Inhalation Sedation

Question 1

What is conscious sedation

Answer 1

a tecnhique in which the use of a drug produces a state of depression of the central nervous systen enabling treatment to be carried out, verbal contact is mintainted

Question 2

drug used for inhalation sedation

Answer 2

nitrous oxide and oxygen

Question 3

properties of nitrous oxide

Answer 3

inhaled gas
sweet smelling
colourless
heavy

Question 4

how do we give nitrous oxide

Answer 4

1. start with 100% oxygen for a minute or two at a flow rate 5-6 litres per minute
2. let patient settle, get used to the mask and check for leaks and the bag is inflating properly
3. introduces nitrous oxide in increments, each increment for a minute or two
4. usual amount for adults - at least 50%

Question 5

Properties of nitrous oxide

Answer 5

rapid onset of action (3-5 minutes)
crosses the blood brain barrier rapidly
elimination also rapid
no stored. in the tissues
no signficant metabolism by kidneys or liver
no hangover effect

Question 6

IHS indications

Answer 6

mild anxiety
needle phobia
straightforward dental tx

Question 7

IHS contraindications

Answer 7

COPD
recent eye or ear surgery
mask intolerance
pregnancy
Vitamin B12 deficiency
methotrexate interaction
chemotherapy interaction

Question 8

signs of overdose

Answer 8

headache
nausea
vomitting
diffusion hypoxia

Question 9

what is diffusion hypoxia

Answer 9

when nitrous oxide is discontinued, it leave the blood more quickly than nitrogen from air is absorbed
can lead to dilution of oxygen in the lungs
which can lead to hypoxia

Question 10

management of diffusion hypoxia

Answer 10

administer 100% oxygen after cessation of nitrous oxide to prevent this