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Recent Curriculum Updates for WFR Students
By Tod Schimelpfenig
Curriculum Director – WMI of NOLS
Updated September 2007
Medicine is dynamic. We stay abreast of changes in practices and knowledge, and regularly update our curriculum. These are summaries of recent updates and enrichment pieces. WMI Curriculum updates and resources are available at: www.nols.edu/wmi/curriculum_updates/
Curriculum Update: Estimated Blood Pressure (May 2008)
One of our tools for measuring blood pressure (BP), in addition to auscultation and palpation, has been estimation. We have been using rules of thumb that a radial pulse indicates a systolic BP of 90, a femoral a systolic BP of 60 and so forth.
We’ve always been skeptical of these numbers. There are a couple of small studies of the accuracy of this method, which show a wide range of systolic BP’s correlated with various pulses, ranging, for example, from 55-90 mmhg for a radial pulse. Estimated BP’s also have a tendency to overestimate the systolic BP. The numbers are not accurate enough to use.
The presence of a strong radial or pedal pulse suggests the patient has a cardiovascular system healthy enough to pump blood to their hands and feet. That’s good. The absence of a radial or pedal pulse, unless explainable by limb injury, suggests that blood pressure may be low. If this is the case it’s likely accompanied by other s/s of shock.
Curriculum Update: Level of Responsiveness (February 2007)
We are changing terminology from level of consciousness to level of responsiveness (LOR). This is the trend in the profession and in EMS textbooks, and it will help us avoid the ambiguity in the word ‘consciousness’. Responsive is a more clinical and specific word. Remember, just as heart and respiratory have attributes of rate, rhythm and quality, LOR should have stimulus (how we stimulated the patient) and response (what they did). We still use AVPU to describe the level of responsiveness.
Curriculum Update: Tourniquet Location (February 2007)
Put your tourniquets on 1-2 inches above the injury site. If it does not work, go above the elbow or above the knee. Most of the wilderness medicine books don’t tell you where to place a tourniquet. One exception says to place it above the knee or elbow, but has an illustration of a tourniquet below the knee. The need for tourniquets is rare in urban and wilderness medicine. The military medic curriculum has the cutting edge information and experience on tourniquets. Our Medical Advisory Panel was unanimous in recommending we teach the practices in the Tactical Combat Casualty Care curriculum which says “place the tourniquet 2 inches above the wound between the wound and the heart.”
Curriculum Update: Heat Cramps and Heat Stroke (September 2006)
We made some changes in our heat illness curriculum to reflect lessons from the Grand Canyon National Park Rangers about heat illness, that is, heat stroke patients may have pale skin and heat cramps are best treated with gentle stretching, not massage, which can make the cramps worse.
Orthostatic Vital Signs (November 2006)
The orthostatic vital sign test should be:
- Test the patient by waiting 2 minutes with the patient supine, then stand the patient and wait 1 minute before measuring vital signs. The sitting position is not helpful.
- A positive test is an HR increase of 30 beats/min or more in adults, or the presence of neurological symptoms (eg. dizziness, syncope).
- This test is only one piece of an assessment that has us looking at HR, RR, BP, LOR, SCTM – the entire picture of the patient presentation.
Curriculum Enrichment: Recluse Spiders (February 2005)
The Brown Recluse spider (Loxosceles reclusa) is regularly spoken of as a cause of necrotic wounds. Finding claims of recluse bites is easy. Finding documentation is difficult. The noted toxicologist Findley Russell MD remarks that 8 out of 10 bites in one study were miss-diagnosed. Spider bites are a wonderful example of our tendency to react strongly and perhaps illogically to unknown or scary risks, such as spiders, than to more common and mundane risks, such as heart disease.
Brown recluse spiders are rarely confirmed in states where they are not resident (mainly the mid west). Stories of brown recluse spiders outside of areas where they are endemic are highly suspect.
The violin-shaped pattern on the cephalothorax is the most often mentioned distinguishing characteristic, but it is unreliable. The eye pattern is the easiest and most accurate way to identify Loxosceles spiders. Most U.S. spiders have eight eyes. Brown recluse spiders have six eyes.
The list of conditions that are frequently mistaken for brown recluse spider bites is lengthy and include staphylococcal or streptococcal infection, herpes, diabetic ulcers and fungal infections.
The hobo spider (Tegenari agrestis) allegedly causes a necrotic wound similar to that of the brown recluse spider, along with a characteristic persistent headache. There is scant documentation supporting claims that hobo-spider bites actually cause necrosis. In its native European habitat, the hobo spider is not considered poisonous to humans.
Curriculum Update: Altitude (February 2004 )
According to altitude expert Peter Hackett MD:
- It is a myth that over hydration protects against altitude illness. Dehydration can impede acclimatization and predispose us to AMS. Hydration is vital to our health and well-being, but pounding extra water does not prevent AMS.
