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Pictured: Not helping SIDS

Pictured: Not helping with SIDS

As a pediatrician caring for hospitalized children, I deal with fear on a daily basis. My day is saturated with it. I encounter fear in a variety of presentations, with parental fear the most obvious but probably least impactful on my management decisions. I do spend a lot of time and mental energy calming the fears of others but more managing my own, both struggling to prevent it from biasing my thought process and harnessing it as a productive motivational force. I devote a significant amount of effort towards teaching residents and students the practice of inpatient pediatric medicine and fear can be a valuable teaching tool when used appropriately.

So I admit that I take advantage of fear to a certain extent in my practice. Most pediatricians do. Maybe we all do. Proper informed consent, for instance, must include potential poor health outcomes related to medical intervention or the refusal of them. I accept that fear is an impetus for seeking medical care. Parents should be afraid of poor health outcomes from vaccine-preventable illnesses, for example. They should be made aware of the repercussions of poor adherence to home asthma management or of not placing their child in a proper car seat every time they put them in a car. Fear can serve the greater good.

But there is a difference between these unavoidable aspects of science-based medical care and the abuse of fear by practitioners of irregular medicine.

Robert T. Carroll, in his excellent book on critical thinking, Unnatural Acts: Critical Thinking, Skepticism, and Science Exposed, discusses the role of fear in decision making:

Nothing can motivate people like fear. Manipulators of beliefs and actions have known this for millennia…Advertisers and phony healers use fear to sell us worthless products. Politicians play on our fears to manipulate us. For some, fear is the weapon of first resort.

In the absence of a plausible mechanism of action and any compelling evidence, what does an alternative medicine practitioner have in his armamentarium? I have little doubt that most readers of this website could competently rattle off a number of reasons why a patient might seek out the care of a chiropractor for a variety of conditions, for example, and why the patient might believe the treatments were effective. Any treatment after all, even the most outlandish, might appear to work when used for conditions that wax and wane in severity, are impacted by subjective variables such as stress and anxiety, or that can spontaneously resolve.

But what about when the condition isn’t self limited and doesn’t wax and wane in severity? How does a bogus alternative practice approach something which isn’t significantly impacted by the many recognized placebo effects? What about terminal cancer or ALS where with even the best science-based care there is no hope of a cure? What about a condition where death is a prerequisite for diagnosis?

The answer is that chiropractors, homeopaths and their ilk don’t simply focus on the diagnosis and treatment of illnesses, some of which only exist in their own fantasies. A very consistent and seemingly across the board claim is that of success in the prevention of illness. It is one of their most widespread selling points, in fact, and often spouted in the same breath as claims that conventional medical practitioners only focus on symptom management in their Western and overly materialistic approach to healthcare. Unless, of course, the tools of our materialistic approach appear to lend support to their personal belief system. Then science is tops.

Naturally readers of this blog will easily recognize straw man arguments such as that. All practitioners of science-based medicine understand the pivotal role of prevention in caring for their patients. There is a wealth of solid scientific data to support general lifestyle recommendations on such things as smoking cessation, healthy diets and daily exercise. A homeopath may give some of the same advice but they are only repeating bits and pieces of what they learned from medical research. They are broken clocks that feel no shame in taking credit for the results of decades of good science.

There are also a wide variety of well-supported disease-specific recommendations that are vital in preventing complications, such as daily penicillin prophylaxis against bacterial sepsis in patients with sickle cell disease. We also are big supporters of vaccines, a science-based intervention that has saved millions of lives. Thinking of this aspect of preventative care only serves to make me more infuriated when reading posts on the naturopathic and chiropractic communities’ attempts to gain primary care practitioner status. What they don’t know might just kill you.

But nothing frustrates me more than chiropractic claims regarding SIDS prevention.

What is SIDS?

