What should a nurse instruct an agitated adolescent donating blood who starts to hyperventilate?

Breathe into cupped hands is the most appropriate response for an agitated adolescent who is hyperventilating. This technique functions by creating a small, enclosed space that helps to increase the carbon dioxide levels in the blood, counteracting the effects of hyperventilation. When a person hyperventilates, they expel carbon dioxide at a higher rate than their body produces it, leading to respiratory alkalosis. Breathing into cupped hands allows the individual to re-inhale some of the exhaled carbon dioxide, which can help alleviate symptoms such as lightheadedness, tingling sensations, and anxiety.

The other options may not effectively address the situation. Counting backward from 100 could be a distraction technique, but it does not directly address the physiological aspect of hyperventilation. Taking deep breaths from the abdomen might seem helpful but could be challenging for someone in an agitated state, as they may not be able to focus and control their breathing effectively. Focusing on the needle insertion could increase anxiety and stress, exacerbating the hyperventilation rather than alleviating it. Therefore, breathing into cupped hands is the most targeted approach to manage hyperventilation in this scenario.