Custom machine kept man alive without lungs for 48 hours

But this patient did not die.

The empty chest problem

To save him, Bharat’s team had to remove the infected lungs, a procedure called a bilateral pneumonectomy, to remove the source of the sepsis. We have machines that can oxygenate the blood. But removing both lungs creates a lethal mechanical problem for the heart.

The human heart is two pumps in one. The right side, called the pulmonary circuit, pumps oxygen-poor blood returning from the body into the lungs, which remove its carbon dioxide and load it with a fresh supply of oxygen. The left side, known as the systemic circuit, receives freshly oxygenated blood and pumps it to the rest of the body. The pulmonary vascular bed, all these miles of tiny vessels inside the lungs, facilitates this gas exchange. But it also acts as a capacitor, absorbing the pressure and volume of the blood ejected by the right ventricle.

If you remove the lungs and simply shut the pulmonary arteries, the right ventricle has nowhere to pump—it would experience an immediate, massive pressure spike, distend like a balloon, and fail within minutes. At the same time, the left side of the heart would have no blood returning to it, leading to a total collapse of blood pressure and systemic circulation.

This is the reason why most double-lung transplants are performed sequentially: The surgeons replace one lung, get it up and running, and then move on to the second. But desperate times require desperate measures.

The last line of defense

In rare cases where both lungs must be removed at once, a patient can still be supported by the Extracorporeal Membrane Oxygenation (ECMO), a mechanical lung that takes blood out of the body, removes the carbon dioxide, adds oxygen, and pumps it back in. The problem is that while ECMO can support a person for up to over a year when their lungs are still in their body, the risks of using it skyrocket when the lungs are removed.