Category: Travel, Wilderness & Preparedness Medicine

Backpacker filtering stream water beside a mountain trail

How to Safely Disinfect Drinking Water in the Wilderness

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness Medicine2 Comments
shutterstock_125263139I credit much of this information to Dr. Howard Donner who has incredible knowledge of both medicine and the wilderness.  He is also an excellent teacher. Drinking water can be contaminated with bacteria, viruses, protozoa and other parasites.  The risks of getting ill depends on the number of organisms that are consumed which is determined by the volume of water, concentration of organisms and how well the water treatment system is working. Disinfection:  Removal or destruction of harmful microorganisms Pasteurization:  Similar to disinfection but uses heat at temperatures below 100 degree C to kill most pathogenic organisms Sterilization: Destruction or removal of all life forms – not to be confused with disinfection or pasteurization Purification:  Removal of organic and inorganic chemicals and particulate matter to remove offensive color, taste and odor.  It may not remove or kill enough microorganisms to ensure microbiologic safety. The goal of disinfecting water is to achieve minimal microbial hazard so that the likelihood of illness is acceptable. Sterilization is not necessary because all life forms are not human pathogens. Water treatment methods:  Heat, Filtration and Clarification, Ultraviolet light Disinfection by Heat: 1)   The boiling time required is important when fuel is limited 2)   Most pathogens including cysts, bacteria, viruses and parasites can be killed at a temperature well below boiling 3)   Thermal death is a function of both time and temperature; therefore, lower temperatures are effective with longer contact times 4)   Microorganisms have varying sensitivity to heat; however all common bacteria that cause diarrhea are readily inactivated by heat 5)   Hepatitis A is a special concern because it seems to have greater thermal resistance 6)   Elevation should not make a large difference unless hepatitis A is a concern because heat inactivation occurs below typical boiling temperatures 7)   The 10 minute boiling rule is for sterilization of water.  Enteric pathogens are killed within seconds by boiling water and rapidly above 140 degrees.  The majority of the time required raiding the temperature of the water to boiling point works toward disinfection so water is safe to drink by the time it has reached a full boil.  For extra safety against hepatitis A, keep the water covered and hot for several minutes after boiling 8)   A pressure cooker saves times and fuel at all elevations 9)   Pasteurization has been achieved using solar heating using a foil-lined cardboard box with a glass window in the lid. Disinfection by Filtration: 1)   Field filters rely on mechanical removal of microorganisms and are adequate for cysts, and bacteria but do not reliably remove viruses which are a major concern in water where high levels of fecal contamination are present (e.g., in developing countries) 2)   The advantage is they are simple and require no holding time 3)   They do not add any unpleasant taste and may improve taste and appearance of the water 4)   Most viruses adhere to larger particles or clump together into larger aggregates that me be removed by a filter, but filtration alone is not adequate because the infectious dose of the virus may be quite small. 5)   Filters are often expensive and can add considerable weight and bulk to the backpack 6)   The filter pore size that is required to remove microorganisms is difficult to determine because the organisms possess elasticity and deform under pressure and that makes it possible for them to squeeze through filter pores. 7)   Filters are rated by their ability to retain particles of a certain size which is described by two terms.  Absolute rating means that 100% of a certain size of particle is retained in the filter.  Nominal rating indicates that more than 90% of a given particle size will be retained. 8)   All filters eventually clog from suspended particulate matter even in clear streams.  This means that they require cleaning or filter replacement.  The ability to field service the unit easily is an advantage. 9)   As the filter clogs, it requires increasing pressure to drive the water through which can force microorganisms through the filter. Reverse Osmosis Disinfection: 1)   Reverse osmosis filters use high pressure (100 to 800 psi) to force water through semipermeable membranes that filter out dissolved ions, molecules and solids 2)   Generally used for desalinating water, but may also be used to remove biological contaminants 3)   Small hand-pumped reverse osmosis units have been developed but their high price and slow output currently limit their use by land based wilderness travelers.  They are an essential survival item for ocean travelers Clarification of cloudy water can be achieved by sedimentation, coagulation-flocculation(CF), or adsorption. 1)   Large particles settle by gravity over 1-2 hours in sedimentation. Which can help if you are using a filter.  Although filters remove particulate debris, thus improving the appearance and taste of “dirty” water, they clog quickly if the water contains large particles. Using sedimentation allows the larger particles to settle out to the bottom of the container helps prevent the filters from clogging so quickly. 2)   Smaller suspended particles can be removed by coagulation-flocculation(C-F).  This is accomplished in the field by adding alum (aluminum potassium sulfate).  Alum is used in the food industry as a pickling powder and is nontoxic.  C-F will remove contaminants that cause unpleasant color and taste as well as some dissolved metals and some microorganisms. Water Clarification using Alum: 1)   Add a pinch of alum to each gallon of water 2)   Mix well, and stir occasionally for 30 minutes then allow 30-60 minutes for settling 3)   The water should be clear, if it is not then add another pinch of alum and repeat 4)   Decant or pour the water through a paper filter to remove clumps of flocculate. Charcoal filters/Granular Activated Charcoal (GAC):  Removes organic pollutants, chemicals, and radioactive particles by adsorption.  This improves the color, taste and smell of the water.  Although some microorganisms adhere to the GAC or become trapped in the charcoal filters, GAC does not remove all microorganisms, so it does not disinfect. 1)   Useful for removing halogens such as iodine or chlorine after disinfection 2)   Wait until after the contact time for disinfection before running water through charcoal if you use it to remove the iodine or chlorine from your water 3)   Some filters use iodine resins followed by GAC and rely on a different dynamic Halogens:  Chlorine and Iodine are effective disinfectants against bacteria, viruses, Giardia and cysts of amebae but not Cryptosporidium.  They are not expensive. 1)   Disinfection with halogens depends on both the concentration of the halogen and the amount of time the halogen is in contact with the water (contact time).  Increase in one allows a decrease in the other (inverse relationship). 2)   Water temperature and the presence of organic contaminants in the water affect this method (colder temperatures slow and organic contaminants decrease its disinfection action).  Thus, in cold water, the contact time or dose should be increased and in polluted water the dose must be increased 3)   Use 4 parts per million (ppm) as a target concentration for surface water and allow extra contact time if the water is cold. 4)   In cloudy water that will not settle out by sedimentation, the halogen dose should be at least 8ppm.  Ideally, use C-F to clarify the water before halogenation, then a smaller amount of halogen may be used. Organism sensitivity to halogens: 1)   Bacteria are very sensitive to halogens 2)   Viruses and Giardia require higher concentrations or longer contact times 3)   Certain parasite eggs such as round worms are resistant but they are usually not spread in the water.  These eggs or cysts are susceptible to heat or filtration 4)   Cryptosporidium cysts are extremely resistant to halogens Chlorine vs. Iodine: 1)   Iodine is less affected by pH and tastes better than Chlorine 2)   Chlorine and Iodine are available in liquid or tablet forms 3)   Some people have allergic reactions to iodine 4)   Iodine use is not recommended for people with unstable thyroid disease or unknown iodine allergy 5)   Iodine should not be used during pregnancy for longer than several weeks because of risk of neonatal goiter 6)   Limit exposure to drinking iodinated water to 1 month or less if all water being consumed is treated with iodine 7)   Iodine resins with GAC filters may reduce iodine exposure because they have lower concentration of iodine and remove it with the filter Problems with halogens: 1)   The taste of water can be unpleasant 2)   The potency of some products (both tablets and solution) decrease with time an are affected by heat or moisture 3)   Liquids are corrosive and can stain clothes or equipment 4)   Cryptosporidium are resistant 5)   The actual concentration (after halogen demand – ie amount of organic material in water) is unknown Improving the Taste of Water that has been disinfected with halogens:  Add flavoring to the water only after adequate contact time because the sugar and additives can reduce the amount of free iodine available.  Also using charcoal (GAC) to remove the halogen after contact time.  You may also reduce the concentration and increase the contact time for clean water.  You can use a collapsible plastic container to disinfect water with low doses of iodine during the day or overnight.  You can also add a few granules per liter of ascorbic acid (vitamin C) in powder or crystal form after the contact time and this will take out the color and taste of the chlorine or iodine.  Superchlorination-Dechlorination:  High doses of chlorine are added to the water in the form of calcium hypochlorite crystals to achieve concentrations of 30-200 ppm of free chlorine that are above the margin of safety for field conditions and rapidly kill all bacteria, viruses and protozoa.  After 10-15 minutes, several drops of 30% hydrogen peroxide solution are added.  The minor disadvantage of the two-step process is excellent taste.  This is a good technique for highly polluted or cloudy water and for disinfecting large quantities of water. Mixed Species Disinfection (Miox Purifier):  Passing a current through a simple brine sale solution generates free available chlorine, as well as other “mixed species” disinfectants that have been demonstrated effective against bacteria, viruses and bacterial spores.  There is potential for malfunction and battery depletion.  A new point-of-use commercial product is available – Miox marketed by MSR. Chlorine Dioxide:  This is capable of inactivating most waterborne pathogens including Cryptosporidium parvum oocysts at practical doses and contact times.  It is at least as effective a bactericide as chlorine and in many cases it’s superior.  It’s far better against viruses. Ultraviolet Light:  In sufficient doses, all waterborne enteric pathogens are inactivated by UV radiation.  UV treatment does not require chemicals and does not affect the taste of the water.  UV works rapidly and overdose to the water does not cause any problems.  It has no residual disinfection power and water may become re-contaminated or regrowth of bacteria can occur.  Particulates in the water however can shield microorganisms from UV rays.  Where strong sunshine is available, solar disinfection of drinking water is an effective, low-cost method for improving water quality and may be very useful in refugee camps and disaster areas. If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Cluster of brown mushrooms growing among moss and fallen leaves

