Infant Apnea Monitors Help Parents Breathe Easy

by Food and Drug Administration (FDA)

It's a rare mother who hasn't tiptoed into her sleeping baby's room and listened just to make sure that tiny chest is moving in a gentle breathing rhythm.

Occasionally, though, that gentle rhythm is broken by periods of stopped breathing. As frightening as that may sound, a temporary pause from breathing, or apnea, is not always cause for alarm.

"All babies pause in their breathing," says Robert G. Meny, M.D., a pediatrician with the University of Maryland Medical School's Sudden Infant Death Syndrome Institute. "Especially after a sigh, a pause of maybe five seconds or eight seconds, depending on the baby, is completely normal."

Meny adds that "when a baby moves around a lot, you'll very often see that the child does not breathe for 10 to 15 seconds. That, too, is normal.

"The question is not if — the question is how much, how often, and how long. I begin to worry especially when I see the pauses for more than 20 seconds."

Apparent Life-Threatening Events

Twenty seconds. That's the point at which apnea does become cause for alarm. When apnea lasts for more than 20 seconds, the baby may begin to turn blue or pale, choke or gag, and go limp. A pause in breathing for less than 20 seconds may also be serious if the heart rate slows significantly.

The official medical term for serious episodes of prolonged apnea that don't result in death is Apparent Life-Threatening Event or ALTE. Babies can be saved if the prolonged apnea is detected quickly enough.

"There are a whole variety of responses to apnea of 20 seconds or more," says Meny. "Very often the baby will respond to mild stimulation — a flick of the fingers on the feet or something like that. If that doesn't do the trick, then the next step is vigorous stimulation, where you give the baby a painful stimulus like a good pinch. And finally, if that doesn't work, then the parent would go to mouth and nose resuscitation."

Do not shake the baby, Meny warns. Infants do not have good head control, and vigorous shaking could cause head injury and even death.

In some cases, the episode of prolonged apnea can be traced to a specific problem such as infection, airway obstruction, heart disease, seizure, or choking, says John G. Brooks, M.D., professor of pediatrics at the University of Rochester Medical School. He adds that in approximately half the cases, however, no specific cause is identified.

When the cause isn't known, there is no known cure for infant apnea except time. The number of apnea episodes decreases as the baby gets older, and "in most cases, the problem is no longer medically significant after the child is 6 months old," says Brooks.

Apnea Monitors

But until this time, many infants younger than 6 months who have experienced an ALTE are put on a home apnea monitor. The main function of these monitors is to sound an alarm if the baby stops breathing.

There are three types of infant apnea:

Central or diaphragmatic — the baby makes no effort to breathe; the chest is still, and no air passes through the mouth or nose.

Obstructive — the chest is moving but no air passes through the mouth or nose (usually due to soft tissue such as the tongue blocking the upper airway).

Mixed — the infant has episodes of both central and obstructive all within the same event.

The variations in types of apnea complicate the function of the monitor. For example, if the apnea is obstructive, the chest will continue to move. If the monitor's only method of detecting breathing is chest movement, this type of apnea might go undetected.

For that reason, effective apnea monitors also measure a physiological function that is adversely affected within a relatively short time after the baby stops breathing. Currently, the function most monitors measure is heart rate. Normally, the monitor's alarm is set to go off if the baby stops breathing for 20 seconds or if the heart rate slows to less than 80 beats per minute.

Government Standards

FDA is developing a mandatory performance standard for infant apnea monitors. At press time, the requirements for this standard were not final.

Many features the agency considers to be mandatory on monitors are already available on some models. Under the tentative performance standard, all monitors must be able to detect both a physiological problem that results from apnea, such as slow heart rate, as well as the absence of breathing. Some of the other requirements FDA may require include:

Battery back-up that can supply power for at least eight hours

Both audio and visual alarms.

Sensors that can detect improper equipment performance, such as damaged electrodes and disconnected or improperly connected lead wires.

Safeguards that prevent inadvertent or unauthorized disabling of the alarms. In some models, for example, an alarm that sounds distinctly different from the alarm that signals apnea sounds whenever the machine is turned off or unplugged without following a set procedure.

A remote alarm unit.

The remote enables parents to leave the baby's room to carry on some of their usual activities. However, parents shouldn't get too far away, warns James J. McCue Jr., director of FDA's office of standards and regulations in the agency's Center for Devices and Radiological Health.

"Once the alarm goes off, you only have a short time to get back and get that child revived before there's a possibility of permanent brain damage," says McCue. "So you don't want parents out in the garden who won't be able to run fast enough to get there in time."

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.