Archive for April, 2009

It is almost a given that anyone who comments on medical issues should be saying something about swine flu and its implications. What more can we say? The stats and real (and imagined) seriousness and pervasiveness change daily. In the end this is still influenza, a potentially lethal respiratory virus that most people survive. It is spread person-to-person by water droplets produced from coughing and sneezing. It is relatively easy to avoid contact by staying home from work but not so easy to isolate oneself on board a small boat or in a tent when pinned down by a raging storm. Wash your hands and be courteous by coughing and sneezing into the crook of you elbow. When water is not readily available and you have the room, alcohol handwash solution is not a bad idea. As it turns out these are good ideas under any circumstances. Oseltamivir (e.g.,Tameflu – an antiviral) may be beneficial, especially if you are planning to head to Mexico or maybe CA or TX (and now even more places) but at $90+ US for ten 75mg tablets (www.drugstore.com) should this be a high priority; how much would you carry? Over-the-counter medications are of little to no use for treatment or prevention.

If you are worried, go to a reliable source, e.g., www.cdc.gov and not the nightly news cast. Remember, this is a quickly moving medical story. The people who know the most and are honest are likely to give fewer definitive, unequivocal answers than those who are removed from the center but seem to know it all.

Dr. David Johnson
President and Medical Director
Wilderness Medical Associates
Wilderness Medical Associates, Canada

When should a blow to the head cause concern? Should stories about head injuries like Ms Richardson’s change anything that we do in a wilderness setting?

1.  “I know someone.”  Anecdotal stories are not helpful for anyone. They make it nearly impossible to verify cause and effect let alone the details of what really happened. Deriving lessons to be learned from them is accordingly difficult. Ms. Richardson is a case and point. Follow-up stories purported to quote experts who advocated that all people sustaining a blow to the head, whether with or without loss of consciousness, are at significant enough immediate risk to warrant an evaluation by a medical professional. By extension, this means an evacuation if in a remote setting. These ideas are disingenuous and ridiculous and help no one.

2. Our position.  We believe that a blow to the head will cause an important brain injury (e.g., ones that require surgery or close hospital observation) only when impaired brain function results. Impaired brain function includes loss of consciousness (LOC), amnesia or at least a brief change in mental status including being stunned, punch drunk; lights on no one home.  Dizziness yes; seeing stars, no.

3. Concussion or TBI (traumatic brain injury)? We switched to TBI because it has become current terminology and seemed clinically based (change in brain function implied brain injury). On the other hand, the term concussion is pervasive but it is non-specific and has a variety of definitions.

4. How frequent is unlikely?  Ms Richardson developed an acute epidural hematoma (EDH), a collection of blood between the skull and the outer membrane around the brain. The frequency of this happening has been reported in 1 to 10% of all head injuries but it is not clear how head injury is defined or what the origins of these numbers are. More recent studies looking specifically at minor head trauma (LOC but awake on evaluation) of people coming to hospital are probably more helpful.  The Canadian Head Rule study reported that 0.5% had EDHs and 0.4% of all patients entered in the study required a neurosurgical procedure.(1) 2% of the patients entered in the New Orleans study had EDHs, 20% of whom required surgery.(2)  In each of these studies everyone had an LOC or something that qualified as abnormal brain function.  It would be hard to believe that the number of EDHs occurring without abnormal brain function would be higher. And not all EDHs are catastrophic, requiring surgery.

4.  Who is at highest risk?  Few people who have a TBI but wake up develop any serious sequelae requiring prompt, hospital-based intervention. Who is at the highest risk? Certainly this would include anyone with early signs of increasing intracranial pressure (ICP – persistently abnormal mental state, recurrent vomiting, worsening headache). According to the largest studies previously referenced, other important risk factors include evidence of a skull fracture (e.g., persistent leaking of blood and/or spinal fluid from the ears or nose not attributable to a local injury, large boggy scalp hematoma), high velocity/high mass impact, current use of anticoagulants/antiplatelet drugs, and age in the sixties.  Duration of LOC and pupil evaluation in an awake person were not listed as important factors. Injuries to the temple should also heighten one’s concern because its thin-walled structure makes the local arterial blood supply particularly vulnerable. According to several online references (no reliable citations given), 80+% of all EDHs occur following a fracture to the temple.

