Breathing

I would like to point out the recommendation in a study published last September (Sleep-related breathing disorders in pre-pubertal children with Prader-Willi Syndrome and effects of growth hormone treatment - http://jcem.endojournals.org/cgi/rapidpdf/jc.2006-0765v1):

"It is important to mention that a relatively normal PSG [polysomnography] does not exclude the possibility of unexpected death during mild URTI. Based on our results cardiorespiratory monitoring during URTI in children with PWS before and during GH-treatment should be considered."

The study authors were obviously shaken by the sudden deterioration and death of a three-year-old boy in the study who had a mild URTI even though he had near-normal PSGs both before (AHI 1.7) and during GH treatment (AHI 1.4), as they mention it several times. The day before he died, the boy had been checked by his pediatrician, was running around, and did not generally act as if he was sick.

Note that although having a home pulse oximetry device is definitely a very good idea, pulse oximetry is not the same as full cardiorespiratory monitoring. Pulse oximetry only monitors blood oxygen saturation (SaO2) levels and pulse rate and as such does not monitor all aspects of respiratory and cardiac sufficiency. For example, during hypoventilation (which is fairly common in PWS, especially during respiratory infections), it is possible for pulse oximetry to register adequate Sa02 levels even though the child is hypercapnic (has elevated carbon dioxide levels) with respiratory acidosis (abnormal acidity of the blood). Also, if the heart isn't pumping enough blood due to cardiac insufficiency, a person can still be hypoxic (that is, not have enough oxygen reaching tissues such as muscles and the brain) even if SaO2 levels are adequate. Full cardiorespiratory monitoring, otoh, monitors all of those things: SaO2, carbon dioxide levels, and cardiac function.

In general, parents should not be afraid to take their child to the emergency room if the child starts to repeatedly desaturate below about 90-92% during an URTI or is lethargic and hard to arouse. In such a situation, it also might be a good idea to print out a copy of the Sept. study and take it with you in case the doctor is reluctant to admit the child for full cardiorespiratory monitoring. Remember, too, that aside from the possibility of sudden respiratory deterioration, hypoxia due to low SaO2 levels can have serious impacts on cognitive and neurological development as well as other physiological processes. (For more about that, see the article on hypoventilation and apnea in PWS if you haven't already done so (http://www.tcmnotes.org/apnea-hypoventilation-in-pws/).)