Unexplained Type 2 DCS Hit - Thoughts?

[Evan McCormick]

Hi all,

My name is Evan. I have completed 70 dives in a few different countries and never had any issues. A couple weeks ago I had a scary DCS experience. I wanted to run it past you all to see what thoughts you have.

• Date: June 4, 2025 @ 11:00
• Location: Green Island, Taiwan

Pre-Dive
This was the first dive of the trip. We had acclimated to the time zone for a couple days. I got 8 hours of sleep the night before. The morning before we had a full breakfast and were well hydrated. I didnt feel stressed at all leading up to the dive either. I'm 5'10" and 195 lbs and in decent shape.

Dive Details

• Type: Shore dive
• Average Depth: 35 feet
• Max Depth: 60 feet
• Duration: 50 mins
• Safety Stop: 3 mins @ 15 ft
• No strenuous parts of the dive
• No uncontrolled or fast ascent

DCS Experience
I didnt experience any syptoms until I was walking out of the water and taking my fins off. There was no strenuous surface swim or exit from the surf. My legs started feeling numb, then my chest and the lower half of my buddy went numb and I started getting confused. My vision got blurry and I fell back into the water.

Response

The dive master kept my head above the waves and my wife got an ambulance coming. Some locals helped drag me out of the water. I was taken to the emergency clinic in an ambulance. I never passed out. After 30 to 45 minutes my heart rate came down, feeling and vision came back. I had a bad lingering headache for the rest of they day. I also eventually realized I was having trouble urinating. We took the next ferry back to the mainland and went to the emergency room. DAN was pretty helpful throughout making sure that I had the resources I needed and checking in with me. The hospital had me do the barometric chamber for 2hrs:15min at 3 atm. This was about 7 hours after the incident. After the chamber I was able to urinate normally again.

The Following days

We took it easy for a few days. I had some very slight lingering pins and needles feeling in my legs that slowly went away over the next couple weeks. I also had a bit of a lingering headache. We cancelled the rest of the dives on the trip and didn't fly for 5 days after the treatment.

Other Thoughts

• All 3 of our tanks had been filled by the same machine
• No funky smell from my tank

Questions

• Any thoughts on what could have caused this DCS hit to happen?
• Is there a higher likelihood of this happening again now?
• What is the recommended amount of time before my next dive?
• Is there recommended medical tests to have performed before diving again? Should I see a specialist?
  • My physician performed a physical and didnt have any concerns

 

[Duke Dive Medicine]

Hi all,

My name is Evan. I have completed 70 dives in a few different countries and never had any issues. A couple weeks ago I had a scary DCS experience. I wanted to run it past you all to see what thoughts you have.

• Date: June 4, 2025 @ 11:00
• Location: Green Island, Taiwan

Pre-Dive
This was the first dive of the trip. We had acclimated to the time zone for a couple days. I got 8 hours of sleep the night before. The morning before we had a full breakfast and were well hydrated. I didnt feel stressed at all leading up to the dive either. I'm 5'10" and 195 lbs and in decent shape.

Dive Details

• Type: Shore dive
• Average Depth: 35 feet
• Max Depth: 60 feet
• Duration: 50 mins
• Safety Stop: 3 mins @ 15 ft
• No strenuous parts of the dive
• No uncontrolled or fast ascent

DCS Experience
I didnt experience any syptoms until I was walking out of the water and taking my fins off. There was no strenuous surface swim or exit from the surf. My legs started feeling numb, then my chest and the lower half of my buddy went numb and I started getting confused. My vision got blurry and I fell back into the water.

Response

The dive master kept my head above the waves and my wife got an ambulance coming. Some locals helped drag me out of the water. I was taken to the emergency clinic in an ambulance. I never passed out. After 30 to 45 minutes my heart rate came down, feeling and vision came back. I had a bad lingering headache for the rest of they day. I also eventually realized I was having trouble urinating. We took the next ferry back to the mainland and went to the emergency room. DAN was pretty helpful throughout making sure that I had the resources I needed and checking in with me. The hospital had me do the barometric chamber for 2hrs:15min at 3 atm. This was about 7 hours after the incident. After the chamber I was able to urinate normally again.

The Following days

We took it easy for a few days. I had some very slight lingering pins and needles feeling in my legs that slowly went away over the next couple weeks. I also had a bit of a lingering headache. We cancelled the rest of the dives on the trip and didn't fly for 5 days after the treatment.

Other Thoughts

• All 3 of our tanks had been filled by the same machine
• No funky smell from my tank

Questions

• Any thoughts on what could have caused this DCS hit to happen?
• Is there a higher likelihood of this happening again now?
• What is the recommended amount of time before my next dive?
• Is there recommended medical tests to have performed before diving again? Should I see a specialist?
  • My physician performed a physical and didnt have any concerns

Hi Evan,

How old are you and how is your health in general? Are you under a physician's care for anything? Any significant medical history?

My first thought is that you were undertreated. The standard of care for neurological symptoms like that is a treatment that's closer to 5 hours long, with follow-up treatments until symptoms resolve or at least don't improve with further treatment.

Before making any return-to-diving recommendations, a provider would want to have a clearer understanding of what caused this to happen. You mentioned that you didn't experience a panic or rapid ascent but gas embolism is still in the differential and could have happened if you have undiagnosed blebs or bullae (spaces that can trap air) in your lungs or if you inadvertently held your breath as a decent-sized wave passed over you in shallow water. You could also be one of those folks who bubbles a lot after diving and shunted bubbles through either a patent foramen ovale in your heart or through your lungs.

I'd strongly recommend that you be examined by a physician who is trained and experienced in evaluating divers before considering diving again. Your home town is closer to Vancouver than Seattle so if care in Canada is an option, the hyperbaric unit at Vancouver General has access to a diving physician. If that doesn't work, the Virginia Mason hyperbaric unit has diving physicians. You'll probably need imaging studies (possibly including chest imaging and a bubble contrast echocardiogram) before any recommendations can be made. Let me know if you'd like contact info for either of those facilities.

Best regards,
DDM