The ratio for adults is 1 breath every 5 seconds, and for children and infants it is 1 breath every 3 seconds. This is what the updated Red Cross standards are.
A breathing barrier device should be used if providing rescue breathing to minimize the risk of disease transmission.
For an Adult, if there are no signs of life, immediately go to CPR. For an Infant or Child, if there is no breathing, but a pulse start rescue breathing; 1 breath every 3 seconds.
During CPR, the chest compressions are applied; during rescue breathing there are no chest compressions used.
If your are not trained in CPR or rescue breathing then you should not be giving rescue breaths as you can injure the victim. The lay rescuer should only provide compressions at a rate of 100 compressions per minute. AHA provides courses to learn CPR/ rescue breathing which are very beneficial.
Agonal breathing will not support life; rescue breathing (or CPR if no pulse) is required.
When a person has stopped breathing and can not breathe on his own, rescue breathing (or Mouth-To-Mouth Resuscitation) is given to try and saved the persons live (in addition to CPR and/or defibrilation).
Causes of collapse for which rescue breathing may be needed are anaphylactic shock, heart attack, and poisoning.
Check to see if they have a pulse, or are breathing. If they have both, no CPR is needed. If they have a pulse but aren't breathing, you can perform rescue breathing only without chest compressions. If they do not have a pulse and aren't breathing, you perform rescue breathing and chest compressions.
Rescue breathing is life saving procedure. It does not transmit any serious disease. The percentage is very low and that is not important. You must go for the rescue breathing so that the other person will help you in emergency.
If there is a pulse, then perform rescue breathing only.
Check for signs of life when performing rescue breathing on a child every 2 minutes.
A Child is someone between the ages of 1 and 12 years old and the normal rate is 15-30 breaths a minute. For providing Red Cross rescue breathing, that equates to a ventilation about every 3 seconds.