In "DNR", Dr. Becker is looking over the chart of a patient named "Mr. Nielsen" and says "These numbers aren't so bad!" This was in reference to the show's cancellation, apparently due to low Nielsen ratings.
In "DNR", Becker complains about a female patient, saying, "I pity the poor bastard married to her." The actress playing the patient is Mary Steenburgen, Ted Danson's real-life wife.
The episode's title D.N.R. is an acronym for the medical term "do not resuscitate" and refers to a legal order to allow natural death of the patient by turning off their life support and withholding resuscitation according to their or their family's wishes. This is also an in-joke reference to the fact that the show was canceled due to low ratings and that this is its last episode as well as to some of the episode's overall themes.
Ted Danson, Hattie Winston, Shawnee Smith and Alex Désert were the only actors to appear in every episode.
Last show of the series.