Safety Features

Question 1

How long can high priority alarms be silenced?

Answer 1

2 minutes

Question 2

High-priority pressure alarm

Answer 2

User limits exceeded, sensed continuous high pressure or negative pressure

Question 3

Disconnect alarms

Answer 3

Low pressure, low exhaled volume or absence of CO2

Question 4

What is breathing circuit pressure limited to?

Answer 4

125 cm H2O

Question 5

Pressure for primary pipeline gas

Answer 5

50 psi

Question 6

Flow meters safety

Answer 6

Single control for each gas, unique shape to oxygen, valve stops so you cannot over-rotate & damage flow meter, oxygen on right side of flow meter so a leak will not dilute oxygen, and an auxiliary oxygen flow meter

Question 7

Common gas outlet shows what?

Answer 7

If you lose electricity can still see FGF by the float ball

Question 8

Supply to anesthesia machine

Answer 8

Pipeline (DISS)- wall outlets, connecting valves/hoses, filters, check valves, pressure gauges OR Cylinder (PISS)- hanger yokes with yoke block (where cylinder hangs from), filters & check valves, pressure gauge & pressure regulators

Question 9

Disposal of gases

Answer 9

Closed or open scavenger systems

Question 10

Devices not reliant on electrical power

Answer 10

Spontaneous/manual assist ventilation, mechanical flowmeters, scavenging, variable bypass vaporizers (though do not count on this)

Question 11

Devices which rely on electrical power

Answer 11

Mechanical ventilators, electronic monitors and display flowmeters, gas/vapor blenders (for Des..) or vaporizers with electronic controls (aladin)

Question 12

Pneumatic high pressure cylinder pressure

Answer 12

1900-2200 psi

Question 13

Pneumatic high pressure parts

Answer 13

Hanger Yoke - PISS
Gas Cylinders - (E)- Oxygen (1900-2200psi with 660L), Nitrous (745 psi 1600 L), Air (1800-1900 psi, 600L)
Cylinder Pressure Gauge- Electronic or bourdin
Cylinder Pressure Regulators- Decreases gas pressure & maintains constant pressure supply to intermediate, outlet pressure is lower than wall pressure to maintain preferential wall pressure supply if tank is left open)
Check Valves- prevent exit of gas from machine when no cylinder is present, prevents transfilling of gas from one cylinder to another

Question 14

Pneumatic intermediate pressure cylinder pressure

Answer 14

37-55 psi

Question 15

Pneumatic intermediate pressure parts

Answer 15

Master Switch- when off, pressure in intermediate system falls to zero
Pipeline Inlet Connections- DISS, check valve at inlet (prevents reverse gas flow from machine to pipeline)
Pipeline Pressure Gauges- Should read 50-55 psi
Oxygen Pressure Failure Device- Loss of oxygen pressure results in cessation of N2O gas flow (ONLY SENSES PRESSURE- not a fail safe to prevent hypoxic mixture if pipeline crossover happens)
Oxygen Supply Failure Alarm
Gas Selector Switch
Second Stage Pressure Regulator (Not on all machines, reduces pressure from pipeline to flowmeters)
Oxygen Flush- 35-37 L/min to common gas outlet
Flow Adjustment Controls
Alternate Oxygen Control- Electronic flowmeter backup in case of electrical failure

Question 16

Pneumatic low pressure cylinder pressure

Question 17

Pneumatic low pressure parts

Answer 17

Flowmeters- electronic or thorpe (low flow-laminar, based on viscosity.. Poiseuille’s law, high flow- turbulent, based on density.. Graham’s law)
Hypoxia Prevention Safety Devices- O2-N2O Link
Unidirection Check Valve- Located between vaporizers & common gas outlet upstream of where oxygen flush flow joins FGF, prevents backpressure to vaporizers & flowmeters from positive pressure in breathing circuit, negative pressure leak test checks function of valve
Pressure Relief Device- Near common gas outlet to protect machine from high pressure
Common Gas Outlet- May be internal or external
Auxiliary Oxygen Flowmeter

Question 18

What should you do if you lose pipeline gas?

Answer 18

Open emergency oxygen cylinder fully, disconnect the wall pipeline connection, ventilate by hand & turn ventilator off

Question 19

Why is oxygen always closest to the common gas outlet?

Answer 19

To prevent oxygen being diluted by other gases and creating a hypoxic mixture

Question 20

Parts of the circle system

Answer 20

Y piece/port, corrugated tubing (adults are coaxial, peds have outer and inner), expiratory limb, expiratory valve, bag/vent selector switch- APL valve- Reservoir bag- Ventilator, CO2 absorber, fresh gas inlet, inspiratory valve, inspiratory limb

Question 21

Advantages of circle system

Answer 21

Stable inspired concentrations, conserve moisture/heat, prevention of OR pollution, low gas flows

Question 22

Purpose of reservoir bag

Answer 22

Reservoir, manual ventilation, visual/tactile monitor, protects from excess pressure

Question 23

Sources of pollution from anesthetic

Answer 23

Failure to turn off agent at end of case, mask fit, flushing circuit, filling vaporizers, uncuffed ETT, leaks, poorly functioning scavenging system

Question 24

CO2 absorber

Answer 24

Eliminates CO2, is required for closed & semi-cosed circuits

Question 25

Interactions with absorbents

Answer 25

Trichloroethylene causes cerebral neurotoxin, Sevoflurane causes Compound A with baralyme, Carbon Monoxide from Des with dryness and/or baralyme

Question 26

Chemical equation of CO2 absorbent

Answer 26

CO2 + H2O H2CO3 –> H2CO3 + 2NAOH (or KOH) Na2CO3 (or K2CO3) + 2 H2O + Heat –> Na2CO3 (or K2CO3) + Ca(OH)2 ,–> CaCO3 + 2NaOH (or KOH)

Question 27

Normal working pressure of most anesthesia machines

Answer 27

50 psi

Question 28

Oxygen supply & regulation pressure

Answer 28

2000 psi, regulated to 45-50 psi after entry

Question 29

Oxygen flush valve l/min

Answer 29

35-75

Question 30

Which float meters read at top and which read at middle?

Answer 30

Top: non-rotating, plumb-bob, skirted, “H”. Middle: ball