Inhalation sedation Flashcards
What does ASA stand for?
American society of anaesthesiologists
Who first produced nitrous oxide?
Joseph Priestly in 1772
Who researched nitrous oxide?
Humphry Davy
What % of Nitrous Oxide will lead to unconsciousness?
80%
What are the average flow rates of an adult & a child?
6L/Min & 8L/Min
What does MAC stand for?
Minimum alveolar concentration
When was the ASA scale created?
1941
What does MDAS stand for?
Modified dental anxiety scale
The MDAS replaced what dental anxiety scale?
CORAH
What is the weight of a full E size cylinder containing nitrous oxide?
8.8kg
What is the weight of an empty E size cylinder?
5.4kg
How many litres in cylinder sized E?
680L
How many litres in cylinder size C?
170L
How many litres in cylinder size D?
340L
How many litres in cylinder size F?
1360L
How many litres in cylinder size G?
3400L
Nitrous oxide has a PSI of what?
800psi
Oxygen has a PSI of what?
2000psi
What are the maximum exposure levels of nitrous oxide?
100ppm over an 8 hour period in 24 hours
Name 4 contraindications to inhalation sedation
Nasal obstruction
Psychiatric patients
Ocular surgery
Sinus surgery/disease
What is the function of the air entrainment valve?
To draw in atmospheric air in the event the oxygen cylinders fail
What does PSI stand for?
Pounds per square inch
What is the colour of a nitrous oxide cylinder?
Blue
What is the colour of an oxygen cylinder?
Black with a white collar
What is the onset time of nitrous oxide?
20 seconds, 3-5 minutes for full effects
What percentage of nitrous oxide is eliminated through respiration once delivery has stopped?
99%, remaining 1% through skin & lungs
What % of nitrous oxide is the patient administered in plane 1 of inhalation sedation?
5-25%
What % of nitrous oxide is the patient administered in plane 2 of inhalation sedation?
20-55%
What % of nitrous oxide is the patient administered in plane 3 of inhalation sedation?
50-70%
What is the 4th stage of inhalation sedation?
Medullary depression (overdose)
What is the 3rd stage of inhalation sedation?
Surgical anaesthesia
What is the 2nd stage of inhalation sedation?
Excitement
Inhalation sedation should be kept within which plane/stage of anaesthesia?
Plan 1 or 2 of stage 1
Name 3 safety mechanisms of an inhalation sedation machine
- Delivery of nitrous oxide stops if oxygen supply fails
- Reservoir bag allows monitoring of patient respiration
- Air entrainment valves draws in atmospheric air if delivery of both gases stop
How much oxygen does the flush button deliver?
30L/Min
What % of excess gas does the scavenging machine remove?
45L/Min
1/4 full cylinder of nitrous oxide, equates to what psi?
200
What is the bodok seal?
Ensures air tight seal between regulator and gas cylinder
What is the pin index system?
Ensures that the correct gas is connected to the correct regulator
What information is found on all cylinders?
- Content,
- Batch number
- Expiry date
- Approximate weight
Name 3 side effects of nitrous oxide
- Infertility in female workers
- Anaemia
- Birth defects
Why must you never lubricate connections, valves and fitments?
There is a danger of explosion
Entonox is a mixture of what % nitrous oxide and oxygen?
50% Oxygen 50% Nitrous Oxide
What is the gravity of nitrous oxide?
1.53
How many times heavier than air is nitrous oxide?
1.5
What is the MAC value of nitrous oxide?
104
It is preferred that gases used in inhalation sedation have a high ___ ? and a low ___?
High MAC and Low solubility
What is the maximum number of nitrous oxide molecules that attach to haemoglobin?
3
What is the mac value of sevoflurane?
below 2
How much does a full nitrous oxide cylinder weigh?
8.8kg
What size is an adult reservoir bag?
2 Litres
What size is a child reservoir bag?
1.5L