Poisonous Plants and Mushrooms You May Encounter Outdoors

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
shutterstock_78360337Traveling out in the wilderness or being in a survival situation can bring people to look for or depend on plants for food/nourishment.  Sometimes these plants can be extremely poisonous and cause illness. Anything in the correct dose can be poisonous.  “The dose makes the poison.” I credit the information that I’ve learned and written here to Richard Clark, MD who is medical toxicologist and expert in Wilderness Medicine. Mushroom ingestion: It’s difficult even for a trained botanist to identify all mushroom varieties and 95% of the time the type ingested is unknown.  There are less than 100 reported fatalities related to mushroom ingestions in 25 years.  Most patients are treated at home.  Most cases reported to the poison control center were related to children, however all reported deaths were in adults.  Mushroom toxicity varies widely.  Management and prognosis often depend on the history and geographical location of the ingestion as well as the initial signs/symptoms.  The largest and most diverse group are the “little brown mushrooms.”  These are often mistaken for edible varieties. Symptoms of toxic mushroom ingestion can be classified as early or late. Early gastrointestinal symptoms may begin in ½ hour to 3 hours after ingestion and may be:
1)  Severe nausea, vomiting and diarrhea
2)  Stools may be bloody
3)  Symptoms may last 6-24 hours
4)  Most of the time no labs are needed, but when symptoms are severe liver enzymes may be monitored
Treatment:  Hydration and anti-nausea medication and possible narcotics for pain. Mushroom ingestion with late gastrointestinal symptoms:  may begin 6-12 hours after ingestion. Mainly differentiated between 2 varieties – Amanita/Galerina and Gyromitra.  There are several liver toxic Amanita species:  phalloides, virosa, verna.  They have a greenish color cap and like to live under oak trees.  They are the most common vegetable cause of human death in the USA.  Phase 1: 8-12 hours after ingestion – abdominal pain, vomiting and diarrhea.  Phase 2:  Begins 12-36 hours after ingestion and patients may actually improve.  Phase 3:  2-6 days after ingestion, the patient may get severe liver death and kidney disease.  There are no antidotes available.  Treatment is supportive care and organ transplant if necessary. Several species may look like a morel (Morchella esculenta) and are the esculenta, infula, ambigua.  These false morel may be edible in some parts of the U.S.  In areas where they are toxic, the toxins may sometimes be destroyed by cooking.  Symptoms including nausea, vomiting, diarrhea seizures and possible liver damage begin 6-12 hours after ingestion. Treatment:  Rehydration, activated charcoal, benzodiazepines, pyridoxine. Plant induced itchy rash (contact dermatitis):
1)  Poison Ivy
2)  Poison Oak
3)  Poison Sumac
Exposure to mango, pistachio and cashew can also cause the reaction. 50% of the population is highly sensitive.  Oils on plant turn black on contact with air.  These plants are found in all 48 continental states.  P. Ivy is mostly in the eastern states, P. oak is mostly in the west and Sumac is mostly in the southeast. Severe cases can progress to a severe type 1 hypersensitivity reason.  Symptoms usually begin with 2-4 hours after exposure and may include:
1)  Redness
2)  Itching
3)  Blisters
4)  More severe cases may cause fever, nausea, vomiting, dehydration
5)  Skin infection secondary
Treatment:  prevent severe symptoms by early washing with soap and water (toxin is oily).  Treat with systemic corticosteroids and topical lotions, steroid creams and antihistamines. There are several products that help prevent exposure to the plants by wearing them – including barrier creams, lotions or sprays – these are poorly protective.  Stoko Gard Outdoor Cream provides great protection if washed off by 8 hours post-exposure.  IvyBlock is another product that can provider good protection. The “Unknown” Berry Ingestion:  Most of these are non-toxic but can cause gastrointestinal illness.  Large quantities of almost any plant can cause nausea/vomiting.Decontamination with pumping the stomach or charcoal is rarely needed.  Rehydrate and give anti-nausea medicines or benzodiazepines for seizures or agitation. Holly:  Over 300 species, causes nausea, vomiting and diarrhea.  Treat with rehydration Pokeweed:  Native to Eastern USA along roads and moist areas.  Rapid onset of severe nausea, vomiting and diarrhea.  Treat with rehydration. Castor bean:  Grows wild in southern California.  The seed is the most toxic part.  Whole seeds are “nontoxic” except for severe gastroenteritis.  Treat with rehydration. Jequirity bean:  Native to Florida and the Keys.  The bean is the toxic portion of the plant.  Causes severe nausea, vomiting and diarrhea.  Treat with rehydration. Ricin and Abrin:  Two of the most toxic substances with the highest concentration in the seeds.  Intoxications result in multisystem organ failure.  Seed coat must be destroyed.  There are few if any reported cases of fatalities when seeds ingested Water Hemlock (Cowbane, false parsley):  Grows throughout the USA along roads and ditches and is often mistaken for wild carrots or wild parsley.  It was used extensively for suicide in ancient Greece.  Most lethal plant in North America.  Tuberous root.  Causes rapid onset of seizures.  Treat with airway protection and anticonvulsants. Nicotine:  Found in woodlands and along roads.  Poisoning from touching on the skin, inhalation or gastrointestinal exposure.  Rapid onset of severe nausea, vomiting, diarrhea, headache, dizziness, confusion, seizures and possible coma and paralysis. Jimson Weed:  Grows along roads and fences throughout the USA.  Seeds are particularly potent.  Mind altering properties noted in ancient literature.  Seeds contain atropine (50-100 seeds may contain 3-6mg).  Anticholinergic toxicity.  Treat with sedation and possibly physostigmine. Foxglove, Lily of the Valley, Oleanders:  Contain heart glycosides that can lead to stopping of the heart, rapid pulse, or arrhythmias. Hellebore:  Found in moist woodlands of eastern and western USA.  Used as a sneezing powder.  Can cause nausea, vomiting, low blood pressure, slow heart rate and heart dysrhythmias. Aconite (Monkshood, wolfsbane):  Can cause cardiotoxicity (dysrhythmias) or neurotoxicity (paresthesias).  Treat with lidocaine and supportive care. Rhododendron including azaleas and laurels:  Leaves and flowers contain small amount of Andromedotoxin or grayantoxin that can cause cardiac dysrhythmia but there has only been one reported case in the last 20 years. Unknown plant ingestion with patient having seizures:  Wide differential of plants that cause this.  Symptoms can advance quickly.  Often symptoms begin with nausea and vomiting and can progress to coma and paralysis. There are many other plants that are toxic.  Please contact your medical provider or your local poison control center.  There are more than 40 nationally certified and they are open 24 hours/day and staffed by specialists in poison information.  There is backup from medical toxicologists. If you have a poison exposure or question, the poison helpline number is:  1-800-222-1222 and is available 24/7 365 days of the year.  Also, the American Association of Poison Control Centers website has some valuable information as well:  http://www.aapcc.org/dnn/default.aspx If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Grilled fish, salad, and rice served overlooking a turquoise seaside village

