Objective.—This exploratory study assessed a potential relationship between elevated carboxyhemoglobin (COHb) levels and acute mountain sickness (AMS) at 4300 m on Denali. Additional analysis assessed the relationship among COHb levels, AMS, and climber characteristics and behaviors.

Methods.—Participants were screened for AMS with the Lake Louise Self-Report questionnaire and answered questions focusing on AMS symptoms, prevention, and previous altitude illness. Levels of COHb were measured by serum cooximetry. Additional questions assessed stove practices, climbing practices, and climber behaviors. Nonparametric statistical analyses were performed to examine potential relationships among COHb levels, AMS symptoms, and climber behaviors.

Results.—A total of 146 climbers participated in the study. Eighteen climbers (12.5%) were positive for carbon monoxide (CO) exposure and 20 (13.7%) met criteria for AMS. No significant relationship was observed between positive CO exposure and positive criteria for AMS. Climbers descending the mountain were 3.6 times more likely to meet the study criteria for positive CO exposure compared with those ascending the mountain (P = .42). In addition, COHb levels were significantly higher for those descending the mountain (P = .012) and for those taking prophylactic medications (P = .010). Climbers meeting positive criteria for AMS operated their stoves significantly longer (P = .047).

Conclusions.—No significant relationship between AMS symptoms and CO exposure was observed. This may have been affected by the low percentage of climbers reporting AMS symptoms, as well as limited power. Descending climbers had a 3.6 times increased risk of CO exposure compared with ascending climbers and had significantly higher COHb scores. Increased hours of stove operation was significantly linked to climbers who also met criteria for AMS.

Objective.—Patients with injuries requiring surgical airway management occurring far from medical care might benefit from the availability of a simple, reliable, improvisational method of cricothyrotomy with materials available in a wilderness or prehospital setting. We evaluated an improvised cricothyrotomy device in an experimental, unembalmed human cadaver model.

Methods.—A high-flow intravenous spike and drip chamber was cut through the drip chamber and used as the sole apparatus for performing cricothyrotomy on unembalmed cadavers whose anterior neck surfaces and deep tissues were warmed to or near body temperature. Correct placement in the trachea and damage to the posterior wall of the trachea were assessed by either fiberoptic bronchoscopy or neck dissection. Video recordings were used to time each procedure. Each operator was responsible for both device insertion and bag valve mask attachment and ventilation, modeling as the sole care provider for the patient.

Results.—One physician and 3 emergency medicine residents, all without previous, specific instruction, performed 10 procedures on 5 female and 5 male unembalmed cadavers weighing a mean of 65 kg (range 45–110 kg). All 10 attempts at placement of the intravenous tubing spike through the cricothyroid membrane were successful. On 2 attempts, the initial placement of the device was incorrect, but the error was immediately identified on attempt to ventilate the patient. Repositioning of the device resulted in appropriate cannulation of the trachea in both attempts. The median time span from manual identification of the cricothyroid membrane to percutaneous access and connection of the bag valve mask with successful ventilation was 27.3 seconds. Violation of the posterior tracheal wall was not seen on any of the 5 procedures in which fiberoptic visualization was available or in the 5 procedures evaluated by neck dissection.

Conclusions.—Cricothyrotomy is the quickest and most effective method for obtaining airway access when nonsurgical methods of securing the airway are contraindicated or fail. Although frequently described, no improvised airway devices of this type have been tested in a systematic manner. We tested the reliability and utility of cricothyrotomy with a high-flow intravenous spike and drip chamber. Our results suggest that the spike and drip chamber is a plausible means of temporarily establishing airway access in patients with acute airway obstruction in a wilderness or prehospital environment.

Objective.—This study aimed to determine the efficacy, tolerability, and practicality of acetazolamide for the prevention of acute mountain sickness (AMS) in Nepali trekking porters early in the trekking season.

Methods.—This study was a randomized, double-blind controlled trial with 400 male Nepali porters in the Mount Everest region of Nepal, trekking from Namche Bazaar (3440 m) to Lobuche (4930 m), the study endpoint. Participants were randomized to receive 250 mg acetazolamide daily or placebo, and AMS symptom scores (Lake Louise) were compared in highlanders vs lowlanders.

Results.—Only 109 (27.2%) of the 400 porters completed the trial (28 highlanders, 81 lowlanders). The rest either dropped out (275/400 porters, 68.8%) or were excluded (16/400 porters, 4%). Acute mountain sickness occurred in 13 (11.9%) of 109 porters; all were lowlanders; 7 were taking acetazolamide, 6 taking placebo. Birthplace, acclimatization in the week before the trial, ascent rate, and rest days were the most important variables affecting the incidence of AMS. No highlanders, but 13 (16.1%) of 81 lowlanders had AMS (P = .016). Acclimatization in the pretrial week reduced AMS incidence (P = .013), as did a slower ascent rate (P = .0126), but rest days were the most potent prophylactic variable (P = .0001). Side effects were more frequent in porters taking acetazolamide than in the placebo group (P = .0001), but there were no serious side effects.

Conclusions.—Acetazolamide was tolerable, but impractical for the routine prevention of AMS in Nepali porters. A good trekking schedule and adequate acclimatization remain the most effective preventive measures. This study identified lowland porters as a high-risk group for developing AMS.

Objective.—A 3-bowl system is used for washing-up eating utensils on many expeditions when running water is not available. The utensils are washed in the first bowl until they are visibly clean, rinsed in the second bowl, and disinfected in the third bowl. The objective of this study was to evaluate the efficacy of this system in reducing bacterial loads on contaminated utensils and to compare it with alternative washing-up methods.

