JamesK
Contributor
LMAO!!! 
Ummm, all three!
Thanks, I'll be safe.
Ummm, all three!Thanks, I'll be safe.
Scuba Nitrox vs. Nitrous at the dentist office?
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JT2
Guest
Hey JamesK, I don't know if you are aware of it or not, but the Nitrous used to refill bottles for use in automotive systems has sulphur added t it, and you don't want to breathe it, they started adding sulphur to it back in about 1990 or so. There are a few folks out there who manage to get fills with medical grade nitrous, but they are few and far between. Nitrous Express, which is the biggest nitrous oxide system manufacturer next to NOS is located here in my home town, and if you are into nitrous for use on you hotrod you should check out their website, they have some really cool new stuff...
JamesK
Contributor
The nitrous that I use has no sulphur added. The shop I get it from buys medical grade nitrous. I guess they like to get silly sometimes! lol..
I know all about nitrous express. Great Stuff. I have used some of their products. I mainly use NOS, and have been using them for about 3 years.
I know all about nitrous express. Great Stuff. I have used some of their products. I mainly use NOS, and have been using them for about 3 years.
The Iceni
Medical Moderator
Just read this thread and the very comprehensive and informative post by Dr Stein.
Correct me if I am wrong, but I think the nitrous used to enhance engine performance is straight nitrous oxide, not the 50:50 mixture of oxygen and nitrous oxide for medical use. I suspect that 50% oxygen would be very dangerous indeed if it got anywhere near a carburetta!!! Very sensible for this nitrous to contain foul-tasting sulhurous component since if it contains no oxygen it will kill. This is why town gas (natural gas from the North sea) still has an odour added. (In the past it was coal gas containing odourless carbon monoxide and we all know how dangerous that is!). Nowadays gas oven cannot so ealily be used for suicides
Entonox (50:50) is widely used in the immediate care environment and it is relatively safe and cheap (compared with other medical treatments) at about $50 a bottle. The DV cost me about $200.
As my professional interests are immediate care and obstetrics I have used it quite a lot, mostly in uncomplicated obstetric cases on our GP obstetric unit.
I also carry a BOC "D" cylinder of 50/50 entonox fixed to its regulator in a blue bag in the back of my Jeep Grand Cherokee -
not to the engine!!
Nor do I have electically contolled pneumatic suspension nor a light under the differential!
My portable oxygen, with a simlar DV, is in an identically shaped but differently coloured black and white bag. The two cylinders are also identical but similarly colour-coded and the valves have a pin index to prevent incorrect cylinder attachement - as in the operating rooms of hospitals.
By the way, in winter, entonox has to be shaken (not stirred) to mix it before it is used because the gasses separate out in the cold. The nitrous oxide component being heavier than oxygen. It may even liquify while oxygen does not. The risk is that depending on the orientation of the equipment you may be giving 100% oxygen at first - with no analgesic effects until it runs out when you are left with nitrous oxide alone. VERY hazardous indeed! (The reverse could also occur, of course.)
In a nutshell, entonox has no role whatsoever in the treatment of diver casualties. It does make DCI, AGE or pneumothoraces (pulmonary barotrauma) worse because of the inevitable N2O on-gassing pressure gradient of 0.5 bar/zero.
A question for Dr Stein.
Do you know if N2O can be converted to nitric oxide (NO) in the brain? NO is a recognised neurotransmitter. If so, its the effects may be biochemical as well as an inert gas effect.
Correct me if I am wrong, but I think the nitrous used to enhance engine performance is straight nitrous oxide, not the 50:50 mixture of oxygen and nitrous oxide for medical use. I suspect that 50% oxygen would be very dangerous indeed if it got anywhere near a carburetta!!! Very sensible for this nitrous to contain foul-tasting sulhurous component since if it contains no oxygen it will kill. This is why town gas (natural gas from the North sea) still has an odour added. (In the past it was coal gas containing odourless carbon monoxide and we all know how dangerous that is!). Nowadays gas oven cannot so ealily be used for suicides
Entonox (50:50) is widely used in the immediate care environment and it is relatively safe and cheap (compared with other medical treatments) at about $50 a bottle. The DV cost me about $200.
As my professional interests are immediate care and obstetrics I have used it quite a lot, mostly in uncomplicated obstetric cases on our GP obstetric unit.
I also carry a BOC "D" cylinder of 50/50 entonox fixed to its regulator in a blue bag in the back of my Jeep Grand Cherokee -
not to the engine!!
