Acute Coronary Syndrome at Altitude: Diagnostic Dilemma on Aconcagua Using Point-of-Care Ultrasound.

At the Plaza de Mulas medical tent, located at 4300 m (14,100 ft) along the Normal Route to the 6960 m (22,837 ft) summit of Aconcagua in Argentina, a Korean male in his 50s with no known medical conditions presented with lightheadedness and shortness of breath. He had taken sildenafil and acetazolamide that morning without improvement. Vital signs on arrival were notable for oxygen saturations in the high 60s with basilar crackles on lung auscultation, concerning for high altitude pulmonary edema. The patient was started on oxygen via nasal cannula and given dexamethasone. History was limited secondary to language barriers, but on review of systems the patient noted mild chest pressure. Bedside cardiac echocardiogram was performed, which revealed a septal wall motion abnormality. The patient was therefore given aspirin and clopidogrel and was flown to a lower trailhead, where he was met by local Emergency Medical Services. A 12-lead electrocardiogram revealed an anterior ST-elevation myocardial infarction, and the patient was taken emergently to the catheterization lab in Mendoza and underwent stent placement with a full recovery.

Search and rescue activity on Denali, 1990 to 2008.

OBJECTIVE: To describe search and rescue activity performed by the National Park Service (NPS) on Denali, the highest point in North America. METHODS: A retrospective review was performed of all search and rescue (SAR) operations by the NPS from 1990 to 2008. Descriptive analysis was used to describe these cases as well as chi-square and logistic regression analysis to determine which mountaineers were more likely to require a rescue. RESULTS: During the study period, 1.16% of all Denali climbers required NPS SAR response. The majority of medical cases (68.9%) were due to high altitude and cold injuries, and the majority of traumatic cases (76.2%) resulted from a fall. Mountaineers that attempt routes other than the standard West Buttress route are more likely to require rescue. Climbers are 3% more likely to require a rescue with each year of advancing age. Similarly, mountaineers from Asia are more likely to require a rescue (odds ratio = 4.1), although this trend has diminished in the past decade. CONCLUSIONS: Mountaineers and rescuers should educate themselves on the environmental, logistical, and medical origins of Denali rescues. Certain demographic groups on certain routes are more likely to require a rescue on Denali. Rescuers should be aware of these groups and have the knowledge and capabilities to care for the medical issues that are common on SAR responses.

The Rusch ViewMax vs Macintosh laryngoscopy in human cadavers: impoved vocal cord visualization?

OBJECTIVES: Adequate vocal cord visualization via laryngoscopy is a key component of successful endotracheal intubation. Several tools exist to facilitate laryngoscopy in difficult airways. We compared one such device, the Rusch "ViewMax" (Rusch, Duluth, Ga), to a standard Macintosh laryngoscope blade (Heine USA Ltd, Dover, NH) using human cadaver models. The purpose of this study was to determine if the ViewMax improved vocal cord visualization. METHODS: Emergency medicine residents and faculty (N = 26) attempted vocal cord visualization with both ViewMax and Macintosh laryngoscope blades for each of 6 cadaver airways at an airway laboratory training exercise. Percentage of glottic opening (POGO) score was estimated for each laryngoscopy attempt. Data were analyzed by nonparametric statistics. RESULTS: Of 6 cadaver airways, 4 had median POGO score estimates of 100% for both ViewMax and Macintosh laryngoscope blades. Two cadavers had median POGO estimates of less than 50% for both blades. No difference was found in POGO score estimates between the ViewMax and the Macintosh blades in any of the 6 cadavers including those with more difficult vocal cord visualization (P = .27, .35, .61, .40, .39, .31). CONCLUSION: The Rusch "ViewMax" was not shown to improve vocal cord visualization over standard Macintosh blade laryngoscopy in these cadaver models. Further study with cadaver models known to have more difficult airways may improve power to detect a small difference in vocal cord visualization, though the clinical relevance of any slight difference remains uncertain.

Investigating carbon monoxide exposure on Denali.

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.

Time to first shock by emergency medical technicians with automated external defibrillators.

UNLABELLED: The interval from collapse to electrical rescue shock is a critical determinant of successful defibrillation in cardiac arrest. In order to achieve the earliest possible defibrillation, many emergency medical services (EMS) systems equip first-responding units with an automated external defibrillator (AED). OBJECTIVE: To measure the time from on-scene emergency medical technician (EMT) recognition of cardiac arrest to AED application and shock in ventricular fibrillation (VF) arrest. In addition, the authors sought to understand the reasons for delays. METHODS: Using the AED recordings and written EMS reports, the authors conducted a retrospective cohort study of all persons who experienced an EMS-attended VF cardiac arrest in which an AED was applied and a shock delivered by an EMT, from January 1999 through December 2000 (n = 177). Based on the bimodal distribution of times, two groups were assembled: no delay (time to shock < or = 90 seconds) and delayed (time to shock > 90 seconds). Patient and event characteristics associated with delay status were determined using Mantel-Haenszel methods. RESULTS: The median (25th, 75th percentile) time from cardiac arrest recognition to shock was 51 (43, 64) seconds. Ninety-four percent (n = 166) of the cohort received a shock within 90 seconds. Delayed shock was associated with unwitnessed arrest status (odds ratio = 9.3, 95% confidence interval = 2.3, 36.8) and nursing home location (odds ratio = 10.0, 95% confidence interval = 2.1, 47.5). CONCLUSION: The findings suggest that a 1-minute goal and a 90-second minimum standard for time to first shock are appropriate for EMT AED defibrillation in the field.