CO poisoning/hyperbarics

[logos]

Yes, I know. That is not my question at all, my question was since the pt was on a vent they would not be breathing the pressureized oxygen from the chamber, they will be breathing the 100% oxygen provided via vent, so what would be the benefit of being in a presureized chamber. That being said would the gas mixture have to be 100% oxygen at all, since he will not be breathing it, and by having standard AIR you could have a tech in with the pt without having to worry about oxygen toxicity. The question is not about risk.

These are questions I had intended to ask the techs but they were not available to me at the time.

The patient will be breathing whatever gas they are administering at the pressure in the chamber. That is, if they dive the pt to 3ATM and give 100% oxygen (probably unlikely) he would be be breathing gas at a partial pressure of roughly 760*3 = 2280mmHg. You can think of partial pressures and concentrations as the same thing. Thus the concentration of oxygen in the blood will be much higher. This pushes the equilibrium between caboxyhemoglobin and oxyhemoglobin towards oxyhemoglobin. That is to say that it "removes" the CO faster.

If the patient were to be pressurized in a chamber, but not ventilated with gas at the concentration of the chamber (the partial pressure) then he would have a very difficult time breathing. If the pressure difference were great enough it would be impossible to breathe.

You can think of it as if they dive the whole patient with his ventilator, which is what some centers with large walk in chambers can do.

[VentMedic]

You can think of it as if they dive the whole patient with his ventilator, which is what some centers with large walk in chambers can do.

Either way the ventilator will be pressure controlled to adjust for the flutuation in VT. They will not allow the volume to expand to 3x normal.

It is frowned upon to take a whole ventilator into a chamber due to machinical parts. The ventilator may be attached from the outside through a special port or pneumatically powered at the simplest level.

Again, just review a few gas laws and a few simple pulmonary equations, which a Paramedic should have at least at introduction to, and this will be easy to see why these things are important when considering dive injuries, flight, HBO, altitude, tank pressures and just plain oxygen carrying capacity.

Yes, I know. That is not my question at all, my question was since the pt was on a vent they would not be breathing the pressureized oxygen from the chamber, they will be breathing the 100% oxygen provided via vent, so what would be the benefit of being in a presureized chamber. That being said would the gas mixture have to be 100% oxygen at all, since he will not be breathing it, and by having standard AIR you could have a tech in with the pt without having to worry about oxygen toxicity. The question is not about risk.

These are questions I had intended to ask the techs but they were not available to me at the time.

The oxygen clock will start but the patient will not be in the chamber for 24 hours. Since HBO greatly reduces the half life of the CO molecule attached to the Hb, the O2 can be weaned quicker once out of the chamber from that 100%.

Edited April 6, 2009 by VentMedic

[Richard B the EMT]

To borrow the movie line yet again, "Explain this to me as if I were a 5 year old child."

Admittedly, I don't really know the physiology too well for the need of a "recompression chamber", except that, in the case of a diver with "the bends", nitrogen bubbles normally dissolved in the bloodstream, cause poor circulation and physical pain, as, on "surfacing", the bubbles expand.

The chamber takes the patient "back down" to depth, from which, the chamber crews slowly bring the patient back to normal surface pressure, allowing the bubbles to be slowly reabsorbed harmlessly into the bloodstream.

If the patient is tubed, would that not simply be a direct way to introduce O2 to the patient's lungs? With the O2 concentration probably being different than what I'd deliver in the ambulance, what is wrong with having a patient on a vent in the chamber?

Despite my time in the EMS field, from 1973, as an EMT doing the BLS level, I have never been to one of these chambers, so I have no idea if the compressed atmosphere within them is just compressed room air, or O2. If compressed with an O2 atmosphere, seemingly a BVM would suffice as the simplest vent available.

Could someone from PADI, or with Respiratory Therapy training set me up with details?