Which is an example of an unintentional injury?

An unintentional injury could be when someone falls off a cliff and breaks their leg, or gets in a car accident.
Hope that helped =)

When someone is skateboarding and breaks their arm

20 times a minute is usually the average respritory rate of an adult. additionally the patient is breathing on his own, is clearly maintaining his airway, and is intaking a sufficient amount of air. you shouldn't use a bag valve mask, cpap, or other form of positive pressure ventilation, unless the patient has lost control of his airway, and is not breathing (apneic) or has rapid breathing or slow and shallow respirations. this patient would most likely and should be put on an non-rebreather mask or nrb attached to 100% high flow oxygen at 15 l/min. don't use a nasal cannula, as the amount of oxygen it provides is limited with a rate of 6 l/min.