It is a good idea to have a titration study performed every few years. As we grow older and our bodies change, so can the type of therapy we require. Changes in weight, certain medications, and our overall health can all have an effect on our breathing during sleep. Disturbances in sleep can result in a higher number of central apneas. After an arousal, it is common for a person to experience a central apnea as they are going back to sleep. Are you on pain medication for herniated disks? Pain meds, especially opiods, can cause a decreased respiratory drive.
The type of mask interface you are using can also play a part. As a technologist in a sleep lab, I generally try to get patients to use full face masks, especially if they will be on higher pressure settings. The reason being is that at higher settings, the air going in through the nose will tend to exit out of the patient's mouth. This can result in sleep disturbances, as well as the person waking with dry mouth. I am not saying this happens with everyone, but I have seen this to be true for many patients. If you were on APAP, your sleep may have been disturbed as the pressure increased. The pressure will only increase if the device senses a blockage occurring. Therefore, if you changed back to CPAP at a suboptimal setting, you may experience more obstructive events in your sleep that the device is not picking up on. Not all events that occur with OSA are apneas. So, my recommendation is to see your physician and schedule a titration study, especially if it has been a number of years since your last titration, and to consider a full face mask.
