Snakebites continue to be a major medical concern in India. However, there is very little hard evidence of a numerical nature to enable us to understand which species are responsible for mortality and morbidity. For many decades, the concept of the “Big 4” Snakes of Medical Importance has reflected the view that 4 species are responsible for Indian snakebite mortality—the Indian cobra (Naja naja), the common krait (Bungarus caeruleus), the Russell's viper (Daboia russelii) and the saw-scaled viper (Echis carinatus). However, a recent discovery that another species, the hump-nosed pit viper (Hypnale hypnale), is capable of causing lethal envenomation, and that this problem was being concealed by systematic misidentification of this species as the saw-scaled viper, has necessitated a review of the concept of the “Big 4.” The concept of the “Big 4” snakes is reviewed to demonstrate its failure to include all currently known snakes of medical significance in India, and its negative effects related to clinical management of snakebite. The emergence of the hump-nosed pit viper (Hypnale hypnale) as a snake of medical significance has rendered the “Big 4” obsolete in terms of completeness. The concept of the “Big 4” is restricting sound epidemiological work and the development of effective snake antivenoms. It should be replaced by the model introduced in the 1980s by the World Health Organization, which has not received adequate circulation and implementation.

Core to incident prevention strategies is the need to identify factors that influence the decision-making process linked to risk-taking behavior. Participants' perception of risk and associated norms and practices may play a key role in relation to decisions to engage with a risk and subsequent risk-management strategies. A range of factors that influence the perception of risk and risk-taking behavior are discussed. It is proposed that prevention strategies need to be sensitive to the context of participation, the attitudes and beliefs of participants, and the motives for participation. To ignore such issues may result in the development of inappropriate approaches to the management of risk that may be discredited, resisted, or negate reasons for participation.

Objective.—To identify injury patterns in canyoneering and develop a sense of their frequency.

Methods.—A web-based survey of canyoneers was developed. Questions regarding injuries experienced or treated, first aid training, and first aid supplies carried were included.

Results.—A total of 38 responses were received. Cutaneous injuries were very common (average \[nm2 per person per year), but of apparently low morbidity (no evacuations required). Orthopedic injuries were also common (1 sprain/strain per person every 3 years on average, and major injuries happening to 1 in 2 canyoneers during their career), as were environmental injuries. First aid preparedness, in terms of training and kits, varied quite widely, but there was significant interest in further training.

Conclusions.—Minor cutaneous and orthopedic injuries are common, but fortunately do not often require outside assistance. More significant injuries are less common and usually involve orthopedic trauma or environmental exposure. A first aid curriculum for canyoneering should cover stabilization of fractures, analgesia and evacuation techniques as well as minor wound care.

Category 1 Continuing Medical Education credit for physicians is available to Wilderness Medical Society members for this article. Go to  http://wms.org/cme/cme.asp?whatarticle=1811 to access the instructions and test questions.

Objective.—The purpose of this study was to characterize big game hunter visits to a rural hospital's emergency department (ED). Using data collected on fatalities, injuries, and illnesses over a 9-year period, trends were noted and comparisons made to ED visits of alpine skiers, swimmers, and bicyclists. Out-of-hospital hunter fatalities reported by the county coroner's office were also reviewed. Cautionary advice is offered for potential big game hunters and their health care providers.

Methods.—Self-identified hunters were noted in the ED log of a rural Colorado hospital from 1997 to 2005, and injury or illness and outcome were recorded. Additional out-of-hospital mortality data were obtained from the county coroner's office. The estimated total number of big game hunters in the hospital's service area and their average days of hunting were reported by the Colorado Division of Wildlife. The frequencies of hunters' illnesses, injuries, and deaths were calculated.

Results.—A total of 725 ED visits—an average of 80 per year—were recorded. Nearly all visits were in the prime hunting months of September to November. Twenty-seven percent of the hunter ED patients were Colorado residents, and 73% were from out of state. Forty-five percent of the visits were for trauma, 31% for medical illnesses, and 24% were labeled “other.” The most common medical visits (105) were for cardiac signs and symptoms, and all of the ED deaths (4) were attributed to cardiac causes. The most common trauma diagnosis was laceration (151), the majority (113) of which came from accidental knife injuries, usually while the hunter was field dressing big game animals. Gunshot wounds (4, <1%) were rare. Horse-related injuries to hunters declined while motor vehicle– and all-terrain vehicle (ATV)–related injuries increased. The five out-of-hospital deaths were cardiac related (3), motor vehicle related (1), and firearm related (1).