When it comes to inducing fear in parents, both new and experienced, few entities are as effective as sudden infant death syndrome (SIDS). SIDS is the leading cause of death in children aged one month to one year in the United States, affecting roughly 2,000 infants annually, and is about as bad as it comes in the world of pediatrics. Although there are risk factors, even some modifiable ones, there is no way to effectively predict which infants are at high risk. There is no screening test for SIDS and we simply do not have a firm grasp of why it occurs in some children and not others, or of the underlying pathophysiology.

To meet the strict diagnostic criteria of SIDS, an autopsy, death scene investigation and review of the clinical history must be performed. These are all very important steps in the process because there are a number of medical conditions, such as abuse, accidental suffocation, and a variety of underlying disease processes, which can mimic SIDS. As our diagnostic capabilities have improved over the past few decades, a large number of deaths that would have been classified as SIDS are now attributed to one of these other conditions. That and the success of science-based public health campaigns like the “Back to Sleep” initiative have led to a dramatic decrease in the incidence of SIDS since the early 90’s.

The fact that SIDS occurs about half as frequently than it did in 1992, however, is no consolation to the parents of a deceased child. The unexpected death of a young child without a satisfactory explanation is a tragedy that is hard for those who have not experienced it to wrap their heads around. Having to tell a family that there is no explanation, leaving them to potentially blame themselves despite our best efforts to educate them otherwise, is one of the most challenging and painful aspects of pediatric medicine.

Not surprisingly, SIDS is an outcome commonly cited by both parents and medical professionals as a significant source of anxiety. I personally have encountered hundreds of parents that have expressed significant fear of their young infant passing away while they sleep, many of which engaged in potentially harmful practices such as foregoing sleep to watch their child for signs of breathing cessation or bed sharing in the hopes of preventing SIDS. Equally unsurprising are the plethora of unscientific concepts and practices invented to both deal with that anxiety and, despicably, to profit from it.

Why does SIDS happen?

The short and frustrating answer to the question of why SIDS happens is that we don’t know. But this doesn’t mean we don’t know anything or that our knowledge isn’t advancing. We actually have learned a great deal about the pathophysiology of SIDS over the past several years.

The long and perhaps equally frustrating answer to the above question is that SIDS is a polygenic, multifactorial condition, with genetic, environmental, and behavioral/sociocultural contributing factors. Some make use of a “triple-risk” model, meaning SIDS occurs in infants with an underlying vulnerability that experience a trigger event at a vulnerable developmental stage of the central nervous or immune system. Most SIDS occurs between the 2nd and 4th months of life, a period of time during which significant developmental changes in the infant brain take place.

Malfunctioning of the infant’s ability to arouse is almost certainly a critical part of the process and researchers are homing in on underlying defects in receptors for the neurotransmitter serotonin in areas of the brainstem that impact arousal and cardiorespiratory responses. There appears to be a deficiency in serotonin and its primary biosynthetic enzyme, particularly in the medulla, an area of the brainstem involved in a wide range of autonomic processes. The autonomic nervous system works without conscious control to regulate functions like respiration, heart rate and digestion to name just a few.

The role of genetics is less clear as there is evidence to support and refute involvement. Siblings of SIDS patients are not significantly more likely to be affected and there is a lack of concordance in twins. But a number of gene polymorphisms have been discovered in SIDS victims that may increase susceptibility by negatively impacting myocardial conduction, serotonergic transmission, or some other vital process. Thus while genetics may not play a large role overall, some infants may have a genetic predisposition and succumb when exposed to certain environmental triggers.

SIDS risk factors and environmental triggers

From decades of epidemiological data, we have become aware of a number of risk factors, both positive and negative, and possible inciting events that play a role in SIDS. Some of these risk factors can even be avoided, the most well-known being the prone sleeping position (on the tummy). When pediatricians in the United States began recommending that all infants be put to sleep on their backs, the incidence of SIDS was cut in half. Other modifiable risk factors include maternal smoking during and after pregnancy (all smoke exposure is bad, not just from mothers), maternal drug/alcohol abuse, loose or excessive blankets/pillows, bed-sharing and overheating.

