Entonox Flashcards
1
Q
Classification
A
Medicinal gas, compressed.
2
Q
Pharmacodynamics
A
- At the concentrations in ENTONOX, oxygen has no discernible pharmaceutical effect other than the beneficial effects of an oxygen enriched mixture in certain cases.
- Nitrous oxide is eliminated unchanged from the body mostly by the lungs.
- Nitrous oxide is a potent analgesic and a weak anaesthetic.
- Endorphins are probably involved in the analgesic effect; a concentration of 25% nitrous oxide is usually adequate to provide a marked reduction in pain.
3
Q
Pharmacokinetics
A
- Onset - rapid
- Peak - immediate
- There are no essential observations about the pharmacokinetics of oxygen at this concentration.
- Nitrous oxide is a low potency inhalation anaesthetic and high potency analgesic.
- At a constant inspired concentration the rise time of alveolar concentrations is faster than that of any other anaesthetic agent.
- The elimination of nitrous oxide equally is faster than that of any other anaesthetic. This characteristic is especially valuable in analgesia for short-term pain relief.
- The blood/gas partition co-efficient of nitrous oxide at 37°C is 0.46 compared with that of nitrogen of 0.015 causing nitrous oxide to expand into the internal gas spaces.
4
Q
Indications
A
- Relief of moderate to severe pain.
- Cardiac related chest pain where nitroglycerin will be of no value or is contraindicated. Must be followed by high flow oxygen when discontinued.
- Isolated extremity injuries, pain associated with burns excluding mechanisms associated with potential inhalation injury, etc.
5
Q
Contraindications
A
- Pneumothroax
- Air emboli
- Inhalation inj
- Nitro last 5 min
- Decompression sickness
- Inability to comply (dloc)
- Enclosed space
