Objective.—High altitude and exposure to cold are associated with significant levels of dehydration because of cold-altitude urine output, high energy expenditures, and poor access to water. The aims of the present study were to measure the fluid intake and urine output among military mountaineers during their stay at high altitude and to study the level of fluid intake and decrease in urine output in relation with acute mountain sickness (AMS).

Methods.—This study used an analytic prospective follow-up design of hydration-dehydration conditions of a group of mountaineers with similar characteristics (military group). Data collected each day included quantity and type of fluid intake, urine output in 24 hours, other fluid output (as diarrhea or vomiting), and symptoms or signs of AMS according to the Lake Louise consensus score. Values are given as mean ± SE. A 1-factor analysis of variance procedure and t test were used to compare variables.

Results.—The mountaineers consumed a variety of fluids, including water, tea, coffee, soup, Isostar, and milk. Daily fluid intake was 2800 ± 979 mL, with a maximum intake of 4700 mL. Daily urine output was 1557 ± 758 mL. When we stratify our sample at the median by fluid intake, a significant correlation is detected with mean balance and mean urine output. Mountaineers developing AMS demonstrated reduced urine output (mean 1336 mL) when compared with those without AMS (mean 1655 mL).

Conclusions.—We found that fluid intake was associated but insignificantly correlated with incidence and degree of AMS. Past research suggests that vigorous hydration decreases incidence and severity of AMS and other altitude illnesses. Our results also imply that aggressive fluid intake is protective, but our limited sample size yielded insufficient power to demonstrate a statistically significant difference.

Objective.—The interaction of 15 variables representing physical characteristics, previous altitude exposure, and ascent data was analyzed to determine their contribution to acute mountain sickness (AMS).

Methods.—Questionnaires were obtained from 359 volunteers upon reaching the summit of Mt Whitney (4419 m). Heart rate and arterial oxygen saturation were measured with a pulse oximeter, and AMS was identified by Lake Louise Self-Assessment scoring. Multiple logistic regression analysis was used to identify significant protective and risk factors for AMS.

Results.—Thirty-three percent of the sample met the criteria for AMS. The odds of experiencing AMS were greater for those who reported a previous altitude illness (adjusted odds ratio [OR] = 2.00, P < .01) or who were taking analgesics during the ascent (adjusted OR = 2.09, P < .01). Odds for AMS decreased with increasing age (adjusted OR = 0.82, P < .0001), a greater number of climbs above 3000 m in the past month (adjusted OR = 0.92, P < .05), and use of acetazolamide during the ascent (adjusted OR = 0.33, P < .05).

Conclusions.—The significant determinants of AMS on the summit of Mt Whitney were age, a history of altitude illness, number of climbs above 3000 m in the past month, and use of acetazolamide and analgesics during ascent.

Objective.—Animal-vehicle collisions are a significant public health concern in the United States. The annual economic cost currently exceeds $1 billion from injuries and property damage. A recent study by the Centers for Disease Control and Prevention evaluated nonfatal injuries from animal-vehicle collisions, but information on fatal animal-vehicle collisions is limited. This study evaluates risk factors associated with fatal animal-vehicle collisions.

Methods.—This study evaluates characteristics of fatal animal-vehicle collisions in the United States from 1995–2004 by using the Fatality Accident Reporting System database of the National Highway Traffic Safety Administration.

Results.—An average of 165 deaths occurred each year during this 10-year time period. Most deaths occurred in rural areas, during the fall months, on straight roads, and in clear weather, and an increasing trend for deaths was noted over this time period.

Conclusion.—The number of fatal animal-vehicle collisions is increasing. Various methods to reduce such collisions are described, with fencing appearing to be the most effective. The use of personal restraints such as seat belts in passenger vehicles and helmets for motorcycle and all-terrain-vehicle riders may decrease fatalities during a collision.

Objective.—We studied 8 triathletes competing in the 3-day World Ultraman Championships (day 1: 10-km swim, 165-km bike; day 2: 261-km bike; day 3: 85-km run) to determine the effect of extreme physical exertion on heart rate (HR), mean arterial blood pressure (MAP) and pulmonary function, and their relation to overall athletic performance.

Methods.—Baseline HR, MAP and pulmonary function measurements were made 2 days before the start of competition. During the competition, HR and MAP measurements were made less than 30 minutes before the start and 10 minutes after the finish each race day. Pulmonary function was measured within 5 minutes of the finish each race day.

Results.—Forced vital capacity and forced expiratory volume in 1 second (FEV_1.0) were reduced from baseline at the end of each race day. Peak expiratory flow (PEF) was reduced from baseline on days 1 and 3. Lower baseline resting HR was correlated (r = 0.77, P = .021) with faster total race times. The decreases in FEV_1.0 and PEF over the whole race also correlated with performance (r = 0.77 and 0.93). Multiple regression analysis of baseline data indicated that HR and MAP had the strongest association with total race time prediction (54% and 19% of total). However, when declines in pulmonary function over the total race were also included, PEF was found to be associated with 87% of the total race time prediction.

