New snake bite device

[David Corbin]

I am posting the abstract of this paper and a link to the corresponding patent application without comment:

J Med Toxicol. 2010 Mar 27. [Epub ahead of print]
A Localizing Circumferential Compression Device Delayed Death After Artificial Eastern Diamondback Rattlesnake Envenomation to the Torso of an Animal Model in a Pilot Study.
Hack JB, Orogbemi B, Deguzman JM, Brewer KL, Meggs WJ, O'Rourke D.

Department of Emergency Medicine
Brody School of Medicine
East Carolina University
Greenville, NC
[email protected]

Abstract:

Nearly all prior studies to delay onset of systemic toxicity and death after snake bite use a model of distal extremity envenomation. In the first of a series of planned studies using snake venoms with different toxicity profiles, the application of a novel device in a new model of torso envenomation in the setting of Eastern Coral Snake (Micrurus fulvius) venom (a potent neurotoxin) envenomation showed promise by delaying systemic intoxication. In this pilot study, we investigated this novel localizing circumferential compression (LoCC) device’s ability to delay onset of life threatening systemic toxicity after Eastern Diamondback Rattlesnake (Crotalus adamanteus) envenomation, a potent hemotoxic and myotoxic venom. With university approval, four juvenile female pigs (22–25 kg) were anesthetized, sedated, and intubated but not paralyzed to allow for spontaneous respirations. Each animal was injected subcutaneously with 50 mg of C. adamanteus venom in identical preselected areas of the trunk. After 1 min, two treatment animals had the LoCC device applied; two control animals had no intervention. Vital signs were recorded every 10 min for the first 2 h and every 30 min thereafter. Endpoints included cardiovascular collapse (fatal arrhythmia, loss of mean arterial pressure, or pulse) or respiratory arrest (<3 breaths/min, saturation < 80%) or survival to 7 h. The pigs in the treatment group reached an endpoint at an average time of 355 (±65) min compared with control 32 (±3.5) min (p < 0.04). In this pilot study, the LoCC device significantly delayed onset of systemic symptoms and death after torso envenomation with Eastern Diamondback Rattlesnake venom in this model.

Full text: http://www.springerlink.com/content/v7x15l00474436t3/fulltext.html

Patent application 20090171384:
EMERGENCY SNAKE BITE TREATMENT DEVICES, MEDICAL KITS AND RELATED METHODS
http://tinyurl.com/y244qzo

[Mike McHenry]

Sounds like bacon is on the menu.

[Ken Thompson]

Who gets bit on the torso? Usually an arm or leg. Still need to get to a hospital for antivenom. Don't go picking things up. Interesting premise though. Sound like a modified tourniquet.

[Sean Walashek]

Drawing on my somewhat foggy wfr training…
An ace bandage, properly applied, can have a reducing effect of cytotoxic (target individual cells) venom infiltration. Sounds like this device is a fancy ace bandage, local concentric compression…
I also seem to remember neurotoxin's (those that target the nervous system) will not be. If there is someone with more info don't hesitate to correct me.

edit.
after scanning the patent it sounds like a ace bandage wrapped over a little box that surrounds the bite.

[David Corbin]

Physicians and lay people are unable to apply pressure immobilization properly in a simulated snakebite scenario.
Norris RL, Ngo J, Nolan K, Hooker G.
Wilderness Environ Med. 2005 Spring;16(1):16-21.

Abstract:

OBJECTIVE: To determine whether volunteers (with or without prior medical training) can correctly apply pressure immobilization (PI) in a simulated snakebite scenario after receiving standard instructions describing the technique.

METHODS: Twenty emergency medicine physicians (residents and attendings) and 20 lay volunteers without prior formal medical training were given standard printed instructions describing the application of PI for field management of snakebite. They were then supplied with appropriate materials and asked to apply the technique five separate times (twice to another individual [one upper and one lower extremity] and three times to themselves [nondominant upper extremity, dominant upper extremity, and one lower extremity]). Successful application was defined a priori by four criteria previously published in the literature: wrap begins at the bite site, entire extremity is wrapped, splint or sling is applied, and pressures under the dressing are between 40 and 70 mm Hg in upper-extremity application and between 55 and 70 mm Hg in lower-extremity use. Pressures were determined using a specially designed skin interface pressure-measuring device placed at the simulated bite site.

RESULTS: The technique was correctly applied as judged by the preset criteria in only 13 out of 100 applications by emergency medicine physicians and in only 5 out of 100 applications by lay people. There was no significant difference in success rates between physicians and lay volunteers. Likewise, there was no significant difference in success based on which extremity was being wrapped. More detailed analysis revealed that the major contributor to failure was inability to achieve recommended target pressures.

CONCLUSIONS: Volunteers in a simulated snakebite scenario have difficulty applying PI correctly, as defined in the literature. The major source of failure is an inability to achieve recommended pressure levels under the dressing. New methods of instructing people in the proper use of PI or new technologies to guide or automate application are needed if this technique is to be used consistently in an effective manner for field management of bites by venomous snakes not known to cause significant local wound necrosis.

Full text: http://download.journals.elsevierhealth.com/pdfs/journals/1080-6032/PIIS1080603205703422.pdf

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