Brain fog during and after deep(ish) /multiple dives

[MykaDives]

This raises the index of suspicion for CO2 retention for me.

Best regards,
DDM

If I had CO2 retention, wouldn't I get a headache? I do not typically get a headache diving. How do I test for this?

Good point! Maybe pulmonary function testing? She could be chronically retaining CO2 and have a reset capnostat with a reduced respiratory drive...

Going to have to use the Google for that one...

Provocative PFT would be very reasonable. It would be interesting to test hypercapnic ventilatory response as well.

@MykaDives , just to cover all the bases, when was the last time you had your regulator worked on? Have you noticed anything about the work of breathing?

Best regards,
DDM

I recently switched from Poseidon XStream to Apeks XTX50. No difference in symptoms. The Poseidons are extremely high flow, and I much prefer them, but GUE does not accept them.

Hmm, something I just thought of...when I was a teen I had an odd addiction. I used to hold my breath, take little sips of air to squeeze more and more in my lungs and hold my breath for a long time (still taking more sips). This was a comfort habit for me that I often didn't notice I was doing until I had to let the air out and get another breath. It took me years to break this habit. I wonder if under the stress of diving I am falling back into this comfort habit? I know I do purposely breathe like that when adjusting buoyancy (take a huge breath and temporarily hold it), so I am definitely "playing" with the old habit of breath hold, and I wonder if I am falling prey to old habits? I will pay very close attention to my breathing this weekend.

 

[doctormike]

Going to have to use the Google for that one...

Sorry! Was just thinking that sometimes people with Asthma have problems moving gas in and out of their airways, so that might lead to you chronically having a high level of CO2. The capnostat is the part of your body that drives you to breathe when you hold your breath and CO2 starts building up (we are more responsive to high CO2 than to low O2). If you are used to a chronically high CO2 level, that may make your body less responsive to normal breathing triggers.

 

[MykaDives]

Sorry! Was just thinking that sometimes people with Asthma have problems moving gas in and out of their airways, so that might lead to you chronically having a high level of CO2. The capnostat is the part of your body that drives you to breathe when you hold your breath and CO2 starts building up (we are more responsive to high CO2 than to low O2). If you are used to a chronically high CO2 level, that may make your body less responsive to normal breathing triggers.

Ah yes ok. I was going down that path, but not understanding to full capacity! When I start to feel the brain fog I will make a point to breathe deeply and continuously and see if I can get the feeling to go away - or maybe even prevent the onset to begin with. I think we have some AOW students this weekend, so I should get a chance at reasonable depth too (~85'). Hopefully they aren't too stressful, and I will have room in my brain to work on this while watching them gracefully flounder around (hehe).

 

[Annika1]

I've discussed this with several people and haven't really had much clarity provided. Maybe you folks have some ideas.

I dive mainly in cold freshwater lakes that vary 38-45F mainly, and the issue becomes apparent when I dive around 80 feet or more, and/or do multiple dives (DM with OW/AOW students over a weekend). The issue is both underwater and on surface. I will feel like my brain is foggy, like I'm just going through the motions, almost like I get really, really tired and want to fall asleep (like when you're watching a movie and kinda falling asleep). I'm not falling asleep, but it's kind of the same feeling, like fogginess/numbness. However, I am still able to perform well. I notice what the students are doing, I can tend to any issues, I can lead a dive with no hitch, I can tie off lines, I can do valve drills, etc. I feel foggy, but I don't perform foggy. The instructors can't tell that anything is "wrong". There was one time when I was tying a line at 87' and I got tunnel vision really suddenly, and really bad (all I could see was the line and my fingers), but as soon as I picked my head up and looked around it went away. Now this all sounds like narcosis, right? Except, I don't feel any clearer when I ascend. This feeling will stick with me on the surface for a few hours after the dive (or after the last dive of the day, whichever is later). I also get this feeling on tropical dive trips (multiple dives, multiple days).

The people I have asked about this generally say something along the lines of, "Ya I kind of feel like that too." Maybe it's normal, and I'm simply hyper-sensitive to the feeling?

