events close together

[Maryd]

Why do events often happen in clusters. I only a few since being on Cpap, but I notice that often they are minutes apart. Does anyone know why this happens?

[cathyf]

Actually it's the events that appear "out of the blue" which are the problematic ones. (There is a running joke around here about "frank events" and what we have against Frank.) The clusters are normal, because the cause of events persists. For example, if your events are caused by the physiological changes of REM sleep, then you will have events over and over until the REM sleep stage passes naturally, or until the events wake you up. Or if your events are caused by sleeping on your back, then they will continue until you roll over or wake up. The clusters are the fundamental underlying logic of how an APAP can work -- the machine sees a couple of events, and runs the pressure up, and that heads off the rest of the cluster. When there is a frank event, the machine has no way to know that it needs to react before the opportunity to act has passed.

[Pugsy]

Clusters of obstructive in nature (OAs and hyponeas) usually just mean that for whatever reason the pressure was not optimal to hold the airway open and prevent the airway collapse...for some reason it works well in parts of the night and not other parts of the night.
The 2 usual suspects for when this happens are supine sleeping or REM stage sleep or maybe a combination of both.
If these are see on a consistent basis then usually a small pressure adjustment is indicated.

Clusters of Clear Airway events (centrals) could just be awake breathing flagged by mistake or could be an indication of a potential problem with unstable breathing if they are present in large clusters that are frequent and we know we were asleep.

Random and small clustering of anything can usually just be a shrug your shoulders moment as long as they are random or rare and the clusters aren't horribly dense.
So it depends on what they are...and just how many are in a cluster and how often they happen as to whether we do anything or worry.
I once had a really ugly central cluster...17 of them in 17 minutes...so one a minute. Have no idea what it was or why. I thought I was asleep but maybe I wasn't. It only happened the one time though so I just shrugged my shoulders and blamed it on alien abduction (aliens get the blame for the weird stuff that occasionally happens that we don't know why ) and moved on.