Chapter 3: Why do I believe that depleted rebreathing is responsible for SIDS deaths?

As I have explained in Chapter 2 depleted rebreathing takes place when an infant suffers from not drawing in a sufficient volume of fresh air, and as a result they are breathing in predominantly redrawn air which is partially spent. The mixture of oxygen and carbon dioxide in their lungs deteriorates to the point of causing harm to the infant. Depleted rebreathing takes place when an infant has their breathing restricted by breathing into a soft toy or bedding over a period of time.

This is the premise under which the Back to Sleep program is supported. Without saying it explicitly, those that champion the Back to Sleep program are suggesting that depleted rebreathing is the cause of SIDS deaths in these cases. The purpose of the Back to Sleep program is the avoidance of any situation whereby an infant’s breathing would be impaired in any way such that depleted rebreathing can take place. I agree with this as it is a simple question of logic; simply put, if the avoidance of depleted rebreathing significantly reduces SIDS deaths (considered to be a reduction of about 50% in the case of the Back to Sleep program), then depleted rebreathing has to be considered as the cause, or the most significant cause, of SIDS.

However, some would argue that many SIDS deaths occur without the child’s mouth and nose being forced into their bedding or a soft toy. They would argue that breathing was not restricted and that therefore depleted rebreathing did not take place. From that observation most conclude that SIDS deaths must be caused by something else, as yet undiscovered. Thus the cause of SIDS has still been declared as an unknown.

Here’s where I disagree. The situation whereby a child has their nose or mouth pushed into a mattress or soft bedding, although a significant condition, is not a necessary condition for depleted rebreathing to occur. I believe that depleted rebreathing does take place in all cases. In what follows I will explain how I believe that could actually take place. I will explain how the physical limitations of the child under certain scenarios can result in depleted rebreathing even if the child is awake and sitting up. First, I will propose those physical limitations or qualities of a newborn child that open up that possibility of depleted rebreathing. Then I will describe those situations or scenarios where these limitations of the child can lead to depleted rebreathing, even when a child is awake or sitting and with no apparent obstruction to their breathing.

In my view the medical profession appears to be looking in the wrong direction when it comes to the cause of SIDS. They are looking for some medical condition, however complex, that is at the root of SIDS deaths. They are not looking at it as an event or an incident. Sometimes the public at large also considers that the answer lies in something as complex as DNA, rather than something much simpler, such as human behaviour or practices. I don’t believe that they will ever find it if they continue to look for complex causes.

If some practitioners consider that depleted rebreathing is the cause in those cases where breathing has been restricted, but not in all cases, then I believe a new and separate class of death must be classified and defined. It seems a matter of definition. Perhaps SIDS should better be understood as a spectrum rather than a syndrome.

Now let us look in Chapter 4 at those physical limitations of a newborn which make depleted rebreathing more of a possibility, and as such, a SIDS death more of a possibility.


Barry Stanley