Debate in the NICU Continues: What’s a CPST to Think When Doctors Disagree?

This article originated in the July/August, 2016 issue of Safe Ride News.

As readers know, I am not a doctor.  Occasionally, though, as CPSTs we must consider certain medical conditions that influence the safety or children as vehicle passengers.  Fortunately, there’s no need for CPSTs to hold a medical degree; simply follow the advice of doctors regarding the relevant symptoms of a diagnosis and how they might influence a child’s safety  (either in a crash or during normal riding).  To guide us, we are fortunate to have peer-reviewed scientific studies and policy statements from the medical community.

A perfect example of this is how to safely discharge infants who were born preterm, especially those who spend their first days, weeks, or even months in a neonatal intensive care unit (NICU).  These infants are often challenged by a host of medical conditions that are beyond my understanding, but I have learned from doctors that breathing and heart rate can be negatively affected when a child who is cardiopulminarily and/or neurologically underdeveloped rides in the semi-reclined position of a CR.  CPSTs, whether working in or providing training for NICUs, can contribute essential safety guidance when its time for an infant to make the transition from the hospital to home.

Therefore, many CPSTs, like myself, will find the recent news from the Canadian Paediatric Society (CaPS) confusing and a bit troubling.  As the article linked here describes, a respected group of Canadian doctors has reviewed the (admittedly limited) research covering the purpose and reliability of the infant car seat challenge (ICSC), and based on that review has issued a formal position statement that it cannot recommend routinely administering the ICSC.  Yet, a similarly qualified panel of doctors with the American Academy of Pediatrics (AAP) has stated the opposite position, recommending the ICSC for all infants born less than 37 weeks gestation.
We can assume that both groups of doctors have the best of intentions for child health and safety.  So, what is a CPST to make of such starkly different recommendations?

Naturally, we can follow recommendations based on nationality:  In the U.S., do as the AAP states, and in Canada, follow the CaPS.  But this does little to alleviate concern, since a preemie is a preemie, regardless of nationality, and vehicles and CRs are essentially the same in both countries.

One might consider which position was stated most recently.  While the CaPS position statement was released this past April, the AAP’s recommendation was published in 2009 and reaffirmed in 2013.  So did new information influence Canada’s revised stance?  This seems unlikely.  Although sources at the AAP have confirmed that its clinical report on transporting premature and low-birthweight infants is scheduled for a routine review soon (which would lead to reaffirmation, revision, or retirement), only two of the 16 studies examined in the CaPS report were published since the AAP’s last review.

Two of the most recent studies, from 2013 and 2014, were ones used by the CaPS to assess the reliability of the ICSC.  The Canadian authors felt the fact that approximately 10 percent of infants scored what could be considered a false negative on the ICSC “cast significant doubt on the reliability and reproducibility of the ICSC.”  However, the ICSC is a screening tool, not a test.  A screening procedure that can produce congruent results roughly 90 percent of the time could just as easily be seen as a useful tool.

When reviewing many of the other studies, one might wonder if other qualified reviewers would come to different conclusions than the CaPS panel did:

While early in the CaPS report, Dr. Narvey states,  “…it is clear that infants placed in a car seat are more likely to experience oxygen desaturation and/or bradycardia than when they are supine…,” it is puzzling that this relationship is later deemed “unknown” simply on the weight of one small 1989 study that somewhat contradicts three other studies that support it (and despite the fact that the contradictory study acknowledges that risks exist).

When examining the likelihood of adverse outcomes, Narvey notes that “reports of infant deaths during travel are exceedingly low, with only one case occurring in a (former) preterm infant.”  But doesn’t this reflect the Catch-22 of using data to assess the value of prevention efforts?  As Boston Children’s Hospital’s Dr. Michele DeGrazia, an instructor of pediatrics at Harvard Medical School who has studied the ICSC extensively, says, “One could argue that the low number of infant deaths associated with car seat use can be related to efforts put forth to screen preterm and at-risk infants in their car seats prior to hospital discharge.”  What might this data show had the ICSC not been routinely administered for the past two decades? A truly informed conclusion would include comparing studies from other developed nations that do not administer this screening, but such studies simply don’t exist.

The CaPS report states, “a paucity of data links adverse neurodevelopmental outcomes in preterm infants with hypoxemia experienced in car seats.”  However, this is not because the relationship has been disproved, but rather because it hasn’t been researched.  Although the CaPS seems to imply that “insufficient data” on this subject supports its conclusion to not recommend routine screening, another panel could just as easily take a more cautious approach to these unknowns and side in favor of screening, especially given that chronic hypoxemia is generally known to be dangerous and cannot always be detected by visual inspection.

Though the CaPS report tends to downplay the risk of adverse outcomes, it also suggests that the ICSC fails to capture all the risks that do exist.  It recommends polysomnography (PSG), a test used for diagnosing sleep disorders, as a more reliable and reproducible alternative.  However, as Dr. Marilyn Bull of Indiana’s Riley Hospital for Children at Indiana University Health explained to SRN, PSG is invasive, time-consuming, and expensive; it is not a realistic alternative for routine screening of preterm infants.

When asked for feedback, the CaPS report’s lead author, Dr. Narvey, replied that these SRN articles represent “a fair commentary,” and that the CaPS had considered many of the points made here.  However, after having reviewed available data, his stance is that “there is really no evidence to support that a fail means anything at all or is predictive of anything either.”
So, for the time being, it seems experts from our two countries will agree to disagree.  SRN will report when the AAP’s updated review is complete, and we can hope that more research will be conducted to shed light on the many unknowns that open the door to differing conclusions.  However, after talking with doctors to prepare this editorial, I’m not expecting our countries’ policies to align in the near future.

Denise Donaldson—Denise Donaldson