Sleep Study Concerns

About eighteen months ago I noticed I was needing significantly more sleep than I ever needed before. I thought it part of the aging process until I found myself sleeping 6-8 hours at night and then falling asleep for a few hours every afternoon, disturbingly cutting into my reading time.

Falling asleep during the day is not something I have had to endure since working nights in my much younger days, so I was very surprised. I put it down to my diabetes being badly controlled and brought it up during my clinic visit in March 2015. Expecting to be told to increase my oral medication, I was somewhat taken aback when my diabetic consultant insisted on a sleep study.

I attended sleep clinic in June 2015 and came home with equipment to monitor my sleep overnight. I was relieved when the results of the study negated my requirement for CPAP, but I was left feeling somewhat alarmed when I saw I spent a significant part of the night with oxygen saturation of around 87%.

My sleep study results were discussed with me by a physiologist rather than a respiratory consultant and when I inquired if these oxygen saturation figures caused any reason for alarm, I was asked to address this back in my routine clinic appointment at the Pulmonary Vascular Diseases Unit at The Royal Hallamshire Hospital, Sheffield.

So during my routine outpatient appointment in November 2015, I asked about low oxygen saturation overnight and my excessive sleeping, which resulted in my referral back to a respiratory physician at sleep clinic. My impression was that my Pulmonary Hypertension doctors felt that I ought to be reconsidered for CPAP, based on my propensity to fall asleep during the day. However, my concern was low oxygen saturation overnight leading to a critical outcome.

This month I was seen back at sleep clinic by a respiratory physician, who went through my results again. He patiently explained in his opinion I did not require CPAP. I was pleased about this as I really don’t want to sleep (no doubt, badly) with a noisy machine and mask strapped to my face, but what about my low oxygen saturation?

On looking back at my results he became thoughtful and suggested oxygen overnight. I was surprised as this wasn’t suggested by the physiologist nor the pulmonary hypertension consultant I saw, so I asked what if we do nothing, as surely it’s a common outcome of in all pulmonary hypertension patients? I seriously just wanted him to say it’s something to be expected and not concerned about. How can low oxygen saturation at night cause me harm or be critical in the long term?

He explained usually if hypoxia occurs in the periphery of the body blood vessels dilate, however, when oxygen saturation falls in the lungs I was told blood vessels constrict causing pulmonary hypertension to worsen.

I had no reason to doubt the respiratory consultant I saw as he was actually quite knowledgeable about my medication and pulmonary hypertension, but I admit to feeling dismayed about the prospect of having home oxygen overnight. Sensing this he suggested a repeat sleep study and return to clinic.

It seems unlikely to me that the sleep study I completed last week will show much improvement in my oxygen saturation, as low saturation at night seems to be a feature of the illness, but I can’t help but feel annoyed with myself in hindsight for bringing up my concerns about my sleep in the first place.

If I had any suspicions it would lead to home oxygen, I probably wouldn’t have mentioned it, but would be potentially risking worsening pulmonary hypertension, which surprisingly was not something my pulmonary hypertension consultant was concerned about. Surely if nocturnal hypoxia is a risk factor in worsening pulmonary hypertension, this would be something the unit I see would have concerns about, not just for me but other patients too?

I would love to have the results of both my sleep studies sent to pulmonary hypertension consultants to have their input on my requirement of home oxygen, as I’m sure there maybe drawbacks. However, the best I can hope for, as a patient in this situation and not a physician, is to see the respiratory physician again and hope he has liaised with the PVDU at The Royal Hallamshire Hospital, and if I need oxygen it’s with the approval of all necessary disciplines. I’m too afraid to ask any consultant anything further as I’m not sure where those answers will lead, but I’ll be seen back in diabetic clinic, where it all began, next week.