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gtzavelas · 27th December 2007, 16:48

This is a short report about my deco hit, 2 months ago.

Dive 1: Monday at noon. Max depth: 115m.
Profile:

Dived with Megalodon rebreather and following setup:
Diluent 10/70, set point 1.1 at depth then switching to set point 1.3 above 30m and flushing with O2 at 6m. Deco by HS Explorer, setting 2, (conservative RGBM) with padded shallow stops (more time at 9/6/3 meters). The set point of the HS explorer is set to 1.1 during the dive, and 1.3 above 30m.
The dive was a sea water cave dive. Water temperature 21 deg C. Dry suit. As the water was warm, suit inflation was via bail out gas.
Towards the end of the deco i did a bounce to 50m, as shown in the profile above. (with quite fast ascent as can be seen)

Less than 1 hour after surfacing dived again to 21 meters:

No symptoms after the dives.

Dive 2: Wednesday noon dive (48 hours after dive 1):

Same mixes / procedures / max depth.
At 161 minutes as soon as I surfaced and stood up (in 1 meter water) both me knees hurt.I then dived immediately (within 1 or 2 minutes) to do additional O2 starting at 9 meters.
After 45 minutes, on resurfacing my knees still hurt.
One hour after exiting the water it was decided to go to chamber. The reason of the delay was because I was not convinced it was a DCS hit as I was feeling OK apart from the knees. During this one hour I was mostly lied down breathing O2 and drinking a lot of water.
Reached chamber after two more hours (mostly breathing O2).
Doctor diagnoses mild case of Type II hit (left legs had a neurological hit – reflexes were a bit off) plus very minor impact on balance.
Did 3 sessions (3 days) and was OK.

Possible Conclusion : The bad (yo-yo) profiles of Monday (bounce dive a 50m at the end of the deco, 2nd dive at 20m) left a small bubble in the knee (with very marginal symptoms that I did not realise on Monday). The bubble was recompressed two days after and produced the hit.

As a final note, my blood tests showed an elevated level of Bilirubin apparently caused by the high level of PO2 that breaks down the red blood ceels. One month after the accident the Bilirubin are still high. I am currently investigating this. (its now 2 months I am out of the water and planning to dive again very soon).

any input is welcomed

George Tzavelas

27th December 2007, 16:48	#1 (permalink)
gtzavelas RBW Member Current Rebreather/s: Megalodon RB80 / Clone Other Rebreather/s: RB80 / Clone Join Date: Jan 2006 Location: Athens,Greece Posts: 281	my DCS Hit This is a short report about my deco hit, 2 months ago. Dive 1: Monday at noon. Max depth: 115m. Profile: Dived with Megalodon rebreather and following setup: Diluent 10/70, set point 1.1 at depth then switching to set point 1.3 above 30m and flushing with O2 at 6m. Deco by HS Explorer, setting 2, (conservative RGBM) with padded shallow stops (more time at 9/6/3 meters). The set point of the HS explorer is set to 1.1 during the dive, and 1.3 above 30m. The dive was a sea water cave dive. Water temperature 21 deg C. Dry suit. As the water was warm, suit inflation was via bail out gas. Towards the end of the deco i did a bounce to 50m, as shown in the profile above. (with quite fast ascent as can be seen) Less than 1 hour after surfacing dived again to 21 meters: No symptoms after the dives. Dive 2: Wednesday noon dive (48 hours after dive 1): Same mixes / procedures / max depth. At 161 minutes as soon as I surfaced and stood up (in 1 meter water) both me knees hurt.I then dived immediately (within 1 or 2 minutes) to do additional O2 starting at 9 meters. After 45 minutes, on resurfacing my knees still hurt. One hour after exiting the water it was decided to go to chamber. The reason of the delay was because I was not convinced it was a DCS hit as I was feeling OK apart from the knees. During this one hour I was mostly lied down breathing O2 and drinking a lot of water. Reached chamber after two more hours (mostly breathing O2). Doctor diagnoses mild case of Type II hit (left legs had a neurological hit – reflexes were a bit off) plus very minor impact on balance. Did 3 sessions (3 days) and was OK. Possible Conclusion : The bad (yo-yo) profiles of Monday (bounce dive a 50m at the end of the deco, 2nd dive at 20m) left a small bubble in the knee (with very marginal symptoms that I did not realise on Monday). The bubble was recompressed two days after and produced the hit. As a final note, my blood tests showed an elevated level of Bilirubin apparently caused by the high level of PO2 that breaks down the red blood ceels. One month after the accident the Bilirubin are still high. I am currently investigating this. (its now 2 months I am out of the water and planning to dive again very soon). any input is welcomed George Tzavelas
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