Changes that affect the ability to breathe which occur as an infant grows into a child

3/3/98

"This finding is also extremely important for the back sleeping recommendation," said Kinney. "We think this new finding fits in with the rebreathing theory -- that infants sleeping in the prone (stomach) position are rebreathing trapped air and, unable to sense and respond to the excess carbon dioxide, die suddenly."

Could anybody explain: how (according to this theory) is it that older children *are* able to respond to this excess carbon dioxide when presumably those older children still have 'faulty' brainstems??

Nobody knows enough yet to answer your question completely. However, I'm an anesthesiologist and can tell you definitely that there are many changes that affect the ability to breathe which occur as an infant grows into a child. For example, an infant's chest is "floppier" than a child's because it has cartilage instead of bone, and so an infant's diaphragm has to work harder to breathe than does a child's diaphragm. The diaphragm also gets tired more easily in a baby, and the trachea (windpipe) is softer and more likely to kink or collapse. So a baby's breathing is always somewhat more at risk than a child's even if the brainstem is normal. Even if an older child has a faulty brainstem, the child would be less likely to suffer respiratory obstruction, and more likely to have the muscle and skeletal support needed to keep going.

Karen Sibert, MD