HAVE MEDICAL BAG, WILL TRAVEL
John R. Richards, MD, Associate Professor, Department of Emergency Medicine, University of California, Davis,
School of Medicine
| FIRST AID KIT FOR REMOTE WILDERNESS TRAVEL
|
| Travel emergency planning: need for extensive kit and equipment increases with distance from emergency services;
when packing kits, anticipate scenarios; in remote destinations like Nepal, emergency transport and facilities pose challenge;
consider duration of excursion and types of environmental risk (eg, climbing, scuba diving, skiing); plan routes of
escape and evacuation when traveling in third world
|
| Wound management top priority: take care of wounds fast before cellulitis or necrotizing fasciitis develops; skin
breaks common on trips; essential supplies—fluids to cleanse, irrigate, and disinfect; suture material, steri-strips or butterfly
closures, and benzoin; moleskin for blisters (duct tape good waterproof alternative); scalpel, latex gloves, suture kit; ointments
(eg, Neosporin, Xeroform or other petrolatum dressing); bandaging materials (bulky dressing, velcro, eye pads,
Band-Aids) that do take up space in kit; scissors, forceps for splinters and ticks, thermometers, temporary dental fillings;
SAM splints
|
| Medications: for traveler’s diarrhea (single most encountered problem); for insect stings and allergic reactions; over-the-
counter remedies, including meclizine, which is also antihistamine and anticholinergic, so good for prophylaxis of motion sickness
|
| Prescription medications: carry wide spectrum of antibiotics; ciprofloxin (Cipro) good choice for traveler’s diarrhea and
skin infections but has lost much efficacy due to overuse; agents to cover gram-negative infections and anaerobic organisms;
in case of acute appendicitis, antibiotics can reduce inflammation during transportation to hospital
|
| Epinephrine and steroids: epinephrine (EpiPen) good idea for individual with history of anaphylactic reaction, especially
if hypotensive; prednisone always good idea; antibiotic eye drops and ointment for treating corneal abrasions (including
local anesthetic, as cornea highly sensitive); ear drops (otitis externa common sequela of water sports); metered-
dose inhaler for those with reactive airway disease
|
| Motion sickness: ondansetron (Zofran) expensive but works well because it does not cause sedation
|
| Water sports: freshwater and saltwater organisms, eg, Pseudomonas putrefaciens; case—man at hot springs in Costa
Rica cut his foot and left on 7-day boat trip; foot became red and purulent; man went into denial and refused treatment; denial
common in travelers, but physician should insist on treating them
|
| High-altitude kit: need some prescription drugs for trips to high altitudes; be prepared for acute mountain sickness and
high-altitude pulmonary edema (acetazolomide, steroids, furosemide, and nifedipine can save life)
|
| Air travel: need for physician greatest on way to destination; vasovagal incidents most common (eg, dehydrated person
has syncope); cardiac events also common; transient ischemic attacks (TIAs) and cerebrovascular accidents (CVAs);
gastrointestinal (GI) complaints; respiratory problems (low-O2 environment); trauma, eg, luggage accidents
|
 | Cardiac arrests: ≈1000 in-flight annually; Airline Medical Assistance Act (1998) requires that every airplane that goes
higher than 30,000 ft needs advanced kit; some carriers have full pharmacopeia; in emergency, make overhead announcement
because passengers carry surprising array of medications and items, eg, nitroglycerin tablets, zolpidem
(Ambien)
|
| History unknown at check-in: recent events that could cause travel problems include myocardial infarction (MI) in weeks
before trip, unstable angina, severe congestive heart failure (CHF), pregnancy within 4 wk of estimated date of confinement
(EDC), recent bowel surgery (gas expands on plane’s ascent), sinus problems (severe pain on descent), severe
anemia, communicable diseases (eg, avian flu); case—41-yr-old woman experienced abdominal distention and pain
in-flight; in emergency department (ED) found to have volvulus that expanded 30% on ascent in plane
|
| Basic kit on every airplane: oropharyngeal airways; intravenous (IV) solution; basic medications (eg, nitroglycerin
tablets, diphenhydramine [Benadryl], dextrose [D50], epinephrine); automated external defibrillator (AED); bag-valve
device; one transatlantic airline provides adrenalin, atropine, glucagon, diazepam, nitroglycerin tablets, naloxone (Narcan),
furosemide, cortisol, ergotamine (for postpartum hemorrhage), metoclopramide (Maxolon), antihistamines, anticholinergic
drugs, airway equipment, and Foley catheter; miscellaneous box contains sutures and IV cannulas
|
| Oxygen supply: people may become sleepy and short of breath in airline environment; O2 supply comprised of large
(3,000L) tanks and small overhead tanks (300 L) with short life at 4 L/min through pop-down mask (demand may exceed