Not every risk factor is completely avoidable, such as young maternal age and preterm and/or low weight birth. Actions that may actually protect against SIDS include room-sharing, pacifier use, breastfeeding, fan use and immunizations. Possible environmental triggers include prone positioning during sleep, cardiac dysfunction and infection.

Again, we don’t know exactly why SIDS occurs. Its mysterious nature and the severe emotional impact of the possibility of it occurring on parents is a perfect set up for the false promises and bogus claims made by the alt med community. Chiropractors in particular like to claim SIDS as falling under their purview.

Why does SIDS happen according to chiropractors?

Not surprisingly, the chiropractic community has come up with their very own hypothesis regarding the etiology of SIDS. And they think that children at high risk of SIDS can be identified, if only they were brought in for examination as soon as possible after birth. Naturally this hypothesis revolves around a vague notion of dysfunction of the vertebral column, in this specific case the relationship between the base of the skull and first cervical vertebra, or atlas. The fictional chiropractic subluxation is invoked as a causal factor, as well as brainstem “microtrauma” that is reminiscent of N-Rays and Ocsillococcus. When all you have is a hammer, everything looks like a nail as the old saying goes.

The internet is overflowing with the chiropractic viewpoint on pediatric conditions such as SIDS, both on individual practice websites and the pages of large organizations such as the ICA’s Council on Chiropractic Pediatrics. The ICA likes to claim expertise in pediatric care, even offering training to chiropractors wishing to become a Diplomate of Chiropractic Pediatrics. According to their online information:

The subject areas covered in the syllabus include all aspects of pediatrics —from pregnancy, birth, infancy to adolescence. Each stage of pregnancy and of a child’s development are covered in-depth so the practicing doctor of chiropractic acquires greater skills and competencies in a wide range of evaluative, diagnostic and assessment procedures, as well as corrective and adjustment skills for different stages of pre-natal care, neonatal and at different ages to adolescence. Also included are expanded modules on radiology, nutrition, functional medicine and immunology, sports injuries, orthopedics, neurology, and special needs. A unique feature of the curriculum is a mandatory observational/training weekend at a chiropractic center for special needs children under multi-disciplinary care.

Yes, there apparently is a chiropractic center for special needs children. The ICA considers enough training to achieve “the expertise to understand and apply appropriate clinical protocols in all situations and provides care that is safe, appropriate and always of a high professional standard”, to be roughly 360 hours spread out over three years. What they call a three year course I call the first four weeks of my residency in pediatrics. Add to that the fact that many of their modules are focused on manipulation techniques such as craniosacral therapy, and that none are taught by an actual pediatrician (they do have a doctor of naturopathy teaching nutrition), and it should be obvious that anyone holding this distinction should be considered dangerous in the presence of ill children.

How do chiropractors know what causes SIDS?

In researching the chiropractic take on SIDS, I found that several studies were discussed but one study was most consistently held up as evidence to support their claims. Published in 2002 by L.E. Koch in Forensic Science International, the study involved documenting what happens when some infants are poked in the neck. I truly wish that I was kidding or exaggerating.

Koch, based on a smaller 1998 study also published by him in the same journal, developed the hypothesis that mechanical irritation of the high-cervical spine might play a role in SIDS. He had observed that infants undergoing atlanto-occipital chiropractic adjustments developed “vegetative reactions” involving flushing, sweating, hyperextension and even apnea (cessation of breathing). The 2002 study looked at 695 infants between 1 and 12 months of age also being submitted to manipulation of the high cervical spinal column for chiropractic diagnoses. What did they find?

They reported that nearly half of the subjects experienced a significant change in heart rate, with 40% of those subjects experiencing a decrease by 15-83%. According to the authors, younger infants (less than three months) were more likely to have more extreme drops in heart rate. They found that 12% of the subjects experienced apnea (despite an earlier caveat that their data on respiratory rate was unreliable). This all sounds very concerning, right?

