Recombinant Factor VIIa for Rattlesnake Envenomation

In a recent issue of Wilderness & Environmental Medicine (Volume 20, Number 2, 2009), Anne-Michelle Ruha and Steven Curry have written an article entitled “Recombinant Factor VIIa for Treatment of Gastrointestinal Hemorrhage Following Rattlesnake Envenomation.” This is a “case report,” meaning that this is a description of a particular medical event, rather than a study. To open the piece, the authors observe that North American rattlesnakes possess venom with properties that can cause severe physiological effects, such as low platelet count and on occasion bleeding. In this report, we learn about a 44 year old man who was bitten on the index finger by an unidentified (unknown for this case) species of rattlesnake. The victim developed massive gastrointestinal bleeding that was treated eventually with a product known as recombinant factor VIIa. His initial clinical presentation included an altered level of consciousness, profoundly low blood pressure (shock), sweating, and vomiting of bright red blood.

The victim was treated with standard aggressive therapy for a rattlesnake bite, which included intravenous fluid replacement and administration of blood and antivenom. However, he continued to bleed, so was administered recombinant factor VII, which is a therapy that has only relatively recently become available to physicians. When the victim had his gastrointestinal tract observed by direct endoscopy, he was seen to have a small tear that accounted for the bleeding. Sadly, the patient grew increasingly ill for a variety of reasons, including kidney failure and overwhelming systemic infection, and died on hospital day 5.

The effects of a venomous snakebite can range from a “dry bite,” in which no envenomation is deemed to have occurred, and for which no particular intervention is necessary, to profound physiological derangement, in which the victim may suffer multi-organ system failure. The important new observation in this case report is the use of recombinant factor VII to treat the bleeding. This product is felt to act directly at the site of tissue injury by a variety of beneficial effects, including generation of blood clotting and activation of specific clotting components (such as platelets). This was a very complicated case, with multiple factors that contributed to the outcome. While it is impossible to attribute the cessation of bleeding entirely to the administration of recombinant factor VII, the timing of the bleeding suggests that it may have had a markedly positive effect. This will bear observation in the future as other clinicians undoubtedly gain experience with this product.

image courtesy of www.EMCrit.org

Tags: snakebite, rattlesnake, snake bite, wilderness medicine, outdoor medicine, healthlineLabels: rattlesnake, rattlesnake envenomation, snake bite, snakebite

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Wilderness Management

The fourth edition of Wilderness Management, authored by Chad P. Dawson and John C. Hendee and published by Fulcrum Publishing of Golden, Colorado, is a gem. Subtitled Stewardship and Protection of Resources and Values, this book is must-read for anyone involved in natural resources management. Given that the entire concept of wilderness medicine is predicated upon there being wilderness, this book should be of great interest to anyone concerned about the environment.

As noted in the Publisher's Preface by Vance G. Martin, President of the International Wilderness Leadership (WILD) Foundation, wilderness is essential to a well-balanced natural resource program, because we need wild places with naturalness and solitude, where biological evolution can proceed to produce the genetic diversity upon which all life and societies are built. True wilderness areas are under enormous pressure, and if we are to begin to understand how to protect them, we first must understand how they evolved, what they are and their role internationally in the structure and function of nature. Mr. Martin appropriately notes that this book is meant for everyone who is concerned about wilderness - land managers, scientists, wilderness users, teachers, students, citizens, environmentalists, natural-resource developers, outfitters and guides, consultants, planners and policy makers worldwide. Everyone has a stake in the future of wilderness.

The book is endorsed by luminaries from the National Park Service, U.S. Department of the Interior; The Wilderness Society; Bureau of Land Management; The Wilderness Foundation (South Africa); National Wildlife Refuge System; U.S. Forest Service, U.S. Department of Agriculture; and the WILD Foundation.

I am going to quote from the Author's Preface:

The book's specific objectives are:

1. To describe the evolution of the U.S. National Wilderness Preservation System: its philosophical, historical, and legal origins; its current size, number of areas, and distribution; and its probable future. We also describe state wilderness in the United States and some wilderness systems in other countries.
2. To provide a common reference for managers, students, scientists, educators, and citizens, who must work together to steward the U.S. National Wilderness Preservation system, state wilderness systems, and wilderness in other countries to protect their resources and values.
3. To propose principles and concepts from which management policy and actions to preserve wilderness might be derived and to describe current wilderness management approaches, policies, procedures, and techniques.
4. To introduce readers to pressing wilderness management issues, impacts, the implications of alternative methods of dealing with them, pertinent literature, current problems, solutions, and research.
5. To describe differences and interrelationships between wilderness designation and wilderness management and between management of wilderness and management of contiguous non-wilderness lands.

The book is divided into the following sections:

1. The Setting
2. U.S. Legal Authority and Process for Wilderness
3. Wilderness Management and Planning Concepts
4. Wilderness Resources, Values, and Threats to Them
5. Wilderness Uses and Their Management
6. The Future

This book in various editions has been available for 30 years, and for very good reason. I highly recommend it.

Tags: Wilderness Management, wilderness stewardship, wilderness, wilderness medicine, outdoor medicine, healthline

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Thank You to Non-Clinical Medical Jobs, Careers, and Opportunities for Grand Rounds

Thank you to Non-Clinical Medical Jobs, Careers, and Opportunities for mentioning my post about sea urchin spine puncture management in this week's Grand Rounds. Grand Rounds is a weekly compilation of health care posts from around the web compiled by a host, who goes to great lengths to make the collection informative and entertaining.

