TORONTO - An anesthesiologist is suggesting recommendations on how to perform cardiopulmonary resuscitation or CPR may need to be changed.

Dr. Anthony Ho says that when CPR guidelines were updated in 2010 a step that is probably needed was taken out.

The international experts who revised the guidelines in 2010 dropped the recommendation that people alternate chest compressions with mouth-to-mouth resuscitation.

They said the idea of breathing into someone's mouth might discourage some people from attempting CPR and the breaths took time away from the more important chest compressions.

But Ho says the 2010 guidelines also dropped a recommendation to tilt back the head and lift the chin of the unconscious person and he thinks that was a mistake.

The Queen's University professor says studies should be done to see if tilting the head and lifting the chin increase survival rates of people on whom CPR is performed.