anesthesia machine intro
TRANSCRIPT
Anesthesia Machine Intro
New Residents July 5, 2007
© Copyright 2000-2007, James H Philip, all rights reserved
ADS1 Ready JHP
Anesthesia Machine Intro
James H. Philip, MEE, MD, CCEAnesthesiologist, Director of (Anesthesia) Bioengineering, Brigham and Women’s Hospital
Medical Liaison, Department of Biomedical Engineering, Partners HealthCare SystemAssociate Professor of Anaesthesia, Harvard Medical School
Patient Anesthetist
ORHospitalWorld
Work-station
observe(senses)
touch
Care Info(lab data, image..)
touchobserve(eyesears)
ADS, monitors,?computer
Inhalant Drugs IV Drugs, Fluids Other
Monitoring
requests
ClincalCare
Interactions
Patient Anesthetist
ORHospitalWorld
Work-station
observe(senses)
touch
Care Info(lab data, image..)
touchobserve(eyesears)
ADS, monitors,?computer
Inhalant Drugs IV Drugs, Fluids Other
Monitoring
requests
ClincalCare
Interactions
Anesthesia Delivery System
Workstation-Patient Interactions
Life Support with oxygen & breathingInhalant Drug (Gas & Vapor) DeliveryIntravenous Drug DeliveryIntravenous Liquid DeliveryMonitoringRecording
Life Support (Oxygen)Inhalant Delivery
OtherIntravenous Drug DeliveryFluid DeliveryMonitoringRecording
Anesthesia Machine
Anesthesia Machine Evolution
1846 Morton Ether Inhaler
Inhaler had limitations
1850 improvement
This 1850 version worked horizontal
with no hands required
Open Circuit Inhaler
Open Circuit = Non-rebreathingPatient breathes in the ether vapor, breathes ether out (and it is discarded)Breathes in new ether vaporBreathes it out again (discarded)
Manual Resuscitator
Open Circuit = non-rebreathing Circuit = what you set is what you get
Give sufficient oxygen to the reservoir bag (not to empty)
Reservoir bag gives 100% oxygen to the breathing bag
The Tidal Volume is determined by the close of your hand and a perfect seal.
Manual Resuscitators
Bag Reservoir Hose Reservoir
Needs a bag reservoirso you can see it provide 100% oxygen to the breathing bag by never emptying
Bag Reservoir
Partial Rebreathing Circuits used in Anesthesia
Don’t throw all the exhaled vapor awayReuse as much as possibleSomehow (learn when you are ready) Remove (Absorb) CO2 and Rebreathe the Anesthetic
Partial rebreathing = semi-closed circuitAll USA ADSs use them
1890 added a
Breathing Circuit
1950added a work
surface
Then, Drawers,
Temperature-compensated
vaporizers,Circuit,
Absorber, Common
gasoutlet
1990 Integrated
Monitorsand
DataRecording
Datex-Ohmeda
Central Display
(CD)ADS
2000
Better ventilation for difficult patientsFGF-independent ventilationCorrects for circuit leaks
More sensitive to water vaporMonitors no longer integrated
GE Aestiva
Draeger Fabius
Gas & Flow Monitor integratedCV Monitor not integrated
GE - Aisys
Basics of the Anesthesia Delivery System
Anesthesia Delivery System - ADS
Anesthesia MachineBreathing CircuitWorkspaceControl
Anesthesia Machine delivers gases and vaporsinto a breathing circuit 2001
Provides continuous flow of -Oxygen for LifeAir to safely lower FIO2
Nitrous Oxide for partial anesthesiaAgent vapor for complete or partial anesthesia
N O2 O2Air
(Continuous Flow) Anesthesia Machine
Vaporizer
1 2 3..
