Central apnea whilst awake after brain surgery

[rachelcci]

LP Hi, I’m wondering if anyone can please help me shed any light on my situation as no one can seem to figure out what’s happening as I’m the opposite to what is usually seen so have drs a bit baffled although they aren’t that clued up in the first place where I am. 
I had brainstem surgery last year to relieve compression off it, unfortunately it hasn’t gone to plan and I am now in respiratory failure secondary to the compression. The weird thing is that no one can figure is that my breathing is only affected in the day and have a lot of O2 drops as low as the 70’s whilst awake. As I’m dropping off to sleep I feel my breathing get easier, I do not snore nor wake in the night short of breath, it takes a few minutes of being awake in the morning before it kicks in again. My diaphragm is not paralysed but I do not use it, my accessory muscles are being used to the maximum just to try and breathe normally and this is constant whilst awake. A sleep study showed a few episodes of central apnea whilst asleep but nothing to be concerned about. I haven’t any treatment apart from clonazepam which works by suppressing my CNS but even that is not much help now.
Appreciate anyone’s thoughts and advise, thank you.

[Gideon]

Welcome to the Apnea Board.

You are definitely outside our wheel house. Daytime Apnea we do not manage. We manage PAP machines for night time use.

One thing I believe you need is a recording oximeter because of your low desats.

[rachelcci]

Thank you for your reply.
Sorry, I know it’s a rather strange case.
I do have an o2 monitor that I wear constantly yet I’m still without any treatment or help. I didn’t know if a BI-PAP machine maybe suitable but for daytime use

[Crimson Nape]

CPAPs are designed to work in concert with the rhythmic breathing patterns we experience while we sleep. I don't think they will be of any use to you while awake.

[rachelcci]

Ah right thank you, even my neurosurgeon is struggling with this one.

[SarcasticDave94]

I would look at devices within CPAP like a ResMed ST-A in iVAPS mode or outside PAP would be NIV ventilators called ResMed Astral 100 or Astral 150, the 150 is preferred. ST-A and Astral have this same iVAPS which is ResMed's version of AVAPS mode on ventilators. The Astral can actually breathe for you more than ASV as the ASV is just to jolt you to inhale.

[Sleeprider]

I agree with Dave, the positive pressure ventilation category machines target minute vent and will maintain respiratory rate and volume. When we get into ventilators for individuals needing daytime respiratory assistance, that is not something we have ever dealt with here. The concept is certainly sound. Are your doctors looking into supplemental oxygen or the "Pacewave" series of positive air pressure ventilators that will maintain respiration rate and volume.

[rachelcci]

Many thanks for both of your replies, very helpful and I will look into those products.
They are looking into supplemental oxygen but aren’t sure if it’s right for me or not, I can’t see how it wouldn’t be if I only took it when I have desats to bring it back up but understand they have to be careful with me.

[Ratchick]

Hi there.

I'm gonna agree with Dave, too. If we use machines to support us at night, then I can't see why using one of the suggested NIVs wouldn't at least boost your oxygen. I have to admit, I'm fascinated by your case. It's definitely above our paygrade, but as I also struggle with central apnea, I'm interested to see if anything comes from this).

Just out of curiosity, and don't feel like you have to answer - during the day, do you find it physically harder to breathe, or is it that you simply don't register that you need to until your sats drop? Have they ever actually had you with arterial access as an inpatient, to check your actual oxygen levels (and carbon dioxide levels) directly using ABGs?

[Sleeprider]

I'm going to briefly discuss respiratory drive as a conversation starter for you with your doctor. Our respiratory drive is not from oxygen (hypoxia), but from carbon dioxide (hypercapnia high CO2), and a complex interaction between how our blood converts excess CO2 to the partial pressure of carbon dioxide (PaCO2) which converts to bicarbonate in the blood when hypercapnia occurs. This is detected by the carotid bodies. Now, linking we can perhaps make some connections to why your situation exists:
This article is mainly focused on anesthesia, but discusses how surgical disruption of the carotid bodies in your neck may disrupt the normal respiratory drive https://www.openanesthesia.org/carotid_b...xic_drive/ This would explain how your cervical surgery may have affected your respiratory drive. If this mechanism is in play, it may argue against a neurological cause in favor of one that is more of a physical disruption of the carotid body. The fact your central apnea is not apparent in sleep might argue in favor of a disruption in the voluntary nervous system. In other words, I don't know, but it's food for thought.
"Carotid body denervation may occur after carotid endarterectomy as a result of surgical disruption. Unilateral loss of function may result in an impaired ventilatory response to mild hypoxemia. Bilateral carotid endarterectomy is associated with loss of the normal ventilatory response to acute hypoxia and an increased resting partial pressure of arterial carbon dioxide. In this situation, the central chemoreceptors are the primary sensors for maintaining ventilation, and serious respiratory depression may result from opioid administration."

This article discusses in more basic terms the mechanisms of respiratory drive https://www.sciencedirect.com/topics/med...moreceptor

This article discusses the logic of the Cartid body and its connection to the brain https://journals.physiology.org/doi/full...00057.2018 I think this article is probably to complex and theoretical to be useful, but it illustrates the complexity of the interaction between the circulatory and nervous systems.

You can do more research by searching for articles pertaining to "respiratory drive carotid body chemoreceptor". Throw in some terms that pertain to your surgery and see what pops up.