Safety features in anesthesia machines-madras medical college
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Transcript of Safety features in anesthesia machines-madras medical college
SAFETY FEATURES IN SAFETY FEATURES IN ANAESTHETIC MACHINESANAESTHETIC MACHINES
-Dr.Prem kumar,
Department of anesthesiology,
Madras medical college
Why safety features?Why safety features?
To safeguard human life from unknown human errors.
Safety devices are to prevent delivery of hypoxic mixture
Regulation to prevent excessive pressure which is traumatic to patient.
Statistics Statistics
Misuse: 70% direct action primary anesthesia provider
30% contributory actions of ancillary personnel
Classification Classification
ELECTRICAL COMPONENTS
PNEUMATIC COMPONENTS.
ELECTRICAL ELECTRICAL COMPONENTSCOMPONENTS
Master switch Power failure indicator Reserve power Automated check out
PNEUMATIC SYSTEMPNEUMATIC SYSTEM
High pressure system
Intermediate system
Low pressure system
Alternative oxygen control
High pressure systemHigh pressure system
GAS CYLINDER –
Color coding
Pin index
Cylinder labels
Safety relief device
COLOR CODINGCOLOR CODING
Oxygen black body,white shoulders[white
for international] Nitrous oxide blue Air white and black Carbon dioxide gray Helium brown Entonox black with blue/white shoulders
PIN INDEX SAFETY SYSTEMPIN INDEX SAFETY SYSTEM
Air - 1,5Oxygen - 2,5Nitrous oxide - 3,5CO2>7.5% - 1,6CO2<7.5% - 2,6Cyclopropane - 3,6N2O-O2 - 7
The safety relief device is composed of atleast one of Frangible disc [bursts under
extreme pressure]
- Fusible plug [wood’s metal which has a low melting Point ]
- Safety relief valve [ opens at extreme pressure ]
WOOD’S METAL
A fusible alloy that contains 50% bismuth, 25% lead, 12.5% tin, and 12.5% cadmium, and melts at 158°F (70-72°C); used for automatic sprinkler plugs.
Cylinder pressure indicator [ bourdon’ s pressure gauge]
Pressure regulator - PRIMARY
Washer [ bodok seal ] – rubber made of neoprene Hanger yoke assembly – has pin index safety system.
one way check valve for unidirectional gas flow
BourdonBourdon’’s pressure gauges pressure gauge
Indication of incoming gas supplyIn O2 cylinder – indicates amount of gasN2O cylinder – pressure is not indicative of
amount b’cos N2O is stored in liquified form.
Curved tube can rupture with high pressure and the gauge has a vent on its back which can release the gas in the event of rupture.
Pressure regulatorPressure regulator
Bodok sealBodok seal
Intermediate systemIntermediate system
Pipeline –
- Gas hoses are named and color coded
- Non interchangeable quick
couplers[shrader’s valve-gas specific]
- NIST
- Diameter index safety system[DISS]
- Pipeline pressure indicators
NISTNIST
- In line filter
- Check valve
- Gas power outlet [auxiliary oxygen
as a source of driving
gas for anesthesia ventilator or jet
ventilation] Oxygen pressure failure device Oxygen supply failure alarm [ richter alarm]
OPFDOPFD
Pressure regulators – second stage
Pressure relief valve
Oxygen flush - O2+
Flow control valve – color coding,fluted[O2], size, distance, placement of knobs,guard
PRESSURE REGULATORPRESSURE REGULATOR
Pressure Relief ValvePressure Relief Valve Pressure relief valves are installed
downstream of all pressure regulators Valves set at no more than 50% above
the pressure regulator setting. Function: Fully relieving the pressure at
the set point in case failure of regulator. All pressure relief valves have piping
connections to allow release of to outside facility.
Low pressure systemLow pressure system
Flowmeters – - Bobbin rotates on flow which prevents it from sticking. - Bobbin is antistatic to prevent sticking to the wall of the flowmeter - Fluorescent coating on the back of flowmeter panel and on the dot of bobbins - Float stop - Arrangement - Auxiliary oxygen flowmeter
An oxygen leak from the flow tube An oxygen leak from the flow tube can produce a hypoxic mixture, can produce a hypoxic mixture,
regardless of the arrangement of regardless of the arrangement of
the flow tubesthe flow tubes
Auxiliary oxygen flowmeterAuxiliary oxygen flowmeter
Hypoxia prevention safety Hypoxia prevention safety devices:devices:
Proportionating devices –
- link 25 in datex
ohmeda[mechanical,pneumatic
and electronic linkage]
- S-ORC in draeger,
- Mandatory minimum oxygen
flow
Vaporizers - Selectatec mechanism,
interlocking,low filling port, indicator
of agent,increased wick capacity,
Fraser sweatman pin safety system Unidirectional [check ] valve Back pressure relief valve [opens when the
pressure exceeds 200 cm H2O] Common gas outlet
Breathing systemBreathing system
APL valve open when pressure exceeds 60 cm H2O
Pressure in reservoir bag shouldn’t exceed 60 cm H2O.
Oxygen analyser Canister – To prevent co2,carbon monoxide.
Dessicated absorbents without KOH or ba(OH)2 and with lesser amounts of NaOH produce less heat and no fires.
VENTILATORS – PRESSURE SENSORS TO DETECT EXCESSIVE AIRWAY PRESSURE DUE TO VENTILATOR MALFUNCTION
Alternative oxygen control
Scavenging system
Wheels in anesthetic workstation is made of antistatic rubber.
Safety features of newer Safety features of newer machinesmachines
Ø More accurate and/or corrected tidal volume through compliance and fresh gas compensation
Ø Potential return of sampled gas[SGR]
to facilitate low-flow
Ø Fresh gas decoupling prevent hyperinflation of the lung
Electronic PEEP
Electronic selection of ventilation parameters
Reduced external connections
Thank youThank you