The coronavirus disease of 2019 (COVID-19) has altered medical practice around the globe and revealed critical deficiencies in hospital supply chains ranging from adequate personal protective equipment to life-sustaining ventilators for critically ill hospitalized patients. We developed the CRISIS ventilator, a gas-powered resuscitator that functions without electricity, and which can be manufactured using hobby-level three-dimensional (3D) printers and standard off-the-shelf equipment available at the local hardware store. CRISIS ventilators were printed and used to ventilate sedated female Yorkshire pigs over 24-h. Pulmonary and hemodynamic values were recorded throughout the 24-h run, and serial arterial blood samples were obtained to assess ventilation and oxygenation. Lung tissue was obtained from each pig to evaluate for signs of inflammatory stress. All five female Yorkshire pigs survived the 24-h study period without suffering from hypoxemia, hypercarbia, or severe hypotension requiring intervention. One animal required rescue at the beginning of the experiment with a traditional ventilator due to leakage around a defective tracheostomy balloon. The wet/dry ratio was 6.74 ± 0.19 compared to historical controls of 7.1 ± 4.2 (not significantly different). This proof-of-concept study demonstrates that our 3D-printed CRISIS ventilator can ventilate and oxygenate a porcine model over the course of 24-h with stable pulmonary and hemodynamic function with similar levels of ventilation-related inflammation when compared with a previous control porcine model. Our work suggests that virtual stockpiling with just-in-time 3D-printed equipment, like the CRISIS ventilator, can temporize shortages of critical infrastructure needed to sustain life for hospitalized patients.