"To Those in the Field"

Appropriate Medical Technology

© 2005 Jeffrey E. Isaac, PA-C

Appropriate Medical Technology for Wilderness Search and Rescue

… a role for the Physician Advisor

             Search and rescue personnel face an unprecedented array of choices in technology and training. The pace of advance and the intensity of the marketing effort can overwhelm the opportunity for critical evaluation. This can easily lead to the purchase of devices or the adoption of techniques that don’t work, are overly complicated, or too expensive to justify the presumed benefit. It can also cause avoidance behavior and the perpetuation of obsolete equipment or protocols that should be replaced or modified.

             A physician advisor with an interest in backcountry medicine is in an excellent position to help team leaders make appropriate choices.  There are new offerings in medical equipment and training that enhance safety and performance, and we owe it to our teams to bring these to light when we can. We also have a responsibility to discourage frivolous spending, the imposition of onerous training requirements, and fostering unrealistic expectations of success. Critical evaluation and selection requires an open mind tempered by a healthy skepticism, attention to the science behind the subject, and real-world clinical experience.

             While recent technological advance is stunning, the basic physical problems faced by SAR teams have changed little. Gravity is still the law, the weather remains uncontrolled, and human evolution has not offered any recent improvements in anatomy and physiology. Most rescue equipment is still hauled and operated by people working in far from ideal circumstances. The value of any technology must be measured against these irreducible realities, regardless of its "tool box appeal”.

Critical Evaluation

             A patient being rescued expects your team to be expert in SAR operations and wilderness medicine. As consumers of medical equipment and training, your team expects its suppliers to be expert in SAR equipment and technique. While some of them are, many are even more expert at marketing and sales. Your perspective can help make the distinction.

 

             Your evaluation should emulate the characteristics of most really good equipment; simple, inexpensive, with few moving parts. Ask yourself and your team the following questions:

· What does device really do?

· Is the advertised benefit supported by real science?

· Do we really need to do what the device does?

· Can you carry it?

· Based on your experience will it really work in the steep, dark, frozen, wet wilderness?

· What kind of trouble will you be in if it doesn’t work?

If the device or technique survives for further consideration, try to avoid the following pitfalls:

· Assuming a device that is friendly and familiar in the ED will be safe and effective in the backcountry.

· Fielding a device that provides only part of a treatment regimen or protocol, the rest of which is unavailable or impossible to accomplish.

· Fielding equipment that creates training requirements out of proportion to the frequency of use or medical benefit.

 

             Consider, for example, the automatic external defibrillator (AED).  Citing the apparent success of the device in the urban context, AED’s are being aggressively marketed to SAR teams, backcountry guides, and offshore sailors. As the size and cost of AED’s come down it would seem to be an attractive option in these environments as well.

             It must be remembered, however, that the AED is just one link in a chain of medical care including CPR, early defibrillation, advanced life support, and transfer to a hospital coronary care unit. Successful defibrillation with an AED depends on application within a few minutes, and the presence of an intact cardiovascular system suffering specifically from ventricular fibrillation or tachycardia. In spite of its urban and EMS application, the chances of a wilderness SAR team being in a position to effectively do what the device does are remote at best.

             The typical EMS-type extrication collar used for spine injury protection provides another example for critical evaluation. These devices are light in weight, relatively inexpensive and, even if properly applied, excruciatingly uncomfortable. While discomfort is not much of an issue on a short ambulance ride to the hospital, it is a major factor in long-term transport in the backcountry. An uncomfortable patient actually moves around more, complains more, and requires more pain medication. Skin ischemia and aspiration of vomit, blood, and secretions also become anticipated problems.

             As any ski patroller can tell you, a stiff cervical collar is difficult to apply around bulky winter clothing. As any ski area practitioner can tell you, they rarely arrive at the clinic adjusted as shown in the training manual. The device was designed for short-term EMS use during extrication, not for wilderness rescue. Yet, they considered by most rescuers to be a standard of care, even in the backcountry.

             By contrast, the old ski patroller’s “horse collar” used with a vacuum mattress or litter offers effective stabilization for everything from the cervical spine through the pelvis and femur. It is also warm and comfortable. The vacuum mattress is moderately expensive and bulky, but it is lightweight and infinitely versatile in the stabilization and positioning of injured patients. It also makes a fine bivy pad if you get stuck overnight some place. Since the mattress is a vacuum device, it is easily repaired in the field with duct tape. A blanket and a vacuum mattress are easier to use and effectively replace cervical collars, backboards, thermal padding, and traction splints. For your money, here’s a simple, multi-purpose tool for packaging and stabilization.

Communication and Telemetry

             Advances in communication technology such as sat phones and telemetry units enable medical control physicians to provide advice and give orders real-time almost anywhere. A hospital-based provider can now receive information by voice, telemetry, and digital image. Orders for treatment can be given and the progress observed from hundreds or thousands of miles away.

