Dr. Pauline Chen has an article about doctors, empathy and time crunches.
She notes that many doctors would like to express empathy to patients when delivering terrible news, but due to the load of cases they are dealing with, are afraid of spending too much time comforting one patient when there are others that need attending to.
She argues that expressing empathy takes less time than one might anticipate, especially if you use the right strategies: for instance, she recommends expressing empathy throughout a consultation instead of waiting until the very end, as some doctors tend to do.
The whole column is interesting and worth a read.