Sudden oxygen deprivation can happen for many reasons, from choking to aspiration to cardiac arrest. In these emergency situations, rapid oxygen delivery can mean the difference between life and death. But what if the person cannot breathe?

In the summer of 2012, John Kheir, MD, of the Heart Center at Boston Children’s Hospital, published a study in Science Translational Medicine describing an alternative oxygen delivery system. Kheir used tiny, gas-filled microparticles with a thin outer layer of lipids (fatty molecules) that combined to form a liquid foam-like substance. Injected into the bloodstream, the particles rapidly dissolved and delivered oxygen gas directly to the red blood cells in animal models. But the bubbles were very unstable and not suitable for clinical use. …