How can you determine if rescue breaths are entering a person's lungs?

When assessing whether rescue breaths are effectively entering a person's lungs, observing the chest rise is a key indicator. When air is delivered into the lungs, the chest should visibly expand and rise, demonstrating that the air is filling the lungs as intended. This visual cue is critical for confirming that the breaths are being successful and not resulting in just inflation of the stomach, which would indicate incorrect technique or an obstruction.

In contrast, other indicators may not accurately confirm the effectiveness of the breaths. For instance, if the stomach becomes bigger, it suggests that air is going into the stomach instead of the lungs, which is undesirable. Noticing a person shaking does not pertain to the effectiveness of rescue breaths and is not a reliable indicator of air entry. Feeling resistance can occur in various contexts, and while it may indicate pressure, it does not provide clear evidence that the breaths are successfully inflating the lungs. Therefore, the visible rise of the chest is the most effective and certain method to determine if the rescue breaths are working properly.