Nitrous Oxide

Question 1

Contraindications for N2O

Answer 1

• Should not be used with any condition where gas is entrapped within a body and where its expansion might be dangerous

Question 2

Diffusion Hypoxia

Effect

Symptoms

How to avoid

Answer 2

• N2O diffuses out of the blood into the alveoli upon termination of flow
• The N2O can dilute the O2 resulting in hypoxia
• Symptoms include
  
  • Nausea
  • lethargy
  • headache
  • syncope
• Always administer100% O2 for 5 mins agter termination of N20

Question 3

N20 Effects on CNS

Answer 3

• Hallucinations and sex arousal
• Can reach stage II anesthesia (excitment Stage)
  
  • Delirious
  • Irregular vital signs
  • Vomitting
  • Breath holding
• Not safe, stop N2O and administer 100% O2 on high flow- 10 L

Question 4

Cardiovascuar

Answer 4

• N2O is an anxiolytic that results in a decreased heart rate and overall myocardial O2 demand
• Decreases vascular resistance by was of vasodilation

Question 5

N2O blood gas solubility coefficient

Answer 5

0.47

Not very solunle in blood, fast on and fast off

Question 6

How fast does N20 leave the blood vs nitrogen

and what effects can it result into

Answer 6

Leaves blood 35X faster

can result in increased volume and pressure of a closed space

Middle ear infections

Pneumothorax

Bowel obstruction

Question 7

Pulmonary Contraindications

Answer 7

• Non-irritating gas
• Not contraindicated in asthma patients
  
  • but can contribute to a reactive airway
• Contraindicated in emphysema, middle ear infections, pneumothorax
• Bronchodilator

Question 8

Dangers of N2O

Answer 8

• Repeated long term exposure is associated with neuropathy
• Possible link to apontaneous abortion
• Decreased fertility in women

Question 9

N2O Tanks storage

Answer 9

• Stored as a liquid and gas
• Gas pressure is approximaely 750 psi at 70 degrees
  *

Question 10

Determiing how much N2O is available

Answer 10

• Gauge will always read full as long as there is gas inside
• The pressure of N2O vapor above the liquid is 750psi until no more liquid is available to replace the gas
• Must weight the tanks to determine how much N2O is present

Question 11

How many O2 tanks per N2O tanks

Answer 11

Need 2.5 times more O2 tanks for every tank of nitrous