Oxygen Administration Skills- Did I miss something (like demand valves comin' back?)

[Skip Parker]

From what horse's mouth? That's probably from the DAN manual or something...

Well, you don't want to come off as arrogant, as you said, but I find it odd that an EMT from Indiana, who IIRC is not even certified, is so convinced he knows more about O2 and scuba related injuries than a leading non-profit orginazation that specializes in this stuff and is closely tied with the Duke Univserity School of Medicine.

Here's a blurb about the author I quoted:

Clendenen holds an MBA from the Fuqua School of Business, Duke University, and a BA from Colby College in Maine. He is a diving instructor and course director for PADI International. Clendenen is the editor and author of several books and articles on oxygen first aid and scuba diving safety; and since 1996, he has served on the National Advisory Board for First Aid Training in Occupational Settings. In 2000, he was named a Special Investigator for Oxygen for that project.

 

[medic_diver45]

I'm not saying I know more about dive medicine than anybody....I'm saying that oxygen administration IS something I know a lot about (since I'm a respiratory therapist by profession, not an Intermediate EMT (although I still volunteer as an EMT-I)) and I hate to burst your bubble, but since when did giving oxygen by mask as a first responder differ as to what the problem is. I probably do know more about oxygen therapy than 99% of the people about there simply because my job demands it. I seem to know more about it than you do (which I don't fault you on, it's not your job to know it inside and out like I have to)- and probably have more experience giving it. Knowledge is great but experience is what matters. Yes there are probably DOCTORS at DAN who know more about it than I do, and I am not questioning the medical knowledge that they possess (actually I am in awe at how much they know) my questioning lays in choosing to advocate a system that is overpriced compared to it's competition among other problems (including the logistical one of oxygen supply). My problem lays more with the business office side of the operation.

It doens't matter if the patient is bent like a corkscrew, is having a coronary, or is the victim of some form of trauma- the technical aspects of the procedure itself do not change and neither do the complications, risks, and contraindications The administration of as much oxygen as needed is the same no matter what the cause (at least in the hands of first aiders and first responders)- it's when the patient gets to the hospital that the treatment changes.

Yes, I am still working on getting my certification (as I have said before I took the class in 2000, and was in a car accident that left me with a cast on my leg unable to complete my last checkout dive).

But that still does not change the fact that we are not discussing something here that is exclusive to divers; but rather you are insinuating (or rather blatantly stating actually) that because I am not a diver that I don't know how to treat a patient with the bends. That is unprofessional, untrue, and uncalled for- and technically if I want to be a real a-- about it taken as libel (but my skin is thicker than that and I realize you're just trying to make me look less qualified to state the facts I am stating). Now if I were blathering on about mixed gas diving or something else of which I have no knowledge or experience, then you would have the right to call me on it and I would expect you to.

Oh as far as your expert, I don't see any sort of actual medical training on his impressive (that is said honestly without sarcasm) list of accomplishments, just a BS and MBA. But I hate to be the bearer of more bad news, but if it were me and him on a dive boat taking care of a patient you who would bear ultimate responsibility as the senior medical person there (especially if the case went to court): me. The only people I defer medical decision making authority to are doctors and physician's assistants. But as first responders the only things (regardless of what training we may have) that can be done are give as much oxygen to the patient, maintain an airway, and haul a-- for the nearest chamber.

Like I have said before, I don't think DAN is purposely misleading you into doing something dangerous, but rather they are just trying to accumulate money through their advocacy of the more expensive gear. I imagine that the money is funnelled back into education and support operations, not into someone's pockets.

 

[lamont]

I have come to the realization that I am not going to convince you to even look at things from the medical grounded side of things. I feel that there is no point in wasting my breath any further and that I need only state that you have been warned on the risks and downsides of these devices. While they make not be dangerous, they are simply not the best choice out there. I know of no other way to demonstrate that to you. If it were me, I'd want a non-rebreather and if I am treating the patient they will get a non-rebreather; As I've said before, there are many ways to do something in medicine, but some of them are just more effective.

We should all be looking out for what is in the patient's best interest, because some day we may be the patient. I think financial reasons have clouded the judgement of the agency upon which you are relying for your information. Relying on only one source of information can be a dangerous thing in medicine.

Thank you for a stimulating conversation that has required me to remain on my toes.

I think you had some very good points that I plan on following up on, but you come off as a raging ******* and don't seem to be able to tolerate people of lesser experience questioning what you say. You also fall back way too quickly on the idea that DAN is pushing demand valves and MTVs for profits sake, which isn't a convincing argument at all.

Also, I have yet to get to the medical library to find your references, but on medline the only reference I could find to barotrauma from pressures that low was in infants.

Did you just recently starting posting a lot on the Internet? As a 20 year veteran of online flamewars, I'd suggest that you change your approach. You might find that a lot of people who you think you are 'not going to convince' would come off as being a lot less argumentative to you.

And unfortunately, I tend to apply the principle of not relying on one source of information more to you than to DAN at this point, based mostly on your approach. I plan on asking an EMT that I work with, doing some research in the medical library and maybe calling up some of the diving docs in the local area. Who knows, you might be right even despite your attitude...

