Inhalation Sedation

Question 1

What are the indications for IS?

Answer 1

Anxiety- mild to moderate
Needle phobia
Gagging
Traumatic procedures
Medical conditions aggravated by stress (asthma)
Unaccompanied adults requiring sedation

Question 2

What are the contraindications for IS?

Answer 2

Common cold- blocked nose etc
Tonsillar/adenoidal enlargement
Severe COPD
First trimester of pregnancy (patients and dentists)
Fear of “mask” / Claustrophobia
Patients with limited ability to understand (over 7 usually)

Question 3

What may nitrous oxide be associated with in male dentists?

Answer 3

Infertility

Question 4

What equipment is required for IS?

Answer 4

Quantiflex machine:
Gas cylinders
Pressure reducing valves
Flow control meter
Reservoir bag
Gas delivery hoses
Nasal hood
Waste gas scavenging system

Question 5

Which gases go in which cylinders?

Answer 5

Blue- NO

Black- Oxygen

-> gases may be piped in hospital

Question 6

What does the flow control meter measure?

Answer 6

Measures flow rates of up to 10 l/min.
-> The reading is taken from equator of ball (Accuracy +/- 5%)

Question 7

What does the mixture control dial do?

Answer 7

Tells you how much oxygen is being given (no less than 30%- still more than air)

Question 8

What happens if oxygen runs out in quantiflex machine?

Answer 8

Machine turns off

Question 9

What is the function of the air entrapment valve?

Answer 9

If gases fail this opens to allow room air in

Question 10

What is the function of oxygen flush button?

Answer 10

Flushes oxygen in at rate of 35L/min if reservoir bag deflates in emergency

Question 11

What are the features of the reservoir bag?

Answer 11

2-3 litre capacity- filled with air or oxygen (smaller available for children)

Made of rubber or silicone

Question 12

What is the purpose of the reservoir bag?

Answer 12

Emulates patients lungs
-> Should move visibly with inspiration and expiration
->Helps determine how much oxygen patient requires
-> aiming for it to be lightly filled- must not collapse

Question 13

What respiratory rate are we aiming for in IS?

Answer 13

12-16 breaths per min

-> hyperventilation may occur in anxious patients

Question 14

What are the features of the Gas delivery hoses?

Answer 14

2.5 cm diameter, corrugated hoses

Universal joints

One hose delivers fresh gases from machine

One hose delivers waste gas to scavenging system

Non return valve in expiratory limb prevents rebreathing expired gases

Single use breathing circuits

Question 15

What are the features of the nasal hood?

Answer 15

Comes in various sizes

Forms seal around the nose

Has two connections to breathing circuit (universal)

Question 16

What is the purpose of the scavenging system?

Answer 16

Removes waste gases to prevent operator breathing them in

Question 17

How else can waste gases be prevented from being breathed in by dentist?

Answer 17

Rubber dam- decreases likelihood of mouth breathing

Changing surgery room air (15x per hour)

Checking mask seal and mouth breathing

Question 18

What are the additional safety features in quantiflex machine?

Answer 18

Pin index system – prevents the wrong cylinder being attached

Diameter index system – prevents cross connection of piping

Minimum oxygen delivery 30%

Oxygen fail safe – operates when oxygen pressure < 40 psi

Question 19

Safety features continued:

Answer 19

Air entrapment valve

Oxygen flush button

Oxygen monitor

Reservoir bag

Colour coding

Scavenging system

Oxygen & nitrous oxide pressure dials

Pressure reducing valves

One way expiratory valve

Quick fit connection for positive pressure oxygen delivery

Question 20

What are the adv of IS?

Answer 20

Rapid onset (2-3 mins)

Rapid peak action (3-5 mins)

Depth altered either way

Flexible duration

Rapid recovery

No injection (for the sedation but obviously LA still required depending on the procedure)

Few side effects to patient

Drug not metabolised

Some analgesia (though better for ischaemic than inflammatory pain)

No amnesia (remember lack of anxiety for next time)

Question 21

What are the dis of IS?

Answer 21

Equipment expensive

Gases expensive

Space occupying equipment

Not potent

Requires ability to breath through nose

Chronic exposure risk?

Staff addiction

Difficult to accurately determine actual dose

Question 22

What are the signs of adequate sedation?

Answer 22

Patient relaxed/comfortable
Patient awake
Reduced blink rate
Laryngeal reflexes unaffected
Vital signs unaffected
Gag reflex obtunded
Mouth open on request
Decreased reaction to painful stimuli
Decrease in spontaneous movements
Verbal contact maintained

Question 23

What are the symptoms of adequate sedation?

Answer 23

Mental and physical relaxation
Lessened awareness of pain
Paraesthesia – lips, fingers, toes, legs, tongue
Lethargy
Euphoria
Detachment ‘floating feeling’
Warmth
Altered awareness of passage of time
Dreaming
Small controllable giggles

Question 24

What ae the signs and symptoms of over-sedation?

Answer 24

Mouth closing – repeatedly
Spontaneous mouth breathing
Nausea/vomiting
Irrational and sluggish responses
Decreased cooperation
Incoherent speech
Uncontrolled laughter, tears
Patient no longer enjoying the effects
LOC

Question 25

What are the pre-operative instructions for IS?

Answer 25

->Have a light meal before appointment
-> Take routine medicines as usual
-> Children accompanied by a competent adult
-> Adults accompanied at their first sedation appt. afterwards may then attend alone
-> Do not drink alcohol on day of appointment
-> Wear sensible clothing
->Arrange care of children during and after your appointment
->Plan to remain in clinic for up to 30 minutes after treatment

Question 26

Steps In IS technique :

Answer 26

1. Set up the machine
2. Select nasal hood (record size in notes)
3. Connect the hoses
4. Set mixture dial to 100% O2
5. Settle patient in dental chair
6. Reinforce explanations of procedure
7. Set flow to 5-6l per minute
8. Position hood on the patient’s nose- encourage nasal breathing (patient should feel comfortable within 1 min)
9. Ask patient to signal when begin to feel different
10. Reduce O2 by 10%
    Wait 1 minute and repeat
11. After O2 reaches 80%, -> reduce by 5% per minute
12. Stop titration when patient ready for treatment

Question 27

What should be done throughout IS?

Answer 27

Constant reassurance & hypnotic suggestion

Monitor for signs & symptoms of adequate sedation

Adjust level of O2 as required

Monitor reservoir bag movements

Question 28

What should be done with regard to excess movement and too little movement of reservoir bag?

Answer 28

Excess- increase flow rate

Too little- check seal, look for mouth breathing (decrease flow?)

Question 29

What should be done if patient over/under sedated

Answer 29

Over- increase oxygen in 5-10% increments until satisfactory

Under- decrease oxygen in 5% increments until satisfactory

Question 30

What should be done following completion of procedure in IS? (recovery)

Answer 30

Gradually increase O2 by 10-20% per minute until 100% or can turn straight to 100%

Administer 100% O2 for 2-3 mins to prevent diffusion hypoxia

Remove hood and turn gas flow off

Return patient to upright slowly, give praise and reassurance

Question 31

What is the success rate with IS?

Answer 31

50-90%

-> better for ortho extractions
-> poorer when patient in pain

Question 32

What occurs following treatment with IS?

Answer 32

Adult patients may leave unaccompanied at dentist’s discretion
Child patients (<16 years) must be accompanied by a competent adult

->Prior to discharge, ask how patient felt procedure went – and listen!
->Patients may feel shivery after I.S- reassure patient that this is common and passes quickly