             In considering these obvious benefits, we must also acknowledge the risks associated with remote decision-making. The medical officer on scene may actually be in a better position to develop a treatment and evacuation plan but obligated to defer to the higher authority on the radio. The need to establish communication with remote medical control may unnecessarily delay transport.

             While adopting these new communication technologies, we must be sure that our virtual presence will enhance rather than inhibit on-scene medical capability. 

Medications and Delivery Systems

             New drug delivery systems offer some good solutions to SAR medicine, particularly in the form of pain relief. Sub-lingual morphine, liquid Vicodin, and Fentanyl pops offer rapid onset and easy administration, and completely avoid the problems associated with contaminated sharps. With appropriate medical supervision, field medical personnel who may not be authorized to perform injections could administer these medications.

             IV fluid replacement, taken for granted in the urban setting, presents some real challenges to the SAR medical team. The market has responded with various forms of pressure infusion systems, warmers, and carrying systems. Infusion Dynamics offers a battery-powered infuser only twice the size of a pack of cards retailing for about $1800. It can be set to deliver a precise flow rate regardless of gravity.

             The evolution of this example also offers a lesson in practical design. The original product used a specialized and expensive battery pack. The newer version uses standard AAA batteries available anywhere, perhaps even stolen from your headlamp in a pinch.

             As appealing as the various new devices for IV therapy are, the justification for their use is limited. Rather than spending thousands of dollars on warmers and infusers, consider a bolus system utilizing a 60cc syringe and a three-way stopcock. For less than $5, you can infuse fluids through a peripheral or IO port in periodic boluses rather than try to maintain a gravity flow or monitor an electronic system. It is simple to set up and purge, requires no batteries, can be packaged and warmed with the patient, and is under direct control of the medic whenever in use.

             Another frequently carried medical technology is the Epi-Pen Autoinjector.  Its obvious benefit is ease and safety of use, but the cost runs about $80 retail for one dose with a shelf life of only 1.5 years. Medics working in remote settings will need to carry two or three of the devices to allow for repeat doses.

             A less expensive alternative is to carry a 1 mg ampoule of epinephrine and a 1cc syringe, which costs about $2 and provides 3 doses. The combination weighs a fraction of the Epi-Pen, and occupies much less space. In freezing weather, it can be easily carried inside insulated clothing. In this case the reduction in technology requires an increase in training and competence, but the trade-off is worth it.

             Since you’re going to provide the extra training, you might also train your team to use diphenhydramine and prednisone. The stand-alone EpiPen is fine for the few minutes that it takes the ambulance to arrive in town. But for prolonged evacuations in the backcountry, epinephrine alone is incomplete treatment.    

Procedures

             Cardiopulmonary resuscitation (CPR) serves as an interesting example of an entrenched program that consumes training resources out of proportion to its value as a treatment technique. Never-the-less, certification in CPR is required by various government agencies for wilderness guide permits. While CPR is appropriate in the urban setting, its requirement as an essential part of wilderness medical care is questionable.

             Numerous studies have confirmed that CPR will not extend survival beyond 30 minutes, or resuscitate trauma patients in cardiac arrest. The success rate of the technique in the backcountry setting is extremely low (zero?). When one compares the value of CPR to the wide variety of other useful medical, rescue, and survival skills, spending more than 30 minutes on CPR training seems excessive.

             Spine stabilization is another entrenched requirement that would benefit from a more realistic wilderness perspective. The incidence of unstable spine injury is very low compared with the incidence of rescuer injury and death associated with technical or aero medical evacuation. The risk of exacerbating cord injury rarely justifies the considerable risk inherent in the evacuation of a patient in spinal stabilization.

             Fortunately, new spinal assessment protocols offer a well-documented procedure for determining which patients actually might benefit from spine stabilization. The next step is to enable rescuers to weigh the benefit of stabilization against the immediate risks to life presented by evacuation hazards, aspiration, hypothermia and other problems created by the procedure. In backcountry and technical rescue, the risks associated with spine stabilization often outweigh the presumed benefit.

             Authorization by a physician advisor for the use of wilderness-specific protocols can free the team from the unrealistic and often dangerous obligation to follow protocols written for street EMS. Offered by a number of sources, these procedures represent a more practical approach to medical care for SAR units. Wilderness medical training and protocols are already wildly accepted by federal agencies and outdoor education institutions. Recognition and use by state and local medical boards and state agencies is increasing.  

Conclusions

             Almost any piece of equipment or technique can look effective in the hands of a skilled operator. "Effective at what?" is the essential question. Critical evaluators need to look beyond the marketing to the science and practical application.

             Generally, a product or procedure reinforced by a number of scientific studies is going to be more valuable than something with little or no research behind it. The limitations of CPR and the validity of "spine clearing" techniques are examples well supported in the medical literature. By contrast, a number of devices are marketed in response to perceived risk or benefit with no scientific support. You might remember the cattle prod re-packaged as an electric shock treatment for snakebite.

             Good science must then be filtered through your own experience. In wilderness rescue, the real experts are the people doing the work. No amount of marketing can overcome the real-world experience of failure or success in the field.