The mainstay of treatment for penetrating chest injuries actually isn't mechanical ventilation, which will often worsen pneumothorax (collapse of the lung from air leaking between lung and chest wall). Rather, treatment even today generally consists of putting a tube into the chest cavity to drain out blood, air, and other miscellaneous fluids (pus, effusions, and the like) and thereby allow the lung to reexpand amd function normally.

This technique goes back a very long way -- the famed Dutch physician Boerhaave in 1715 described it as follows:

"It is necessary to evacuate the extravasated blood [from the pleural cavity in traumatic hemothorax] by 1) posturing the patient and by appropriate exercises; 2) suction applied through a blunt-tipped flexible tube perforated laterally; 3) the injection of anticoagulant fluids; 4) enlarging the wound; 5) making a counterincision between the two lowest true ribs, four fingerbreadths from the vertebrae and the inferior scapular angle, using bistoury directed inferiorly, the incision placed between and parallel to the two ribs."

Unfortunately tube thoracostomy didn't become widely available and accepted until after WW2. Before that needle aspiration or open drainage were the main ways of treating penetrating chest injuries and were considerably less effective. If you survived your initial injury, there was a very good chance you'd come down with a chest infection and empyema -- accumulation of pus in the chest. These could be drained -- Hippocrates describes the surgical technique -- but in the preantibiotic era most victims would have succumbed to sepsis.