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Thursday, March 29, 2012

Doc, what is a cryogenic burn?

 ( Liquid nitrogen burns, cryogenic liquid burns, liquid propane, hydrogen, methane, liquefied natural gas, aerosol sprays, R22 Chlorodifluromethane gas- air conditioner and refrigerant gas, liquid ammonia burns, frost bite, cold burns++…..)

Cryogenic liquids  are gases that are liquefied at very low temperatures and high pressures. In their liquid state they are extremely cold (-150 deg C) and small quantities of liquid can expand to large volumes of gas. When these liquids are converted to gases or vapors they condense the moisture in the air and create a visible fog. Some cryogenic liquids are flammable when converted to gas like: hydrogen, methane and liquefied natural gas, while others are inert like nitrogen, helium, neon, argon and krypton. Other cryogenic liquids include liquid ammonia, propane, aerosol sprays and R22 Chlorodifluromethane gas that is used in refrigerators and air conditioners. Cryogenic liquids are stored in special containers that are able to withstand varying temperature and pressure changes.
Cryogenic liquids are dangerous and should be handled with great care. They can cause injury due to their extremely low temperatures by producing skin and tissue changes similar to a thermal burn. The nature of the injury will depend on the temperature, time of exposure and the chemical constituent of the cryogenic liquid itself. The eye has delicate structures like the cornea which can get severely damaged by contact as well as by the cold vapours. Sudden contact with cryogenic liquids can cause the skin to stick to the metal that is cooled by the liquid and trying to pull away the skin can cause a skin tear. Another mode of injury occurs by breathing the cold gases and vapours which can cause lung damage. Small amounts of cryogenic liquid can turn into very large volumes of gas when warmed or released into air. These cold gases are heavier than air and displace the air thereby reducing the oxygen available to the victim who may then suffer from asphyxiation or oxygen deficiency which can be fatal especially in closed spaces. The chemical nature of the cryogenic liquid can itself add to the danger. Some of them are flammable like liquid oxygen and fires and explosions can result. Non combustible substances like carbon, cast iron, aluminium and steel can burn in the presence of liquid oxygen. Sudden change of temperatures and rapid expansions can lead to dangerous explosions and blast injuries.

When liquid propane is sprayed on the skin for 12 seconds epidermal damage or necrosis can occur. Similarly the spraying of aerosols on the skin for 20 seconds can result in temperature of -150 deg centigrade. The initial appearance depends on the depth of the burn and the cold temperatures reached and the time of exposure. Thus the burn may be superficial or deep and if deep may even extend to the underlying muscles and bone. For identifying the depth of burn please refer to our previous article: http://asktheburnsurgeon.blogspot.com/2009/11/1.html

Cold burns or frostbite must receive medical attention as early as possible. First aid treatment must be aimed at getting the temperature slowly back to normal. The victim must be first removed from the site of the accident to a safe zone and all tight clothing must be loosened. The burn area should be placed in tepid water (40-42 deg c) or one can pour tepid water over the area for about half an hour or till the skin returns back to pink or red color. Water temperatures above 45 deg c can itself cause a burn to the tissues and therefore direct heat or hot water must be avoided. Arrangement should be made to shift the patient to the nearest casualty department. If a large area of the body has been exposed to the cold injury then hypothermia or lowered body temperature may result which can be fatal. The body needs to be rewarmed without much delay. One can place the patient in a warm water bath (40-42 deg C). Monitoring the patient is important as shock or circulatory failure may result. As the frozen tissues are thawed, cellular disruption, swelling and edema can occur. Analgesics should be given to avoid pain and antibiotics must be added to decrease the chance of infection. The burn wound from a cryogenic liquid will have to be treated like a thermal burn wound.
Here we present a cryogenic burn from liquid nitrogen suffered by one of our readers Mr Carlos Martinez . The events that followed over 4-5 weeks have been described in detail by Mr Carlos. We hope that this story will be helpful to our readers in handling such unusual burns.

Week one..
Mr Carlos wrote....
Dear doc,
I was testing a Nitrogen system a couple of days ago and got into a pool of it with both my feet for a few minutes. I thought there was only gas but it was actually liquid Nitrogen. When I felt some pain I jumped out of it and couldn't make a clear assessment to what happened. After a couple of minutes of walking (I was only wearing socks) a sudden shock of pain hit me. It was excruciating. I felt dizzy and almost passed out. We searched what to do on the Internet but couldn't find anything related with this extreme cold, only frostbite. I put my feet in warm water waiting for the doctor to arrive.

He told me he hoped it was only a superficial wound but it remained to be seen after 24 hours. We waited. The result is clear and you can see it in the attached pictures. After a bit more than a day, the doctor excised most of the blisters, since more were not fully formed and treated the wound with a closed dressing, using a sterile gauze soaked with Argentafil. Pain was bearable now, especially after the excision. The day after, he removed the dressing and, in some small spots, it adhered to the profusely exuding wound that's been moist since skin removal and is still exuding clear and fresh serum. More blisters are forming slowly in places where everything seemed OK. He removed more skin today and dressed the wound with Acticoat after immersing the film in sterile water for two minutes, added a pad of gauze to keep it in place and a larger and thicker apposite of gauze and cotton. The wounds (sorry, both feet were burnt but with very different sizes of wounds) are still exuding clear serum through the Acticoat dressing. He also brought a different film from a different manufacturer. He wants to try it after nine days (when Acticoat is used completely).

