Presiding Officer Training module 2024 lok sabha elections
Safety features in anesthesia machines-madras medical college
1. SAFETY FEATURES IN
ANAESTHETIC MACHINES
-Dr.Prem kumar,
Department of anesthesiology,
Madras medical college
2. 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.
5. ELECTRICAL
COMPONENTS
Master switch
Power failure indicator
Reserve power
Automated check out
6. PNEUMATIC SYSTEM
High pressure system
Intermediate system
Low pressure system
Alternative oxygen control
7. High pressure system
GAS CYLINDER –
Color coding
Pin index
Cylinder labels
Safety relief device
8.
9. COLOR 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
14. 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 ]
15. 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.
16. 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
17. Bourdon’s pressure gauge
Indication of incoming gas supply
In O2 cylinder – indicates amount of gas
N2O 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.
22. Intermediate 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
25. - 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]
29. Pressure 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.
30.
31. Low 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
32.
33.
34.
35. An oxygen leak from the flow tube
can produce a hypoxic mixture,
regardless of the arrangement of
the flow tubes
37. Hypoxia prevention safety
devices:
Proportionating devices –
- link 25 in datex
ohmeda[mechanical,pneumatic
and electronic linkage]
- S-ORC in draeger,
- Mandatory minimum oxygen
flow
38.
39. 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
40.
41. Breathing 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.
42. 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.
43.
44.
45.
46. Safety features of newer
machines
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
47. Electronic PEEP
Electronic selection of ventilation
parameters
Reduced external connections