supply); low humidity always problem on flights; high risk for deep venous thromboses (DVTs); dehydration universal
cause of vasovagal syncope; even in healthy person, O2 saturation drops to ≈90%; for travelers with pulmonary disease,
low O2 saturation much more serious
|
| Good Samaritan Law (1996): case—speaker carried out delivery for pregnant 35-yr-old woman on airplane; malpractice
attorney told speaker that by stepping forward, physician-patient relationship created and that birth not seen as medical
emergency; if outcome bad, physician may be at risk for lawsuit despite Good Samaritan law; some airlines cover legal action
against volunteer physicians; malpractice insurance usually does not cover
|
| Accepting gift: physician should not accept anything from airline for helping out because some airlines might consider
that payment for services rendered
|
| Lawsuits: physician can be sued in whichever country or state physician and patient flying over at time of incident, regardless
of where each one resides; case—woman with fatal mid-flight asthma attack on trans-Atlantic flight; first-year
surgery resident (speaker) along with another physician, nurse, and flight crew performed cardiopulmonary resuscitation
(CPR) for 2 hr; lawsuits brought in federal and state courts; resident’s hospital provided legal support; resident dismissed
from lawsuits on basis of Good Samaritan law
|
| Lessons of 1964 Four Inns Walk (United Kingdom): competitive 45-mile cross-country hike; of 240 hikers who
started, only 22 finished; 3 died of hypothermia, 4 rescued in critical condition; deaths and hypothermia attributed to harsh
conditions (rain and temperatures of 32ºF-45ºF), inadequate clothing (cotton not good insulator), and inadequate prewalk
nutrition
|
| Hypothermia defined: mild hypothermia 32ºC, but 35ºC enough to produce unwellness and hypothermic symptoms;
moderate hypothermia <32ºC, severe <28ºC
|
| Signs and symptoms: mild—starting at 37.6ºC (normal rectal temperature) and moving down to 33ºC, symptoms range
from normal function to frank ataxia, apathy, and cold diuresis; apathy means patient does not care about rescuing self and
getting to warm spot; moderate—patient in stupor and no longer shivering; at 30ºC, people become poikilothermic (like
reptiles; rely on external heat to heat themselves); humans can heat themselves above 32ºC; severe—cardiac arrythmias,
loss of pain response, brain starting to fail; at 22ºC, victim becomes moribund, and just moving him or her usually precipitates
ventricular fibrillation
|
| Other causes: anything that decreases heat production or increases heat loss (many medical conditions and disease processes);
impaired thermoregulation (anything that affects brain, ie, temperature regulation center in hypothalamus); miscellaneous
causes seen frequently in ED, eg, sepsis
|
| Populations at risk for hypothermia: young with proportionally larger body surface area and larger heads (scalp
highly vascular); elderly, malnourished, and sick people; alcoholics (alcohol interferes with shivering, is peripheral vasodilator,
and acts as antidiuretic hormone antagonist, resulting in diuresis and chronic dehydration)
|
| Epidemiology: 1000 deaths annually (probably more) in United States, 50% of patients >65 yr of age; male-to-female ratio
3 to 1; many elderly; socioeconomic factors; mentally ill and homeless people at 5 times greater risk
|
| Thermoregulation: anterior portion of hypothalamus controls heat loss, posterior portion controls heat retention; most
thermoregulation occurs in skin, ie, peripheral vasoconstriction determines temperature control (vasodilation if too warm,
vasoconstriciton if too cold); sweating increases rate of heat loss; exercise—cannot usually exercise enough to overcome
hypothermia; prolonged heavy exercise can raise body temperature; however, if sweating impaired, hyperthermia and heat
stroke possible; amount of heat generated through exercise and metabolism usually not enough to counteract heat loss in
cold environment; O2 consumption—in hypothermia, increases until person becomes stuporous, then respiratory rate decreases
|
| Cold adaptation: humans not meant to live in arctic conditions and cannot adapt to them; we have to bring our tropical
climate (clothing) with us when we travel; shivering—important physiologic signal to go to warmer location or add
clothing; generates heat; difficult to perform fine motor tasks while shivering; useful work more effective for heat generation
than shivering; alcohol, medications, hypoglycemia, and exercising to exhaustion interfere with shivering and can
induce hypothermia; signs of hypothermia—stumbles, mumbles, fumbles, grumbles; irritability and refusal to cooperate;
all indicate changes in motor coordination and levels of consciousness; watch out for these in companions
|
| Prevention: eat diet sufficient for energy needs in cold (frequent meals); avoid alcohol and caffeine (vasodilators); stay
well hydrated (cold induces diuresis); stay dry because wetness reduces efficiency of keeping warm
