Outdoor Survival/First Aid
Wilderness first aid is the provision of first aid under conditions where the arrival of emergency responders or the patient evacuation may be delayed due to constraints of terrain, weather, and available persons or equipment. It may be necessary to care for an injured person for several hours or days.
In the United States and United Kingdom, Wilderness First Aid (WFA) is the name of a certification in wilderness medicine that covers wilderness first aid; depending on the laws applicable where it is practiced, it may impose specific responsibilities and confer specific immunities on duly-diligent practitioners. For instance, the practicing of certain rules of WFA, by someone certified in the usual "street" First Aid discipline but not in WFA (or a higher Wilderness Medicine qualification), could result in civil liability or perhaps even criminal prosecution.
A classic problem is whether to leave an injured person or stay if only one person is ambulatory. Barring special circumstances, the injured one should be stabilized, placed in shelter, and marked in a way visible from the air (usually a single, long line of cut brush or trampled snow). Then the injured one should be left alone, while the other goes for help.
If there are three or more, the healthy group should be split into halves by speed, with the fastest going for help, and the others remaining to make the preparations. (In a party of four, it would be a rare hiker who would be better sent for help alone, rather than sent in a sub-party of two.)
Ensuring the rescuers can find the injured person is crucial. If a Emergency Position-Indicating Radio Beacon is available, it should be triggered and placed with the injured person. If enough help is available, air-visible markings may be worthwhile. Where surveyor's tape is available within the party (and assuming clear trails are available), it should be used by the sub-party going for help, to back up memory and notes with tape-flagging of the toward-the-injury-location choices of trail at intersections. (When an injury location is off clear trails, by distances that make it impractical to keep blazes of tape within sight of each other, forks in watercourses should be treated as substitutes for trail intersections.)
Training in wilderness first aid is available in the the US and UK. Any group of persons traveling in wilderness should have at least one person trained in wilderness first aid and carry a first aid kit designed for the area they are traveling in.
Nursing care is not part of normal first aid but is part of wilderness first aid.
Exposure, sometimes called hypothermia, is a normal hazard of temperate wilderness. It occurs when a person's core body temperature falls below 33.7C (92.6F). If a person is wet, in a mild wind, it can occur in less than an hour at temperatures as high as 15°C (59°F).
The basic early symptoms are uncontrollable shivering, stiffness and confusion. The conclusive evidence is a cool or cold stomach. If the hypothermia has not yet advanced to a critical stage, basic treatment is to warm the person in a sleeping bag. People with hypothermia may have such depressed metabolisms that they can no longer heat themselves. However, if the hypothermia has become severe - the victim is confused or unconscious - it is critical not to warm them suddenly. Evacuation would be the preferred option, with warming undertaken in a controlled medical environment. Sudden warming of a severely hypothermic person can send the heart into a fatal, irregular beating pattern or arrhythmia.
Heat syncope: heat exhaustion or sunstroke
Both maladies tend to occur during heavy exercise in high humidity, or with inadequate water. Some chronically ill persons enter these state normally.
The basic symptom of heat syncope is a body temperature above 40°C (104°F) with fainting, or weakness but without mental confusion. If unconsciousness, confusion or convulsions are present, it is sunstroke which is rarer, but far more severe condition, a true medical emergency.
Note that some authorities do not distinguish heat syncope from sunstroke, and treat heat syncope as sunstroke in order to be safe. All authorities recognize that these are stages in the same process.
Heat syncope is caused by mild overheating with inadequate water or salt. In young persons, it is far more common than true sunstroke. Blood pressure is lowered when the body dilates (widens) capillaries (small blood vessels) in the skin to radiate heat. Also, water is evaporated from the blood, reducing the blood's volume and therefore lowering blood pressure further. The result is less blood to the brain, causing light-headedness and fainting.
The basic treatment for heat syncope is to treat it like fainting: Have the victim sit, if sitting lay down, if laying down, raise legs. Then, administer water, and oral rehydration salt, slowly, and move the victim to a cooler area.
