Article from August, 2016

Breathing Easier in the Field

Breathing in the field

by Michael J. Manyak, MD, MED 92

A healthy respiratory system is key to safe adventure travel due to the exertion required no matter what the activity.  This is especially true on an expedition where greater demands on respiration are more likely than on ordinary travel.  A person breathes about 25,000 times a day taking in oxygen and expelling carbon dioxide as a critical part of our metabolism.  Risk to the respiratory system on travel includes increased exposure to infectious diseases, exacerbation of existing conditions, respiratory difficulties related to the altitude or environment, and development of disorders involving respiration.

Perhaps the most common respiratory ailment associated with travel is seasonal flu.  Common colds, incorrectly called flu, are almost always due to a viral upper respiratory tract infection (URTI).  Over 200 viruses are potential culprits though most are in the class of rhinoviruses.  There is no cure for viral URTIs though the symptoms can be treated.  Transmission occurs by aerosolized droplets or direct contact with contaminated objects making handwashing a key component of prevention.  There are no data to support the impression that recirculated air in an airplane increases infections but proximity to a person suffering from a viral URTI does increase risk.

It is recommended to have a seasonal flu shot for prevention for yourself but also to protect any indigenous people you may encounter, they are unlikely to have immunity.  Viral strains are predicted for the coming season and annual vaccines are matched to those expected strains.  But rapid rates of viral mutation may render the vaccinations only partly effective after production.  This year it was about 25 percent effective.  Viral strains often differ in northern and southern hemispheres and the “flu” season is different.

Risk from the more dangerous viral respiratory diseases such as the Middle East Respiratory Syndrome (MERS) or the bird and swine flus is extremely low, but one must heed current international travel warnings about a particular area if an outbreak is detected (see the U.S. Department of State or CDC websites).  Follow the precautions to reduce transmission of any respiratory disease.

Chronic respiratory diseases like lung cancer, emphysema, and cystic fibroses are serious, but the normal traveler is at no increased risk from them.  However, travel to areas with highly polluted air can compromise breathing and lead to a serious exacerbation of symptoms for those with such problems.  Persons with a history of asthma should be especially careful and determine before travel the best management for an acute asthmatic attack in an isolated area.  Travelers with asthma need to bring their own medication including an extra amount in case of trip delays or voluntary extension.  Always notify the medical officer on an expedition about your asthma.

Tuberculosis (TB) is a common disease in many parts of the world.  Travelers to high-risk countries, particularly sub-Saharan Africa, South Asia, and Southeast Asia, are more likely to be exposed to TB.  A traveler in close contact with infected persons is at risk.  In the case of airline exposure to someone with active TB, people in the proximate two rows to the infected person are at highest risk.  Symptoms such as persistent fever, night sweats, and weight loss may take weeks to many months to develop.  Although TB can present in almost any organ system, respiratory problems are the most likely and well known.  The emergence of drug-resistant TB strains is very concerning but incidence is still slight.  Consult your physician if you think you have been exposed to TB.  If exposure has occurred, your physician will likely order a skin test, called PPD.  A positive test may signify active disease or previous exposure.  A chest xray will help determine whether there is active disease.

Other unusual infectious respiratory diseases are more common in specific geographical areas or environments though the individual risk for these diseases is usually low.  For example, the fungal infection coccidioidomycosis, also known as San Joaquin Valley Fever, is a greater risk to people in parts of the southeast United States than other areas.   If you go into caves, histoplasmosis is another serious respiratory fungal infection you may encounter.  Make sure to report your travel history to your medical provider if you become ill after your return home.

One other risk related to the respiratory system deserves mention. Travelers on long airplane fights and other situations where they are immobile for long periods are at risk for a pulmonary embolism.  A blood clot can develop in the legs from immobility, break off, and lodge in the blood vessels of the lungs.  The person experiences shortness of breath and may have pain in the lower leg.  A pulse oximeter which measures blood oxygen levels may be in the first aid kit.  A pulmonary embolism is a serious and potentially fatal medical emergency requiring immediate medical intervention.

Take a deep breath…….and enjoy your adventure.

Related columns:
Winter 2010/2011
Fall 2015
Spring 2015
Fall 2013

 

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This article was published in The Explorers Journal

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THE EXPLORERS JOURNAL.
The Official Quarterly Of The Explorers Club Since 1921
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