Completely normal nitrox dive to 25m gave me DCS

[SFJCody]

Hi guys,

Apologies for bothering you with this. Four days ago I did a completely normal nitrox (36%) dive to 25m, the first of a liveaboard weekend and my first dive in 6 months. Safety stop observed, nothing strange or risky occurred. On the surface I began compulsively yawning and felt waves of nausea. It passed after a couple of hours, I drank lots of water and continued diving. I did ten dives total over three days, all but one (10m night dive) on nitrox. I noticed that I had a faint background nausea that disappeared at depth but came back steadily on the surface. In the coach on the way back i began to feel quite rough and queasy. This is 6 hours post the last dive. Paranoia led me to check into a hyperbaric clinic.

I've now undergone two sessions in the chamber on table 6 separated by 24 hours, max depth 18m total time (each) 3.5 hours. At 18m the symptoms disappeared. At <14m the symptoms steadily returned- but worse than before. Now I have tingling, numbness, confusion, my hands feel 'crabbed', my joints pop and ache and my skin itches. Two sessions, and it gets worse with each one. I'm due for another check up tomorrow. The doctors are telling me it's normal to have residual nausea but this feels awful. What should I do? Worried that the next session will make things even worse.

 

[RyanT]

I'm not qualified to give medical advice, but worsening symptoms with hyperbaric treatments doesn't seem like DCS. Of course hyperbaric treatments are not necessarily a "cure" for any and all DCS symptoms, but it shouldn't get worse with continued treatments. I'd be interested to hear what the physicians on SB have to say.

 

[scubadada]

Did you discuss with DAN? Emegency: +1-919-684-9111, routine: +1-919-684-2948

 

[SFJCody]

I have not. I'll email them now.

 

[scubadada]

I have not. I'll email them now.

Good idea, there is an email link on the DAN Medicine page Scuba Diving Medical Services — Decompression Illness — DAN | Divers Alert Network

Let us know how it turns out

 

[Seya]

I hope things get better for you soon.

 

[Duke Dive Medicine]

Ditto RyanT, you should not be getting worse with hyperbaric treatment. Are you sure the treatments are 3.5 hours long? A U.S. Navy treatment table 6 is 4 hours and 48 minutes long without extensions. How are you getting the oxygen in the chamber, via mask or head tent; or, were you in a monoplace?

 

[Kevrumbo]

As a former DCS patient, I would recommend calling the DAN telephone numbers listed above and talk with a Hyperbaric Doctor for a second opinion, before undergoing any additional Hyperbaric Oxygen Therapy sessions.

 

[SFJCody]

I can confirm that the oxygen was administered by a head mask, which was poorly fitting. The time was less than 3.5 hours. I measured the ascent rates at 0.5 metres per minute, both from 18m to 9m and 9m to surface.

 

[Kevrumbo]

I can confirm that the oxygen was administered by a head mask, which was poorly fitting. The time was less than 3.5 hours. I measured the ascent rates at 0.5 metres per minute, both from 18m to 9m and 9m to surface.

US Navy Treatment Table 6 should be around 4.8 hours. . .
Descent rate 6 mpm to 18m;
Three Oxygen periods of 20min and three Air breaks of 5min at 18m;
Ascend to 9m at 0.3 mpm on O2; Two O2 periods of 60min and two Air breaks of 15min (or alternatively six O2 periods of 20min and six Air break periods of 5min);
Final ascent to surface at 0.3 mpm on O2.
Total time 288min or 4.8 hours.