Knowing what to do with a choking infant can be the difference between life and death.
The steps that you need to take are shown in the diagram below.
The first step is to determine if the infant has an effective cough or not, ie is it likely that they will be able to clear the obstruction by themselves?
If an effective cough is absent but they are conscious, you should deliver 5 back blows and 5 chest thrusts as shown in the pictures below.
If the child is unconscious you should proceed to opening the airway and delivering CPR as per the section on basic life support which can be accessed using the following link: Infant Resuscitation
Identify the area at the base of the breast bone (sternum) where the ribs from the left & right sides of the chest meet and move up at least one finger breadth. Your fingers should now cover the area at the lower third of the breast bone.
Using to fingers, deliver a short sharp movement compressing the chest by about 4cm. Ideally this should be done with the head lowered so that any obstruction that is dislodged will fall out.