Conclusions.—Fatal outcomes in big game hunters most commonly resulted from cardiac diseases. Gunshot injuries and mortalities were very low in this population. Knife injuries were common. Hunters and their health care providers should consider a thorough cardiac evaluation prior to big game hunts. Hunter safety instructors should consider teaching aspects of safe knife use. Consideration should be given to requiring and improving ATV driver education.

Category 1 Continuing Medical Education credit for physicians is available to Wilderness Medical Society members for this article. Go to  http://wms.org/cme/cme.asp?whatarticle=1812 to access the instructions and test questions.

Objective.—Cuzco, Peru, is host to a dangerous mix of high altitude and rapid access from low elevation, which results in a high prevalence of acute mountain sickness (AMS). Thus, it is important that travelers entering Cuzco understand the basics of AMS. To this end, we assessed travelers' awareness of AMS, especially the resources used to obtain this knowledge. With this information we make recommendations with regard to better avenues for distribution of AMS information.

Methods.—One hundred foreign travelers, representing an international population, completed a 45-item written questionnaire that was subsequently analyzed.

Results.—Over half of the respondents (51%) rated their knowledge of AMS as “low” or “none.” Furthermore, very few respondents knew about acetazolamide (Diamox) as prophylaxis for (9%) or treatment of AMS (5%). People who consulted physicians for AMS information were more likely to know about the utility of acetazolamide than those who depended on a guidebook (P = .0266) but were less likely to correctly identify the symptomatology of AMS (P = .047). While AMS knowledge was poor, the majority of travelers (90%) indicated compliance with recommended pretravel vaccinations.

Conclusions.—This survey adds to the body of knowledge that indicates a lack of AMS knowledge among travelers. In addition, this survey identifies 2 potential avenues for improved dispersal of information: 1) guidebooks for countries of concern and 2) national health agency Web sites linked to information on pretravel vaccinations. Recommendations are made to utilize these commonly accessed resources to increase AMS information distribution to the general populous.

Category 1 Continuing Medical Education credit for physicians is available to Wilderness Medical Society members for this article. Go to  http://wms.org/cme/cme.asp?whatarticle=1813 to access the instructions and test questions.

Objective.—Experimental data indicate that when using a sit harness alone, any major fall during rock climbing may cause life-threatening thoraco-lumbar hyperextension trauma or “head down position” during suspension. To clarify the actual influence of the type of harness on the pattern and severity of injury, accidents involving a major fall in a climbing harness were analyzed retrospectively.

Methods.—Individuals with a height of fall equal to or exceeding 5 m were identified through a search of accident and emergency records for the period from 2000 to 2004. Data concerning the circumstances of the fall and the patterns of injury were obtained from personal interviews, flight and accident reports, as well as hospital medical records.

Results.—Of a total of 113 climbers identified, 73 (64.6%) used a sit harness alone, whereas 40 (35.4%) used a body harness. Fractures and dislocations of the extremities, the shoulder, and the pelvic region were the most common injuries, while the most severe injuries occurred in the head and neck region. Although most falls were associated with mild or moderate injuries, 13 (11.5%) climbers sustained severe or critical multisystem trauma. Falls on more difficult routes were associated with less severe injury. The type of harness used did not influence the pattern or severity of injury. In particular, no evidence was found for the existence of a thoraco-lumbar hyperextension trauma.

Conclusions.—The type of harness does not influence the pattern or severity of injury, and the forces transferred via the harness do not cause a specific harness-induced pathology. We did not find any evidence that hyperextension trauma of the thoraco-lumbar region is an important mechanism of injury in climbers using a sit harness alone. Rock contact during the fall, and not the force transferred through the harness, is the major cause of significant injury in climbing accidents.

Objective.—The objective of this study was to determine the incidence and patterns of injury and illness among passengers aboard a cruise ship in Antarctica.

Methods.—Demographic data on passengers were collected for all participants aboard Antarctica cruises on a single ship during the Antarctic summer cruise season of November 2004 through March 2005. Medical logs from each of 11 cruise trips were reviewed for presentation of injuries and illnesses.

