You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is The minimal concentration of oxygen that should be used with Nitrous oxide analgesia is: and explain in detail?
Nitrous oxide is a weak anaesthetic and while some patients can be brought to an unconscious level by mixture of Nitrous oxide and Oxygen containing at least 20% Oxygen.