Gluten Free Travel Tips: How to Eat Well While Abroad

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
For a variety of reasons, some patients prefer a gluten-free diet.  I am not promoting a Gluten-Free diet here, but just pointing out what some patients are doing and some ways to continue to be Gluten-Free if that is your choice. Gluten is a protein that is found in foods processed from wheat and related grains including barley and rye.  It gives a kind of chewy texture to many of the food products that we eat. 1)   The Airlines are not “Gluten Friendly” so it’s safe to assume that you’ll need to pack your own pic-nick style meals.  Bringing fruits, nuts, tail-mix, cheeses and meats that you would normally eat at home and pack them into soft-sided cooler type containers or your carry on bag. 2)   Packing your own nutritional supplements containing digestive enzymes may be helpful if you can’t be entirely sure that the food your eating is totally free of glutens.  Digestive Gold is one supplement may be helpful.  Your local health-food store or Amazon.com may have digestive enzymes, but your favorite drug store may not. 3)   Cook for meals yourself.  When you travel, consider renting a place with a kitchenette if you can so you have the space available to create your own meals that you know are gluten free. 4)   Find a decent grocery store with a good deli instead of eating out at restaurants and fast food joints.  That way you can make your own salads, buy some meats and cheeses and create something both tasty and healthy. Eating gluten free is definitely more work, but for those of us with Celiac Disease, on dietary restrictions or who just want to eat healthier I think the advance preparation is worth the investment. For more information about the Gluten Free Diet, check out the Mayo Clinic Article – Gluten-Free: What’s Allowed, What’s Not: http://www.mayoclinic.com/health/gluten-free-diet/my01140   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Coiled rattlesnake resting on a sunlit desert rock

Snakebites and Envenomation: What You Need to Know

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
shutterstock_93999454I credit the information that I’ve learned and written here to Richard Clark, MD who is medical toxicologist and expert in Wilderness Medicine.
 Snakebites are fairly common, but rarely cause death.  There are 350,000 snakebites each year in the world with 35,000 deaths annually worldwide and only 10-15 deaths per year in the US.
In the U.S. there are 3 main types of snakes:  Colubrids, Elapids, and Crotalids.  Most snakes in the U.S. are nonpoisonous and have fixed hind fangs.  The Garter snake is a common example of this kind of snake (a Colubrid).  The Colubrids have round pupils. The Elapidae are snakes that have front fixed fangs with modified grooved teeth such as Cobras and Mambas and Coral Snakes. They require a longer bite time to envenomate than the Crotalids. Coral snake venom is neurotoxic and causes parasthesias, weakness, paralysis and cardiovascular collapse.  The treatment is supportive care and prophylactic antivenom. Crotalidae are the pit vipers that have mobile front fangs that are a very efficient envenomation apparatus.  In the U.S. the Crotalidae are the Rattlesnakes, the Cottonmouth and Copperhead.  They have a triangular shaped head and heat sensing organs around their nose.  They have elliptical pupils and don’t always rattle before striking. Death is actually rare from Rattlesnake bites although tissue damage is common and can be severe.  The pit viper venom can cause tissue damage, coagulopathy, thrombocytopenia, neurotoxicity, shock and pulmonary edema.  The area of the bite usually has swelling, blebs, and sometimes necrosis.  The incidence of wound infection after being bit by a Rattlesnake is very low because the venom actually prevents bacterial infections.  If bitten by a Rattlesnake and there is no swelling/pain, there is no envenomation.  This is called a dry bite and happens in up to 25% of these bites. There has been some controversy over whether to use ice, incision, constrictive bands, or perform excisions or fasciotomy.  We generally don’t recommend any of these treatments any longer and have found that they are not effective and may cause more harm. Rattlesnake first aid: 1)   Seek medical care 2)   No suction 3)   No ligatures 4)   No cutting 5)   No ice 6)   The Anti-Venom is called Crofab.  We generally give anti-venom until the proximal swelling halts, and coagulopathy is resolving, the thrombocytopenia is resolving and the systemic toxicity is resolving.  This may involve many doses of anti-venom.  The initial dose is 4-6 vials in 100 mL of NS.  Begin slowly and infuse over 1 hour.  Redoes with 4-6 vials as needed for “stabilization.”  One problem with the anti-venom is that some people are allergic.  The majority of allergic symptoms are rash.  It is also very expensive and not readily available. 7)   If the bite is on the face, empiric intubation should be done to protect the airway because facial bites can lead to significant swelling. If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Woman in a beanie holding a steaming mug by a fireplace

