A Break in the Action

My blog entitled "Medicine for the Outdoors" will cease to publish in its current form with this post, as Healthline works on the creation of a learning center in which the posts will be part of a more comprehensive approach to offering readers accurate and timely information about health issues and other topics regarding wilderness and outdoor medicine, and related activities and topics. This is a large undertaking that is not quite ready to launch, so stay tuned and look forward to improved coverage of medicine for the outdoors.

Thank you for being loyal and interactive readers. I look forward to being online with you again soon.

Best wishes,

Paul

Paul Auerbach, M.D.

Labels: Learning Center, Medicine for the Outdoors, wilderness medicine

Permalink and Comments | | Email Post

Bacterial Diarrhea

Foodborne bacterial diarrhea is a common problem of backpackers, kayakers, divers - of anyone who ventures into the outdoors and is therefore associated with ingestion of fresh fruits and vegetables, travels to developing countries, practices inadequate hygiene, or even dines in public restaurants. Diagnosis and treatment of infectious diarrhea (bacterial, protozoal, viral, and other causes) is an essential skill for the wilderness medicine practitioner.

In an article (New England Journal of Medicine 2009;361:1560-1569) entitled "Bacterial Diarrhea," my good friend Dr. Herbert DuPont of the University of Texas School of Public Health and the Baylor College of Medicine provided a phenomenal update on the topic. There is a wealth of information in the article, so I will hit a few of the facts and figures that should be of greatest interest to this particular readership.

Campylobacter, nontyphoid Salmonella, Shiga toxin-producing E. coli, and Shigella bacteria are common causal agents of bacteria-induced diarrhea in the U.S. Other bacteria are more frequently associated with particular environments, such as Aeromonas in tropical regions. Plesiomonas shigelloides is associated with seafood ingestion and international travel.

The article was U.S.-focused. Acute watery diarrhea should bring to mind E. coli, Salmonella and Campylobacter. Bloody diarrhea ("dysentery") is suggestive of colitis. The four major U.S. causes, in descending order, are Shigella, Campylobacter, nontyphoid Salmonella and Shiga toxin-producing E. coli.

Food poisoning is the term used when a preformed toxin in good is eaten, which causes intoxication rather than an infection. A common culprit is Staphylococcus aureus. Others are Clostridium perfringens and Bacillus cereus.

Traveler's diarrhea can be caused by many different bacteria, but the most common is E. coli. Persons with traveler's diarrhea may be treated empirically with antibiotics without having their stool examined under the microscope or by stool culture. To prevent the disease, rifaximin in a dose of 200 mg once or twice a day taken with major meals while in the affected area appears to be effective. Indications for prophylaxis include an important trip, underlying illness that might be worsened by the disease, condition in which someone might be more prone to diarrhea, or suggestion that a person has increased susceptibility for some other reason.

Treatment recommendations are discussed. For all cases of diarrhea, attention to fluid and electrolyte replacement is essential. A diet of easily digestible food or a diet of bananas, rice, applesauce and toast is often recommended, but there is no evidence that such diets hasten recovery. It is important to keep the victim hydrated and nourished as best possible, which supports the concept of oral feeding. Drugs that diminish the number of bowel movements, such as loperamide, may be helpful. If the victim suffers from fever or dysentery, then antimotility drugs should only be used in combination with antibiotics.

This is an important and comprehensive review article for anyone interested in bacterial diarrhea. There are complete antibiotic recommendations, lists of complications, and discussion of areas of uncertainty. While the article is written for doctors, it has much information that can be understood and used effectively by laypersons.