The authors state that pronounced drops in heart rate are known to precede occurrences of SIDS. This is true in the sense that dead kids don’t tend to have heart beats, but it isn’t established that severe bradycardia (abnormally low heart rate) is causally associated with SIDS. These infants may stop breathing first, which then leads to physiologic changes that injure the brain and stop the heart. They may have sudden cessation of breathing and heartbeat. Or perhaps their heart slows down first. We just don’t know, and neither do chiropractors.

They state that bradycardia precedes apnea (again, we don’t know that), which is followed by gasping for air which, they claim, fails to evoke an arousal response. As previously mentioned in this post, arousal mechanism dysfunction likely does play a key role in SIDS, but there is no evidence that their described pattern is what really happens. Infants who die of SIDS are notoriously quiet. Several documented cases of SIDS have occurred while being watched in daycare centers and there have been cases described of SIDS occurring in hospitals while on monitors, just not enough to reliably know what happens to them.

According to the authors, “the atlanto-occipital region controls crawling, movement during the night, vagal autonomic nerve function, phrenic nerve function and vertebral artery blood flow.” There is some truth to this but it is still classic chiropractic nonsense. Injury to the spinal cord/brainstem at that level could result in paralysis, fatal inability to breath and stroke, but chiropractors aren’t talking about actual injury, they are talking about the chiropractic subluxation. This is a fictional entity without validity or a reliable means of diagnosis. Chiropractors often base their determination of the presence of a subluxation on how the muscles feel, skin temperature differences, leg length discrepancies, and x-ray imaging of which ten different chiropractors might give ten different interpretations. This study only in a roundabout way might support these claims. We are supposed to make the connection that when someone, in this case a chiropractor, irritates the high cervical spine it is essentially mimicking what happens when a child has a subluxation in that area or when they are in a prone sleeping position.

The upper cervical manipulation in this study took the form of a brief “impulse” to the side of the neck just under the base of the skull using the edge of a finger. The amount of force applied is described as ranging from 30 to 70 Newtons (roughly 6 to 15 pounds of force) and sounds like a fairly low velocity push over about half a second. This would have no lasting impact whatsoever on the alignment of the spine or skull. The authors do not describe the state of the subjects after the application of the impulse outside of heart rate (kind of), respiratory rate (not really), and the presence or absence of flushing. We don’t know if the subjects were irritated and crying, awake, asleep, alert and interactive or demonstrating evidence of pain such as facial grimace to just give a few examples.

There was no control group in this observational study. It is worthless. I believe they have done a mediocre job documenting random noise. A comparison to infants undergoing ICA-endorsed chiropractic tummy tickles would have been more interesting. But I will forge ahead. Resting heart rate in infants under a year of age can range from 80 to 150 beats per minute with the higher values typically seen in those less than 3 months of age. There is significant heart rate variability in infants. There is heart rate variability in everyone, particularly associated with breathing cycles (up with inhalation and down with exhalation), but it is more pronounced in infants.

The authors compared each subject’s resting heart rate with the heart rate during (not sure how they measured heart rate over 600 milliseconds) and after the impulse. The average change in heart rate documented was an increase of 14%. That would be an increase of 16 beats per minute for a baseline of 120 beats per minute. Some children had significant drops by as much as 40% to 83%. That would take the same child with a baseline of 120 beats per minute down to 20. That is severe and life-threatening bradycardia. But that isn’t what happened in this study.

These drops in heart rate were noticed over a few seconds and then quickly corrected over a few seconds or less. Any nursing or medical student should be able to tell you what a big mistake that is. I am generally not pleased (that is how we describe being furious in pediatrics) when I catch someone taking a pulse for six seconds and multiplying by ten. You will often mistakenly diagnose abnormally low or high heart rate doing so in a child. They noticed more of this in the subjects less than three months of age. Of course they did because the heart rate is faster at that age and more prone to a random error because of increased variability.