Hypothermia: Staying Safe When It’s Cold Out There

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
shutterstock_171146414I credit the information that I’ve learned and posted here to Eric Weiss, MD who is an international expert in Wilderness Medicine and Hypothermia. Patients with accidental hypothermia come to medical providers year-round and in all climates.  Hypothermia is defined as a decrease in core body temperature below 95 degrees F (35 degrees C). For purposes of emergency management and resuscitation, hypothermia can best be characterized as either mild or severe.  In mild hypothermia (core temperature 87.8-95 degrees F), the victim is conscious, still shivering and generally not prone to developing abnormal heart rhythms.  In severe hypothermia (core temperature below 87.8 degrees F), the patient has altered level of consciousness, diminished or absent shivering and is prone to abnormal heart rhythms. Mild hypothermic victims can still generate heat through shivering so they generally do well without intensive rewarming.  In severe hypothermic patients, active rewarming techniques such as extracorporeal blood rewarming, inhalation therapy, peritoneal lavage, thoracic cavity lavage or thoracotomy with mediastinal irrigation may be needed. Pre-hospital Treatment of Mild Hypothermia:  Preventing further heat loss and facilitate rewarming are the goals.  The rescuer should remove all wet clothing and replace it with dry clothing, insulate the patient with sleeping bags, blankets, extra clothing or other suitable material.  Use insulation underneath the patient as well as on top.  Encourage drinking of warm fluids and sugary drinks if they can swallow without aspirating (inhaling the drink into their lungs).  It is not uncommon to observe a continued decline in core temperature after a hypothermic patient is removed from the cold environment and external warming is initiated.  This phenomenon is called core temperature afterdrop. Pre-hospital Treatment of Severe Hypothermia:  Careful handling is necessary because these patients are prone to develop abnormal heart rhythms through rough handling.  If in the backcountry, consider helicopter transport to prevent jostling that might occur with an overland evacuation.  Keep them horizontal when possible to minimize orthostatic hypotension.  Provide oxygen if you have it.  Administer a minimum of 500ml of heated (98.6-105.8 degrees F) IV normal saline or D5NS.  Lactated ringers should be avoided because when the liver is cold, it poorly metabolizes lactate.  Consider intraossious (I/O) infusion for alternative pathway for fluid replacement for a dehydrated patient who you cannot get IV access. Hot water bottles or heat packs can be placed in the axillae and groin area and along the neck where large blood vessels course near the surface.  Hot water bottles should be wrapped with insulation to prevent thermal burns. In a severely hypothermic patient, they may feel/look clinically dead. Breathing may be difficult to detect if the breathing rate is significantly depressed. The rescuer should listen to the chest and palpate over carotid or femoral arteries for at least 1 minute to detect a pulse.   If the patient has any sign of life, chest compressions should not be initiated as they may precipitate ventricular fibrillation (abnormal heart rhythm). At a core temperature of 20 degrees C, cardiac arrest is tolerated for up to 30 minutes without clinically significant neurologic or neuropsychological deficits.  This knowledge and the fact that a dead victim may be clinically indistinguishable from one that is severely hypothermic and alive has lead to the adage that “No one should be pronounced dead, until they are warm and dead.” A serum potassium greater than 10mmol/L in a non-hemolyzed specimen however has been proposed as a reasonable ceiling for viability. Negative Pressure Rewarming (Thermarescue):  A non-invasive way of creating a direct thermal pipeline between the skin and body core.  The patients forearm is fitted through an acrylic sleeve with an air tight seal around the arm.  Vacuum pressure of -40 mm Hg is established and the thermal load is applied via a chemical heating pad. If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Gloved hands warming over a campfire in a snowy forest