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5.  We are at least 2 hours from help.  The risk factors listed above should be helpful when a decision to evacuate poses significant risk to the rescuers and additional risk to the patient. But even a prompt evacuation of an EDH may still result in a horrible outcome because one can evolve so quickly.  An EDH in the posterior fossa (back of the skull near its base) is particularly devastating because one can present with few signs and proceed catastrophically in minutes.

Bottom line:  This is a horribly tragic story.  Even if she had developed an EDH without an apparent TBI, it would not be the basis for policies that mandate evacuations for everyone with a blow to the head.  Ultimately we know this by reading the literature and seeing real patients on a regular basis.  Despite these rare occurrences, we owe it to our students and their clients/patients to address blows to the head rationally.  Was there a TBI?  If so, the anticipated problem list includes increased ICP.  An appropriate plan is one that weighs the risks and benefits including some of the high risk factors list above.  If there is no TBI, bleeding and/or increased ICP are not going to develop.  In such a case, an urgent evacuation for further evaluation and treatment would not be warranted.  Increased ICP, on the other hand, is an emergency.  Its signs and symptoms, regardless of the cause, known or not, whether or not diagnosed as a TBI, need to be taken seriously.

If we want to practice and teach medicine, we have to accept the fact that there is no 100% or 0%.  In this case, it is a pretty safe bet.

1.  Stiell, et al.  Comparison of the Canadian CT rule and the New Orleans Criteria in patients with minor head trauma. JAMA 2005;294:1511-1518.
2.  Haydel MJ, et al. Indications for computed tomography in patients with minor head injuries. NEJM 2000;343:100-105.

PS This past week there was an article in the New England Journal of Medicine (Vol 360:1588) on the implications of the number of TBIs and subsequent post concussive syndromes being reported in the SW Asian theatre. Among other issues, the author questions the use of mild TBI instead of concussion. This is a subject worthy of more lengthy commentary.

A student shares an experience that occured the day after they attended one of WMA’s Wilderness Advanced First Aid courses.

At work for a half hour. Monday morning. Phone rings, client with severe drug addictions and Borderline Personality Disorder calls. She wants to talk about not taking methadone in four days. She is speaking softly. She regularly comes on and off opiates, and while the detox is always serious, I now knew to focus on the PAS to determine what was actually life-threatening. I began asking her about her breathing which was fine, and there were no other issues for immediate death, but I did go to ins and outs, which I may not have done before the WAFA training. She reported that she hadn’t eaten since last Tuesday and vomited when she did, didn’t know when her last bowel was, hadn’t peed in at least 24 hours and didn’t remember drinking anything since some juice last night. (I later learned she was drinking alcohol up until Sunday). The flags went up for where the real problems were and I instructed her to get to the ER. She was treated for severe dehydration and electrolyte imbalance. Aside from being helpful, what I was struck by was my immediate confidence in how to handle and assess the situation. While not the most dramatic first aid story, this client can be extremely difficult to know what to do with and at least in this case I knew.

Have you had to use your skills since your course?

Click here to watch a great video on Dave Ramsey and why he teaches for Wilderness Medical Associates. Dave has been instructing for WMA for over 6 years and teaches courses around the world! He is also co-owner of Backcountry Rescue Institute, Inc. located in Kentucky.

Wilderness medicine providers know that prevention and early intervention are critical to a successful day hike, camping trip, or multiple week expedition. Those same skills of prevention and early intervention are applicable to all aspects of life. Some things you probably do already (or should be) include wearing a seatbelt, not using tobacco, wearing a cycling helmet, and eating whole grains, fruits, and vegetables.

This week is National Public Health Week. Take a moment to watch this video about the important public health challenges facing us and the simple steps we can all take to make the Healthiest Nation in One Generation.

Learn more at generationpublichealth.org.

This blog was submitted by:

Greg Friese, MS, NREMT-P, WEMT
President, Emergency Preparedness Systems LLC