If someone experiences pulmonary embolism should i give them cpr?

Absolutely: If someone's heart has stopped (regardless if it was due to a heart attack, pulmonary embolism or other cause) you should immediately perform cpr, if you are so trained. In addition there is a new recommendation that just came out this year from the american heart association, that supports "hands only" CPR (no breaths) for witnessed events in adults.

Yes: The truth is you will not know someone is having a pulmonary embolism. If it is bad enough, they will die immediately... At this point CPR is the best we can do (make sure to call 911 as the first step).

CPR when appropriate: You should always apply CPR to someone who has stopped breathing and/or their heart has stopped pumping, regardless of the cause. Let a physician decide when it's time to stop CPR and whether or not CPR is appropriate.

Maybe...: CPR should be administered any time a person suffers a cardiac arrest no matter what the cause is. So, if you see a person who is unresponsive, call 911 and they can help you determine if the person needs CPR while you are waiting for emergency personell to arrive. You can learn CPR in a training class, if interested.