Chapter 5: What SIDS is not

One thing I wish to point out is that the deaths that were avoided through the Back to Sleep program point to the fact that SIDS deaths are not “sudden”. The time it took from when the child’s breathing was first restricted until the time that the child died can only be speculated. However, we can assume that it was not sudden, but occurred over a period of time, perhaps five to fifteen minutes, an unknown time period.  We just don’t know. But we do know that in these cases it was not sudden. The only thing that was sudden was the discovery of the child. If we believe that SIDS was avoided by the avoidance of depleted rebreathing because of the Back to Sleep campaign, then we have to change our thinking about SIDS, and stop calling it “sudden”. This term is misleading. To continue using that name quite possibly will cause many researchers to look for a sudden cause overlooking any possibility that it is a longer process, involving a number of variables.

It can be and has been inferred that, through depleted rebreathing, oxygen is reduced and carbon dioxide has been increased, and as a result this deficiency of O2 and excess of CO2 lead to death. Note that SIDS babies in many cases have been described as passive (limp and unresponsive) prior to death. This again suggests that SIDS is not a sudden event but is a process that occurs over a period of time. The low level of oxygen may very well be the cause of this sluggishness or passivity, and the observation of this lethargy in a baby may be a helpful indicator for SIDS prevention.

Carbon dioxide has been considered to serve two purposes. In the lungs it regulates the depth and frequency of breathing, while in the blood it regulates the pH level of the blood, making it alkali or acidic. When a child suffers from high levels of CO2 and low levels of O2 because of depleted rebreathing, it can be expected that the chemistry of the blood will change. Many SIDS cases describe blood or pink fluid in the nostrils of the child. The change in blood chemistry caused by harmful rebreathing may be the cause of blood seeping past the sensitive blood vessels of the nose. Although not considered as a nose bleed, the blood chemistry may have weakened the sensitive membranes of the nose walls enough to allow fluid seepage. The observation of pink fluid in or around the nostrils may be considered as another pre-SIDS indicator.

Researchers are wise to consider that this change of blood chemistry may ultimately be the cause of death, or works alongside the low levels of oxygen to cause death. This change of blood chemistry may damage brain cells as it changes brain chemistry, and in turn may interfere with the normal regulation of the heart and lungs. It has also been noted that, when monitored, some SIDS cases appear to have gone into shock, which is normally what happens to someone who has suffered loss of oxygen. Again this change in blood chemistry would not be immediate but occur over a period of time, also pointing to the notion that SIDS is not “sudden”. 

It has been discovered in Italy that in SIDS deaths there has been high levels of serotonin discovered in the brain. Is this the cause of the death of the child, or is this the result of the changes in blood chemistry due to depleted rebreathing? Researchers should not jump to the conclusion that serotonin is the cause of SIDS deaths, when it is very possible that serotonin in the brain is the result of depleted rebreathing, as the blood chemistry effects the brain cells. More research is needed in this area as serotonin is involved, in part, with breathing and temperature control which are related to SIDS deaths.

Research has stated that there are no near-SIDS (or pre-SIDS) events, or any apparent life threatening events (ALTE) related specifically to SIDS. Given the evidence of passivity of the early infant and/or seepage of pink fluid around the nose from the nostrils, I would have to disagree. Some want to distance these episodes from that of SIDS, but I believe that this would be a mistake. SIDS should not be considered sudden but the end result of a process that occurs over a period of time, which occasionally can be observed through pre-SIDS events.

Apnea, the occasional stoppage of breathing for a period of time, and suffocation are not SIDS related events.  The main difference is that with apnea and suffocation breathing is immediately stopped, while with SIDS breathing continues. Someone who suffers apnea or suffocation can be resuscitated if it is done soon enough before damage to their brain occurs, while the sufferers of SIDS cannot be resuscitated because they continued to breathe long past the point where brain cells have been damaged.  Apnea and suffocation will pass a point of no return also at which time they cannot be revived. SIDS cases pass that point well before their death has been noticed. Therefore they never can be revived (unless by chance they were picked up before the harmful rebreathing had progressed to the point of death, and at which time I believe that they have incurred partial brain damage which will show up later as a learning disability).

I believe that SIDS research may be short-sighted if it rules out any near-SIDS event or condition. Just because no event has been observed, doesn’t necessarily mean that none exist. Is SIDS a brief event, that happens within seconds (unexplained and impossible to prevent or predict) or is SIDS a longer process, taking perhaps 5, 15 or 30 minutes with the final outcome as death.  Is SIDS sudden or does it only appear sudden because the only observable part of the event is the final outcome?  This I believe to be the case. I believe that SIDS is a longer event or process and that by understanding this process, we may be able to put in place practices that avoid the process, or we may develop devices or strategies that help us observe and  prevent the condition continuing once it has been detected, if that is possible. By understanding the process, we may be able to uncover other indicators that will help us avoid SIDS tragedies. As an example, if we were able to ascertain which infants have he least sensitivity to carbon dioxide in the lungs, we would be more vigilant to protect these specific infants.

There has also been evidence in many cases that newborns who suffer SIDS are also significantly overheated. Overheating has been considered as one of the stressors or risk factors of SIDS. Perhaps.  However; it could also be that overheating is the result of harmful rebreathing (rather than a cause of SIDS), as the change in blood and brain chemistry fail to cool the body properly, or some other reason which will be discussed following.  It is important to note that overheating would not be instantaneous at death, but the result of a longer process. Therefore, overheating could be considered as a third indicator that shows that SIDS is not a sudden event, and that observation of this overheating may lead to action that could prevent a SIDS death.