5
21
34
6789
21
34
6789
55
21
34
6789
mL/mL/mL/mL/m
300
200100
400
50
600900
000
IsofluraneSevofluraneDesflurane FGF
(FreshGasFlow)
CommonOutlet
Flow Tubes
Sevo Iso Des
Direct-reading temperature-compensated
Vaporizers
Agent-specificFiller Port
Dial ReleaseAttachment
LeverDial
Direct Reading
Vaporizer
ExclusionInterlock
Dial Setting
2
3
4
5
1
2 4
1
2
3
4
5
6
06 8 10
Flow rate (L/min O2)
% is
oflu
rane
0
Performance curve, Tec 4(Isotec 5%)
Anesthesia Machine
Anesthesia Machine
Schematic
O2
2000psi
O2 SERVICE
INLET55psi
35 psi
35 psi
50 or 250ml/min
NEEDLEVALVE
FAILSAFEVALVE
CALIBRATEDVAPORIZERS
Fresh Gas Flow (FGF)
OXYGEN FLUSHVALVE[first]
ON/OFFSWITCH
CHECKVALVE PRESSURE
REGULATOR
N2OSERVICE
INLET 55 psi
O2
N2O
FRESHGAS HOSE
Flush Flow(last)
[Anesthetizinggases flow]
COMMON OUTLET
N2O
750psi
N2O
750psi
O2
2000psi
FILTER
WALL
DISSdiameter
indexsafetysystem
CONNEC-TION
O2
N2O
D S I
SIMPLIFIED ANESTHESIA MACHINE SCHEMATIC DIAGRAM
Patient Breathing Circuit
Allows cyclic flowTo and from the patient
(AKA Breathing)
Circle absorption anesthetic breathing circuit
flipped
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
Rebreathed
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
Rebreathed
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
Rebreathed
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
Rebreathed
To Patient
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
Rebreathed
From Patient
The Circle-Absorber System
Sampled
Exhaust (APL)Expired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
Rebreathed
The Circle-Absorber System
Sampled
Exhaust (APL)Expired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
RebreathedGases (O2, N2O, Agent)
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
RebreathedGases
No CO2 rebreathed
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
RebreathedGases
No CO2
No
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFresh
Gas Flows
RebreathedGasesNo CO2
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFFGF , CDEL
FE FI
FE , CE
FI , CI
Gas Flows,Concentrations
~=
F = Flow C = Concentration
The Circle-Absorber System
Sampled
ExhaustExpired
CO2
Ab-sorb-ant
200 mL/min
InspiredFFGF , CDEL
FE , CE
FI , CI
FE FI~=
CI~=
FFGF x CDEL
+FFGF x CDEL FE x CE
Inspired Concentration =Flow-weighted average ofFresh Gas and Expired GasConcentrations
Low FGF
More rebreathingInspired more dependent on ExpiredInspired less dependent on Vaporizer
View the Breathing CircuitThe Circle-Absorber System
Absorber opened - w gas channels shown
Absorber opened - w gas channels shown
Exp
Insp
Absorber Assembly Top CoverOhmeda GMS 1985-2000-present
The Anesthesia Workspace
BWH Anesthesia Workspace
Don’t clutter ADS with Airway EquipmentMy view
MRSMAIDWorkspace Setup
MachineRoomSuctionMonitorsAirwayI V Drugs
MRSMAIDWorkspace Setup
MachineRoomSuctionMonitorsAirwayI V Drugs
MRSMAIDMachineRoomSuctionMonitorsAirwayI V Drugs
Workspace Setup
Suction off if:DISS hose unscrewedWall switch offHose disconnect from CanisterCanister switch off Insert seated incorrectlyAny hole openFlap valve closed
because unit was shakenor canister is full
Flexible hose kinkedFlexible hose stepped on
Workshop this afternoon
Evelyn Fan, OR Clinical EngineerErnst Daniel, OR Clinical EngineerBMETs (Biomedical Equipment Technicians)
BWH Biomedical Engineering OR Team
Ernst Daniel CE
Evelyn Fan CE
James Philip MD
Clair Cabral
Jeremy Essex
Ed Holmes
Rossiny Jacques
M Anthony Johnson
C Trevor Roberts
Frantz Teleau
WorkshopADS Safety Check
Day Check Case Check
Anesthesia MonitorsZero/CalibrateAttaching trodesControlling monitor measurementsObserving results
Numerals nowNumeric TrendDigital Trend
These are in your Goals for Week 1, Week 2, Life !
BWH July 2007 Abbreviated Pre-Use Check
Perform Machine-Assisted TestsGE Modulus 2 Plus - noneGE Aestiva - Minor
12 Hour switch off and onCircuit Oxygen Sensor Cal via SmartVent
GE Aisys - MajorMost circuit tests are automatedBellows volume & pressure can feel the circuitand make great ventilation modes
Draeger Fabius - MajorMost circuit tests are automatedVentilator Piston can feel the circuitand make great ventilation modes
Calibrate Oxygen Monitor
Oxygen Monitor ON & sensor in air with hole plugged. Calibrate to 21%. Reconnect sensor in circuit
Check Machine for Gas Delivery
Machine OnOxygen flows smoothlyDisconnect oxygen hoseOxygen alarm soundsSwitch ON oxygen tank. Verify P > 1000 psi and Alarm
silences.Tank off with wrenchTurn oxygen flow upAlarm sounds oxygen failureConnect oxygen hose to silence alarm.Turn up nitrous and observe alarm and/or control.Negative Pressure Test - later
Check Breathing Circuit for Integrity
Attach circuit including reservoir bagOcclude “Y” with thumbFlush and fill bag to 30 cmH2O.Test pressure alarms
NAD - Continuing pressure alarm, high pressure alarmOhmeda - High pressure relief
Open relief valve and verify that reservoir bag emptiesObserve scavenger bag fill and empty
Check Function - Ventilator, Suction
CHECK VENTILATOR FOR FUNCTIONVentilate reservoir bag and observe no volume loss.
CHECK SCAVENGER FOR FUNCTIONCheck that reservoir bag fills and empties. Check valves
not stuck.
Thank you
James H. Philip, MEE, MD, CCE
Office Neville House NH 2-24E617 732-7330 Page [email protected]
http://local.bwh.harvard.edu/intranet
End