On March 31 2008 American Heart Association announced Hands Only CPR Adults who nearly-drown or have cardiac arrest due to a respiratory cause need conventional CPR.
The AHA states:
Bystanders must take action when they see someone suddenly collapse and stop breathing normally. When effective bystander CPR is given immediately after sudden cardiac arrest, it can double or triple a victim’s chance of survival. Hands-Only CPR can help save lives.
Do not give Hands-Only CPR to infants and children — all infants and children who have a sudden cardiac arrest need conventional CPR.
If you have taken conventional CPR and are comfortable with your skills, You should always use the conventional CPR method of breathing and compressions.