Push hard and push fast

If you are scared of giving mouth to mouth if you see someone collapse (with cardiac arrest) give the chest compressions anyway.

Basic Life Support (BLS) and Advanced Cardiac Life Support (ACLS) guidelines call for 2 breaths for every 32 compressions...and you should be giving 100 compressions per minute. If you are certified in either of these protocols, keep going as you are taught (I will).

But for everyone else, and that is most of America, there is A LOT of benefit to compressions only. If you would rather stand by idly (as many would understandably do) when someone has a cardiac arrest rather than give mouth to mouth, at least conisder doing chest compressions.

here is some new cardiology literature...

Survival Is Similar After Standard Treatment and Chest Compression Only in Out-of-Hospital Bystander Cardiopulmonary Resuscitation
-Bohm K, Rosenqvist M, Herlitz J, et al. Circulation 2007;116:2908-2912.

Effectiveness of Bystander-Initiated Cardiac-Only Resuscitation for Patients With Out-of-Hospital Cardiac Arrest
-Iwami T, Kawamura T, Hiraide A, et al. Circulation 2007;116:2900-2907.

Continuous-Chest-Compression Cardiopulmonary Resuscitation for Cardiac Arrest
-Ewy GA. Circulation 2007;116:2894-2896.