Frostbite and cold induced injuries

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness Medicine1 Comment
Photo credit:  http://www.everester.org/BlogViewer.aspx?Id=DCD57FDDA64B2206   Much of the information presented here comes from Peter Hackett, MD who is an expert in Wilderness Medicine and especially mountain and high altitude medical illness and care. Frostbite:  A severe, localized cold-induced injury.  Tissue destruction of frostbite is due to both immediate cold-induced cell death and more gradual development of localized inflammatory process and tissue ischemia.  Following exposure to subfreezing temperatures, ice crystals form outside the tissue cells.  If freezing is rapid, ice crystals may also form inside cells.  The initial cellular damage and subsequent inflammatory process are made worse in the setting of thawing followed by refreezing of the area. Areas most often affected:  Ears, nose, cheeks, chin, fingers and toes Causes:  Anything that increases localized heat loss or decreases heat production.  Exposure to wind, or conductive heat loss due to contact with metal or water 1)   Inadequate insulation 2)   Circulatory compromise 3)   Dehydration 4)   Moisture Behavioral risk factors: 1)   Mental illness 2)   Alcohol and drugs 3)   Fear, apathy, panic Vascular Stage- Post thaw:  Recovery of circulation and then thrombosis, ischemia, necrosis and even gangrene can result.  Intracellular ice and tissue death occurs if there is refreezing. Classification of frostbite injuries: 1)   Mild or Superficial (no tissue loss) 2)   Severe or Deep (with tissue loss) 3)   Historical classification 1st to 4th degree had no clinical usefulness Treatment (Pre-Hospital): 1)   Supportive care for trauma, and dehydration (splint/pad affected area) 2)   Avoid additional heat loss – remove wet clothing 3)   If frozen and rescue is near keep frozen unless you can do a warm water thaw and there is no danger of refreezing. 4)   Do not rub frost bitten areas as this can cause further tissue damage 5)   If already thawed, avoid refreezing 6)   Avoid using stoves or fires to rewarm frostbitten tissue Treatment (Hospital): 1)   Hydration 2)   Wound care – early debridement or amputation of dead or dying areas while preserving viable tissue 3)   Pharmacology – Dextran, NSAIDs, Nifedipine 4)   Imaging studies (X-rays may show coincidental trauma related fractures or cold-induced soft tissue swelling), Technetium (Tc)-99 scintigraphy is commonly used to predict long-term tissue viability. 5)   Sympathetic block or surgery if needed Methods of Thawing: 1)   Rapid rewarming in warm water (37-41 degrees C) is optimum 2)   Gradual thawing – often unavoidable 3)   Harmful methods – delayed thawing with ice or snow or excessive heat Non-freezing Cold Injury:  Frostnip, Chilblain/Pernio, Trenchfoot, Raynaud’s Frostnip:  Cold-induced, localized parasthesias that resolve with warming and there is no permanent tissue damage. Pernio/chilblain:  Localized inflammatory lesions that can result from acute or repetitive exposure to damp coldness above the freezing point.  Lesions are swollen, often reddish or purple and may be painful or itchy.  Pernio is most common in young women but both sexes and all age ranges may be affected. Trenchfoot (immersion foot):  Injury to the sympathetic nerves and small blood vessels of the feet.  First described in 1914 during WWI during trench warfare.  It results from prolonged exposure of the feet to a combination of dampness and cold.  Tight-fitting boots exacerbate the condition.  Feet, and sometimes hands are red, swollen and can be extremely painful and often are covered with bloody blisters.  Tissue loss can occur. Prevention: 1)   Pay attention to weather forecasts (predicted high and low temperatures, forecasted precipitation and wind chill index) 2)   Dress appropriately for the weather 3)   Have an emergency plan when going into remote areas 4)   Avoid alcohol consumption and smoking 5)   Avoid exposure to metal surfaces 6)   Maintain adequate calorie intake 7)   There is inadequate evidence to support the use of applying emollients to exposed skin to prevent frostbite and it is not suggested 8)   Carry emergency supplies in the backcountry or in remote areas in case your group becomes stranded 9)   Use a buddy system for monitoring 10)  Perform an equipment and clothing check 11)  Keep hydrated 12)  Carefully wash and dry feet 13)  Do not sleep in wet socks 14)  Avoid tight socks and shoes 15)  Do not add socks for warmth, get a larger shoe 16)  Rewarm gently, do not use a strong heat source 17)  Do not rub the skin, use passive skin-to-skin contact 18)  Elevate the feet above the level of the heart 19)  Consider antiperspirant with aluminum hydroxide for a week before exposure Raynaud’s Vasodilation Training: (Physician Sports Med, March 1990; vol18 no3) 1)   Immerse hands in hot tap water 2)   Stay indoors for 5 minutes, then in the cold for 10 minutes, then back indoors for 5 minutes (one cycle) 3)   Do 3-6 cycles per day every other day 4)   50 cycles established effect, but variable Tips to control moisture and cold: 1)   Wear socks with moisture-wicking capabilities 2)   Change socks and dry them frequently 3)   Use foot powders that control fungus and absorb moisture 4)   Wear shoes with adequate draining capabilities or make holes 5)   Consider waterproof socks, either SealSkinz, Waterproof MVT, Seirus Neo-Sock or Stormsock 6)   When resting or sleeping, take off wet shoes and socks to allow feet to breath and socks to dry against your body in your sleeping bag If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Two hikers climb a snowy mountain ridge with snow-covered peaks behind them

Altitude Illness

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
shutterstock_163362512Much of this information comes from Peter Hackett, MD, a wilderness medicine expert on mountaineering and altitude related illness and treatment. Altitude illness is usually due to the stress of decreased oxygenation in the setting of an individual who is not acclimatized.  It can happen at any altitude over 8,000 feet and usually occurs during the initial ascent. Two areas of the body that are most affected by altitude illness are the brain and the lungs.  When altitude illness strikes the brain it is divided into two groups called Acute Mountain Sickness (AMS) and High Altitude Cerebral Edema (HACE).  Lung injury is usually due to lung edema called High Altitude Pulmonary Edema (HAPE). Risk factors for altitude illness: 1)   Genetic susceptibility 2)   Live at an altitude of less than 3000 feet 3)   Fast rate of climb/ascent 4)   Past history of high altitude illness (HAI) 5)   Age less than 50 years old (for Acute Mountain Sickness – AMS) 6)   Heavy exertion/exercise 7)   Pre-existing illness (especially for High Altitude Pulmonary Edema – HAPE) Acute Mountain Sickness (AMS): Diagnostic Criteria 1)   Recent gain in altitude 2)   Headache and any of the following
  1. Gastrointestinal upset
  2. Fatigue or weakness
  3. Dizziness or lightheadedness
  4. Difficulty sleeping
3)   Feels like a hangover Treatment of Acute Mountain Sickness:  Usually gets better on it’s own.  Average duration of symptoms is about 16 hours.  It may persist for weeks at higher altitudes however.  There may be progression to High Altitude Cerebral Edema (HACE) with or without High Altitude Pulmonary Edema (HAPE).  It responds well to descent/treatment. 1)   Oxygen therapy 2)   Descent 3)   Hyperbarics 4)   Acetazolamide (Diamox) – 125 to 250mg every 8-12 hours – start taking the day before travel until day 2 or 3 at altitude. 5)   Hyperventilation 6)   Dexamethasone 4mg every 6 hours – careful because this can lead to adrenal failure if used at high doses and if it’s not tapered gradually. 7)   Treat symptoms of headache with ibuprofen/naproxen, codeine, etc. and nausea with Zofran or Phenergan Acetazolamide Prophylaxis:  125-250mg twice a day (5mg/kg/day) starting the day before travel and continued until day 2 or 3 at altitude.  If allergic to sulfonamides (sulfa) be cautious.  Side effects of the medication are dose related.  More commonly a feeling of numbness/tingling, metallic taste in the mouth, generalized fatigue, nausea and blurry vision can occur. Prevention of altitude sickness: 1)   Go up slowly in staging – avoid a sea level to 9,000 foot climb in one day 2)   Sleep at a max of 2000 feet higher elevation each night 3)   Acclimatize to 10-12,000 feet before going any higher High Altitude Pulmonary Edema (HAPE):  Symptoms Early:  Fatigue, weakness, dry cough, shortness of breath with activity.  May progress to increased respiratory rate, increased heart rate. Late:  Pink or blood-tinged sputum from lungs, crackles heard with stethoscope in the right axilla/arm pit. Treatment for HAPE:  Oxygenation is the highest priority.  Descend with minimal exertion.  For mild/moderate cases use bed rest with oxygen.  For severe illness use high flow oxygen with descent and perhaps a hyperbaric bag.  There is some thought about using pulmonary vasodilators such as calcium channel blockers, nitric oxide, Viagra and/or Dexamethasone. Preparation:  Take a medical kit with Diamox and dexamethasone and albuterol inhalers.  If you’re with medical providers, you may have access to nifedipine or Viagra also which may be helpful. For more information: 1)   www.altitudemedicine.org 2)   www.hypoxia.net 3)   Auerbach’s Wilderness Medicine 4)   DuPoint Travel Medicine 5)   Tintinelli Emergency Medicine If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Open suitcase packed with clothes beside a passport and sunglasses

