Anesthesia Machine

Question 1

Noninterchangeable gas-specific connections to pipeline inlets (DISS) w/ pressure gauges, filter, & check valve

Purpose?

Answer 1

Prevent incorrect pipeline attachments;

detect failure, depletion, or fluctuation

Question 2

Pin index safety system for cylinders w/ pressure gauges, and at least one oxygen cylinder

Purpose?

Answer 2

Prevent incorrect attachments; provide backup gas supply; detect depletion

Question 3

Low oxygen pressure alarm

Purpose?

Answer 3

Detect oxygen supply failure at the common gas inlet

Question 4

Minimum oxygen/nitrous oxide ratio controller device (hypoxic guard)

Purpose?

Answer 4

Prevent delivery of less than 21% O2

Question 5

Oxygen must enter the common manifold downstream to other gases

Purpose?

Answer 5

Prevent hypoxia in event of proximal gas leak

Question 6

Oxygen failure safety device (shut-off or proportioning device)

Purpose?

Answer 6

Prevent administration of nitrous oxide or other gases when the oxygen supply fails

Question 7

Oxygen concentration monitor and alarm

Purpose?

Answer 7

Prevent administration of hypoxic gas mixtures in event of a low-pressure system leak; precisely measure oxygen concentration

Question 8

Automatically enabled essential alarms & monitors (ex: oxygen concentration)

Purpose?

Answer 8

Prevent use of the machine without essential monitors

Question 9

Vaporizer interlock device

Purpose?

Answer 9

Prevent simultaneous administration of more than one volatile agent

Question 10

Capnography & anesthetic gas measurement

Purpose?

Answer 10

Guide ventilation; prevent anesthetic overdose; help reduce awareness

Question 11

Oxygen flush mechanism that does not pass through vaporizers

Purpose?

Answer 11

Rapidly refill or flush the breathing circuit

Question 12

Breathing circuit pressure monitor & alarm

Purpose?

Answer 12

Prevent pulmonary barotrauma and detect sustained positive, high peak, and negative airway pressures

Question 13

Exhaled volume monitor

Purpose?

Answer 13

Assess ventilation & prevent hypo- or hyperventilation

Question 14

Pulse oximetry, blood pressure, ECG monitoring

Purpose?

Answer 14

Provide minimal standard monitoring

Question 15

Mechanical ventilator

Purpose?

Answer 15

Control alveolar ventilation more accurately and during muscle paralysis for prolonged periods

Question 16

Backup battery

Purpose?

Answer 16

Provide temporary electrical power (>30 min) to monitors and alarms in event of power failure

Question 17

Scavenger system

Purpose?

Answer 17

Prevent contamination of the OR w/ waste anesthetic gases

Question 18

how gases and electrical power enter the machine

Answer 18

Supply

Question 19

preparation of gases prior to delivery to the patient

Answer 19

processing

Question 20

gases going to the pt and returning from pt, their control and monitoring

Answer 20

delivery

Question 21

disposal of gases

Answer 21

disposal/scavenging

Question 22

gas supplies connected to the machine

also includes cylinder of o2 on side of machine

Answer 22

high pressure system

Question 23

blending of gases and volatile agent based on control settings

• also regulates high pressure to prevent barotrauma
• includes vaporizers

Answer 23

low pressure system

Question 24

fresh gas mixture passes from machine to patient

Answer 24

breathing system

Question 25

What psig should hospital pipeline gases show on the pressure guage?

Answer 25

50 to 55 psig

Question 26

these prevent retrograde flow and leakage if pipeline supply is disconnected and cylinder supply is in use

Answer 26

check valves

Question 27

What is blue hose

Answer 27

nitrous

Question 28

what is green hose

Answer 28

oxygen

Question 29

what is yellow hose

Answer 29

air

Question 30

reserve supply of gases oxygen, nitrous oxide, and air

Answer 30

cylinder gas inlet

Question 31

What does pressure regulator reduce pressure to in high pressure system

Answer 31

45 psig

Question 32

occurs if two cylinders of the same gas are both open and gas flows from the higher pressure to lower pressure cylinder instead of going to the flowmeters -check valve prevents this

Answer 32

transfilling

Question 33

type of gauge where flexible tube within the gauge straightens when exposed to gas pressure, causing gear mechanism to move the needle pointer

Answer 33

bourdon type gauge

Question 34

why do you need to bleed pressure to allow guage to read 0?

