Canadian Red Cross Basic Life Support (BLS) Practice Test

Using back blows is appropriate when dealing with a conscious adult or child who cannot cough, speak, or breathe due to choking. This scenario indicates that the airway is obstructed, but the person is still conscious, which allows for immediate intervention to relieve the blockage.

In this situation, back blows serve as a first line of defense to help dislodge the object causing the choking. The force of the back blows can create enough pressure to help expel the obstruction from the airway. It's crucial that this action is taken before considering other techniques, such as abdominal thrusts, especially since the person can still respond and may benefit from a combination of techniques.

Other contexts provided by the remaining options do not warrant the use of back blows. For instance, in an unconscious individual, different protocols, including calling for emergency services and initiating CPR, are indicated. If the person has a strong cough, they are still able to expel air and may be able to clear their own airway without assistance.