Essential Foreign Travel Tips: What to Know Before You Go

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
shutterstock_144889000The information listed below is a smattering of information gained from real life experience, Wilderness Medicine Conferences, and is mostly credited to Gene Allred, MD a very experienced physician and world traveler. Two major categories for foreign travelers: A)  The senior traveler (age 65 and above) who have the resources to travel and may have a bucket list.  They have chronic medical conditions and in many foreign countries, access to medical care and medications is more difficult.  Think about access – i.e. there is probably not a wheelchair ramp available in many areas.  Bring your medications.  I don’t know how many times I’ve had patients travel here to Hawaii and not bring enough of their blood pressure medications with them, and I’m sure it happens when the go other places too.  Many seniors may might not get altitude sickness but may have cardiac strain from lower levels of oxygen or increased physical exertion.  Plan accordingly. B)  The adventure/exotic traveler (all ages) who tend to participate in more dangerous activities – mountain climbing, rock climbing, wilderness expeditions like kayaking the Nile river, etc.  These travelers have a higher incidence of trauma from MVA or injury from their activities.  Homicides in some areas may be more of a problem than an MVA.  We don’t think twice about putting on our seatbelt when we get in a car here in the USA, so don’t get in a taxi or bus without a seatbelt (the roads are often worse in other countries and there may be less lighting and more people).  If you do get into an MVA abroad, the medical care is probably not going to be as good as you would get in first world countries. Causes of death in foreign travelers: 1)   Almost 50% are from heart attacks and strokes, the other 50% is from trauma (motor vehicle accidents, drowning, falls and homicide) – also be aware that most counties outside of the US, Canada, Australia, New Zealand, Europe and Japan don’t screen their blood for HIV or Hepatitis C. 2)   Only 1% of death in foreign travel results from Infectious disease Most dangerous aspect for foreign travel:  Motor Vehicle Accidents – account for 25% of fatalities of U.S. travelers.  In Langos, Nigeria buses are called danfos “flying coffins.”  The rate of motor vehicle deaths compared to the USA: 1)   Sri Lanka – 23x more deaths from MVA than USA 2)   Turkey – 44x more deaths from MVA than USA 3)   China has 2% of the worlds driver’s and 15% of the fatalities – WHO 2007 4)   In Ghana 722 drivers were selected at random and 21% had blood alcohol level >80 mg/dl; 4% of the bus drivers had this level.  70% of the trauma patients here are transported by taxi or bus, and 22% and transported by private vehicle.  5% are transported by police and only 3% of trauma victims are transported by ambulance. In the USA, 60% of the motor vehicle crash deaths occur among the drivers.  In the 3rd world countries, 90% occur among passengers, pedestrians and cyclists.  Urban pedestrians account for 50-70% of the deaths due to motor vehicle accident. In contrast, the leading cause of injury/illness in foreign travel is infectious disease.  Up to 75% of travelers become ill from infectious disease, however only 1% of the deaths of international travelers are from infectious disease. Recommendation:  Before you travel, consult your physician, CDC or travel clinic.  Let your medical provider know the type of activities you are planning including whether going to a remote region, participating in a strenuous activity (cycling, mountain climbing, swimming in fresh water, or diving, etc.) Resources: http://www.travelhealthassist.com http://www.cdc.gov/travel http://travel.state.gov/travel/tips/safety/safety_1747.html Everyone needs Hepatitis A immunization when traveling to a high endemic area. Hepatitis A and B vaccinations are a lifetime investment. There are stories about bogus drugs and dirty needles used in certain areas. New Delhi, India (CNN) 2/21/09 – “Authorities were carrying out raids in India’s western Gujarat state for bogus drugs and recycled syringes after a hepatitis B outbreak left 32 people dead, officials said Saturday.”             *  Five medical practitioners were also arrested for violations             *  One arrested for reusing injection syringes             *  111 cases of hepatitis B in the district over two weeks with 32 dead I’m not saying that you should bring your own needles when traveling, but the news report above is frightening. Before your travel, consider the following: 1)  Plan at least three months ahead (buy your tickets, look into what visas you might need, if there a restrictions  and plan what to bring with you). 2)  Look at the CDC website – http://www.cdc.gov/travel and study up on where you are going and what diseases you need to be protected against. 3)  Get excellent travel insurance – there are many companies that offer this – International SOS is one of them https://www.internationalsos.com/en/.   Read the fine print and make sure the company that you go with doesn’t say something like “will evacuate to most appropriate facility” and something more specific like “Will evacuate to USA, Canada, Japan, Australia, New Zealand, or Europe” 4)   Decide what medical resources are available in the foreign country 5)  Plan for diarrheal illness – bring antibiotics (sometimes you might take prophylaxis) and medications to help slow the bowls such as Imodium. 6)   How will I get around while there?  Avoid car crashes – don’t get on a crowded bus, a motorcycle or scooter.  Wear your seatbelt! 7)  Stay sober when out in public – you are more of a helpless target if you’re drunk.  If you drink – do it in the hotel where it’s safer. 8)  Don’t look rich – avoid wearing fancy jewelry/watches or you’ll look like a good target. 9)   Problems of counterfeit drugs – i.e. take own medications 10)   Take a copy of your medical history/prescriptions, driver’s license, passport and visas.  Leave one copy at home with a friend and bring the original and one copy with you. 11)   Consider the season you are traveling in when going to a foreign country i.e. rainy vs. dry.  In malaria endemic regions, this may dramatically influence your risk 12)   Traveling in motor vehicles at night in third world countries substantially increases your risks of injury or death 13)   Acclimatize yourself to the altitude 14)   Bring sunblock 15)   Think about heat exposure 16)  Take drinking water precautions (chlorine dioxide, etc.) 17)  Be wary of swimming in fresh water or going barefooted – consider infections due to Schistosomiasis, Leptosirosis or Cryptosporidium 18)  Think about safety/security – 9% of U.S. travel fatalities are due to homicide.  9000 homicides in Sao Paulo in 1999, compared with 700 in New York City. 19)  Avoid dangerous situations – khakis = N. American, avoid going out alone at night, don’t wear expensive jewelry, carry no more cash than you need for the day and don’t flash roll of bills.  Use a hotel safe when available.  Fanny packs and purses are “one-stop” shopping targets – be aware of “slash and grab.”  Don’t accept food from strangers – “drug and rob scam,” Beware of “spilled food scam” (e.g. mustard), use licensed taxis over unlicensed taxis.  Scan your passport and then email it to yourself so you’ll be able to retrieve a copy. 20)  Protect yourself from insects – Dengue fever, Malaria (1-2 million deaths/year), West Nile Virus, etc.   The higher the concentration of DEET, the longer lasting it is – 99% DEET = 10 hours, 30% DEET is safe in kids down to 2 months of age.  DEET + Permethrin is > 99% effective.  Most malaria is Chloroquine resistant.  Three drugs of choice for malaria are Mefloquine, doxycycline and malarone (primaquine is 2nd line option). 21)  The unexpected usually happens.  Accept the things that are beyond your control.  Resign yourself to the fact that your luggage will be lost, your hotel reservations will be canceled, and your last flight out will leave without you.  They key is to then decide what you are going to do about it.  No matter how bad you think things are now, they can always get worse.  Always have a contingency plan.  Research alternative travel arrangements such as accommodations, research climate, local health risks, etc.  Instead of letting problems accumulate, deal with each challenge “head on.”  Work to “fix” one problem at a time and then move on to the next. If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medicine society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Lifeguard seated on an elevated chair overlooking a busy outdoor swimming pool

