L6 Nitrous Oxide Sedation Flashcards
What is nitrous oxide made of
Dinitrogen monoxide (g) Stored as a liquid
What are properties of N2O
- Analgesic (like morphine)
- Anxiolytic
- Colourless
- Non-flammable
- Slightly sweet
odour - Low solubility in blood
- Rapidly diffuses across membrane
- Excreted unchanged from lungs
What affects does nitrous have on BP and heart rate?
No change to BP (if at all a slight increase)
No effect on HR
Where does N2O act?
On opioid receptors in the mid-brain - same is morphine and heroin
Descending inhibitory pathway
Altering pain processing in the spinal cord
What do the effects of N2O feel like?
Alcohol
What is the common percentage of N2O
40-70%
Usually used with other things as well - ex. will not be used alone for GA
What is the onset time of nitrous?
2-5 minutes
What are potential uses for nitrous?
Start GA
Titrate GA
Anxiolytic
Reduce pain
What must be given in first and last 5 minutes?
Oxygen
What is a general effect of N2O?
Calm, comfortable, relaxed, reduced fear/anxiety
Aware patient, that responds, but has a glazed look in eyes
What are the general sensations people feel from nitrous?
- tingling extremities
- heaviness, heaven ness
- warmth
- Chills
- Floating sensation
- Vasodilation
Loss of gag reflex
What is involved in the metabolism of N2O
Oxidizes cobalt enzyme of vitamin b12
– b12 required for myelin sheath synthesis
Pressure volume problems
N2O pressure is 31x more than N2
N2O physically replaces N2 and increases the volume +/or pressure of that space
N2O 34x more soluble in blood, replacement of N2 faster than N2 is taken out, increasing pressure in air filled spaces
What are some benefits of nitrous?
Good for long procedure, good for pain and anxiety, quick and easy to reverse, easily titratable
Still lets people have protective reflexes, with few side effects
Is nitrous stored in body or metabolized by the liver?
Neither
99% eliminated through lungs without biotransformation