This depends on what level of training you have received. The American Heart Association guidelines no longer recommend a pulse check for non-medical professionals.
Infants should receive chest compressions in a ratio of 30 compressions: 2 breaths if they are unresponsive to verbal and tactile stimulation (tickle their foot) and are not breathing. Direct someone to call 911 immediately.
Additionally, if an infant chokes the guidelines recommend five back slaps followed by five chest compressions. Seek training in this if you have a child or will spend time around children - simply reading about it on the internet does not give you the practice needed to learn this simple and life-saving skill.
For medical professionals, the answer is simple: Do chest compressions on an infant when there is no pulse at the femoral or brachial artery. This assumes competency in a variety of skills including but not limited to pulse checks and oxygen delivery.
Perform CPR on an infant when it is determined there is no breathing and no pulse.
When they are in shock, fainted or suddenly passed out.
If someone else is with you to make the call, activate the EMS as soon as it is determined the infant is unconscious. If no one else is with you, call EMS after 2 minutes of CPR.
Perform chest compressions for an infant at a rate of at least 100/minute.
Compress the infant's chest about 1/2 to 1 inch for CPR chest compressions.
you give 30 compressions to 2 breaths
Ratio of compressions to breaths for a toddler is 30 compressions to 2 breaths.
For infant CPR, give cycles of 15 compressions to 2 breaths; rate of compressions are at least 100 per minute.
Half inch - one inch
1/2 to 1 inch compression depth.
Thirty compressions and two breaths per cycle.
You are correct; 30 chest compressions and 2 rescue breaths.
Both the American Red Cross and the American Heart Association train 2 breaths to 30 chest compressions for child/infant CPR, for either 1 or 2 rescuers.
Perform Adult CPR by 30 chest compressions to 2 breaths.
The rate for CPR chest compressions is 100 per minute; adult, child, and infant.