Drowning and Near Drowning: Water Accidents Explained

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
shutterstock_106770593I credit the information that I’ve learned and presented here to Karen Van Hoesen, MD who is an expert in Wilderness Medicine and has specialized training in Dive Medicine and water related injuries and illness. Drowning is the 3rd most common cause of accidental deaths in the U.S, and the leading cause of death in children < 5 years old.  Every year drowning accounts for a least 500,000 deaths worldwide and about 4,000 fatalities in the US.  2005 WHO Definition:  “Drowning is the process of experiencing respiratory impairment from submersion/immersion in liquid.” There are several factors that are common to drowning: 1)   Age:  More common in toddlers and teenage boys 2)   Location:  Most frequent in home swimming pools, bathtubs and buckets 3)   Sex:  More common in male than female 4)   Race:  Happens more commonly in ethnic minorities 5)   Drugs:  Being under the influence of alcohol contributes greatly to drowning accidents (more than 50% of adult drowning deaths are believed to be alcohol related). 6)   Trauma:  More common secondary to diving or falls 7)   Drowning is the leading cause of death in Scuba The effects of drowning on the organ systems involve spasm of the larynx, and flooding of the lungs with water causes loss of surfactant (a fluid that helps keep the small air sacs of the lung open).  The decreased oxygenated blood flow leads to decreased cardiac output and abnormal heart rhythms may occur. Decreased oxygenated blood to the brain causes damage to the brain in multiple areas.   Decreased blood flow to the kidneys can lead to kidney failure. Clinical presentation of the drowning victim:  There is a broad spectrum to how they look clinically.  They can be alert or comatose.  They can have signs of decreased blood flow such as blue tone to the skin, or have signs of coughing, increased respiratory rate, increased heart rate and low grade fever.  A chest X-ray may be normal or can show signs of severe damage to the lungs called ARDS (acute respiratory distress syndrome).  Imaging of the brain might show swelling. Early complications (within 4 hours) of Near Drowning: 1)   Spasm of the upper airway 2)   Vomiting with breathing in vomit 3)   Hypothermia 4)   Seizures Late complications (after 4 hours) of Near Drowning: 1)   ARDS – Lung failure 2)   Anoxic-ischemic encephalopathy – brain damage due to low oxygen 3)   Pneumonia due to inhaling water 4)   Lung abscesses 5)   Renal failure 6)   Sepsis – overwhelming infection of the body  Near Drowning Treatment (Before reaching the Hospital):  Training in basic life support is very helpful! 1)   Call for Help! 2)   Mouth-to-Mouth in shallow water or stable surface – do not wait for ambulance 3)   Do not give chest compressions in the water 4)   Do not give Heimlich maneuver 5)   Give oxygen at highest concentration available (if you have an oxygen tank) 6)   Think about head or neck trauma 7)   Rewarm the patient Outcomes:  90% of children survive submersion.  68% of patients need CPR, success of resuscitation at the site of the drowning/near drowning is key.  Poor outcomes are more common for those patients who don’t get CPR until they get to the hospital or are submerged for more than 10 minutes.  Cold water is beneficial because it tends to decreases the oxygen needs of the body. Prevention:  Pool covers, pool alarms, and fences around pools can be very helpful. Supervise young children when around water. Train young children in aquatic programs for infants and toddlers.  Have personal floatation devices available.  Do not drink alcohol or use illicit drugs if you are around the water!   Please seek training by a medical professional to help prevent water related injuries.  I highly recommend that everyone get basic life support training.  To find the nearest place to get CPR training for the non-medical person, check out:  http://www.heart.org (American Heart Association) If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medical society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Open expedition first-aid kit on a rock overlooking snow-capped mountains