Nor do I have electically contolled pneumatic suspension nor a light under the differential!
My portable oxygen, with a simlar DV, is in an identically shaped but differently coloured black and white bag. The two cylinders are also identical but similarly colour-coded and the valves have a pin index to prevent incorrect cylinder attachement - as in the operating rooms of hospitals.
By the way, in winter, entonox has to be shaken (not stirred) to mix it before it is used because the gasses separate out in the cold. The nitrous oxide component being heavier than oxygen. It may even liquify while oxygen does not. The risk is that depending on the orientation of the equipment you may be giving 100% oxygen at first - with no analgesic effects until it runs out when you are left with nitrous oxide alone. VERY hazardous indeed! (The reverse could also occur, of course.)
In a nutshell, entonox has no role whatsoever in the treatment of diver casualties. It does make DCI, AGE or pneumothoraces (pulmonary barotrauma) worse because of the inevitable N2O on-gassing pressure gradient of 0.5 bar/zero.
A question for Dr Stein.
Do you know if N2O can be converted to nitric oxide (NO) in the brain? NO is a recognised neurotransmitter. If so, its the effects may be biochemical as well as an inert gas effect.
Laurence Stein DDS
Medical Moderator
Dear Doc P,
I don't know if N2O splits to NO+N in the brain. I know that the nitrous oxide is exhaled as the same gas as is inhaled. I don't know if there have been studies with isotope "tagged" N to see if it recombines and the molecules going in are exactly the same as the molecules going out. Nor do I know if NO is present within the biologic system and is active. Wouldn't the presence of NO possibly lead to the formation of nitric acid (HNO3)?
My understanding is, that it is the nitrogen from the nitrous oxide that causes the analgesic/anesthetic effect. Scubadoc recently posted a thread which mentioned the name of a theory that links the nitrogen to this effect and is also responsible for the narcosis that occurs at depth.
Is it true that years ago patients in labor were allowed to "self medicate" with nitrous oxide? She would hold a mask on her face during contractions and when she got deep enough, the mask dropped off her face. Sounds risky to me.
At the office, the nitrous oxide supply is in large cylinders. It is liquid under pressure, at room temperature. It actually causes a problem because the tank will read full right up to the time all the liquid has vaporized, then the tank goes empty fairly rapidly. The oxygen, on the otherhand is simply compressed gas and there is a pressure change we can measure and determine if the tank is nearly empty. Fortunately, there is a required "fail safe" valve on the manifold. No gas can be administered without O2 pressure keeping the circuit for the nitrous oxide open. Hospital anesthetic machines don't necessarily have this safety feature--at least not way back when I was passing gas during my residency.
A lot of the old McKesson machines were like this. Perhaps, standards have changed in hospitals now.
This Entonox stuff actually sounds kind of scary--I've had patients react to 50/50 N2O/O2 with panic. Although, under circumstances of great anxiety or pain, it takes more nitrous for a given effect. The longer the gas is administered, the lower the concentration that is needed for anxiety control--at least in the dental setting.
Following the administration of nitrous oxide/oxygen, it should be "flushed" with pure O2 because the nitrous oxide exchanges so rapidly, it can theoretically cause hypoxia by offgasing faster than room air can carry it away.
Until I read this thread, I always thought that nitrous oxide--medical grade, was used in racing. It's a good idea to "odorize" it. The same thing is done to propane and natural gas (methane, I believe) to make it presence noticable. It is not mixed with oxygen first.
BTW, you sound worse than me--I carry my own O2 on the boat with my buddies. I also carry a spare radio, GPS, EPIRB, flares, a "handheld antipirate device" (not usually available in the UK) and an inflatable life preserver. There is the bag with an entire extra scuba set-up and a save-a-dive kit that can rebuild a reg. Throw in my "medical/first aid kit and people start throwing "stuff" off the boat. I don't even own a boat--instead 5 of my buddies have them--so why bother! (maybe I need a "spare"). Actually, I'm a believer in self extracation. I won't usually trust that others will have something I may need to solve a problem. You wouldn't believe how many times my GPS was the only working one on the boat! We have sunk a number of 55 gal steel drums with the "antipirate" device--hazards to navigation. On trips to Bimini from Miami, we usually carry several, "longer" antipirate devices--they are documented in customs and there is no problem. It takes about 1 hr on a good day to cross the Gulf Stream to Bimini.
So, in answer to your simple question--I don't know! Enjoyed the thread though.