Tags: infectious diarrhea, diarrhea, bacterial diarrhea, wilderness medicine, outdoor medicine, healthline

Labels: bacterial diarrhea, diarrhea, infectious diarrhea

Permalink and Comments | | Email Post

Sugar-Sweetened Beverages

We are a nation stricken with an epidemic of obesity, which contributes to the incidence of diabetes and heart disease. Each of these has been linked to consumption of sugar intake, and in particular, sugar-sweetened beverages. There is nothing evil about sugar - it's just that too much of it in certain forms is bad for you. For the purpose of definition, sugar-sweetened beverages contain added, naturally-derived caloric sweeteners such as sucrose (table sugar), high-fructose corn syrup, or fruit juice concentrates.

In an article (New England Journal of Medicine 2009;361:1599-1605) entitled "The Public Health and Economic Benefits of Taxing Sugar-Sweetened Beverages," Kelly Brownell, MD and colleagues used a discussion about a proposed tax system to highlight the trends in consumption of sugar-sweetened beverages and the evidence linking these beverages to adverse health outcomes. Leaving the effects and wisdom of a tax system aside, it's noteworthy to examine the trends and health effects. I'm certainly guilty of drinking more than my fair share of these beverages so far in my lifetime, and the more I learn about them, the harder I try to avoid them.

The statistics are informative. Between 1977 and 2002, the per person intake of caloric beverages doubled in the U.S. across all age groups. There appears to be a strong association between the intake of sugar-sweetened beverages and body weight. Weight gain over time is influenced by the consumption of these beverages. The weight gain is adipose tissue - translated, that means the weight gain is not muscle, not bone, not brain tissue, but rather, it is fat. Furthermore, the strongest effect appears to be in person who are already overweight. So, too much sugar in the diet creates a vicious cycle. Next on the list of "bads" is the positive association between the consumption of sugar-sweetened beverages and diabetes. It is possible that this risk is at least in part a function of weight gain. The same holds true for coronary artery (heart) disease - the risk is increased by consuming these beverages, and that risk may be associated at least in part as a function of weight gain.

Drilling down into the physiological details, consumption of sugar-sweetened beverages has been shown to increase blood triglyceride levels and blood pressure, and to decrease high-density lipoprotein cholesterol levels. These increase the risk of coronary artery disease (e.g., heart attacks) and perhaps stroke. The high glycemic load of these beverages may increase insulin resistance, and thus promote diabetes. In addition, people may become psychologically habituated to tasting the sweetness, and therefore select sugar-containing foods, not because they need the sugar, but in order to satisfy a food preference. If they do this to the exclusion of healthful foods, then the impact upon health is obvious.

Under the assumption that persons who love the outdoors are to a certain extent health-minded, and trying to not be "preachy," I would suggest that you review your diet and do what you can to eliminate sugar-sweetened beverages, indeed all unnecessary sugar, from your diet. If you can move gradually to a more healthful diet, you will come to recognize the incredible value of proper nutrition in keeping you fit and feeling well, and will take more enjoyment out of the physical activity that is part and parcel of the outdoor experience.

Tags: sugar-sweetened beverage, sugar, obesity, wilderness medicine, outdoor medicine, healthline

Labels: soda, sugar, sugar-sweetened beverages

Permalink and Comments | | Email Post

Obesity, Smoking and Life Expectancy in the U.S.

When we think of people who enjoy the outdoors, the images in our minds are often of healthy and vibrant individuals - stereotypes are young athletes engaged in vigorous activities like climbing, biking, skiing, etc. Of course, going outdoors is for everyone, and persons may be young or old, active or sedentary, and healthy or infirm. We carry our personal health status with us wherever we go, and the health habits we pursue in our daily lives form the framework for our participation in adventures, recreation and other outdoor activities. Therefore, public health issues are important, be they adherence to precautions to avoid infectious diseases or life style modifications to maintain optimal physical and mental health.

Someone once mentioned to me that if there were three things one could do to maintain proper health, it would be to control my blood pressure, never use tobacco products, and follow proper nutritional habits. With regard to the latter, that can be further refined by avoiding excess processed sugar and hydrogenated fats. So, it was with great interest that I read the article entitled "Forecasting the Effects of Obesity and Smoking on U.S. Life Expectancy," by Susan Stewart, Ph.D. and colleagues in the New England Journal of Medicine (2009;361:2252-60).

