EMTLife.com - The #1 Online Forum for EMS-Related Discussion  

Go Back   EMTLife.com - The #1 Online Forum for EMS-Related Discussion > Main EMS Forum > BLS Discussion

BLS Discussion For all that fun stuff specifically related to basic life support.

Reply
 
Thread Tools Search this Thread Display Modes
Old 03-11-2011, 09:50 AM   #1
JOgershok
Forum Probie
 
JOgershok's Avatar
 
Join Date: Mar 2011
Location: Pennsylvania
Posts: 11
Training: EMT-Basic
Send a message via AIM to JOgershok Send a message via Skype™ to JOgershok
Science behind occlusive dressings


Where do I find the "science" behind 3 sided vs. 4 sided occlusive dressings?

My state protocol is tape 3 sides and the military TCCC is 4 sided occlusion with needle decompression.

Does it really "burp" when an Asherman is used or does it just clog with clotted blood?


JOgershok is offline   Reply With Quote

Old 03-11-2011, 09:54 AM   #2
TransportJockey
Community Leader Emeritus
Community Leader Emeritus
 
TransportJockey's Avatar
 
Join Date: Dec 2007
Location: TX/NM
Posts: 5,856
Training: FP-C, NRP
THe three sides is so you can burp it. Our protocol says three sided, but I usually will dart the chest and tape on all four.
__________________
N. Zecco
FP-C #003175, NRP, NM & TX EMT-P
"EMS does not save lives, EMS is to care for people. It is 95% of what we do."
Quote:
Originally Posted by usalsfyre
TransportJockey as my partner sound like it would be made of win smothered in awsomesauce...
Stretcher Monkey Photography
TransportJockey is offline   Reply With Quote
Old 03-11-2011, 10:38 AM   #3
JOgershok
Forum Probie
 
JOgershok's Avatar
 
Join Date: Mar 2011
Location: Pennsylvania
Posts: 11
Training: EMT-Basic
Send a message via AIM to JOgershok Send a message via Skype™ to JOgershok
Quote:
Originally Posted by jtpaintball70 View Post
THe three sides is so you can burp it. Our protocol says three sided, but I usually will dart the chest and tape on all four.
What you told me is what I have been told countless times, I am looking for the science behind it. Although my protocols no longer metion "burping", you telling me to do it does not get me off the hook. I would still need medical command to authorize it or get a paramedic with a needle. (Actually the three sided concept is to creat a one way valve.)

Compression only CPR and other changes in CPR are based upon science not just antidotal observations.

Thanks.
JOgershok is offline   Reply With Quote
Old 03-11-2011, 10:46 AM   #4
TransportJockey
Community Leader Emeritus
Community Leader Emeritus
 
TransportJockey's Avatar
 
Join Date: Dec 2007
Location: TX/NM
Posts: 5,856
Training: FP-C, NRP
Quote:
Originally Posted by JOgershok View Post
What you told me is what I have been told countless times, I am looking for the science behind it. Although my protocols no longer metion "burping", you telling me to do it does not get me off the hook. I would still need medical command to authorize it or get a paramedic with a needle. (Actually the three sided concept is to creat a one way valve.)

Compression only CPR and other changes in CPR are based upon science not just antidotal observations.

Thanks.
As I understand the science behind it, if it's an open chest wound and you seal it on all sides you have essentially created a place for a tension pneumo to form. Burping the dressing will allow the air to escape just like it would if you darted the chest.
I have read a few studies on it, and if they're not posted by Sunday when I get home, I'll look them up. I can't look them up currently on my phone.
EDIT: Can't say anything about commercial chest seals, as all we use here are standard petroleum gauze or just something like plastic wrap.
__________________
N. Zecco
FP-C #003175, NRP, NM & TX EMT-P
"EMS does not save lives, EMS is to care for people. It is 95% of what we do."
Quote:
Originally Posted by usalsfyre
TransportJockey as my partner sound like it would be made of win smothered in awsomesauce...
Stretcher Monkey Photography

Last edited by TransportJockey; 03-11-2011 at 10:47 AM.
TransportJockey is offline   Reply With Quote
Old 03-11-2011, 11:15 AM   #5
JOgershok
Forum Probie
 
JOgershok's Avatar
 
Join Date: Mar 2011
Location: Pennsylvania
Posts: 11
Training: EMT-Basic
Send a message via AIM to JOgershok Send a message via Skype™ to JOgershok
Quote:
Originally Posted by jtpaintball70 View Post
I have read a few studies on it, and if they're not posted by Sunday when I get home, I'll look them up. I can't look them up currently on my phone.
EDIT: Can't say anything about commercial chest seals, as all we use here are standard petroleum gauze or just something like plastic wrap.
Sweet. It is the studies for which I am searching.
JOgershok is offline   Reply With Quote
Old 03-11-2011, 11:34 AM   #6
systemet
Forum Asst. Chief
 
Join Date: Feb 2011
Posts: 816
It's about pressure. Boyle's law, if you think about it. Pressure is inversely proportional to volume.

