Home sleep testing in children: we probably can, but should we?

The current issue of the Journal of Clinical Sleep Medicine features a study of 15 children with suspected obstructive sleep apnea (OSA) who underwent testing with a home sleep apnea device (HSAT) that included electroencephalogram as well as assessment of airflow with nasal pressure, electrocardiogram, respiratory effort by inductance plethysmography, oxyhemoglobin saturation, and accellerometry.¹ Essentially, a full polysomnogram (PSG) without leg leads and end-tidal carbon dioxide. The HSAT device was used in the laboratory as well as in the home, and the investigators found that HSAT correctly identified OSA status from PSG in 14 of 15 children. The study was well designed (except for the small number of children) and analyzed thoroughly. The authors also found, as have many others, that only about half of children with suspected OSA have the diagnosis confirmed on PSG, thus emphasizing the importance of obtaining a study before subjecting the child to a likely surgical procedure. However, there are a few important caveats, some related to this particular study and some related to pediatric HSAT in general.

First, the study was performed under research conditions. Thus, closer attention was more likely paid than under clinical conditions or in less skilled hands. The researchers were able to be sure that all the home devices were returned. In the larger, diverse clinical population, many home devices are unrecoverable.

Second, the study was performed in a children’s hospital skilled in the handling of children (and parents!), as well as the differences in scoring and interpreting pediatric studies. These data might not be so robust were they acquired in a less skilled adult-oriented facility.

The youngest participants had the poorest quality of home studies. This is not surprising. Should home studies be restricted to older children?

The authors acknowledge these questions. The larger question, though, is should we perform home studies at all on children? The use of home studies in adults was driven by the payers, initially Medicare and Medicaid, who noticed they were spending a lot of money on laboratory PSG tests in adults. The prevalence of OSA in children, while significant, does not approach the prevalence of OSA in adults so the financial pressures are not there. A home study might be reasonable in an adult for whom the likely treatment is continuous positive airway pressure, with very few side effects. In fact (and I may get drummed out of the American Academy of Sleep Medicine for this!), one might make an argument that no study is needed for an adult with a high clinical suspicion for OSA, but rather a clinical trial of continuous positive airway pressure, then applying my three laws of medicine (borrowed from Dr. Don George): (1) If it works, in this case, the continuous positive airway pressure, keep doing it; (2) If it does not work, stop, and (3) Never call a surgeon. (Sometimes I break Rule #3!) In children, however, the first line treatment is generally surgery, and although an adenotonsillectomy is generally safe, bad outcomes do occur and we do not want to put a child under anesthesia unless we need to. Thus, it is important to get the diagnosis right. There are also several studies showing that the rate of perioperative complications rises with the severity of the condition, and children with severe OSA should probably be observed overnight in a hospital with pediatric intensive care unit backup. Thus, it is important to know not only the presence of OSA, but its severity as well, and simply looking at whether a HSAT can differentiate OSA from primary snoring is not enough; it must accurately describe its severity as well. It is noteworthy that in the current study the similarity between HSAT and PSG decreased at higher values.

Of course, that raises the question of what is “severe” OSA in children. The authors use the commonly used characterization of an obstructive apnea-hypopnea index < 1–2 events/h of sleep as “normal,” 2–5 events/h as “mild OSA,” 5–10 events/h as “moderate” OSA, and more than 10 events/h as “severe” disease. There are some data that more than 1 obstructive apnea per hour of sleep is statistically abnormal, but several studies of the consequences of pediatric OSA do not show sequelae such as higher blood pressure until an apnea-hypopnea index of about 5 events/h.² I am unaware of any data showing a marked increase in clinical consequences of pediatric OSA with an apnea-hypopnea index of 10 events/h. I suspect this number was arrived at for the same arbitrary reason that a 10-second respiratory event is scored in an adult, likely because we have 10 fingers! In addition, a good clinician will adjust his/her assessment of severity by taking oxyhemoglobin desaturation into account. Thus the “poly” in PSG!

So, should we do pediatric HSAT? I would argue nay. Even a study as thorough as Stefanovski suggested more difficulties in younger children, and less concordance with PSG at higher apnea-hypopnea index, when the need for accuracy is greatest. Almost one-third of the parents approached declined to participate, preferring only the in-laboratory study, suggesting “family convenience” is not a major factor in needing home studies. Our technologists can testify how hard they work to maintain good signals in the lab, a job that must be performed by the parents at home. And even this thorough home testing, while it included electroencephalogram, did not include end-tidal carbon dioxide, limb leads, or visual monitoring making it impossible to assess obstructive hypoventilation, movement disorders, or really anything other than sleep apnea, and perhaps seizures. Are pediatric sleep labs unavailable? There are three in the greater Philadelphia area alone. Most cities have a children’s hospital, and most children’s hospitals have a sleep center. And there are plenty of unused beds in adult labs! For my child (or grandchild at this point), if I notice snoring almost as loud as mine plus at least one other factor: daytime sleepiness, poor behavior, poor school performance, or witnessed apneas, I would opt for a good in-laboratory PSG. And that’s the same thing I would want for my patients.

DISCLOSURE STATEMENT

The author reports no conflicts of interest.