(img) Wanna see a DCI-causing gas bubble doing the nasty?

[Duke Dive Medicine]

He'd have been intubated so respiratory depression wouldn't necessarily be a problem. I wonder how deep they had him and what made him so susceptible to seizures.

Also not so sure about the conclusion that bilateral femoral vein bubbles can be a useful CT indicator in DCS.

 

[DocVikingo]

He'd have been intubated so respiratory depression wouldn't necessarily be a problem.

Good point, DDM.

I guess since select benzodiazepines are used both for rapid sequence intubation & long-term sedation following the procedure respiratory depression wouldn't necessarily be a problem.

Regards,

Doc

---------- Post added April 30th, 2012 at 04:32 AM ----------

Is it standard practice to discontinue decompression because of seizures?flots.

Morning flots am,

Just out of interest, here's a bit of research suggesting how uncommon oxygen toxicity seizures are given customary hyperbaric oxygen therapy. E.g., for the initial recompression of DCS with the standard USN Treatment Table 6, the rate was 0.56%.

BTW, 1kPa=0.01 bar;=0.15 psi;=0.01 atm.

"Banham ND
Oxygen toxicity seizures: 20 years' experience from a single hyperbaric unit.
Diving Hyperb Med 2011 Dec; 41(4):202-10.

Oxygen toxicity seizures (OTS) are a known complication of hyperbaric oxygen therapy (HBOT). The incidence of OTS has been variously reported and appears to be related to the duration and pressure of exposure in addition to individual susceptibility factors.

All OTS occurring in patients undergoing HBOT during the first 20 years of operation of the Fremantle Hospital Hyperbaric Medicine Unit were reviewed. During 41,273 HBOT in 3,737 patients, 25 OTS occurred; a rate of 0.06% (1/1,650 or 6 per 10,000) HBOT exposures.

For the initial treatment of dysbarism with United States Navy Treatment Table 6, the rate was 0.56%. (4/714) and for the treatment of carbon monoxide (CO) poisoning was 0.18% overall but 0.49% for the first HBOT. There was an increasing OTS rate with increasing pressure with a statistically significant difference (P < 0.001) in OTS rate at 203 kPa or less versus > 203 kPa (OR 8.5, 95% confidence intervals (CI) 2.0 to 36.1), and for comparison of two commonly used pressures of 203 kPa versus 243 kPa (P = 0.028, OR 5.1, 95% CI 1.1 to 22.8), but not with first versus follow-up HBOT at 284 kPa for dysbarism (P = 0.061) nor CO (P = 0.142).

This study reports all OTS in a single hyperbaric unit over a 20-year period, the longest observational study period yet reported for OTS during HBOT for all indications. The incidence of OTS in this study compares favourably to previously reported rates, and shows an increasing OTS rate with increasing pressure."

Regards,

DocVikingo

 

[gkwalt]

Just a sobering thought... a corpse has a GCS of 3! I am a bit skeptical regarding the etiology of the air in the femoral veins. It would seem unlikely(IMO) that a DCS bubble load that significant should only be limited to just the femoral veins. Unfortunately, the case report didn't go into detail regarding the specifics of the injury. I have seen intravenous bubbles in patients who did not suffer DCS. Regardless, it was unfortunate that this gentleman had this problem. And its a reminder that that there are inherent dangers with diving and God bless all the researchers that are trying to better understand DCS.

 

[blue sky]

Thanks to all the Doc's for helping the rest of us understand. It is very interesting. Your willingness to share your knowledge is one of the reasons I enjoy this board. Thanks

 

[DocVikingo]

I am a bit skeptical regarding the etiology of the air in the femoral veins. It would seem unlikely(IMO) that a DCS bubble load that significant should only be limited to just the femoral veins. Unfortunately, the case report didn't go into detail regarding the specifics of the injury.

Hi gkwalt,

As you say, it's too bad the piece doesn't go into more specifics, but as was mentioned earlier "Images in emergency medicine" items typically are brief (often even briefer than this one) and without much clinical detail.

The CT pictured is a scan performed at another facility at which time paralysis of the lower half of the body appeared to be the primary concern. This was before the development of a GCS=3 and arrival at the reporting ICU. This dramatic image with accompanying text was what the authors submitted/the journal accepted.

I'm quite sure that neuroimaging was done after transfer, but didn't reveal anything worthy of mention. However, given the patient's alarming level of consciousness, there almost certainly was free gas phase involvement of brain.

Regards,

DocVikingo

 

[gkwalt]

Doc
Thanks for the additional info.
Jerry