What should be done to keep a patient calm during hyperventilation?

Encouraging slow, deep breathing is the most effective way to help a patient who is experiencing hyperventilation. When a person hyperventilates, they exhale too much carbon dioxide, leading to symptoms such as dizziness, lightheadedness, and anxiety. By encouraging the patient to breathe more slowly and deeply, you help them restore the balance of carbon dioxide in their bloodstream. This controlled breathing can reduce symptoms and help calm their nervous system.

The other options may not effectively address the situation. For instance, advising someone to laugh may not be suitable, as laughter can lead to more rapid breathing and exacerbate the hyperventilation. Similarly, providing a mirror might distract the patient but does not help with breathing control. Reassuring the patient without physical assistance may provide some comfort but is less effective than actively guiding them to slow their breath, which directly tackles the physiological problem they are facing.