The authors note the occurrence of apnea in 12% of the subjects, making their conclusions sound all the more impressive. They note that apnea usually occurred with a delay of several seconds after the impulse. The authors note that because of “ethical reasons” they did not actually wait to see if the infant would resume breathing on their own so they “restored normal breathing immediately after the onset of the apnea by blowing air into the baby’s face.” But they defined apnea as cessation of respiratory effort that exceeded the time it took for the infant to go through one normal breathing cycle.

The breathing or respiratory cycle is the act of taking a breath in and letting it out. The average time it takes for a single cycle is easy to determine. A healthy young infant may breathe anywhere from 30 up to 50-60 times each minute, thus a respiratory cycle typically lasts 1-2 seconds. Pediatricians define apnea in an infant as cessation of respiration longer than 20 seconds or shorter if associated with bradycardia (the real kind), cyanosis (turning blue), or marked hypotonia (floppy). They have made up their own definition of apnea, which if followed would mean that every single young infant has repeated daily occurrences because pauses in breathing are normal.

This study is being used by chiropractors all over the country, including state chiropractic organizations, to scare parents into having their newborn infants “screened” for subluxations to prevent SIDS. Parents are warned that their child may have a life threatening subluxation and immediate correction is necessary to prevent the death of their child. These recommendations are not based on good science but cherry-picked poorly designed research and anecdotal observations. Once in the chiropractor’s office, parents are often exposed to a variety of anti-medicine or anti-vaccine propaganda, and they may be less likely to seek out medical care when there truly is something wrong with their child. There is more harm than merely the loss of money.

I found one chiropractor discussing the topic of SIDS in an online video. In it he describes how birth trauma leads to subluxations. He also describes treating a 4-hour-old infant with temperature instability, which is truly terrifying to a former neonatal hospitalist who has cared for many septic newborns whose only early manifestation was the inability to maintain a normal temperature. Luckily most instances of this occur secondary to the baby being left unwrapped and/or wet and not to illness. His video is a classic example of how someone we can be fooled into thinking a treatment has a true effect.

Trauma experienced at birth is often blamed for the development of the subluxations, which seems plausible at first glance. I have cared for many children with injuries related to the birthing process. Broken clavicles, injured nerves, and complications from bleeding are all known risks. But there is no evidence that birth trauma is related to chiropractic subluxations, because they don’t exist, or to the subsequent development of SIDS. In rare cases some children do die from complications of birth, but that is not SIDS. And the type of birth, C-section versus vaginal, does not appear to be related to SIDS.

And now a dose of reality

So what can be done to decrease the risk of SIDS? The following list comes from the most recent AAP Policy Statement:

  1. Back to sleep for every sleep
  2. Use a firm sleep surface
  3. Share a room but not a bed
  4. Keep soft objects and loose bedding out of the crib
  5. Get prenatal care
  6. Avoid any smoke exposure during pregnancy and after birth
  7. Avoid alcohol and illicit drug use during pregnancy and after birth
  8. Breastfeed
  9. Offer a pacifier at onset of sleep (you don’t need to put it back in if it falls out while asleep)
  10. Avoid overheating
  11. Immunize your babies
  12. Avoid commercial devices marketed to reduce the risk of SIDS
  13. Avoid use of home cardiorespiratory monitors as a strategy to reduce the risk of SIDS
  14. Supervised awake tummy time

SIDS is not common. Many pediatricians and family practice doctors will go their entire career without encountering it. Chiropractors don’t see a fraction of the number of pediatric patients that physicians do, so it would be extremely unlikely for them to have a patient die from it either. This can lead to a false impression that an intervention is effective at preventing SIDS. I worry that parents receiving false reassurance that their child is protected might feel less inclined to follow evidence-based recommendations.

 

 

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  • Clay Jones, M.D. is a pediatrician and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @SBMPediatrics and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey. The comments expressed by Dr. Jones are his own and do not represent the views or opinions of Newton-Wellesley Hospital or its administration.

Posted by Clay Jones

Clay Jones, M.D. is a pediatrician and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @SBMPediatrics and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey. The comments expressed by Dr. Jones are his own and do not represent the views or opinions of Newton-Wellesley Hospital or its administration.