The pain after removing the first dressing was huge where I felt it sort of adhered to the wound, and it happened on both feet. The dermis underneath is pink or reddish. There is more skin to be removed, maybe some 10% of the whole wound, especially the very edges of it that go about 1cm above the sides of the soles that are just starting to blister.
That's the story, now the questions:
My doctor is not a traumatologist or dedicated to burn patient but has treated a lot of diabetic foot wounds (smaller ones). Should I find a specialist?
He's a good surgeon and did the job really fast since the first day. Is he doing the right treatment?
As for healing: will it be 3 to 4 weeks to recover functional skin on my feet. (this I ask because of the super intense stress our feet are subject to)
Should I do anything else?
How can I minimize the intense pain from dressing removal? (I am concerned because I feel I'm passing out when the procedure is done)
Thanks a lot for being there for us and your time for reading this. I suppose there's a lot to be said on cryogenic burns since the Internet (and most physicians) know very little about them.

Best Regards,
Carlos M. Martinez

asktheburnsurgeon replies.....
Dear Mr Carlos,
Thank you very much for your letter. I am sorry to hear you had a burn. What you have is a like a frostbite or a cold burn that is similar to a thermal burn. Since liquid nitrogen is at very low temperature the burn can be a deep one. The back of the heel appears to be on the deeper side. the one on the side appears to be less deep. You are lucky that the area is small. Blistering usually is a sign of a superficial 2nd degree burn.
About your concerns here are a few points: your doc is doing fine. Continue with the debridements as and when required. Continue with you dressings as is being done. If the pain is not very severe then regular pain killers may be adequate, but if the pain is severe while the dressing is done, your doc may give you some intravenous medications. If signs of infection are found then an antibiotic may be needed. Check out our article: http://asktheburnsurgeon.blogspot.com/2010/01/management-of-2nd-degree-superficial.html
for the basics of wound care and pain management. The back part of the heel burn which now appears to be red needs a good follow up. and if it appears to be really deep then you may need a skin graft there. Still the heel skin is quite thick, as compared to the skin of the other areas of the body, so keep you fingers crossed and pray that the wound may heal without the need for any surgery. We will have to wait and continue with the present treatment till the depth of the burn manifest itself over time. Burn healing takes time!!
best regards

week 2..
Carlos Martinez writes again....
Dear doc,
Thanks a lot for your response. Tomorrow I'll go through surgical removal of dead skin and debridement. We'll replace the Acticoat dressing.
I have a couple more questions:
One of my toes has a blister but everything seems evolving as a normal second grade burn: should we remove all the skin there or just let it drain and treat it as a small wound?
Second: can Aquacel AG do the function of Acticoat for 14 days? We read that Aquacel can be doing its job as it gets integrated with the fluids and is not necessary to have dressing removals every four days as with Acticoat.
I infer it's a better strategy to cause less trauma to the wounds on every redress and it avoids going under anesthesia so often.
I'll keep you posted and I'll pray for the heel wound not to evolve badly. Personally I really appreciate your words and concern for my case. I should've been a Doctor myself! I've done this so many times for others and feel a bit lost when it comes to myself!
Best regards and 1000 thanks again,

asktheburnsurgeon replies....
dear Carlos,
thank you very much for keeping me updated. It is nice to know that you are doing fine.

Aquacel is a hydrofibre dressing that is highly absorbent and locks in exudate and at the same time provides a moist environment for wound healing .While Aquacel Ag is  the same but has silver ions impregnated in them that gives an additional antimicrobial activity.
Acticoat consist of Silver coated high density polyethylene meshes designed to be barriers against microbial infection of a wound. It also has a Rayon/polyester absorbent inner core which helps to maintain the moist environment that can facilitate wound healing. The silver provides additional antimicrobial activity.

 The small blisters can be punctured or slit open to let the fluid out as other wise with the blisters getting tense pain can result. Keeping a burn wound closed for a long time is not a good idea especially if its deep. If there is a lot of oozing of serous fluid, the whole wound and skin around can get very soggy and may even get infected. Besides you don’t even know whats going on down in the wound. So changing the dressing at least by 3 or 4 days should be a better idea in your case.
best regards,
asktheburnsurgeon +

week 3..
Mr Carlos writes again....
Dear doc,
Thanks a lot for the input. I'm sending you some other photos as of the day before yesterday. Tomorrow, all Aquacel AG will be replaced. There are no odors or strange smells, just a small bleeding spot at the very bottom of the right heel. The instructions in the Aquacel AG say they should be left on for three days at the beginning, and when the wound seems to be re-epithelizing, the dressings could be left for up to 14 days. Should we change dressings every 2-3 days? Is the bleeding spot strange? My surgeon seems to be pretty happy with the evolution, but I'm concerned about that spot and now about the dressings! The wounds have been progressively drying as new skin grows, there are only small spots of still-fresh wounds that were revealed a couple of days ago after removing the remaining blistered skin. It seems that the silver coming from the dressings keeps the infections at bay, but I don't want to risk it all just to that idea, even when the left foot wound has evolved amazingly well.
Thanks a lot again for your time and input!
Hope the photos come in handy to better assess the injury.

