Inhalation Sedation Flashcards
Indications for inhalation sedation
- Mild-mod anxiety
- Needle phobia
- Gagging
- Traumatic procedures (eg extractions/ surgical procedures even if child not anxious)
- Medical conditions aggravated by stress (e.g. asthma- can stop asthma attack if becoming anxious)
- Unaccompanied adults requiring sedation
Contraindications of Inhalation Sedation
•Common cold (need to breathe in + out nose as gas comes out from nose piece. If bunged up and cannot breathe through nose properly)
• Tonsillar/adenoidal enlargement (pt natural mouth breathers)
• Severe COPD (these pt not getting enough air in)
• 1st trimester of pregnancy
• Fear of “mask” / Claustrophobia
• Patients with limited ability to understand (eg small children.
Blanket rule- children must be 7+ to get IS. SN- not suitable if they don’t understand concept of breathing through nose)
Equipment for IHS
-Quantiflex machine (blue tank- N20, black tank- 02) -Gas cylinders -Flow control metre -Reservoir bag -Gas delivery hoses -Nasal hood -Waste gas scavenging system
What does the flow control metre do
Measures flow rates of up to 10L/min
Reading taken from equator of ball
Accuracy +/- 5%
ie flow rate / how much oxygen l/min you are giving to pt
What does the mixture control dial do
tells you how much o2 you are getting compared to N20.
Take from middle of indicator ball
Accuracy +/- 5%
–>Cannot turn down <30% O2
What does the flow control knob do
How many L/min pt is getting
What does the air entrainment valve do?
If gases fail= machine turns off
Valve opens to allow room air into circuit
What does the oxygen flush button do?
Flushes O2 35L/min
FOR EMERGENCY USE ONLY
What does the reservoir bag do?
- 2/3L bag
- Used to EMULATE PTS LUNGS
- Filled with air + oxygen
- Should move visibly with inspiration & exhalation
- Helps to monitor respiration (ie hyperventilation (short shallow breaths) due to anxiousness can be detected.
Ideal= 12-16 breaths/ min)
What do the gas delivery hoses do?
-universal joints
1 hose= delivers fresh gases from machine
1 hose= delivers waste gas to scavenging system (N20 taken out of atmosphere so we don’t inhale it)
-Non-return valve in expiratory limb= prevents rebreathing expired gases
What is the nasal mask/ hood & its function?
Should form a seal around pts nose.
2 connections to breathing circuit.
Explain the scavenging system
–>Active scavenging of waste gases: small negative pressure change
–>Changing surgery air reduces nitrous oxide levels- 15 changes of room air/ hr
–>Watch for pt mouth breathing (expelling waste gas into atmosphere rather than into scavenge).
=check mask seal to reduce contamination & remind pt to breathe through nose
–>rubber dam will decrease likelihood of mouth breathing
What are the safety features of the quantiflex machine
Pin index system- prevents the wrong cylinder being attached
Diameter index system- prevents cross connection of piping
Min oxygen delivery- 30%
Oxygen fail safe- operates when oxygen pressure <40 psi
Inhalation sedation procedure- ADV
- Rapid onset (2-3 mins)
- Rapid peak action (3-5 mins)
- Depth altered either way
- Flexible duration - No time limit
- Rapid recovery
- No injection (for the sedation but obviously LA still required depending on the procedure)
- Few side effects to patient
- Drug not metabolised – N2O doesn’t go to liver, all blown back off pt lungs
- Some analgesia (though better for ischaemic than inflammatory pain)
- Oral dysesthesia (can reduce pain from LA) and tingling in hands + feet
- No amnesia
Inhalation sedation procedure- DISADV
- Equipment expensive
- Gases expensive
- Space occupying equipment
- Not potent – wont disarm anyone, for people who just need a little push/courage to help them cope. Need pt to be cooperative.
- Requires ability to breath through nose
- Chronic exposure risk? – scavenger system helps this
- Staff addiction
- Difficult to accurately determine actual dose (indicator ball - +/-5% accuracy not v good. If leakage through mask/ pt speaks to you/ cries/ nasal hood doesn’t fit properly= can affect dose)