|
| Mechanisms of heat loss: convection—moving water or air over body; most prevalent mechanism of heat loss in cold
environment; radiation—heat loss from body to environment; evaporation—of vapor on skin and in respiratory tract; most
effective way to lose heat; conduction—heat conduction from body (ground and rocks good conductors, so put something
between sleeping bag and ground); alcohol good conductor, so best to avoid
|
| Effects of hypothermia: blood—third spacing occurs, blood volume reduced, and hemolysis may occur; viscosity increased,
placing victim at risk for DVT or other thrombotic event; O2 delivery diminished, although hemoglobin curve
shifts and more O2 in solution; however, acidosis eventually develops; cardiac—endocardium more at risk for arrhythmias
because of alteration in ion function and membrane receptors; traditional cardiac therapies, eg, defibrillation, unpredictable;
at 30ºC to 32ºC, expect ventricular arrythmias; renal—renal blood flow decreased, cold diuresis occurs, and
antidiuretic hormone released, so patients need fluid; central nervous system (CNS)—brain protected during hypothermia
because metabolism declines and less ATP used; O2 free radicals not generated (avoid hyperoxygenating victim);
when brain reaches 20ºC, function not likely to return; lungs—alveolar damage, hemorrhages, pulmonary edema; can
develop pneumonia due to decreased ciliary action; respiratory acidosis
|
| Tissue freezing: as tissues begin to freeze, ice crystals form in cells, bringing potential to rupture cells; when rewarming,
do not rub tissue because tearing could occur, eg, blow into hands instead of rubbing
|
| Medical complications: frostbite—affects entire epidermis and dermal layer; loss of sensation in limbs distinguishing
sign; do not rub; treat by immersion in water at temperatures of 105ºF to 110ºF; problem for emergency facilities of providing
large enough baths and one-on-one nursing care this demands (continuing to add warm water to bath); limb should
be immersed for ≈30 min, then reevaluated; return of sensation usually manifests as extreme pain; then immobilize, dry,
wrap in sterile gauze, and observe; cannot assess extent of damage until days later; trench foot—feet wet but victim fails
to realize; wetness causes evaporative loss of heat 24 times faster than normal; potential for permanent damage; treat by
careful washing, drying, and debriding lesions; immobilization of feet critical; pain common complaint; chillblains—
capillary injury typically seen on cheeks and earlobes; fair-skinned people more susceptible; prolonged cold exposure
leads to permanent damage
|
| Avoiding frostbite: travel companions should check each other frequently; denial can occur, even among health professionals;
wear adequate clothing; wool good and stays relatively dry when wet; down good but only if not wet; Gore-Tex
allows escape of vapor but prevents moisture from coming in; cotton poor insulator
|
| Treatment: head protection—critical out of doors to keep body warm; in patients admitted with hypothermia or trauma,
covering head critical; temperature monitoring—rectal temperature lags behind core temperature and may not be most
accurate; tympanic thermometry not effective at <34°C; esophageal temperature accurate until warm air introduced;
epinephrine—do not use until patient warm; avoid at body temperatures <30ºC
|
| Rewarming: most feared complication “core afterdrop,” ie, continued drop in temperature after removal from cold and
rewarming started; speaker advises to continue warming; passive rewarming—for mild hypothermia; patient rewarming
on own and assisted, eg, by covering and drying; active rewarming—for body temperatures <35ºC; involves directly
transferring heat to patient; variety of techniques and indications; Bair Hugger—efficient, easy to obtain,
noninvasive; 2 blankets under and over patient with forced air blown through them by convection; rewarming rate 1ºC to
4ºC per hour; worry about core afterdrop, but this has not been problem; warm water baths—immersion could save victim’s
life; must continuously add warm water; arteriovenous (AV) anastomoses—immersing AV junctions (eg, forearm,
tibia-fibula, feet) in very hot water baths prevents core afterdrop by removing anatomic problem of taking cold
peripheral blood back to core; other techniques—heated inflation of intubated patient (make sure air humidified; expect
increase of 1ºC to 2.5ºC per hour); warmed IV fluids; cardiopulmonary bypass—gold standard and strongly recommended,
especially for patients <30ºC or 32ºC; may be only chance of survival; 1ºC to 2ºC every 5 min
|
Educational Objectives
| The goal of this program is to educate the listener about equipment and medicines needed for emergency care during travel
and the management of hypothermic patients. After hearing and assimilating this program, the clinician will be better able
to:
|
| 1. Assemble a wilderness medicine kit for handling wound management and other travel emergencies.
