How long should each breath last during mouth-to-mouth resuscitation?

During mouth-to-mouth resuscitation, each breath should last about 1 second. This duration is crucial because it allows enough air to be effectively delivered to the victim's lungs without causing excessive pressure that might lead to complications such as gastric inflation. The goal is to achieve visible chest rise, indicating that air is entering the lungs properly. Holding the breath for this length of time ensures that the victim receives adequate oxygen while also maintaining a rhythm that is easy to follow for the rescuer.

Longer breaths can be less effective and could potentially lead to an increased risk of causing harm, such as hyperventilation or ineffective ventilation if the air is delivered too forcefully. Maintaining a consistent rhythm of 1 second per breath aligns with the recommended guidelines established in CPR protocols.