Last week we got a call from Seattle Children's Sleep Center with a cancellation spot for an overnight sleep study. We took it.
While Evanna's anxiety did kick in as soon as we parked and then again when we started placing the probes, she made it through the process and fell asleep 11 minutes after lights out.
For the first 132 minutes, Evanna slept without her bipap. Our goal was to get a new baseline and find out if she could sleep without the bipap. Around 11:30pm, I discovered that the answer was no; the tech came in to put her mask on and the rest of the night was spent titrating her ventilator settings (changing the settings to see which resolves the apnea the best).
Today, only one week later, I got a call with the sleep study results. The above picture is a chart I created comparing most of important values from all three studies.
Since her last study, the number of apnea-hypopnea events per hour has decreased from 22.7 down to 17.2. Besides the overall lower number of events per hour, her obstructive apnea-hypopnea events have nearly resolved completely. I'm not too surprised because we've seen evidence of this in her sleep and the fact that she passed her swallow study (it is assumed her vocal cords play a role in the obstructions). That leaves her with primarily central sleep apnea, which is caused by the damage to her brain stem by the chiari malformation.
The lowest her oxygen level drops to is 80%, which is up from 73% last time and 39% right after her shunt revisions when this all started.
Given all this, she will need to remain on bipap. I should be getting a call from the DME to walk me through changing her settings. Unfortunately, she still needs high pressure on her inhales. They are slightly lowering her pressure on her exhales and significantly decreasing her breathing rate. It be interesting hearing such a major change in the rate.
With her remaining on bipap with high pressures, there are more questions to ask and new doctors to consult concerning her midface retrusion... preventing further deformity and repairing what has occurred so far. But that's another discussion for another time
