diving after brain surgery

[DocVikingo]

I think you'd be hard pressed to get enough tissue shrinkage to cause relief just from the increased pO2 of SCUBA diving. At a minimum, it takes a pO2 of about 0.6 ATA to get any anti-inflammatory effect from oxygen, and if we're shooting for that in a treatment we'll use at least 2 ATA and sometimes up to 3.DDM

Thank you, DDM.

IMHO, positing relief based on mechanisms such as reflex shrinkage of cerebral vasculature in response to the elevations of pp02 typical of recreational SCUBA and on dehydration in response to immersion diuresis is really reaching for it.

Regards,

DocV

 

[wardric]

Thanks all. He has been visiting this thread and I know he appreciates your help.

 

[cutlass]

So we can rule as unlikely that air spaces and ppO2 contribute to the reported relief of head "pressure"?

That would seem to leave changes of body water. One telling clue would be if there's a relationship between thirst and the reported relief. In the coarsest terms of total body water, by the time thirst registers, a person is already down about 1L. This would be about 2% of a model 70kg adult male with 42L TBW.

Mannitol by bolus infusion lowers ICP in the neighborhood of 7mmHg (+/- 2mmHg). It's specifically a fast-acting intracellular diuretic; relating it back to TBW will be some work.

 

[DocVikingo]

So we can rule as unlikely that air spaces and ppO2 contribute to the reported relief of head "pressure"?

I believe this to be accurate.

That would seem to leave changes of body water. In the coarsest terms of total body water, by the time thirst registers, a person is already down about 1L. This would be about 2% of a model 70kg adult male with 42L TBW.

2% strikes me as a very small number upon which to support a transition from a sensation of "a lot of pressure in the head" to feeling "so good."

IMHO, you're reaching way long, cutlass.

Regards,

DocV

 

[wardric]

My friend and long time buddy passed away this afternoon after fighting as much as he could. He had sold his diving equipement recently, knowing he was done with this sport and had not much time left.

He enjoyed a last tropical vacation 2 weeks ago, at a place we had gone diving many times in Cuba. The doctor was kind enough to let him go, probably knowing it was his last wish. He went quickly and peacefully.

Thanks for all your advice

Wardric

 

[Duke Dive Medicine]

Eric,
I'm sorry to hear about your friend. It sounds like he made the best of it and went out the way he wanted, and I guess that's all anyone could ask for. My condolences.
Best regards,
DDM

 

[TSandM]

Sorry to hear of his death, but it sounds as though it was as good an ending as that particular problem can have. And bless the doctor who looked at the whole patient, and not the disease.

 

[annewa]

My son had a non malignant brain tumour removed 2 years ago. It was diagnosed after he had a sudden seizure. For 6 months following surgery he did not take anti convulsant medication, but after having 2 separate seizures (3 months apart) he was advised to begin taking medication as the after affects of brain surgery can cause susceptibility to seizures, even after the tumour, which was the original cause, was removed.

He has been seizure free and fit and well for the last 18 months and any seizure activity appears to have been easily controlled. My question is will he ever be able to scuba dive again? He drives and surfs and so I wonder whether there is any additional risk involved if he dives. Does the physical action of scuba diving increase the risk of a seizure occurring? Apart from the obvious risk if a seizure occured underwater, is there any reason for a seizure to be triggered by diving ie pressure changes etc?

I have read that you can consider diving if you have been seizure free and off meds for 5 years. My son prefers to remain on his medication even if it is only as a precautionary measure.

 

[Duke Dive Medicine]

Annewa,

That's a highly individual question. The short answer is, it's not impossible to return to diving after something like that but he will have to be evaluated in person by a physician trained in diving medicine. This is an older thread but if you look back at the descriptions of how diving gases act on the circulation you'll see that hyperoxia results in net vasoconstriction; however, this effect is transient in the cerebral circulation. Diving also can result in CO2 retention. Since CO2 is a potent vasodilator, cerebral blood flow may be increased in a diver. If the diver is using a hyperoxic mix like nitrox or is diving extremely deep (roughly 180 feet and beyond) on air, he or she will be at risk of oxygen toxicity. The mechanism of O2 toxicity seizures is still under investigation, but it's possible (perhaps likely) that your son's seizures arise from a different mechanism and diving would not increase his risk of having the type of seizure that he's been having. That said, it's difficult to determine how all of this fits together to form a picture of individual risk for him. If you provide your location here or via PM I may be able to refer you to someone.

Best regards,
DDM