SIDS and Older Infants

>...they have told me that he was too old to be a SIDS baby. Connor >died on his 14 month birthday that would make him 5 weeks over a year.

The official NIH definition of SIDS limits the diagnosis to infants less than 1 year of age. The NIH made the decision to restrict the definition to infants less than 1 year of age for epidemiological research purposes. However, this is a RESEARCH DEFINITION.

Sudden unexplained death *does* occur in infants over 1 year of age and it is no less tragic because it doesn't fit the NIH's research definition. Unfortunately, this change of definition (while it may be good for research) has had some undesirable side effects for parents of infants > 1 year who die suddenly and unexpectedly.

There are some potential medical implications of age at death. When an older child dies suddenly with no cause apparent, we tend to look more closely for metabolic diseases and other (fortunately rare) disorders that can cause sudden unexpected infant death that tends to strike an older age group than classic SIDS. This has been discussed here several times before and I think Chuck Mihalko has posted some of these discussions on the website.

Hope this is helpful,
John L. Carroll, MD
The Johns Hopkins Children's Center

The NICHD defined SIDS as the sudden unexpected death in an infant up to one year of age. That is to say that sudden unexpected death with no apparent cause does not occur in older infants. In fact it does occur but is rare. The causes of SUD (sudden unexpected death) in 1-2 year olds are many. They can be classified into the following groups:

1) Respiratory

asphyxiation
bronchpneumonia
bronchiolitis / reactive airway disease
drowning

2) Cardiac

myocarditis
Tuberous sclerosis (rhabdomyosarcoma)
cardiomyopathy
congenital heart disease
arrhythmias (prolonged QT syndrome)

3) Nervous system disorders

post-traumatic
meningitis
encephalitis
arteriovenous malformation
aneurysm

4) Endocrine

congenital adrenal hypoplasia or hyperplasia
Pancreatic islet cell disorder
cystic fibrosis

5) others

gastroenteritis with dehydration
sepsis
poisoning

When no cause is found we would call it unknown or idiopathic. If the definition of SIDS were to change to include infants up to two years of age then it would be called SIDS. There has been some discussion to increase the age criterion in the definition of SIDS to include these infants. One major reason to do this is to provide bereavement and social services for these families and provide them with the rich resource information available through the SIDS alliance and other groups. But they are probably not the same things. Infants most susceptible to SIDS are between the ages of 2 and 4 months with the majority of deaths occurring by 6 months of age. If the definition were to include older infants to two years of age the above statement would still be true.

If the definition were to extend to two years old how would the SIDS parents feel when their subsequent sib made it to one year old ??
How would they feel about monitor discontinuation at 6 months?
12 months??

I hope this helps.

JDDeCristofaro, MD
University Medical Center
Stony Brook, NY
Infant Apnea Program

In So. California have had at least one set of parents over the last ten years whose 2 year old child was diagnosed as having died of SIDS. We have always considered this as a highly unlikely "aberration" to the statistics of SIDS. I'd be interested in your response to this...

SIDS, according to the latest NIH version of the definition, is restricted to infants <1 year of age. this was done because the group who reviewed the data felt that sudden unexpected death in children> 1 year of age is probably due to a variety of causes (eg., metabolic disorders) that may not be related to the cause(s) of SIDS in younger infants.

Sudden unexpected death of infants/children > 1 year can be caused by a variety of things such as metabolic disorders, degenerative brainstem disorders, anomalous coronary artery, etc. Because sudden unexpected death is rare in children > 1 year, some authors have proposed that intentional injury is more likely in this age group. In any case, for research purposes, I think it is correct to exclude these infants from the definition of SIDS.

Best regards,
John L. Carroll, M.D.
The Johns Hopkins Children's Center
Baltimore, MD

Dear Dr. Carroll;
I have great respect for you and you have really helped me out in finding a local SIDS Support for the monitoring of my upcoming child. However, I have to totally disagree with you in regards to not including infants of any age. My daughter died of what looks to be SIDS but it went listed "undetermined" due to the fact that she was 40 days over the one year age.

Hi and thanks for the reply. I think we have a basic misunderstanding here... I must not have communicated well what I wanted to say.

Let me try again... there is no question what-so-ever that sudden unexpected death of infants occurs > 1 year of age. I talked about it in my original posting. It certainly does occur. I never meant to imply otherwise.

When I said I agreed with restricting the definition to infants <1 year of age, I was referring **only** to research purposes. **if** one is talking about research, then I still think it is better to keep the definition to infants < 1 year. this is because 1) there are a variety of causes of sudden unexpected death for infants> 1 year, 2) there is a unique age distribution for SIDS such that > 95% has occurred before 6 months of age, and 3) it is unlikely that sudden unexpected death in a child > 1 year old is due to the same physiological mechanisms as for 2-4 month olds.

Please don't misunderstand that I meant that either one should be researched preferentially over the other. Infant deaths at ALL ages needs intensive research in order to try to understand the causes and stop it from happening.