With sunstroke, cool the victim. Remove their clothing, shade them, fan them and sponge with cool water. Massage limbs vigorously to move cooled blood into the body cavity. Ice or alcohol can cause damage. Get help immediately. Sunstroke, especially when the victim has been unconscious, often causes major damage to body systems such as brain, kidney, liver, gastric tract. Unconsciousness for more than two hours usually leads to permanent disability.
There are two basic causes of cramping. One is inadequate oxygenation of muscle, and the other is lack of water or salt. Cramps from poor oxygenation can be improved by rapid deep breathing, and stretching the muscle. Cramps from lack of salt and water can be treated by stretching the muscle, drinking water and eating salt. Pounding on the muscle can increase soreness.
What happens in a cramp is that lactic acid builds up because of normal anaerobic muscle metabolism. When the muscle burns sugar without enough oxygen, it makes lactic acid. The lactic acid finally becomes concentrated enough to trigger the contraction of the muscle. When the muscle lacks salt, the nerves firing the muscle are unable to recharge properly, causing a similar effect.
Insect and animal bite
Most animal bites should be considered as possible sources of infection, including rabies. Wash the wound, ideally with povidone iodine soap. Loosely bandage it, and do not suture it. Know the venomous animals in your area.
Animal bites by carnivores other than rodents should be considered possible cases of Rabies. If you are bitten, try to capture alive or kill the animal and preserve its head. Look for signs of Rabies (foaming mouth, self-mutilation, growling, jerky behavior, red eyes). If the animal lives for ten days and does not develop rabies, then no infection has probably occurred. The head can later be analyzed to detect the disease.
If the animal is gone, prophylactic Rabies treatment is recommended in most places. Certain places, such as Hawaii, are known not to have native Rabies. Treatment is generally available in North America, Britain and the Northern European states. Away from these areas, try to get to the nearest embassy of one of these states and indicate an acute medical emergency. The embassy doctor is usually willing and able to help.
Many snakebites, even by venomous snakes, are not envenomed, and these can be treated as animal bites. Croatilid (rattlesnake and pit-viper) venoms cause the bitten area to turn green or purple. Elapsid (coral and monay other non-U.S. snakes) venoms cause swollen lymph nodes. If symptoms appear, they should be treated by compressing and cooling the bite(many say the bite should not be cooled, http://www.fda.gov/fdac/features/995_snakes.html) and evacuating the victim, on a litter if possible. If a victim is unable to reach medical care within 30 minutes, a bandage, wrapped two to four inches above the bite, may help slow venom. The bandage should not cut off blood flow from a vein or artery. A good rule of thumb is to make the band loose enough that a finger can slip under it(American Red Cross, FDA/Office of Public Affairs:http://www.fda.gov/fdac/features/995_snakes.html). If available, antivenim should be administered. See below for phone numbers to locate antivenims.
The black widow spider, and some scorpions are dangerous mostly to small children and elderly adults. Only the Sydney funnel-web spider of Australia is frequently dangerous to adults, and it resides only within 100 miles of Sydney Australia. Treat as snake-bite. Antivenins are available in the U.S. for black widow spiders and the dangerous scorpions native to the U.S.
To locate antivenims, the Anti-venim index in Oklahoma City, Oklahoma, United States (1-405-271-5454) maintains a 24-hour hotline to help locate rare antivenims. Another possible number is the Poisondex central office in Denver, Colorado, USA (1-800-332-3073). In Australia, contact Commonwealth Serum Laboratories, Parkville, Victoria, Australia. In Asia try Haffkine Biopharmaceutical Corporation, Parel, Bombay, India. In Africa try the South African Institute for Medical Research, Johannesburg, Republic of South Africa. In most moderately developed countries, the national hospital can treat local venomous bites.
Insect bites as well as exposure to allergens can trigger anaphylaxis in some people. Anaphylaxis is a life-threatening medical emergency because of rapid constriction of the airway, often within minutes of onset. Call for help immediately. First aid for anaphylaxis consists of obtaining advanced medical care at once; rescue breathing (a skill that is part of Cardiopulmonary resuscitation, or CPR) is likely to be ineffective but should be attempted if the victim stops breathing. Look to see if a device such as an Epi-pen is available for administration of epinephrine by a layperson.