Larry Stein
I don't know if N2O splits to NO+N in the brain. I know that the nitrous oxide is exhaled as the same gas as is inhaled. I don't know if there have been studies with isotope "tagged" N to see if it recombines and the molecules going in are exactly the same as the molecules going out. Nor do I know if NO is present within the biologic system and is active. Wouldn't the presence of NO possibly lead to the formation of nitric acid (HNO3)?
My understanding is, that it is the nitrogen from the nitrous oxide that causes the analgesic/anesthetic effect. Scubadoc recently posted a thread which mentioned the name of a theory that links the nitrogen to this effect and is also responsible for the narcosis that occurs at depth.
Is it true that years ago patients in labor were allowed to "self medicate" with nitrous oxide? She would hold a mask on her face during contractions and when she got deep enough, the mask dropped off her face. Sounds risky to me.
At the office, the nitrous oxide supply is in large cylinders. It is liquid under pressure, at room temperature. It actually causes a problem because the tank will read full right up to the time all the liquid has vaporized, then the tank goes empty fairly rapidly. The oxygen, on the otherhand is simply compressed gas and there is a pressure change we can measure and determine if the tank is nearly empty. Fortunately, there is a required "fail safe" valve on the manifold. No gas can be administered without O2 pressure keeping the circuit for the nitrous oxide open. Hospital anesthetic machines don't necessarily have this safety feature--at least not way back when I was passing gas during my residency.
A lot of the old McKesson machines were like this. Perhaps, standards have changed in hospitals now.
This Entonox stuff actually sounds kind of scary--I've had patients react to 50/50 N2O/O2 with panic. Although, under circumstances of great anxiety or pain, it takes more nitrous for a given effect. The longer the gas is administered, the lower the concentration that is needed for anxiety control--at least in the dental setting.
Following the administration of nitrous oxide/oxygen, it should be "flushed" with pure O2 because the nitrous oxide exchanges so rapidly, it can theoretically cause hypoxia by offgasing faster than room air can carry it away.
Until I read this thread, I always thought that nitrous oxide--medical grade, was used in racing. It's a good idea to "odorize" it. The same thing is done to propane and natural gas (methane, I believe) to make it presence noticable. It is not mixed with oxygen first.
BTW, you sound worse than me--I carry my own O2 on the boat with my buddies. I also carry a spare radio, GPS, EPIRB, flares, a "handheld antipirate device" (not usually available in the UK) and an inflatable life preserver. There is the bag with an entire extra scuba set-up and a save-a-dive kit that can rebuild a reg. Throw in my "medical/first aid kit and people start throwing "stuff" off the boat. I don't even own a boat--instead 5 of my buddies have them--so why bother! (maybe I need a "spare"). Actually, I'm a believer in self extracation. I won't usually trust that others will have something I may need to solve a problem. You wouldn't believe how many times my GPS was the only working one on the boat! We have sunk a number of 55 gal steel drums with the "antipirate" device--hazards to navigation. On trips to Bimini from Miami, we usually carry several, "longer" antipirate devices--they are documented in customs and there is no problem. It takes about 1 hr on a good day to cross the Gulf Stream to Bimini.
So, in answer to your simple question--I don't know! Enjoyed the thread though.
Larry Stein
The Iceni
Medical Moderator
Hi larry,
Pretty primitive here in the UK, heh? We still allow some of our pregnant ladies to have normal deliveries and Entonox is widely, if not routinely, used as you described - but it is pre-mixed in large cylinders AT ROOM TEMPERATURE so it is quite safe. (The CS rate is rapidly increasing though.)
I contributed to the thread you mentioned but cannot remember the title. Basically the Meyer-Overton priciple states that the anaesthetic properties of an inert gas are determined by its molecular weight and lipid/aqueous solubility. The Mol wt of N2O = 44, whereas that of nitrogen N2 = 32. Xenon is much heavier and is a general anaesthetic at lower than atmospheric partial pressures.
I very much doubt that Nitric acid is formed in the body so there can be little dissociation of the N2O molecule. I do think I read somewhere that nitric oxide is a natuaral neurotransmitter, perhaps I am confusing this with another oxide of nitrogen NO2???
Dr Deco will know, I am sure.
Sounds like the Entonox is the evolution of the Nitronox - our unit actually used two "E" cylinders (one 100% O2 and one 100% N2O) and had a mixing unit. There were several contraindications that we were trained with (realize that this was in 1979):
1. Any trauma (especially respiratory, like a pneumo, hemo, flail, etc.) where the administration of 100% O2 was indicated.