Methods.—Different washing-up systems were tested with a simulated dish washing of 5 contaminated mess tins followed by 5 uncontaminated mess tins. Porridge was used to simulate food residue and was mixed with Escherichia coli to produce bacterial contamination. Reduction of bacterial load on the mess tins was measured, as were subjective observations regarding the various systems.

Results.—Bacterial load on contaminated tins is reduced when the 3-bowl system is used. Uncontaminated tins become contaminated in bowl 1, but this is then reduced in subsequent bowls. Disinfectant use, especially bleach, produced a marked reduction in bacterial load on contaminated and uncontaminated tins when used in bowl 2. Detergent is needed to remove grease, and a final rinse removes the smell of disinfectant.

Conclusions.—Overall, the most effective washing-up system in the laboratory was removal of most food residue with detergent in bowl 1, finish washing with bleach until visibly clean in bowl 2, and a final rinse in drinkable water in bowl 3. This system has advantages over the established 3-bowl system by getting mess tins clean more easily, killing potentially harmful bacteria, and removing the smell and taste of disinfectant.

Objectives.—To describe physiological attributes (height, weight, sex, resting heart rate, etc) of climbers attempting to summit Mt Everest and to investigate differences between successful and unsuccessful summiteers.

Methods.—One-hundred thirteen Everest climbers were surveyed by questionnaire before and after the spring 2003 climbing season. Climbers' previous high-altitude climbing experience and physical characteristics were recorded, as well as health before and during expedition, medication used, body weight before expedition and after summit attempt, and ultimate summit success or failure.

Results.—The most common afflictions among climbers were cough, diarrhea, nausea, and vomiting, and the most common medications used were acetazolamide, aspirin, and antibiotics. Average postacclimatization, presummit “rest” altitude was 4571 m, and average weight carried 10.7 kg. Average body mass loss during expedition, regardless of success, was 7%.

Conclusions.—Oxygen use and existence of gastrointestinal disorders are strongly correlated with success in summiting Mt Everest. On the other hand, a history of acute mountain sickness before the attempt is correlated with failure in summiting Mt Everest. Several other factors were found to be marginally correlated with chance of success, but the power of the study was limited by a low postsummit attempt questionnaire return rate (34%).

Objective.—It is well known that physical trauma to skin caused by repetitive friction is a primary component of blister formation. Although friction blisters in a wilderness setting particularly occur on the feet and ankles, they often form on the hands and fingers during such activities as white-water rafting, kayaking, and canoeing. These blisters are often incapacitating and can have disabling consequences. This article describes laboratory and clinical experiments testing the efficacy of a new bandage technology in reducing shear and friction forces on the skin.

Methods.—A custom-made apparatus was used in a laboratory setting to measure and compare the surface coefficient of friction of 11 bandages. In addition, a controlled clinical study was conducted on 15 healthy, able-bodied female subjects (mean age 35 years), where the same apparatus was used to measure the coefficient of friction of the skin over the medial tibial cortex with and without the new technology device in place.

Results.—This laboratory study demonstrated the new device to have the lowest surface coefficient of friction of any bandage tested (0.57). For example, the common product Moleskin was 21% higher (0.67), with all other products testing at least 64% higher (>0.94). In the clinical study, the new technology device reduced the coefficient of friction on the skin by 31% (0.225 vs 0.327), and this difference was statistically significant (P < .001).

Conclusions.—A bandage containing a new technology demonstrated the lowest surface coefficient of friction of any bandage tested. In addition, clinical tests performed with the same bandage demonstrated significant reduction of the coefficient of friction on the skin.

Allergic contact dermatitis caused by the Toxicodendron (formerly Rhus) species—poison ivy, poison oak, and poison sumac—affects millions of North Americans every year. In certain outdoor occupations, for example, agriculture and forestry, as well as among many outdoor enthusiasts, Toxicodendron dermatitis presents a significant hazard. This review considers the epidemiology, identification, immunochemistry, pathophysiology, clinical features, treatment, and prevention of this common dermatologic problem. Recent research in prevention is emphasized, and resources to help in the identification of plants are provided in the bibliography. The literature was searched using a MEDLINE query for “Toxicodendron dermatitis,” and the identified article bibliographies were searched as well.

Patellofemoral pain syndrome is a common diagnosis in athletes and especially runners. This article discusses 3 cases of patellofemoral pain caused by pronounced inactivity and prolonged knee hyperflexion at altitude in a unique population of Tibetan Buddhist monks. In this case, the monks responded well to a program of activity modification and exercises.

We report the case of a previously healthy 32-year-old man presenting with severe headache on 2 separate expeditions to Cho Oyu (8201 m). No brain imaging was performed after the first expedition. On the second expedition, thrombosis of the superior sagittal sinus was detected. Investigations for hypercoagulable states, including polycythemia, were negative. He had no neurological symptoms except headache, vomiting, and slight drowsiness. In retrospect, there are strong indications that cerebral thrombosis caused his headache on the first expedition as well. Severe headache occurring at high altitude that persists despite adequate treatment for high-altitude cerebral edema should raise suspicion of a cerebrovascular disorder.

High-altitude pulmonary edema (HAPE) is a potentially life-threatening condition that is rapidly and definitively treated by descent. We report a case of worsening HAPE, presenting more than 18 hours after descent to sea level. The patient was treated with diuretics, calcium channel blockers, and oxygen and improved during a 24-hour observation period. To our knowledge, this is the first reported case of HAPE symptoms increasing after descent from altitude.