Results.—A total of 1057 passengers were included in the study, of which 47.4% were male. The mean age of the passengers was 54 years (±16.5 years). The overall incidence rate of injury and illness was 21.7 per 1000 person-days. Motion sickness was the most common condition, comprising 42.3% of all medical encounters by the ship physician, followed by infectious diseases (17.2%) and injury (15.0%). The incidence rate of injury increased significantly with age, whereas the incidence rate of motion sickness decreased significantly with age. There was little variation in the incidence and patterns of injury and illness between genders.

Conclusions.—Most illnesses and injuries were due to the motion of the ship, and a large proportion of the passengers aboard the cruise ship in Antarctica were elderly. Injury among older passengers is of special concern.

As a result of the successful restoration and conservation programs deployed by state and federal agencies, populations of the North American river otter (Lontra canadensis) are increasing in many states. Recreational activities such as swimming, boating, and fishing increase the likelihood of human interactions with this charismatic, nonendangered mustelid. Otters tend to avoid areas of high human activity, occur at low population densities, and in some habitats in the United States have not recovered from population declines. Therefore, interactions with humans are rare, and aggressive encounters by otters are even less frequent. We report a recent, aggressive, and unprovoked attack that was followed by immediate medical treatment, including postexposure rabies prophylaxis, extensive suturing, and subsequent reconstructive surgery. We discuss river otter biology, the prevalence of diseases in wild populations of river otter, and otter attacks on humans and their treatment.

Headache is the cardinal symptom of acute mountain sickness (AMS). The headache normally worsens, with increased cerebral affection and the development of high-altitude cerebral edema (HACE). A Norwegian expedition aimed to climb Baruntse (7129 m) in Nepal in 2003. At 5400 m a 35-year-old man felt exhausted. The next day he aborted his attempt at further climbing as a result of extreme fatigue. Over the next 24 hours he developed cough, dyspnea, and severe hypoxia before progressing to ataxia and blurred vision. At no point did he experience headache or nausea. The patient was evacuated by helicopter. He improved immediately after descent and recovered completely within a week. The speed of progression from AMS to HACE varies. Abrupt onset of HACE is occasionally reported. High-altitude pulmonary edema (HAPE) may induce severe hypoxia that can lead to rapid development of HACE. High-altitude cerebral edema in the setting of HAPE was the most likely diagnosis despite the unusual lack of headache. Rapid onset of HAPE with subsequent severe desaturation should raise awareness of the development of HACE, even in the absence of headache.

Objective.—Direct evidence that dehydration results from scuba diving is scanty. Increased hematocrit (Ht) is a commonly used proxy measure for dehydration. This study sought evidence that an increase in Ht occurs over the course of a scuba dive in tropical conditions. As a secondary outcome, evidence was sought that the degree of Ht increase is correlated to pressure exposure.

Methods.—Twenty male and 21 female scuba divers were recruited at a remote tropical dive site. Water temperature was 30°C (±1°C). Each diver gave venous blood relating to 1 dive only. Mean maximum dive depth was 13.6 m (±3.7 m [SD]) and mean duration 39.5 minutes (±4.5 minutes [SD]) using air as the breathing gas. Blood was taken at a mean of 12.4 minutes (±3.5 minutes [SD]) before diving and a mean of 16.2 minutes (±3.7 minutes [SD]) after diving. After centrifugation of microcapillaries, Ht was estimated on a visual plate reader.

Results.—A paired Wilcoxon test showed evidence (P < .001) for a change in Ht. The mean difference between predive and postdive measurements was 0.0073 (95% confidence interval: 0.0104– 0.0042), equating to a mean relative Ht increase of 1.78%. Similar results were found for the sexes individually. A correlation between maximum depth of dive and Ht increase was statistically significant, although the correlation itself was weak (P = .049, Spearman's r = .326).

Conclusions.—There is evidence of a statistically significant increase in Ht over the course of a single warm-water scuba dive. This increase is small and is within the range of error associated with the techniques of Ht estimation employed in this study. Depth exposure was found to correlate with Ht increase. In view of the small magnitude of change in the Ht, there is no reason to amend protocols for fluid resuscitation of recreational scuba divers suspected to have experienced decompression injury in tropical locations.