Altitude sickness can begin in susceptible people as low as 8,000ft. The early symptoms are drowsiness, feeling unwell, and weakness, especially during exercise. More severe symptoms are headache, poor sleep, persistent rapid pulse, nausea and sometimes vomiting, especially in children. More severe symptoms include pulmonary edema (fluid in the lungs- persistent coughing), confusion, psychosis, hallucination and death.
Victims can sometimes control mild altitude sickness by consciously taking ten to twelve rapid large breaths every five minutes. If overdone, this can blowoff too much carbon dioxide and cause tingling in the extremities of the body. The quickest cure is to reduce the victim's altitude if possible. Some mountain rescue groups carry acetazolamide (a prescription drug) to treat mountain sickness, injectable steroids to reduce pulmonary edema, and inflatable pressure vessels to relieve and evacuate severe mountain-sick persons.
Altitude acclimatization has two stages. Overnight, the body can adjust its carbonic acid balance, and substantially improve its performance. Over four to six weeks, the body can grow more blood cells, strengthen the heart and make other tissue changes. Above 18,000ft, further altitude exposure weakens one, rather than strengthening one's acclimation.
Wounds with spurting, bright red blood require immediate pressure to stop the bleeding. If necessary, you may need to use your finger to push on the bleeding artery.
Follow this with a pressure bandage so you can rest, but make sure the wound is not continuing to bleed into the bandage. Oozing, slower wounds can be treated the same way, but it's reasonable to clean them first.
Antibiotic ointment, if available, is helpful if medical care is many hours away. It should be spread freely on wounds. Some authorities even advocate gently packing it into deep, dirty, slowly-bleeding wounds.
Some authorities believe that it is better not to change dressings, if the dressing change does not include good quality cleaning and debridement. Otherwise, dressings should be changed at least daily.
If sterile normal saline is available, it is useful for rinsing most dirt out of wounds.
Regardless of the severity of the wound, proper cleaning and disinfection is essential on longer stays in the wilderness where an evacuation is not deemed necessary or is not possible. Relatively harmless local infections at the wound site can quickly escalate into life-threatening systemic infections if proper care is not taken. Some WFA courses provide instruction on the proper administering of antibiotic drugs to help treat serious infections.
Sucking chest wounds
See open pneumothorax. A person with a penetrating chest wound is experiencing a life-threatening medical emergency and needs immediate access to advanced medical care and equipment to save their life. One standard first-aid treatment is to cover the wound with a pressure bandage made air-tight with petroleum jelly or clean plastic sheeting. It is important not to completely close off the opening. Leave a flap or corner open so that air does not build up in the lungs yet the patient can still breathe.
Stabilize the break with splints, and move the injured party as little as possible unless they are certain to die from lack of shelter or care. The object is to prevent the bone from causing more injuries. If the skin is broken, treat it as a major wound.
Broken ribs are stabilized with tape. A person with a broken arm, collarbone or ribs can often be stabilized enough to walk out, however large amounts of pain indicate this is a bad idea. Waxed cardboard splints are inexpensive, very lightweight, quite waterproof and quite strong.
The basic treatment is oil of cloves on packing in the sore tooth to reduce the pain. Systemic antibiotics and analgesic such as acetaminophen (paracetamol) or NSAIDs may also help if available. Although teeth may hurt terribly, most severe tooth infections simply result either in a dead tooth, or a tooth that falls out and are rarely life-threatening.
CPR (Cardio-Pulmonary Resuscitation)
CPR is often portrayed in movies and television as being highly effective in rususcitating a person who is not breathing and has no circulation. A 1996 study by the New England Journal of Medicine showed that CPR success rates in television shows was 75%. The reality is that CPR administered outside hospitals has a 2-15% success rate on its own, and is most importantly used to sustain oxygen supply to the brain until specialized medical equipment and personel can reach the scene (see defibrillator).
If you are performing CPR in the wilderness, you may want to stop:
- when a competent health professional takes responsibility for the patient; or
- when the rescuers are in danger.