On top of that she had a ALTE three days before the final event and the doctors basically sent her home saying " couldn't be a SIDS event as she is to old".

I would not take this approach in my own practice. An ALTE is an ALTE, no matter what the age. If an apparently life-threatening event has occurred, it must be treated as such, no matter what the age.

How does anyone know how rare or not Sudden Infant Death in older infants is if no is tracking or there is no defined cause. I tell you I know of 1 other person personally and have been told of 6 other cases where the infants died suddenly with no apparent cause and I am just one person. I bet if we tracked it we would find that in fact sudden death in older infants occurs more frequently than currently thought.

Sudden unexpected death certainly does occur in older infants (> 1 year) and this is well known. However, the feeling of the folks at NIH who looked into this was that, for research purposes, it was probably better to exclude these infants from the definitions, on the grounds that the **underlying cause(s) of death** are likely different from what causes SIDS in the typical <6 month old. this is what I agree with. however, you are certainly correct that sudden unexpected death does occur in children>1 year of age... and it needs the full attention of researchers.

My biggest complaint is that the doctors at the hospital should have been aware that an ALTE does happen in older infants and requires a monitor after the event. In all likelihood if a ALTE does occur it probably will occur again and needs to be monitored.

I agree... I tell people this all the time.

In fact an ALTE is a warning sign and frequently results in unexpected death. (undefined- just like SIDS)

The highest mortality rate in any general study of ALTE I'm aware of was 6%. This is quite high indeed, but it is the highest. Other studies have found lower rates.

In the old study of Oren and Kelly, they looked at a group of children with recurrent ALTE and identified a "high risk subgroup" in which the mortality rate was nearly 30%. However, this has not been well studied. The numbers are all over the place. More research is needed in this area.

If they knew that SIDS does happen to older infants, I might have gotten a monitor and my daughter might still be alive today. They denied me a monitor because she was quote "to old".

For clinical purposes, every pediatrician needs to know that sudden unexpected death can occur at any age. There is **nothing** magic about 1 year -- for clinical practice purposes.

So maybe for research purposes somehow it makes life easier. But children are dying and doctors are not recognizing what it is. Worse than that if just one child could be saved from educating the public it would be worth it.

I still think it clearly is better, for research purposes, not to "lump together" kids <6 months (the typical SIDS infant) with infants who die suddenly and unexpectedly> 1 year of age. I think deaths in infants of ALL ages deserve intensive research study... the only point I was trying to make is that it makes sense, for research purposes, not to mix them up in any given study.

I have had my daughters autopsy reports, medical history and hospital reports examined by several experts in the SIDS field. Guess what they say..."if she was just 40 days younger we would call this SIDS." So please don't tell me or others that it does not happen to older infants.

I didn't say this. I would never say this. In my original posting I specified "for research purposes" the NIH restricted the definition to infants <1 year of age.

It does and it hurts that these children are dying and no one wants to recognize it for what it is. How can we help these children and stop this terrible tragedy if no wants to even admit or track it.

Again, I think there is a misunderstanding here. Sudden unexpected death in infants > 1 year is well known in the medical literature and there is a great deal written about many of the causes. There certainly is more work to do. However, many scientists think, for good reason, that the mechanism of unexplained death in an older infants (> 1) is likely different from that in infants <6 months of age.

I strongly oppose the NIH's decision to make the classification of SIDS to just babies under the age of 1. It should be extended to babies of any age. I know, I am living with this every day. The fact is; there is a chance that my child might be living today if the medical community had taken the high road; recognizing and educating that SIDS can happen to any age baby. Any age baby that has a ALTE should be on a monitor and all precautions should be taken for another event. This will only happen when the medical community opens SIDS up for a age unlimited diagnosis.

In the case of NIH, defining SIDS the way they did, they are (in my opinion) on the right road as far as research is concerned (only research). From a clinical standpoint, I thought it was well known that sudden unexpected death of an infant can occur at any age and I'm not aware of any widespread belief to the contrary. Your experience with these particular doctors may or may not be generalizable to the "medical community". I don't know. I wouldn't have thought so but maybe I'm not fully aware of what pediatricians are thinking out there. Maybe others on the list have experience with this.

That being said, I want to do everything I can to change these rules. If we do, maybe we can save at least one child's life.

To my knowledge neither the AAP (American Academy of Pediatrics) nor NIH has ever put age limits on the indications for home monitors. I follow many children on monitors who are 12-24 months and even older.

All I can say is that I agree with you completely that sudden unexpected death can and does occur in kids > 1 year, any signs of ALTE in this age group MUST be taken very seriously, and that monitoring is indicated when it's indicated... no matter what the age.

If there *is* a widespread belief out there in the medical community that **clinically** sudden unexpected death ends at age 1, then I would agree completely that this needs to be addressed and changed.

Thanks and best regards,
John L. Carroll, M.D.
The Johns Hopkins Children's Center
Baltimore, MD

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