Hello from JustAnswer.
I am sorry for your loss.
I can explain each of these terms, but there is still a level of underlying cause that is missing.
A cardiopulmonary arrest is when the heart suddenly stops beating. It is called a cardiopulmonary arrest because the body will typically stop breathing when the heart stops beating.
However, in this case, the cause of the cardiopulmonary arrest was identified as a respiratory arrest. A respiratory arrest means that the breathing stops. So in his case, the breathing would have stopped first, which then caused the heart to stop beating.
Saying that someone had a respiratory arrest, though, does not say why the respiratory arrest occurred. It would most often be due to a condition affecting the lungs
, but there also could be certain neurologic causes of a respiratory arrest.
In some cases, the underlying cause of the respiratory arrest is not readily apparent, so may not be specified, but just saying that there was a respiratory arrest does not explain why the respiratory arrest occurred.
If I can provide any further explanation, please let me know.