 

[medic_diver45]

Actually, I'm not a raging a--hole.....I'm a pretty nice person. What I don't like is that since I am not towing the party line, I am the thorn in everyone's side. I apologize for coming across as overbearing or egotistical (I'm not really, I'm just good at what I do and I want everyone to be as skilled as I am- that's why I tried to remain positive and teach rather than lowering myself to personal attacks the way some people have). But like I said, I find most people are bullheaded and you can't change their minds even when they are wrong (we see lots of people get killed making the same mistakes as others before them because they think they are too smart to mess up). Oh well whatever....I really don't care what any of you think anymore. I know that what I am saying is correct and backed up by professional practice standards and the basic underlying theories of respiratory care, and my ego is no more bruised by you disagreeing with me than yours is by my telling you that there's a better way to do it. The problem here is so much who is right and who is wrong (as their seems to be nothing technical wrong with administering O2 by demand valve to a patient who is breathing, just that there are some undesirable aspects to that approach) but rather personal insecurities on the part of a lot of the people who have responded to my posting here.


If you would like, contact me off list and I will photocopy the pages out of the book I am referencing on barotrauma (it specifically referenced damage to the alveolar-capillary membrane; the mechanism behind air embolism) and send them to you. Most medical libraries don't carry copies of Egan's for some reason.....but most hospital's respiratory therapy departments have a copy.

To each and to their own- just keep the demand valve off of me if I need O2; give me a NRB.

 

[TheAvatar]

See I think the demand reg system would be superior to a Non Rebreather or breathing patiens in a situation where you have a long transport and a small O2 supply Primary thought, when you only have a D or Jumbo-D and a 5 hour rescue to extricate, say, a incapacitated HAPE patient from a mountain. They do not teach these in EMT courses. They aren't really usefull for EMT-B or Is or Ps who have 10 minute transport times (or M cylinders in their rigs). I don't even know if they are in the scope of practive, but it definately has application for allowing increased O2 flow or extending O2 flow time in WEMT and DMT applications. Unless the patient has hyperpnea you are going to extend the life of an O2 cylinder at least 2-3X for highflow O2.

How much do these demand rigs cost?

 

[medic_diver45]

They start at around $250 each from what I have seen. But even is the patient has a normal minute ventilation (for the sake of argument lets say 10 L/min- the high end of normal) and you have a D tank (352 liters @ 2200 psi) that still is only going to extend that tank life to 35.2 minutes. Not much of an extension if you you really stop and look at it.

Compare that with:
Nasal Cannula at 4 liters (~36% oxygen)= 88 minutes
Nasal Cannula at 6 liters (~44%)= 58 minutes
Simple Face Mask at 8 liters (~50%)= 44 minutes
Simple Face Mask at 10 liters (~60%)= 35.2 minutes
Nonrebreather at 12 liters (~68-78%)= 29.3 minutes
Nonrebreather at 15 liters (~85-95% avg)= 23.46 minutes


I don't have any mountaineering experience (other than just the normal hiking up looking around and coming down) and correct me if I am wrong but don't people normally become tachypneic and hyperneic at altitude to compensate for the lower atmospheric PO2?

 

[medic_diver45]

Oh, and something else I thought of....just something to bear in mind. Most patients (DCS and air embolism patients being the major exceptions) do NOT need 100% O2. Actually we respiratory therapists tend to try to keep people on as little O2 as possible. The general rule of thumb (for when you don't have a pulse oximeter handy) is to titrate the oxygen to the lowest possible level that relieves the patient's shortness of breath. This can help extend the life of an O2 bottle. But when in doubt (or close to shore ) don't hesitate to put them on high flow O2.

 

[TheAvatar]

Lets say they have respirs of 15/min. Lets say they have a tidal volume of 0.5L. Minute volume is 7.5L. On these simple second stage demand masks they'd use 7.5LPM for close to 90-95% O2 (right?). Otherwise you get 15LPM for something like 95% O2 on a nonrebreather (right?). You've extended your O2 2X.

I don't have any mountaineering experience (other than just the normal hiking up looking around and coming down) and correct me if I am wrong but don't people normally become tachypneic and hyperneic at altitude to compensate for the lower atmospheric PO2?

They will definately breath faster and deeper to compensate for lower ppO2, tachypnea may not result though (unless they are exerting themselves, which may be the case in evacing certain patients when you don't have enough rescuers (or time) for a litter evac.

That aside, you can get all sorts, especially on the long evacs. Backboarded hypovolemic patients from trauma are much more common than having to evac someone with HAPE or AMS/HACE. High flow is a good thing ideally. An evac from 13000+ft isn't rare nor is a 14 hour technical evac. You may get a bonus because of the lower ambient pressure, but it might also be -20F and the tank was 2000psi at 70F.

The general rule of thumb (for when you don't have a pulse oximeter handy) is to titrate the oxygen to the lowest possible level that relieves the patient's shortness of breath.

Good SoP for anyone, but when you have sick/injured at 12000ft, I've heard of people not satting above 94 even with highflow.

 

[medic_diver45]

The reason I used a higher minute ventilation is simply because:
1. Murphy's law.....if you plan for the low end, the patient will end up being at the high end.

2. Most patients who are in frank distress (defined as sick enough to make it apparent to a lay person) are not breathing at 15 bpm. Respiratory rate is one of the first variables to change once the body senses something is wrong (along with heart rate). The problem is that most people don't pay that close of attention to RR.....most people when taking vitals guess this one.....

 

[TheAvatar]

Hijack: So I figure a respiration guy would know these phsyics: when a D cylinder is said to have 352L @ 2200psi (my book says 350L @ 2000psi) that means it contains enough gas to fill a volume of 352L. I assume that all of those values based on STP (20C 1ATM). Is that correct?

Edit: And if the flow rate dial on a portable O2 reg is set to a given value, is the actual flow rate affected by temperature or ambient pressure or does the regulator compensate for that?