- Oxygen is the drug of choice for HAPE, but early recognition and descent are still key.
- Diamox and Decadron can help prevent and treat AMS (but slow ascent is still the mainstay in prevention).
Curriculum Update: Abdominal Pain Evacuation Guidelines (November 2004)
We have added “Peritoneal signs,” movement pain or pain with foot strike, to the evacuation criteria for abdominal pain. We reviewed several recent field cases with difficult abdominal pain diagnoses, and our physician advisors thought this criteria should be included. Pain on movement or foot strike may indicate an inflamed appendix.
CPR in Severe Hypothermia (February 2004)
This continues to be a controversial area. Starting chest compressions on a patient with severe hypothermia risks triggering ventricular fibrillation if the patient in fact has a heartbeat. Assessing a pulse in a severely hypothermic patient can be very difficult. We advise avoiding CPR, using a hypothermia wrap to prevent further heat loss, rescue breathing to avoid ventricular fibrillation and as gently as possible transporting the patient.
Fish Eyes and Water Disinfection (November 2004)
The common diarrhea-causing microorganisms are killed as water is heated, and immediately when water is boiled. The protozoa Giardia dies after two to three minutes at 140oF (60oC). Viruses, diarrhea-producing bacteria, and Cryptosporidium cysts die within minutes at 150oF (65oC).
Fish eyes are the bubbles rising from the bottom of the pot as water is heated. Some people believe this is hot enough for reliable disinfection. We disagree. “Fish eyes” are subjective. Bubbles start to form at different temperatures depending on the initial temperature, altitude and other factors. They may form at water temperatures that have not killed microorganisms. It's much easier to recognize a boil. Although "fish eyes" could be sufficiently hot, WMI teaches that it is more reliable to wait the few extra minutes for the rolling boil.
What is the effectiveness of CPR in lightning victims? (October 2004)
There has been a statement in wilderness medicine circles that 7 of 10 people with cardiac arrest from lightning strike will survive with prompt and effective CPR. The available statistics show that 7 of 10 lightning strike patients survive, but it does not specify how many of these people had a cardiac arrest. The available data is not specific enough to say whether there is a higher survival rate for cardiac arrest from lighting versus cardiac arrest from other causes. In favor of the patient who has a cardiac arrest from lightning might be youth, health, the absence of underlying heart or lung disease and no hypoxia before arrest. Not in their favor might be trauma, burns and remote location.
The Focused Spine Assessment (February 2004)
You probably learned this as "spine clearing", a protocol for deciding if spinal immobilization is warranted. The protocol hasn't changed, just our vocabulary. We want to move away from the common phrasing of "spine clearing", which can imply a bias toward a positive result, and move toward language that promotes this procedure as a focused assessment of the spine, after which we can make an informed decision whether or not to continue to immobilize the spine
Do we really need to dilute sports drinks? (February 2003)
The recommendation to dilute sports drinks is out of date - left over from a time when we were conservative regarding the use of glucose-electrolyte beverages and in fact, some of them did have a higher carbohydrate content than what was optimum for gastric emptying.
These drinks are designed to hydrate athletes. People may dilute sport drinks to adjust the taste, and endurance athletes often have individual preferences on the sugar and electrolyte content of their beverages. This is fine, but WMI no longer recommends automatically diluting sports drinks.
Does the Sawyer Extractor work? (November 2003)
WMI has changed it’s curriculum on the Extractor, based on the opinions of experts and research that indicates the Extractor has not lived up to it's original promise. A study published in the February 2004 Annals of Emergency Medicine found little to no venom was extracted by the extractor. A companion commentary article reviewed past studies of the extractor and weighed pros/cons. The authors overall recommendation was "This study should change our practice. We should stop recommending Extractors for pit viper bites, and the manufacturer should certainly stop advertising that they are recommended medically as the only acceptable first aid device for snakebites."
HIRICE Change (August 2003)
We no longer recommend high NSAID (ibuprofen/naproxyn) dosing as a treatment for musculo-skeletal injury. There is limited evidence it helps, and concerns about the risks of high NSAID dosing causing gastrointestinal bleeds, and suggestions it delays healing.
How effective are heat packs at hands and feet of the hypothermic patient? (2001)
Not very, says Gordon Giesbrecht, PhD, a Canadian and a leading researcher into hypothermia. With one heat pack or warm water bottle place it in the hands and hold it over the chest. With two water bottles/heat packs place them at hands and feet, with three place them at hands, feet and armpits, with four place them at hands, feet, armpits and groin. Wrap the heat packs or hot water bottles. Take care not to burn the patient.
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