange

(decelerating flow)

When ? : PCV

pediatric, obesity, COPD

laparoscopic surgery

LMA

endotracheal without cuff

synchronized : ITU

PCV

Pcontrol

I:E, Time

rise time

Rate

PEEP

FIO2

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Rise time : PCV,PS

Tslope, rise rate, flow

40 PCIRC

cmH2O

INSP

L

min

EXP

PLOT SETUP

30

20

10

0

10

-20

80

60

40

20

0

20

-80

40

60

V .

0 4 8 12s 2 6 10

UNFREEZE

Slow rise Moderate rise Fast rise

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• spontaneous breathing

• augment tidal volume

• pressure limit , flow cycle

• variable tidal volume

comfortable

PSV (PS,PSVPro)

(pressure support ventilation)

Why ? : PSV

spontaneous breathing

: atelectasis

: gas exchange

anesthesia ; LMA, ET tube

: resistance

: respiration

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When ? : PSV

LMA ( PSV )

PaCO2 < spontaneous breathing

Brimacombe. Anesthesiology 2000;92:1621-3.

Pressure support ventilation versus continuous positive

airway pressure with the laryngeal mask airway.

PSV

Psupport

Trigger

Rise time

CPAP

FIO2

End of

breath

sensitivity,trigger

flow

adult 2-3 L/min

child 1-2 L/min

infant 0.3-1 L/min

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End of breath

PS : flow cycle

25% peak flow

Leak ? : time cycle

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SIMV

(synchronized intermittent

mandatory ventilation)

spontaneous + mandatory breath minimum minute ventilation

When ? : SIMV

spontaneous breath

minimum guarantee

light anesthesia , during emergent

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Dual control mode

PCV, guarantee TV

Avance, Aisys : PCV-VG

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Chigh Clow

pressure controlled ventilation

VT

Pressure

Flow

Autoflow

PCV - VG

VT

Flow

Pressure

When ? : PCV-VG

PCV

automatic : TV

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accuracy : TV

fresh gas flow

circuit compensation

leak , sample gas

oxygen flush valve

ตั้ง TV 500 มล. time 1 วินาท ี

เปิด ออกซิเจน 1 ลติร / นาท,ี

ไนตรัสออกไซด์ 2 ลติร / นาท ี

ใน1วนิาท ีจะมก๊ีาซไหลเพิม่ bellow 50 มล.

จะได้ TV เพิม่เป็น 550 มล.

anesthesia ventilator

bellow : 2 circuit

inside bellow : flow from flow meter

piston : decoupling valve

blower : calculated injection

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anesthesia ventilator

bellow : 2 circuit

inside bellow : flow from flow meter

piston : decoupling valve

blower : calculated injection

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anesthesia ventilator

bellow : 2 circuit

inside bellow : flow from flow meter

piston : decoupling valve

blower : calculated injection

accuracy : TV

fresh gas flow

circuit compensation

leak , sample gas

oxygen flush valve

TV ???

10 cc./kg. PEEP 0-5 cm H2O

6-8 cc./kg. PEEP > 5 cm H2O

( plateau pressure < 30 cm H2O )

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N Engl J Med 2013:369;428-37.

A trial of intraoperative low-tidal volume

ventilation in abdominal surgery.

( IMPROVE study group )

TV 6-8 cc/kg PEEP 6-8 cm H2O

recruitment 30 cm H2O : 30 sec : every 30 min

pulm complication, hospital day, NIV

Perioperative positive pressure

ventilation

ค าแนะน า

TV 6-8 cc/kg , PEEP 6-8 cm H2O

recruitment maneuver ?

RR 12-25 breaths/min

FIO

2 0.3-0.5

plateau pressure < 25 cm H2O , SPO

2 > 95%

Automated control of end-

tidal gas concentration

low flow

decrease cost, environment pollution

set : % oxygen, minimal flow, ET-volatile

manual : % oxygen, FGF, % vaporizer

safety : use only one agent, leakage

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monitor

ET O2

ET volatile

Thank you