Amarillo Texas diver dead in Florida Keys

[iamrushman]

condolences to family, friends, and colleagues.....

 

[boulderjohn]

Ive read pacemakers are rated to a max of 2 atm.

Different models of pacemakers have different depth ratings. In many cases, they really haven't been tested very deep, and their rating shows the limits of their testing more than the limits of the pacemaker.

A number of years ago I posted a statement from a major pacemaker company, St. Jude, that said the specific pacemaker they were talking about was tested to 7 ATA, which is roughly 200 feet. It did not fail at that pressure--that was the limit of their ability to test. They further said that if it were to fail at greater pressure, there would not be any actual damage, and it would resume working when returned to a lesser pressure. I know someone with that pacemaker who has taken it beyond that depth MANY times, with a maximum of 320 FSW. It has never stopped working.

Different pacemakers also have different functions, and different people have different needs for it. In some cases, the pacemaker is essential for the user's continued living. In the case of the diver I mentioned in the second paragraph, the pacemaker is only in the patient because of an extremely slow resting heart rate, especially while sleeping. The pacemaker keeps the heart beat above 60 BPM under those circumstances. There is little danger of the diver taking a nap at 300 feet, so even if it failed, there would be no problem.

 

[Capt Jim Wyatt]

Now what is the deal with using an AED on someone with a pacemaker when you don't know they have one?

 

[boulderjohn]

Now what is the deal with using an AED on someone with a pacemaker when you don't know they have one?

As far as I can tell, you can use them with some caveats. The key idea is not to put the AED pads directly over the pacemaker. Since you have to get to bare skin to put on the pads, the presence of the pacemaker should be evident. The surgery leaves a scar, and there is usually a lump under the scar as well. It is also pretty much always in about the same place. That is not the place I would normally put an AED pad anyway.

https://www.bostonscientific.com/co...CL_CPR_and_External_Defibrillation_063008.pdf

The biggest issue is when the pacemaker has a built in defibrillator that is working independently from the AED. You don't want to be delivering the shock while the pacemaker is delivering a shock. Not all pacemakers have internal defibrillators.

 

[Norwegian Cave Diver]

Is this an internal pacemaker? Wonder why an internal pacemaker would have a depth rating? How would it receive pressure from an external force (water in this example).

 

[Bob DBF]

Same way you receive pressure underwater. The difference is the pacemaker is in a sealed with 1 atm inside so there will be a differential pressure, say 2 atm at depth, whereas your body is at 3 atm throughout and no chance of collapsing.


Bob

 

[boulderjohn]

Is this an internal pacemaker? Wonder why an internal pacemaker would have a depth rating? How would it receive pressure from an external force (water in this example).

As Bob said, pressure affects you internally during a dive. That is why we have to worry about decompression. When we breathe compressed air at 99 FSW, we inhale 4 times as many molecules in order to maintain the size of our lungs. That leads to an increase in nitrogen entering our tissues.

 

[Norwegian Cave Diver]

Pressure creates additional nitrogen and oxygen in our bloodstream which in turn adds nitrogen and oxygen into our tissues. This isn't the case with an electronic device. I would suspect since an internal pacemaker would be just under the skin that it may recieve external pressure from the skin and therefore from the weight of the water. Our body's are only really affected internally where there is a air source. So the pacemaker doesn't recieve pressure from the inside of our body's.

 

[boulderjohn]

Any device with an outer wall and inner space is subject to the effects of pressure.