From the August 1946 copy of Popular Science, here's an article by Leon Shloss on ways to save someone from drowning (before the advent of modern CPR techniques). To wit, the "Eve Method," which was invented by Dr. Frank C. Eve.
Eve: The rocking ventilates the lungs by alternately pushing and pulling the diaphragm up and down. At the same time, blood is forced through the oxygen-starved heart muscle, helping to start it or to restore a feeble beat. Further, the nerve cells of the brain and breathing center receive blood at normal pressure. When the feet-down tilt is made, blood from the extended arms fills the heart and encourages it to beat and pump. Dr. Eve goes beyond the blankets-for-warmth phase, when the equipment is available, in recommending application of hot bottles over the neck to revive the chilled nerve cells at the base of the brain.
If you read the article, you'd notice a reference to the Schafer Method of Resuscitation - if you're curious, here's how it was performed.