As you inhale, your ribcage expands. It's volume becomes larger, hence the pressure in the lungs (or for that matter the thoracic cavity) becomes lower relative to the external environment. Air will flow from regions of high pressure to low pressure. This drives everything from weather systems to breathing.

The air on the outside of the body is now at a higher pressure relative to the air inside the chest. So air flows through the pharynx, larynx, trachea, bronchi, broncioles into the alveoli, filling the lungs. Until the respiratory muscles relax, and passive elastic recoil causes the size of the thoracic cavity to shrink, pressure in the chest to go up, and air to be exhaled to the now relatively lower pressure external environment.

Now that's in the normal situation. Of course, if you then go and punch a hole in the rib cage into the pleural space or further, when the pressure in the chest goes down, air has two ways to flow into the thoracic cage. It has the nice / good pharnyx/larynx/trachea/bronchi/bronchioles/alveoli that gets pulmonary gas exchange going and keeps us happy and pink, and it has the easier option of just going through the big hole in the chest, where it's highly unlikely to end up too close to too many respiratory exchange surfaces. Generally, the larger the hole in the chest, and the more air moving through it, the greater the problem.

So by sealing off the sucking chest wound, we're getting rid of this alternate route for air to get into the thoracic cavity. This is good.

The problem comes when the knife, bullet, fencepost, crossbow, lamprey, or swordfish has also punched a nice hole into the lung. If we now close off the surface of the chest, we have the potential for a pneumothorax to form. When we exhale, and the pressure in the chest goes up, there's a chance that some of that air is going to go through the hole in the lung, and end up in the pleural space or the mediastinum. This can potentially lead to a pneumothorax.

The idea behind a three-way dressing is that it should open when the patient exhales, preventing air from accumulating in the pleural space, by allowing it to leave but close when the patient inhales, preventing air from entering the pleural space from outside the body.

Patients with a sucking chest wound are going to end up with a chest tube in the ER. The idea behind burping the wound is simply that if you're going to decompress to relieve a tension, or you suspect the patient is developing a pneumothorax, if there's already a great big hole in the chest that you've covered up -- perhaps opening this hole is going to allow you to vent the extra pressure. There's definitely a potential for the wound to clot. It's going to depend on the size.

A lot of people just cover the wound on all four size out of habit, and get away with it because the chance of developing a tension pneumo in the relatively short transport times most EMS providers have is fairly small. Covering the wound also becomes less important if you have the patient intubated, and you're doing PPV, in contrast to the body's physiologic negative-pressure ventilation.
systemet is offline   Reply With Quote
Old 03-11-2011, 11:44 AM   #7
systemet
Forum Asst. Chief
 
Join Date: Feb 2011
Posts: 816
Here's a couple of case series here describing the use of the Asherman chest seal.

Case series (n=2)
http://www.ncbi.nlm.nih.gov/pmc/arti...v019p00590.pdf

Allison K, Porter KM, Mason AM. Use of the Asherman chest seal as a stabilisation device for needle thoracostomy. Emerg Med J. 2002 Nov;19(6):590-1.

Another case series here, in the hospital,

http://icvts.ctsnetjournals.org/cgi/reprint/6/6/691
systemet is offline   Reply With Quote
Old 03-11-2011, 12:00 PM   #8
JOgershok
Forum Probie
 
JOgershok's Avatar
 
Join Date: Mar 2011
Location: Pennsylvania
Posts: 11
Training: EMT-Basic
Send a message via AIM to JOgershok Send a message via Skype™ to JOgershok
Quote:
Originally Posted by systemet View Post
Here's a couple of case series here describing the use of the Asherman chest seal.

Case series (n=2)
Allison K, Porter KM, Mason AM. Use of the Asherman chest seal as a stabilisation device for needle thoracostomy. Emerg Med J. 2002 Nov;19(6):590-1.

Another case series here, in the hospital, xxxxxx
This IS the kind of information for which I am making this inquiry.

Last edited by JOgershok; 03-11-2011 at 12:13 PM. Reason: Spelling
JOgershok is offline   Reply With Quote
Old 03-11-2011, 12:01 PM   #9
JOgershok
Forum Probie
 
JOgershok's Avatar
 
Join Date: Mar 2011
Location: Pennsylvania
Posts: 11
Training: EMT-Basic
Send a message via AIM to JOgershok Send a message via Skype™ to JOgershok
Quote:
Originally Posted by JOgershok View Post
This IS the kind of information for which I an making this inquiry.
I am still under 5 posts so I can not PM. Maybe now I can.
JOgershok is offline   Reply With Quote
Reply

Bookmarks

Tags
chest trauma, occlusive dressing

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fire Science Degree and EMS FutureRescue EMS Talk 9 12-27-2010 03:30 PM
Fire Science Degree for a Volunteer?? bryncvp EMS Talk 7 07-01-2010 11:10 PM
Occlusive Dressings guamie BLS Discussion 13 02-28-2009 02:45 PM
Associate of Applied Science in What? rhan101277 Education and Training 14 07-28-2008 05:17 PM


All times are GMT -4. The time now is 11:32 PM.


Powered by vBulletin
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2001-2014, EMTLife LLC. All rights reserved.