asktheburnsurgeon replies..
dear Carlos,
thank you very much for your letter. I am glad to know that you are doing well. As new epithelium forms sometimes you can get small bleeding since the capillaries are also newly forming- these being delicate can easily bleed, especially when you are changing the dressing. As the wound gets better and as the fluid discharge from the wound decreases the Aquacel Ag dressing can be kept for a longer time. The silver ions help the combat the microorganisms causing infection.
With best regards,

week 4....
Carlos Martinez writes again...
Dear doc,
I feel really blessed, indeed. Every thing's dried up and new skin is almost everywhere. No more fluids at all, except for a small bleeding from a blood scar a few days ago: clear and iron smelling red stuff. There are just two very small spots with these kind of scars. I'm working on stretching the new skin and using light pressure to make it more supple.
I do thank God for all these things and for all the people who have been helping me with their support, their knowledge and their commitment. I must give back a lot after this thing ends. My sight is on the 7th floor of our Civil Hospital. It's the Burn Center for Children. I owe you at least three. I'll send in the pics after Friday's assessment. I hope they'll be good news. I just can't go tiptoeing forever!
Thanks a lot again!

asktheburnsurgeon replies...
Dear Carlos,
Thanks for the update.
You seem to be doing fine by God's grace.
Change the dressing more frequently if the discharge is too much or smelly.
Besides that, we have to wait and watch the healing process.
best regards,

week 4....
Carlos writes again...
dear doc,
I'm still tiptoeing, since my toes were just little less than scalded -and just a couple of them, both balls of my feet are healthy: I can go to the washroom and take a shower without much fuss.
What I don't have the slightest idea about is how to assess when should I try to put my weight on the much more damaged heels and the right side of the right foot... I feel there's still some scar tissue to come out on itself and new epithelium to emerge, but these spots are the ones that feel pretty tight still.
Tomorrow will be the most revealing day, I hope. I'll keep you posted and have my fingers still crossed and lots of people praying for me... I'm trying to bounce these to the thousands who suffer terrible wounds everyday.
And... thanks again!

week 4 …
asktheburnsurgeon replies....
dear Carlos,
good to hear you are feeling and doing fine. praise God!!
burn wound healing always takes time and one must have patience.
let the burn areas heal completely before you try exercising as the new delicate skin may break up and avoid any weight bearing on the healing areas.
best wishes,

 week 5.....
Carlos writes again....

Dear doc,
here's how the wound feels presently:
1. itchy if scabbing (very tolerable)
2. Extremely sensitive to the touch or dressing contact (sort of a cautionary pin-point pain spot) on the very edge of the heels and the larger tender (or scab) spot there
3. There are some spots that are almost insensitive but with good blood flow on two toes
4. I've been exercising by flexing both feet and now everything seems looser, except for the tight spots where scabbing occurred.
Just one more question: how long can it take the skin to bear weight?
Cheers and thanks again!

week 5..
asktheburnsurgeon replies....
Dear Mr Carlos,
Thank you very much for the mail and keeping me updated. You seem to have done very well by God's grace. I was worried in the beginning since cryogenic burns can be deep and some of the ones i have treated needed skin grafting !!
To answer your question about weight bearing:
Once the wounds have healed, avoid direct weight bearing for two weeks.
Then gradually start bearing some weight on the foot. see how its going and then gradually increase the weight bearing. If the skin starts to break down or appears unhealthy avoid this. Usually it takes about 6 weeks before one can be back to being completely normal.
best regards,
asktheburnsurgeon+ ++

week 1- liquid nitrogen burns, heel, foot burns (cryogenic burns,
cold burn, frost bite)

week 1- liquid nitrogen burns, heel, foot burns (cryogenic burns,
cold burn, frost bite)

week 2- liquid nitrogen burns, heel, foot burns (cryogenic burns,
cold burn, frost bite)

week 2- liquid nitrogen burns, heel, foot burns (cryogenic burns,
cold burn, frost bite)


week 3- liquid nitrogen burns,  acquacel dressing (cryogenic burns,
heel, foot burns, cold burn, frost bite)

week 5- healed liquid nitrogen burns, heel, foot burns
(cryogenic burns, cold burn, frost bite)

week 5- healed liquid nitrogen burns, (cryogenic burns,
heel, foot burns, cold burn, frost bite)

week 5- healed liquid nitrogen burns, (cryogenic burns,
cold burn, frost bite)

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