Microscopic oxygen bubbles, injected directly into the bloodstream, could soon begin saving the lives of patients who have stopped breathing. Researchers at Boston Children's Hospital encased microscopic pockets of oxygen in a layer of lipids, the fatty molecules that make up cell membranes. Then they administered a shot of the bubbly mix into test animals. The fatty bubbles diffused instantly and saturated the blood within seconds. When given to rabbits with obstructed airways, the solution kept the animals alive and stable for 15 minutes without their taking a single breath. If this type of therapy proves safe in humans, a syringe full of oxygen microbubbles could help avert brain damage and death for the victims of cardiac arrest, asthma attacks, strokes, and injuries to the lungs, airway, or face. Says intensive care doctor and lead researcher John Kheir of Children’s Hospital, "We hope someday the drug will be stored on code carts and ambulances across the world to reverse brief, severe, and life-threatening episodes of hypoxemia."