Medical Kits for Expeditions and Backcountry Travel

On By Dr. Scott RennieIn Travel, Wilderness & Preparedness MedicineLeave a comment
shutterstock_35627896I give credit for the information learned and presented here to Howard Donner, MD who is an expert in Wilderness Medicine. Those of us who enjoy traveling in the backcountry understand there are inherent dangers and risks for serious injury and even death.  Many people go out into the wilderness and travel far into remote areas and might be days away from the nearest medical clinic.  I think it’s important for everyone to carry a first aid kit, and someone in the group to carry more advanced supplies if needed. I realize that organizing medical equipment for an expedition into the backcountry requires a lot of planning.  You cannot be prepared for every possible illness and accident no matter how many supplies you bring with you.  There are many opinions on what should be brought and the opinions here are my own after my travels, adventures and taking multiple classes in Wilderness Medicine and Search and Rescue disciplines.  Remember that when the medical kits are too heavy they are more likely to be left behind and not be available when they are desperately needed.  I try to take into consideration size and weight constraints and I choose items for my kits with that in mind. The contents of the kits may depend on: 1)   Age of the hikers 2)   Distance from local medical care 3)   Number of people in the trip 4)   Environmental extremes of the trip 5)   Length of the expedition 6)   Diseases endemic to the area of travel 7)   Medical expertise of the medical officer 8)   Availability of rescue (helicopter for example) 9)   Medical experience of the other expedition members 10)  Pre-existing health problems of the participants I generally recommend that each hiker carry their own personal first aid kit, and then have a base camp kit for the entire group depending on the size. Personal first aid kits might have the following: 1)   Pain medications such as ibuprofen and Tylenol 2)   Sunscreen and lip protection 3)   Water disinfection supplies 4)   Blister care 5)   Minor wound care – band aids/ointment 6)   Insect repellent 7)   Personal medications (for pre-existing problems) 8)   Malaria prophylaxis (if there is risk) 9)   Throat lozenges/cough drops Base Camp Kits will depend on the factors described above, but may contain some of the following – note that I would pick and chose from the list below but usually not take everything here: 1)   Antibiotics – Preparation for common problems. i.e. upper and lower respiratory infections, skin and soft tissue infections and bacterial diarrheas.  I usually carry azithromycin (i.e. Z-Pack) for the respiratory illness.  Duricef (which has the advantage of dosing once to twice a day) is useful for skin infections but consider Bactrim for MRSA.  I usually carry Ciprofloxacin for bacterial diarrheas although there are some newer agents out there (see my blog on traveler’s diarrhea).  Also consider taking antibiotics for protozoan infections if going on longer or more remote trips (i.e. metronidazole or tinidazole). 2)   Analgesics – I like to have a strong oral narcotic medication in case of  a serious  medical problem such as a broken bone or worse.  Consider Percocet or Vicodin. 3)   Respiratory – I have asthma, so I carry albuterol, but it is also useful for exercise induced bronchospasm.  Prednisone is also useful to have for asthma exacerbations and to treat poison ivy, poison hemlock, or poison oak exposure. 4)   ENT (Ear/Nose/Throat) – Rhinorockets are essentially nasal tampons that are useful for nosebleeds.  They are lightweight and simple for anterior nasal packing.  Afrin nasal spray is a great topical decongestant and is useful for nosebleeds and Eustachian tube dysfunction during altitude changes.  Zyrtec or other antihistamine for allergies. Throat lozenges or hard candy are very useful for cough or sore throat.  Sudafed or other oral decongestants. 5)   Eye – Topical eye antibiotic such as Ciprofloxacin ophthalmic for the treatment of corneal ulcers.  Cyclopentolate HCL can be helpful for relieving the ciliary spasm of photokeratitis or uveitis.  A topical anesthetic such as Tetracaine is useful for corneal exam and to help get a climber off the mountain – but should not be abused.  Fluorescein for staining corneal defects.  Ketorolac Ophthalmic solution for minor irritation, Zaditor for allergic conjunctivitis and a penlight or blue LED. 6)   CNS/Brain – Ativan or Xanax for anxiety.  Anxiety can be common with individuals travelling far from home.  Caffeine (No-Doz) useful to relieve caffeine withdrawal headaches or for a little extra “get up and go.” Motion sickness medication – i.e. scopolamine or antihistamines. 7)   Cardiovascular – A beta-blocker such as Lopressor or Tenormin for chest pain or heart attack.  Nitroglycerine for chest pain/MI, Aspirin for chest pain or heart attack, Nifedipine for HAPE (High Altitude Pulmonary Edema) or hypertension. 8)   Gynecological – Urine pregnancy test – rule out an ectopic pregnancy in a female in reproductive age with pelvic pain or bleeding.  Oral birth control pill for hormonal cycling or dysfunctional uterine bleeding.  Fluconazole for yeast vaginitis 9)   Gastrointestinal – Pepto-Bismol for non-dysenteric diarrhea, Imodium for long bus rides, etc., Miralax for – “Freeze dried megacolon” i.e. constipation as a result of eating freeze-dried food.  An anti-nausea medicine such as Zofran – I prefer the oral disintegrating tablets.  An antacid such as Prilosec, oral rehydration solution (dehydrated packets) – i.e.. “Jeevan jal”, or other Sports Drink.  Annusol HC or Tucks pads to treat hemorrhoids. 10)  Altitude illness – Acetazolamide (Diamox), Dexamethasone (for cerebral edema), Compazine for altitude associated nausea and ibuprofen or naproxen for altitude associated headache.  Albuterol inhaler.  Nifedipine for field HAPE treatment. 11)  Topicals – Lamisil AT (or other antifungal cream), Lidex or other topical steroid cream (good for insect bites), Insect repellant with DEET, Silvadene cream for burns or Bactroban for topical antibiosis.  Aloe Vera Gel is excellent for minor burns and irritation.  Vaseline for chapped lips or fever blisters.  Labosan or other sun protection for lips.  Betadine solution (not the scrub). 12)  Blisters – Moleskin (lots of it), Adhesive foam for making donuts and padding for boots, Compeed is a very durable, product for painful blisters or Blistoban to reduce friction.  Duct Tape – good for preventing blisters (i.e. a new pair of boots on a long trip). 13)  Wound Care – Steristrips (multiple sizes), Tegaderm or Opsite for abrasions, Staplers (the small 15 shot  3M are great), Sutures – multiple sizes of both nylon and absorbable.  Superglue for instantaneous treatment of painful skin fissures.  Dermabond and misc. gauze and Band-Aids. 14)  Surgery – Angiocath for emergency tube thoracotomy, Uncle Bill’s tweezers, Sliver pickers (for foreign object removal), #11 scalpels for incision and drainage.  Instruments:  Bandage scissors, tissue scissors, needle drivers, and tissue forceps.  20 or 30cc syringes with 18 G. angiocath for wound irrigation and TB syringes for administration of lidocaine.  Gloves, Safety pins. 15)  Orthopedics – SAM splints, both full-length and finger sizes (great for improvising just about anything).  Kendrick Traction Device – very lightweight design for femoral traction.  Another newer splint is the Slishman Traction Splint (STS) for femoral fractures.  Adhesive tape for splinting ankles and fingers.  ACE Wraps, Fiberglass 3M One “One Step” splints, Air casts or gel casts are great for sprained ankles. 16)  Injectable Medications – Epinephrine 1:1000 (anaphylaxis treatment), Morphine sulfate or consider ketamine.  Dexamethasone, Ondansetron or Compazine, Benadryl, Ativan or Valium (consider rectal administration), Lidocaine, Toradol, Antibiotics such as Rocephin might be an option. 17)  IV’s – Multiple sizes of angiocaths (16, 18 & 20G).  Intraosseous needle for IO infusions, Heparin locks, Bacteriostatic normal saline or heparin flushes, IV fluid volume expanders 18)  Airway – Oral airways such as the LMA, pocket mask 19)  Dental Kit – Cavit (no mix temporary filling), Eugenol (topical analgesic), Dental floss 20)  Miscellaneous items to consider – Stethoscope, snakebite kit, paper/pencil, headlamp, tongue blades, sterile applicators, Foley catheter (16F with 30cc balloon).  A Foley can be used as a urinary catheter, improvised chest tube or posterior nasal pack for bloody nose.  Water disinfection system, spare sunglasses, urine chemstrips. If you are interested in learning more about wilderness medicine, a great resource for information is the wilderness medical society:  http://www.wms.org/   I hope that you have found this information useful.  Wishing you the best of health,

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.