In this very interesting article, the authors forecasted life expectancy and quality-adjusted life expectancy for a "representative 18-year-old," assuming a continuation of past trends in smoking (e.g., a reduction in the amount of smoking) and past trends in body-mass index (BMI), for which an increasing number (it is indeed trending up) indicates a propensity for obesity. In this evaluation, the negative effects of increasing BMI in the U.S. overwhelmed the positive effects of declines in smoking. In other words, even though there are positive effects gained from declining smoking rates, these are more than neutralized by the negative effects on the health of the U.S. population due to increases in obesity.

These are trends and therefore, as the authors point out, do not necessarily apply to any given individual based on his or her particular smoking habits and BMI combination. However, if this analysis is correct, the implications are fairly clear - we must do everything we can to control our epidemic of obesity, which contributes heavily to morbidity and mortality. It is not a good thing from a health perspective to be obese under any circumstance, and certainly - notwithstanding the possible luxury of an insulating layer of fat on a cold day - not beneficial in the outdoors. When one puts stress on the cardiovascular system (which leads to strokes, heart attacks and other serious medical problems), this can be magnified in a situation of high physical stress, such as commonly occurs outdoors. I have had to good fortune to be trekking on mountains, scuba diving, river rafting and so forth over the past few years, and have noticed that people are seemingly larger, and not in a good way. This paper is a graphic example of how serious has become our nation's battle with obesity.

Tags: obesity, life expectancy, smoking, wilderness medicine, outdoor medicine, healthline

Labels: life expectancy, obesity, smoking, tobacco

Permalink and Comments | | Email Post

Summiting Success and Acute Mountain Sickness on Mount Kilimanjaro

Mount Kilimanjaro is the highest mountain in Africa and a popular tourist destination. Because it is easy to access and is a commonly attempted summit, this mountain is frequently attempted by persons with little mountaineering experience and no technical climbing ability. As such, and because of the rapidity with which it can be ascended by trekkers, it is also the site of many cases of acute mountain sickness (AMS).

Andrew Davies and colleagues published an article entitled "Determinants of Summiting Success and Acute Mountain Sickness on Mt Klimanjaro (5895 m)" in Wilderness and Environmental Medicine, volume 20, pages 311-317, 2009. The purpose of their study was to determine the incidence of AMS, the frequency of summiting success and the factors that affected these in trekkers on Kilimanjaro. In their study, 312 trekkers were measured for various physiological parameters and the Lake Louise Score, which is a measure of AMS. Out of the 312 trekkers, 181 complete sets of data were collected.

Seventy-seven per cent of the 181 trekkers developed AMS and 61% of the trekkers attained the summit. Trekkers who used acetazolamide (Diamox) were more likely to attain the summit and less likely to suffer AMS than were those who did not use acetazolamide. This was a factor on the five-day route, but not on the 4-day route. The authors concluded that the risk for developing AMS is high on Kilimanjaro. Their opinion was that while it appears to be beneficial to take an extra day to ascend and to take acetazolamide (both of these to improve acclimatization and thus diminish the incidence of AMS), it makes most sense to use a more gradual ascent profile for climbing Kilimanjaro. Such a route (Western Breach Route) is available, and requires 6 or more days for the ascent, as opposed to the Marango route, which was utilized during this study.

It makes perfect sense to take longer to ascend and/or to use acetazolamide, which is well known to decrease the incidence of AMS in susceptible individuals. Why do people rush to the top? No doubt, this is to accommodate busy schedules and to keep down expenses. What is the cost of this haste? It is likely the discomfort and risks of AMS, as well as the possibility that after all of that effort, one might not only become ill, but not attain the summit.

Labels: acclimatization, acetazolamide, acute mountain sickness, AMS, high altitude, Mount Kilimanjaro

Permalink and Comments | | Email Post