Nitrous Oxide (Entonox)

Question 1

Drug code for Nitrous Oxide (Entonox)?

Answer 1

NOO

Question 2

Presentation of Nitrous Oxide (Entonox)?

Answer 2

Nitrous Oxide (Entonox) 1ml per 1ml medical gas is a combination of nitrous oxide 50% and oxygen 50%. 
It is stored in medical cylinders that have a blue body with white shoulders

Question 3

Indications for use of Nitrous Oxide (Entonox)?

Answer 3

Moderate to severe pain

Labour pains

Question 4

Actions of Nitrous Oxide (Entonox)?

Answer 4

Inhaled analgesic agent

Question 5

Contra-indications of Nitrous Oxide (Entonox)?

Answer 5

Nitrous oxide may have a delirious effect if administered to patients with closed body cavities containing air since nitrous oxide diffuses into such space with resulting increase in pressure
Do not give Entonox to patients with:
- Severe head injuries with impaired consciousness due to possible presence of intracranial air
- Decompression sickness (the bends)
- Violently disturbed psychiatric patients
- Intraocular injection of gas within the last 4 weeks
- Abdominal pain where intestinal obstruction is suspected

Question 6

Why should Nitrous Oxide (Entonox) not be administered to patients with suspected decompression sickness (the bends)?

Answer 6

Entonox can cause nitrogen bubbles within the blood stream to expand, aggravating the problem further.
Consider anyone who has been diving within the previous 24 hours to be at risk

Question 7

What is meant by the term Intraocular injection of gas?

Answer 7

often used as a tamponade agent at the end of vitrectomy surgery to secure the retina.

Question 8

Cautions of use of Nitrous Oxide (Entonox)?

Answer 8

Any patient at risk of having a pneumothorax, pneumomediastinum and/or a pneumoperitoneum

Question 9

What is a pneumomediastinum?

Answer 9

The abnormal presence of air or another gas in the mediastinum.
The mediastinum is the center of the chest and is located between the lungs. Air can get stuck in this area because of trauma or leakage from the lungs or windpipe.

Question 10

What is a Pneumoperitoneum?

Answer 10

Is pneumatosis (abnormal presence of air or other gas) in the peritoneal cavity, a potential space within the abdominal cavity.

Question 11

What is meant by the term poly trauma?

Answer 11

(multitrauma) is a short verbal equivalent used for severely injured patients usually with associated injury (i.e. two or more severe injuries in at least two areas of the body), less often with a multiple injury (i.e. two or more severe injuries in one body area).

Question 12

Common examples of a patient more at risk of having a pneumothorax, pneumomediastinum and/or a pneumoperitoneum?

Answer 12

polytrauma

penetrating torso injury

Question 13

Side effects of Nitrous Oxide (Entonox)?

Answer 13

Minimal side effects

Question 14

What can prolonged use of Nitrous Oxide (Entonox) lead too?

Answer 14

Prolonged use is classed as more than 24 hours or more frequently than every other 4 days
Can lead to vitamin B12 deficiency

Question 15

What should administration of Nitrous Oxide (Entonox) be in conjunction with?

Answer 15

Pain score monitoring

Question 16

Advantages of Nitrous Oxide (Entonox)?

Answer 16

Rapid analgesic effect with minimal side effects
No cardiorespiratory depression
Self-administered
Analgesic effect rapidly wears off
The 50% oxygen concentration is valuable in many medical and trauma conditions
Entonox can be administered whilst preparing to deliver other analgesics

Question 17

Dosage and administration of Nitrous Oxide (Entonox) in adults?

Answer 17

Entonox should be self-administered via a facemark or mouthpiece, after suitable instruction
It takes about 3-5 minutes to be effective, but it may be 5-10 minutes before maximum effect is achieved

Question 18

How does administration of Nitrous Oxide (Entonox) in children differ?

Answer 18

Entonox is effective In children provided they are capable of following the administration instructions and can activate the demand valve

Question 19

What additional preparations must be done in low temperatures when administering Nitrous Oxide (Entonox)?

Answer 19

The cylinder must be inverted several times before use to mix the gases