CPR

CPR, or Cardio-Pulmonary Resuscitation, known colloquially as "the Kiss of Life," was a medical technique used on humans. It also worked on Time Lords. With Time Lords, however, given their binary vascular system, CPR had to be performed on both hearts. (TV: Smith and Jones)

In 1699, Amy Pond used CPR to revive Rory Williams from near drowning, the effects of which he began to suffer after she released him from the medical care of the Siren. (TV: The Curse of the Black Spot)

In 2007, when Gwen Cooper accidentally killed Ed Morgan, Dr Owen Harper started to perform CPR on him, but soon stopped, realising it futile. (TV: Ghost Machine)

In 2008 Martha Jones performed CPR to revive the Tenth Doctor from hypervolemic shock when the Plasmavore drank his blood. (TV: Smith and Jones)

She later performed it on him again after he fell into a coma as a result of one of his hearts failing. He woke up unharmed. (COMIC: The Forgotten)

In 2009, when Henry Parker was dying of a heart attack, Owen Harper attempted to perform CPR on him, before realising that he was no capable as he now lacked a respiratory system. (TV: A Day in the Death, Dead Man Walking)

In the same year, Ianto Jones saved Carlie Roberts from death using CPR after an encounter with a parasite. (AUDIO: Submission)

Behind the scenes
In the real world, a provider of CPR uses chest compression and rescue breathing to continue blood flow, which provides oxygen to body tissues even if the heart and lungs have stopped. This allows time for advanced medical treatment.

Events in the DWU seem to imply that CPR is restorative. However, in the real world, this is a last chance technique. Further medical attention is required and, even then, it is frequently unsuccessful.