Sudden and complete hearing loss from freediving. No "pop," no pain but now deaf in one ear for more than a week.

[crofrog]

Well, not quite the same thing. If the ambient in the chamber is just standard air (~21% O2) then the body is not experiencing the pressurized application of 100% O2 like she did in the monoplace chamber. There are plenty of strip mall "standard air with O2 masks" vendors around but that's not what she used, thus we would not be replicating the same conditions. That's what I'm trying to do: Replicate the 100% O2 at pressure over her whole body, like last time. I have considered trying to convince our health insurance provider to pay for diving trips, using 40% Nitrox. It might not be 100% O2 but I personally believe the experiment to be worthwhile, and I'm willing to attend as her medical assistant. Might need to try multiple dive destinations to compare results. {grin}

@Duke Dive Medicine is there any literature that supports THBO over HBOT?

 

[chris_b]

OP here, I was able to get an earlier appointment with the ENT by calling first thing every morning and asking about cancellations. This morning he confirmed what I suspected about the prednisone dosage (supposed to be ~1mg/kg bodyweight, I was on 20mg/day and should have been on 60mg/day). Two days ago after reading this thread I decided to be a "naughty" patient and upped my dosage from what my PCP had prescribed for me. About 24 hours after upping the dose I noticed I could now hear my finger tapping on my earlobe whereas before I heard nothing.

Anyway, the ENT didn't seem to have any experience with dive-related injuries like this but he leans toward PLF as the diagnosis. He's ordered an audiogram for me this afternoon and after reading more literature I'm concerned that immediate surgery might be the best bet for me to regain my hearing (attached a couple of papers that suggest early surgery is a major factor in recovering hearing). He said that dive related IEBT resulting in PLF was not well studied but a 1992 paper I found has this abstract suggesting that this has been a known effect for at least 40 years now (bold inserted by me):

The association between diving, barotrauma, and the production of perilymphatic fistula has been known for almost 20 years. Forty-eight cases of round and oval window fistulas following diving have been reviewed and essentially corroborate previous findings. Any patient with a history of diving and subsequent sensorineural hearing loss within 72 hours should be suspected of having a round or oval window perilymphatic fistula and surgical exploration and closure of the fistula should be undertaken. Patients who have a loss of hearing, vertigo, nausea, or vomiting following a decompression dive should be re-compressed and fi symptoms do not clear, exploration should be performed. Surgical treatment should be executed as soon as possible after the diagnosis si suspected for the best possible results.

I did also talk to the DAN medic line who confirmed that they don't know of any dive-experienced ENTs in Honolulu. University of Hawaii (who happens to be my employer) has a hyperbaric clinic that I contacted thanks to a suggestion by Eric, but they only take people by referral and don't seem to have an ENT on staff anyway.

Not sure what next steps I should take. The ENT wants me to do 6 days of 60mg/daily prednisone followed by a two-day 20mg taper, then follow up at 10 days out from today and maybe switch to ear perfusion if oral steroids don't resolve the symptoms. Planning to see if I can push for a surgery option ASAP as it's now been two weeks since the incident, I worry that waiting even longer reduces my chances of recovering.

 

[Duke Dive Medicine]

@Duke Dive Medicine is there any literature that supports THBO over HBOT?

If by THBO you mean topical hyperbaric oxygen, then no, not to my knowledge.

Best regards,
DDM

 

[crofrog]

If by THBO you mean topical hyperbaric oxygen, then no, not to my knowledge.

Best regards,
DDM

Then forgive my ignorance is there any advantage to being in a pure o2 chamber vs standard chamber with a mask? Other than patient comfort?

 

[Duke Dive Medicine]

Then forgive my ignorance is there any advantage to being in a pure o2 chamber vs standard chamber with a mask? Other than patient comfort?

Ah I see where the question came from. Sorry I didn't pick that up. Monoplace chambers are smaller, more portable (they have wheels), and usually less expensive. It's not the O2 that surrounds the patient that does the work, so to speak, it's the O2 that the patient breathes inside the chamber when it's under pressure. Whether that comes from a mask in a multiplace chamber that's pressurized with air or from the ambient chamber atmosphere in a monoplace that's pressurized with O2 doesn't make a difference.

Best regards,
DDM

 

[TNEngineer]

Not the same conditions. Her body would not be exposed to 100% ambient O2, just 100% seawater. While I agree that's therapeutic {grin}, it doesn't replicate the test.

 

[Duke Dive Medicine]

I did also talk to the DAN medic line who confirmed that they don't know of any dive-experienced ENTs in Honolulu. University of Hawaii (who happens to be my employer) has a hyperbaric clinic that I contacted thanks to a suggestion by Eric, but they only take people by referral and don't seem to have an ENT on staff anyway.

Not sure what next steps I should take. The ENT wants me to do 6 days of 60mg/daily prednisone followed by a two-day 20mg taper, then follow up at 10 days out from today and maybe switch to ear perfusion if oral steroids don't resolve the symptoms. Planning to see if I can push for a surgery option ASAP as it's now been two weeks since the incident, I worry that waiting even longer reduces my chances of recovering.

UH wouldn't have an ENT on staff but they probably have at least one they work with who is familiar with the effects of pressure changes on ears. Hyperbaric patients suffer from middle ear barotrauma just like divers and sometimes need PE tubes placed.
If PLF is suspected then immediate surgery is indicated. Surgery is also (kind of ironically) the only way to definitively diagnose PLF. If that's what is suspected, then they should have you on complete bed rest and stool softeners to prevent straining prior to surgery.

Best regards,
DDM

 

[TNEngineer]

It's not the O2 that surrounds the patient that does the work, so to speak, it's the O2 that the patient breathes inside the chamber when it's under pressure. Whether that comes from a mask in a multiplace chamber that's pressurized with air or from the ambient chamber atmosphere in a monoplace that's pressurized with O2 doesn't make a difference.

Wouldn't that be condition specific? They use hyperbaric for open wound treatment, and it would certainly seem that high pressure ambient O2 (at the skin) would have more effect than high pressure air.

 

[Duke Dive Medicine]

Wouldn't that be condition specific? They use hyperbaric for open wound treatment, and it would certainly seem that high pressure ambient O2 (at the skin) would have more effect than high pressure air.

The mechanism of action of hyperbaric oxygen isn't through the skin or the wound bed itself. It's through the bloodstream. You're an engineer so I'm sure you're already familiar with this, but FWIW: Henry's Law states that the amount of gas that will dissolve in a liquid (key part) is directly proportional to the partial pressure of that gas on the liquid. Since the gas/liquid interface in the body is in the lungs, increasing the partial pressure of inspired O2 will cause O2 to dissolve in the plasma. It's then carried to the affected area where it activates the healing cascade, which generates new capillaries that in turn facilitate wound healing.
This does not happen with topical oxygen.

Best regards,
DDM

 

[TNEngineer]

I do understand how gases work with permeable membranes. But I'm startled to hear that for topical treatment, there is no benefit to 100% O2 at the surface and that all benefit comes from respiration regardless of the type of location of the affected area.

If that is truly the case, then those strip mall party chambers with masks would be just as effective as the individual cylinders.