Answer 34

If 0 is not baseline, the gauge will only read pressures that are higher than the baseline

Question 35

What does the second stage regulator decrease O2 pressure to?

Answer 35

16-20 psig

Question 36

what does the second stage regulator decrease nitrous to?

Answer 36

32 psig | in tank nitrous is 745, then decreased to 50-55, then 32

Question 37

- bypasses flowmeters and vaporizers - delivers breath directly to breathing system at 50 psig (barotrauma!) - delivers 35-75 L/min flow (max on flowmeters is 10) - reinflates reservoir, bellows

Answer 37

O2 flush valve

Question 38

controls gas flow though the flowmeter | includes a knob, needle valves, and an indicator float

Answer 38

flow control valves

Question 39

tapered, calibrated to specific density and viscosity of gas, coated with conductive substance to minimize static electricity.

Answer 39

flow tubes, thorpe tubes

Question 40

what is the ratio of nitrous to oxygen delivery?

Answer 40

3:1 managed by proportioning system -link-25, chain link

Question 41

pneumatic, mechanic control | dependent on 32 psig of nitrous and 16-20 psig of O2

Answer 41

oxygen ratio monitor controller

Question 42

What is the minimal oxygen flow?

Answer 42

150 ml/min | meets basal metabolic O2 needs

Question 43

Why are O2 flowmeters ALWAYS nearest to the vaporizers?

Answer 43

to minimize risk of hypoxic mixture being delivered if leak occurs in the flowmeters

Question 44

where gases from different flowmeters mix together and have opportunity to enter into a vaporizer which is attached

Answer 44

manifold

Question 45

supplies gas mixture to breathing system

Answer 45

common gas outlet, "fresh gas outlet"

Question 46

Used in bag mode to deliver positive pressure breath. 0 = OPEN -Do not go above 20 mmHg when bagging to prevent inflating stomach

Answer 46

Adjustable pressure limiting valve | APL or pop off valve

Question 47

How much peep do anesthesia machines have intrinsically?

Answer 47

4 PEEP

Question 48

vacuum (negative pressure) from hospital disposal system withdraws gas from the scavenging system

Answer 48

active system

Question 49

slight positive pressure of excess gases in the machine moves it into the evacuation hose and into the disposal system

Answer 49

passive system

Question 50

opens with too much pressure to vent waste gases into the room and helps prevent a positive pressure in the patient circuit

Answer 50

positive pressure relief valve

Question 51

opens with too much suction to allow room air into the flow of waste gas to the vacuum source and helps prevent a negative pressure in the patient circuit

Answer 51

negative pressure relief valve

Question 52

if vacuum not high enough, pressure will not back p into breathing system

Answer 52

positive pressure relief mechanism

Question 53

if vacuum is too strong, the gases to be delivered to the pt will not be affected

Answer 53

negative pressure relief mechanism

Question 54

during manual ventilation, when does gas enter the scavenging system?

Answer 54

when the peak pressure exceeds the opening pressure of the APL valve

Question 55

when does gas enter scavenging system during mechanical ventilation?

Answer 55

during late exhalation and the expiratory pause after the ventilator bellows have returned to full position

Question 56

When does gas enter during spontaneous ventilation?

Answer 56

during late exhalation and the expiratory pause after the reservoir bag is full.

Question 57

1. Go to oxygen flowmeter 2. Go to O2 flush 3. Activate oxygen pressure failure safety mechanism 4. Activate oxygen low pressure alarm 5. powers the mechanical ventilator bellows

Answer 57

five functions of oxygen

Question 58

How can you defeat the anti-hypoxic safeguards?

Answer 58

- wrong gas in the O2 pipeline or cylinder - defective pneumatics or mechanics - leaks downstream of flow control valves - inert third gas administration

Question 59

- to provide oxygen - to blend an anesthetic gas mixture - to allow ventilation of pts lungs, whether spontaneous, assisted or controlled

Answer 59

primary purposes of anesthesia machine

Question 60

What is patient ready?

Answer 60

APL valve open, flowmeter and vaporizers off, minimal flow 150, bag mode and mask on end of circuit