Labels: Grand Rounds, Non-Clinical Medical Jobs Careers and Opportunities

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Jellyfish and Such

This is the fourth post based upon my presentation given at the Wilderness Medical Society Annual Meeting held in Snowmass, Colorado from July 24-29, 2009. The presentation was entitled “Just When You Thought It Was Safe to Go Back in the Water.”” The topic was an overview of hazardous marine animals and it was delivered by me. In the previous posts, there was information about sharks, stingrays and scorpionfishes, and sea urchins. In this post, there is information about injuries from jellyfishes incurred in the marine environment.

Jellyfishes are stinging creatures with stinging “cells,” which are highly specialized and designed to inoculate prey with venom. There may be millions of these stinging cells on the tentacles or near the mouth of the animal. When the cells are stimulated, they shoot out a stinging thread that releases microscopic granules of venom into the victim.

The victim may suffer immediate burning pain, skin rash, blistering, allergic reaction, or a number of systemic symptoms, including neurological sydromes, low blood pressure, abnormal heart rhythms, difficulty breathing, abdominal pain, nausea and vomiting, diarrhea, muscle cramping, and many others.

Treatment should be swift in order to minimize the clinical syndrome.

1. Rinse the wound with seawater or concentrated salt solution if possible. A gentle fresh water rinse may cause more stinging cells to discharge their venom.
2. There is growing support for hot water immersion therapy (113 degrees Fahrenheit or 45 degrees Centigrade), similar to that for a stingray or scorpionfish envenomation, for treatment of certain jellyfish stings. This recommendation emanates from experts in Australia. It is not known if this therapy is effective against North American, European, and non-Australian (Indo-Pacific) jellyfish species.
3. Anticipate an allergic reaction and be prepared to treat with injectable epinephrine and/or oral antihistamines.
4. Do not rub the wound.
5. Wear protective gloves (double thickness of a surgical glove or a thick dishwashing glove preferred).
6. If the sting is from the box jellyfish Chironex fleckeri, flood the area with topical acetic acid 5% (vinegar) immediately and with a continuous application for a minimum of 30 minutes.
7. Remove large tentacle fragments with forceps.
8. DO NOT apply the pressure immobilization technique.
9. Other topical decontaminants that may work, depending on the jellyfish species, include isopropyl (rubbing) alcohol, dilute ammonium hydroxide (household ammonia), powdered bicarbonate (baking soda), unseasoned meat tenderizer (papain), papaya fruit or juice, or lime or lemon (citrus) juice.
10. After decontamination, remove adherent nematocysts by applying shaving cream or a paste of baking soda and shaving with a sharp edge, such as a safety razor.
11. For a mild skin reaction, apply a topical corticosteroid (“steroid”) cream, ointment or lotion.
12. If the reaction is moderate to severe, a physician may prescribe a systemic steroid or administer a steroid injection.
13. Anti-tetanus immunization is standard.
14. Observe closely for development of a wound infection.
15. If the sting is from the box jellyfish Chironex fleckeri, there is an antivenom available in certain locales. The true efficacy of this therapy is currently under scrutiny.

Tags: jellyfish, marine envenomation, box jellyfish, wilderness medicine, outdoor medicine, healthline

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Sea Urchins and Such

This is the third post based upon my presentation given at the Wilderness Medical Society Annual Meeting held in Snowmass, Colorado from July 24-29, 2009. The presentation was entitled “Just When You Thought It Was Safe to Go Back in the Water.”” The topic was an overview of hazardous marine animals and it was delivered by me. In the previous post, there was information about stingrays and scorpionfishes. In this post, there is information about injuries from sea urchins incurred in the marine environment.

Sea urchins are free-living echinoderms with egg-shaped, globular or flattened bodies. They are covered by tightly arranged spines and/or triple-jawed pedicellariae, which are seizing and envenoming organs. The spines can be brittle, hollow, sharp and venom-bearing or blunt and non venom-bearing (such as with Hawaiian pencil urchins). Most persons are envenomed when they step upon or brush against an urchin.

The clinical aspects are characterized by intense local tissue pain, which may radiate deeply into muscle. There may be redness and swelling, or perhaps punctate purple discoloration. The latter may represent dye leached from the surface of a spine, rather than indicate a retained spine. If a spine resides near a joint, particularly in the hand, there may be inflammation, which can cause swelling of a finger or the entire hand. When multiple spines enter a victim, there may be nausea, vomiting, numbness and tingling, nerve dysfunction causing weakness or paralysis, fainting, low blood pressure, or difficulty breathing.

Therapy for a sea urchin puncture(s) is as follows:

1. Extract any easily grasped spine fragments. Do not crush spines within the soft tissues.
2. If any pedecellariae (seizing organs) are still attached, remove these with a sharp edge and something like shaving cream.
3. For pain relief at any time during the process, immerse the wound(s) into non-scalding hot (113 degrees Fahrenheit or 45 degrees Centigrade) water to tolerance for 30 to 90 minutes. If pain recurs, repeat the hot water immersion.
4. A doctor may need to use a local anesthetic for pain control.
5. A doctor may need to obtain an x-ray, computed tomography (CT), magnetic resonance imaging (MRI) or ultrasound exam to locate the spine(s).
6. If a spine is situated near or within a joint and is causing severe symptoms (e.g., inflammation, infection), it may need to be removed.
7. A deep puncture wound of immune suppression of the victim is a possible indication of administration of a prophylactic antibiotic (such as ciprofloxacin, doxycycline, or trimethoprin-sulfamethoxazole).

These treatment suggestions are similar to those that are recommended for puncture wounds from the spines of crown-of-thorns starfish.

Tags: marine envenomation, sea urchin, urchin puncture, wilderness medicine, outdoor medicine, healthline

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