|
| 2. List the basic requirements for an airplane emergency medical kit.
|
| 3. Cite the mechanisms of heat loss and the temperature ranges and symptoms of mild, moderate, and severe hypothermia.
|
| 4. Describe safe rewarming of a limb with frostbite.
|
| 5. Review techniques for rewarming victims of hypothermia.
|
Discussed on This Program
Acetazolomide [Dazamide, Diamox, Diamox Sequels]
Diphenhydramine HCl (Benadryl, others)
Ciprofloxacin [Ciloxan, Cipro, Cipro I.V., Cipro XR, Proquin XR]
Epinephrine [Adrenalin Chloride, Adrenalin Chloride Solution, Epifrin, EpiPen, EpiPen Jr., Glaucon, microNefrin,
Nephron, Primatene Mist, S2]
Ergotamine [Ergomar]
Furosemide [Lasix]
Metoclopramide [Maxolon, Metoclopramide Intensol, Octamide PFS, Reclamide, Reglan]
Meclizine [Antivert, Antivert/25, Antivert/50, Antrizine, Dramamine Less Drowsy Formula, Meni-D]
Nifedipine [Adalat, Adalat CC, Nifedical XL, Procardia, Procardia XL]
Nitroglycerin tablets (several trade names)
Ondansetron HCl [Zofran, Zofran ODT]
Zolpidem tartrate [Ambien, Ambien CR]
Suggested Reading
Basnyat B et al: Acetazolamide 125 mg BD is not significantly different from 375 mg BD in the prevention of acute
mountain sickness: the prophylactic acetazolamide dosage comparison for efficacy (PACE) trial. High Alt Med Biol 7:17,
2006; Basnyat B et al: Acute medical problems in the Himalayas outside the setting of altitude sickness. High Alt Med
Biol 1:167, 2000; Braude D et al: The Mt. Tyndall incident. Prehosp Emerg Care 3:167, 1999; Centers for Disease
Control and Prevention (CDC): Illness surveillance and rapid needs assessment among Hurricane Katrina
evacuees--Colorado, September 1-23, 2005. MMWR Morb Mortal Wkly Rep 55:244, 2006; Connolly E et al: Induced
and accidental hypothermia. Crit Care Resusc 2:22, 2000; Daleau P et al: New epilepsy seizure at high altitude without
signs of acute mountain sickness or high altitude cerebral edema. High Alt Med Biol 7:81, 2006; Davies A: Nursing a patient
with frostbite. Nurs Times 101:52, 2005. Davis PR et al: Accidental hypothermia. J R Army Med Corps 151:223,
2005; Delaune EF 3rd et al: In-flight medical events and aircraft diversions: one airline's experience. Aviat Space Environ
Med 74:62, 2003; Kinoshita K et al: Rewarming following accidental hypothermia in patients with acute subdural
hematoma: case report. Acta Neurochir Suppl 96:44, 2006; Lichtman AD et al: Malignant hyperthermia following
systemic rewarming after hypothermic cardiopulmonary bypass. Anesth Analg 102:372, 2006; Murdoch D: Altitude
sickness. Clin Evid:1570, 2005; O'Brien FE et al: Delayed whole-body cooling to 33 or 35 degrees C and the development
of impaired energy generation consequential to transient cerebral hypoxia-ischemia in the newborn piglet. Pediatrics
117:1549, 2006; Oelz O: Death from high-altitude pulmonary edema preventable by appropriate treatment. Wilderness
Environ Med 11:299, 2000; Rice R: Hypothermia—potentially deadly year round. JAAPA 18:47, 2005; Saleh M et al:
The impact of slow rewarming on inotropy, tissue metabolism, and "after drop" of body temperature in pediatric patients. J
Extra Corpor Technol 37:173, 2005; Sirven JI et al: Is there a neurologist on this flight? Neurology 58:1739, 2002;
Wright HE et al: Cranial-neck and inhalation rewarming failed to improve recovery from mild hypothermia. Aviat
Space Environ Med 77:398, 2006; Young CC: Extreme sports: injuries and medical coverage. Curr Sports Med Rep
1:306, 2002.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial relationship
with the manufacturer or provider of any commercial product or service discussed. For this issue, the speaker reported
nothing to disclose.
Dr. Richards was recorded in San Francisco October 20-22, 2005, at Rural, Remote and Wilderness Medicine: What Every
Provider Needs to Know, sponsored by the University of California, Davis, Health System, Department of Emergency
Medicine, and Continuing Medical Education. The Audio-Digest Foundation thanks the speaker and the sponsor for their
cooperation in the production of this program.
|