Conclusions.—The strong association in the decline in PEF to race time, though just correlative, suggests a link between pulmonary function and ultratriathlon performance.

Each hurricane season, emergency-preparedness deployment teams including but not limited to the Office of Force Readiness and Deployment of the US Public Health Service, Federal Emergency Management Agency, Deployment Medical Assistance Teams, Veterinary Medical Assistance Teams, and the US Army and Air Force National Guard are at risk for deploying into hurricane-stricken areas that harbor indigenous hazards, including those posed by venomous snakes. North America is home to 2 distinct families of venomous snakes: 1) Viperidae, which includes the rattlesnakes, copperheads, and cottonmouths; and 2) Elapidae, in which the only native species are the coral snakes. Although some of these snakes are easily identified, some are not, and many rank among the most feared and misunderstood animals. This article specifically addresses all the native species of venomous snakes that inhabit the hurricane-prone regions of North America and is intended to serve as a reference to snake identification, basic field safety procedures, and the currently recommended first-aid measures for snakebite casualties.

Caiman crocodilus, commonly called the spectacled caiman, is a very widely distributed resident of the western-hemisphere wetlands. Caiman bites to humans can cause trauma and infection. There are few reports of caiman bites; however, there is information about bites by other members of the same family, including Alligator mississippiensis. A case of acute caiman bite to the hand is described, including initial treatment and outcome. The bite resulted in multiple lacerations, interarticular fracture, and infection. One of the lacerations was closed, and the patient was started on moxifloxacin hydrochloride. Preventive care and treatment including wound care and antibiotics are discussed. The patient recovered with only a slight long-term functional deficit.

Despite the presence of a number of anecdotal reports in the mountaineering literature, mucociliary dysfunction at high altitude has received little scientific attention. However, the dry, cold, thin air at high altitude has the potential to undermine normal mucociliary function. This seems increasingly likely in mountaineers who also experience dehydration, nasal obstruction, and extremes of aerobic respiration when climbing in such environments. These factors may result in a number of clinical conditions that range from sore throats and coughs commonly seen at altitude to rarer cases of bronchiolar collapse and lung atelectasis. The purpose of this review is to discuss the etiology of mucociliary dysfunction at altitude and outline a number of potential solutions to the problems this phenomenon presents.

Although avian influenza A (H5N1) is common in birds worldwide, it has only recently led to disease in humans. Humans who are infected with the disease (referred to as human influenza A [H5N1]) have a greater than 50% mortality rate. Currently there has not been documented sustained human-to-human transmission; however, should the virus mutate and make this possible, the world could experience an influenza pandemic. Probable risk factors for infection include slaughtering, defeathering, and butchering fowl; close contact with wild birds or caged poultry; ingestion of undercooked poultry products; direct contact with surfaces contaminated with poultry feces; and close contact with infected humans. Possible risk factors include swimming in or ingesting water contaminated with bird feces or dead birds and the use of unprocessed poultry feces as fertilizer. Clinically, early human influenza A (H5N1) resembles typical influenza illnesses, with fever and a preponderance of lower respiratory tract symptoms. Often, patients develop rapidly progressive respiratory failure and require ventilatory support. Treatment is primarily supportive care with the addition of antiviral medications. Currently, travelers to countries with both human and avian influenza A (H5N1) have a low risk of developing the disease. There are no current recommended travel restrictions. Travelers are advised to avoid contact with all birds, especially poultry; avoid surfaces contaminated with poultry feces; and avoid undercooked poultry products. The use of prophylactic antiviral medications is not recommended.

The approaching 90-year anniversary of United States entry into the Great War is an apt time to examine the response to trench foot (now called nonfreezing cold injury [NFCI]) in this conflict. Trench foot appeared in the winter of 1914, characterized by pedal swelling, numbness, and pain. It was quickly recognized by military-medical authorities. There was little debate over whether it was frostbite or new condition, and it was quickly accepted as a specific disease. The major etiologies proposed were exposure, diet, and infection. The opinion emerged that it was caused by circulatory changes in the foot caused by cold, wet, and pressure. Predisposing factors included dietary inadequacy and fatigue. A number of labels were first given to the disease. However, the name “trench foot” was eventually officially sanctioned. Trench foot became a serious problem for the Allies, leading to 75 000 casualties in the British and 2000 in the American forces. Therapy for trench foot involved a number of conventional, tried-and-tested, and conservative methods. Some more innovative techniques were used. Amputation was only used as a last resort. Prevention involved general measures to improve the trench environment; modification of the footwear worn by the men; and the provision of greases to protect them from moisture. The medical reaction to this condition seems to have been relatively effective. The causation was identified, and prophylactic measures were introduced to fit this model; these seem to have been successful in reducing the prevalence of the condition by 1917–18.