Inhalation Sedation Flashcards
What are the indications for IS?
Anxiety- mild to moderate
Needle phobia
Gagging
Traumatic procedures
Medical conditions aggravated by stress (asthma)
Unaccompanied adults requiring sedation
What are the contraindications for IS?
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)
What may nitrous oxide be associated with in male dentists?
Infertility
What equipment is required for IS?
Quantiflex machine:
Gas cylinders
Pressure reducing valves
Flow control meter
Reservoir bag
Gas delivery hoses
Nasal hood
Waste gas scavenging system
Which gases go in which cylinders?
Blue- NO
Black- Oxygen
-> gases may be piped in hospital
What does the flow control meter measure?
Measures flow rates of up to 10 l/min.
-> The reading is taken from equator of ball (Accuracy +/- 5%)
What does the mixture control dial do?
Tells you how much oxygen is being given (no less than 30%- still more than air)
What happens if oxygen runs out in quantiflex machine?
Machine turns off
What is the function of the air entrapment valve?
If gases fail this opens to allow room air in
What is the function of oxygen flush button?
Flushes oxygen in at rate of 35L/min if reservoir bag deflates in emergency
What are the features of the reservoir bag?
2-3 litre capacity- filled with air or oxygen (smaller available for children)
Made of rubber or silicone
What is the purpose of the reservoir bag?
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
What respiratory rate are we aiming for in IS?
12-16 breaths per min
-> hyperventilation may occur in anxious patients
What are the features of the Gas delivery hoses?
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
What are the features of the nasal hood?
Comes in various sizes
Forms seal around the nose
Has two connections to breathing circuit (universal)
What is the purpose of the scavenging system?
Removes waste gases to prevent operator breathing them in
How else can waste gases be prevented from being breathed in by dentist?
Rubber dam- decreases likelihood of mouth breathing
Changing surgery room air (15x per hour)
Checking mask seal and mouth breathing
What are the additional safety features in quantiflex machine?
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
Safety features continued:
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
What are the adv of IS?
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)
What are the dis of IS?
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
What are the signs of adequate sedation?
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
What are the symptoms of adequate sedation?
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
What ae the signs and symptoms of over-sedation?
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
What are the pre-operative instructions for IS?
->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
Steps In IS technique :
- Set up the machine
- Select nasal hood (record size in notes)
- Connect the hoses
- Set mixture dial to 100% O2
- Settle patient in dental chair
- Reinforce explanations of procedure
- Set flow to 5-6l per minute
- Position hood on the patient’s nose- encourage nasal breathing (patient should feel comfortable within 1 min)
- Ask patient to signal when begin to feel different
- Reduce O2 by 10%
Wait 1 minute and repeat - After O2 reaches 80%, -> reduce by 5% per minute
- Stop titration when patient ready for treatment
What should be done throughout IS?
Constant reassurance & hypnotic suggestion
Monitor for signs & symptoms of adequate sedation
Adjust level of O2 as required
Monitor reservoir bag movements
What should be done with regard to excess movement and too little movement of reservoir bag?
Excess- increase flow rate
Too little- check seal, look for mouth breathing (decrease flow?)
What should be done if patient over/under sedated
Over- increase oxygen in 5-10% increments until satisfactory
Under- decrease oxygen in 5% increments until satisfactory
What should be done following completion of procedure in IS? (recovery)
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
What is the success rate with IS?
50-90%
-> better for ortho extractions
-> poorer when patient in pain
What occurs following treatment with IS?
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