2. Any patient with decreased perfusion for whatever reason.
3. Any head injury
We only used it for isolated trauma, such as extremity fractures with no shock, etc. Using the above criteria, the field use of nitrous oxide would be contraindicated for any DCS emergency (since 100% O2 was indicated).
It never caught on in the area since it was restrictive in it's use, costly (unit was several thousand $$$) and large size (case holding mixing unit and two cylinders). We pulled the only unit we had around 1981, I still have it in my barn out back with some old red lights, sirens, and other antique EMS/Police stuff. Went and looked at it, the hydro's went out in 1983!
1. Any trauma (especially respiratory, like a pneumo, hemo, flail, etc.) where the administration of 100% O2 was indicated.
2. Any patient with decreased perfusion for whatever reason.
3. Any head injury
We only used it for isolated trauma, such as extremity fractures with no shock, etc. Using the above criteria, the field use of nitrous oxide would be contraindicated for any DCS emergency (since 100% O2 was indicated).
It never caught on in the area since it was restrictive in it's use, costly (unit was several thousand $$$) and large size (case holding mixing unit and two cylinders). We pulled the only unit we had around 1981, I still have it in my barn out back with some old red lights, sirens, and other antique EMS/Police stuff. Went and looked at it, the hydro's went out in 1983!
The Iceni
Medical Moderator
Hi again larry,
I gather NO is found in the brain and acts as an inhibitory neurotransmitter, and it is poisonous when inhaled.
I imagine the following reaction is theoretically possible with sufficient N2O and a suitable enzyme.
2(N2O) + O2 = 4(NO).
I understand that in the past certain navies used nitrous oxide to prepare their student divers for the effects of narcosisis. :goofy:
I gather NO is found in the brain and acts as an inhibitory neurotransmitter, and it is poisonous when inhaled.
I imagine the following reaction is theoretically possible with sufficient N2O and a suitable enzyme.
2(N2O) + O2 = 4(NO).
I understand that in the past certain navies used nitrous oxide to prepare their student divers for the effects of narcosisis. :goofy:
Laurence Stein DDS
Medical Moderator
Dr. P
Do you work all night...er, rather, do you ever sleep? I signed on at nearly 11 PM Eastern Daylight Time and you were on. I couldn't send a private message--no address on your personal info page.
I really love the differences in spelling when you use the Queen's English compared to us Anglos, "across the pond", eg. odour for odor, anaesthetic for anesthetic and carburetta for carburetor.
BTW, I do, indeed seem to experience the same effect of N2O as narcosis. I don't do well on the gas, however. It can nauseate me--even at low concentrations. I've never had a patient get sick though. I still ask that they are NPO before administration.
Narcosis has never nauseated me.
Regards,
Larry Stein
Do you work all night...er, rather, do you ever sleep? I signed on at nearly 11 PM Eastern Daylight Time and you were on. I couldn't send a private message--no address on your personal info page.
I really love the differences in spelling when you use the Queen's English compared to us Anglos, "across the pond", eg. odour for odor, anaesthetic for anesthetic and carburetta for carburetor.
BTW, I do, indeed seem to experience the same effect of N2O as narcosis. I don't do well on the gas, however. It can nauseate me--even at low concentrations. I've never had a patient get sick though. I still ask that they are NPO before administration.
Narcosis has never nauseated me.
Regards,
Larry Stein
The Iceni
Medical Moderator
Larry,
I've tried many times to switch on the private message handler in order to send private messages such as this one and perhaps the last one, without success.
Please email me paul@gippingvalleypractice.co.uk to tell me how to do it, as I'm sure the readers are fed up with much of this esoteric stuff!
Yes, a bit of a workaholic. Nowadays, if I have to deal with an emergency (even just a phone call) at 2 am I often find it difficult to get back to sleep - hence my odd times on the forum!
Tah!
Yes, Randyjoy.
I suppose as our NHS paramedics only get 6 weeks full-time threoretical training the powers that be consider it safer to use than any conotrolled drug.
I've tried many times to switch on the private message handler in order to send private messages such as this one and perhaps the last one, without success.
Please email me paul@gippingvalleypractice.co.uk to tell me how to do it, as I'm sure the readers are fed up with much of this esoteric stuff!
Yes, a bit of a workaholic. Nowadays, if I have to deal with an emergency (even just a phone call) at 2 am I often find it difficult to get back to sleep - hence my odd times on the forum!
Tah!
Yes, Randyjoy.
I suppose as our NHS paramedics only get 6 weeks full-time threoretical training the powers that be consider it safer to use than any conotrolled drug.
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