All of the following are advantages of using nitrous oxide analgesia EXCEPT one. Which one is the EXCEPTION

• Correct answer

  Lowers pain threshold

• Rapid onset of action

• Produces euphoria

• Pleasant induction

• Titratable

• Rapid and complete recovery

• Virtually no adverse effects in absence of hypoxia

• Therapeutic sedative for many medically compromised patients

• Suitable for all ages