Any ideas?

Take a thermometer with you next time and check your temp when you get out of the water. Try a hot tub or hot shower after diving so your body doesn’t have to work so hard to get back to normal temp.

 

[BRT]

Do you dive nitrox? If not I'd sure try a couple of tanks. Some people think they feel a lot better after dives with nitrox.

 

[Duke Dive Medicine]

If I had CO2 retention, wouldn't I get a headache? I do not typically get a headache diving. How do I test for this?



Going to have to use the Google for that one...



I recently switched from Poseidon XStream to Apeks XTX50. No difference in symptoms. The Poseidons are extremely high flow, and I much prefer them, but GUE does not accept them.

Hmm, something I just thought of...when I was a teen I had an odd addiction. I used to hold my breath, take little sips of air to squeeze more and more in my lungs and hold my breath for a long time (still taking more sips). This was a comfort habit for me that I often didn't notice I was doing until I had to let the air out and get another breath. It took me years to break this habit. I wonder if under the stress of diving I am falling back into this comfort habit? I know I do purposely breathe like that when adjusting buoyancy (take a huge breath and temporarily hold it), so I am definitely "playing" with the old habit of breath hold, and I wonder if I am falling prey to old habits? I will pay very close attention to my breathing this weekend.

That's a good insight about the breathing. Couple that with some reactive airway disease and CO2 comes up again as a strong possibility. Headache is one symptom of CO2 retention but it's not the only one.

Best regards,
DDM

 

[EFX]

If I had CO2 retention, wouldn't I get a headache?

I haven't read all the replies in this thread so maybe this was mentioned somewhere. A headache and a general feeling of malaise could be a sign of dehydration. I would make sure I'm fully hydrated before diving to eliminate this cause as a possibility. Hydration should start days before the dive and not the morning of.

 

[drk5036]

Something no one else has mentioned, have you ever had a sinus squeeze? I get them, usually minor, just resulting in a tingle above my eyebrow. But one time (not diving related) I got a full blown squeeze on an airplane during descent. Thought I was having a stroke. The rest of the day I felt really out of it and generally uncomfortable.

When I dive, if I do more than one dive I’ll sometimes get that tingling feeling. I think the first dive irritates the sinus cavities, and it makes those specific areas more difficult to equalize, causing this fog feeling. “Fog” is the best way I can describe it.

For me, I now always take one, 12 hour extended release Sudafed before diving. I haven’t had this problem once since I started proactively taking Sudafed. I also started doing a netipot to try to help with any chronic irritation. This has let me reduce the Sudafed requirement. Now if I’m just doing two dives I usually don’t take anything prior.

I know it probably seems unrelated, but try giving Sudafed a shot. I bet it helps.

 

[Skeptic14]

Have you ever had your B12 levels tested?

 

[Esprise Me]

Something no one else has mentioned, have you ever had a sinus squeeze? I get them, usually minor, just resulting in a tingle above my eyebrow. But one time (not diving related) I got a full blown squeeze on an airplane during descent. Thought I was having a stroke. The rest of the day I felt really out of it and generally uncomfortable.

When I dive, if I do more than one dive I’ll sometimes get that tingling feeling. I think the first dive irritates the sinus cavities, and it makes those specific areas more difficult to equalize, causing this fog feeling. “Fog” is the best way I can describe it.

For me, I now always take one, 12 hour extended release Sudafed before diving. I haven’t had this problem once since I started proactively taking Sudafed. I also started doing a netipot to try to help with any chronic irritation. This has let me reduce the Sudafed requirement. Now if I’m just doing two dives I usually don’t take anything prior.

I know it probably seems unrelated, but try giving Sudafed a shot. I bet it helps.

Hmmm. I had a fleeting feeling of slight vertigo coupled with a weird but not unpleasant sensation in my head-- almost like being high--once on a night dive. Narcosis was my first thought when it happened, but then when it passed a second or two later without my having ascended, and given that I was only at 80 feet, I decided that probably wasn't it. Maybe it was a squeeze.