Is there a neurologist on this flight?

OBJECTIVE: To analyze the frequency of neurologic events during commercial airline flights and to assess whether onboard emergency medical kits are adequate for in-flight neurologic emergencies. METHODS: Collaboration of the Mayo Clinic's Departments of Emergency Medicine and Medical Transportation Service and the Division of Aerospace Medicine to provide real-time in-flight consultation to a major US airline that flies approximately 10% of all US passengers. We analyzed all medical events reported from 1995 to 2000 in a database that catalogs the air-to-ground medical consultations. All cases with potential neurologic symptoms were reviewed and classified into various neurologic symptom categories. The cost of diversion for each neurologic symptom was calculated and then extrapolated to assess the cost of neurologic symptoms to the US airline industry. RESULTS: A total of 2,042 medical incidents led to 312 diversions. Neurologic symptoms were the single largest category of medical incidents, prompting 626 air-to-ground medical calls (31%). They caused 34% of all diversions. Dizziness/vertigo was the most common neurologic symptom followed by seizures, headaches, pain, and cerebrovascular symptoms. Whereas seizures and dizziness/vertigo were the most common reasons for diversion, loss of consciousness/syncope was the complaint most likely to lead to a diversion. The estimated annual cost of diversions due to neurologic events is almost 9,000,000 dollars. CONCLUSION: Neurologic symptoms are the most common medical complaint requiring air-to-ground medical support and are second only to cardiovascular problems for emergency diversions and their resultant costs to the US airline industry. Adding antiepileptic drugs to the onboard medical kit and greater emergency medical training for in-flight personnel could potentially reduce the number of diversions for in-flight neurologic incidents.

GPS signal reception under snow cover: a pilot study establishing the potential usefulness of GPS in avalanche search and rescue operations.

Avalanches are one of the major threats to life in high-mountain terrain and account every year for approximately 150 accidents causing injury or death in the United States alone. Every year avalanches cause significant property damages and a death toll of approximately 15 people in the United States. The specific characteristic of the avalanche accident is the extreme importance of getting to the buried victim as soon as, possible to improve survival. Approximately 40% of all buried victims survive 1 hour, and only about 20% survive 2 hours. Newer studies from Europe indicate that the initial survival probability is 92% at 15 minutes, 30% at 35 minutes, 27% at 90 minutes, and finally drops to 3% at 130 minutes. Unless prompt and efficient search and rescue are ensured, the prospect of buried victims is rather grim. Many tools have been used in the past to aid in retrieving buried victims including the avalanche cord, probing techniques, and in more recent time, the use of electronic beacon devices that allow search teams to locate the buried victim. The advent of satellite navigational aids (GPS, GLONASS) makes it possible to determine one's position with remarkable accuracy. We studied the degree to which the GPS satellite signal could penetrate through snow and be received by a commercially available GPS receiver. This information may lead to the development of an additional tool for precise and quick localization of buried victims in avalanche accidents and thus may substantially improve their survival by shortening the search time at the accident site. In this study we used a Motorola Traxar six-channel GPS receiver with amplifier unit connected to an antenna by means of a shielded coaxial cable. The antenna was buried under incremental covers of compact snow, and the reception of the GPS signal was measured at each burial depth: 5 cm, 15 cm, 25 cm, 35 cm, 45 cm, 55 cm, 1 m, and 1.5 m. The variables that were measured included signal quality, number of satellites received by the receiver, and their respective signal strength. A reference reading was taken from the GPS receiver above the testing site before measurements under snow cover were started. The satellite signals were received with good quality and precise readings up to a burial depth of 1 m. Under 1.5 m of snow the receiver was able to lock on only one satellite, making a positional reading impossible. The reception of the GPS signals under snow cover is possible and warrants further study directed toward the development of a search and rescue device using this technology.

Epidemiology and outcome of cervical dystonia (spasmodic torticollis) in Rochester, Minnesota.

The natural history of cervical dystonia (spasmodic torticollis) was investigated in a population-based study in Rochester, Minnesota. Eleven new cases were identified with onset during the 20-year period 1960-1979. The overall incidence rate was 1.2 per 100,000 person-years (95% confidence interval 0.5-1.9) with a female:male ratio of age-adjusted incidence rates of 3.6:1. A unitary etiology was not apparent: injury antedated onset in four of the 11 patients, whereas six had documented thyroid disease and four had diabetes. A family history of movement disorder was recorded for only one subject. Only one of the cases would have been classified as moderate in severity; the others were mild. In follow-up through 1993, progressive disability was noted in only two patients, and two others went into remission. Three cases of intracranial aneurysm were confirmed, two of which produced fatal subarachnoid hemorrahage. A third death was due to amyotrophic lateral sclerosis.

Effect of dietary protein on high-producing dairy cows in early lactation.

Thirty Holstein cows capable of producing at least 30 kg of milk per day were assigned to one of three completely mixed rations containing corn silage, chopped alfalfa hay, and concentrate mixture. These rations differed only in crude protein content (12.7, 16.3, or 19.3% dry matter). All cows were fed their assigned ration continuously for 90 days beginning on the 4th day post-partum. Differences in average 4% fat-corrected milk, persistency of production, change in body weight, milk protein content, blood ammonia, plasma albumen, and rumen pH between groups of cows were not significant. Cows fed the higher protein rations had more 4% fat-corrected milk and feed intake throughout the trial. Groups of cows differed in average rumen ammonia and urea in blood plasma in relation to the protein content of the ration. Income above cost of feeds for the 90-day trial was greatest for the group fed the 16.3% crude protein ration and lowest for the group fed the 19.3% crude protein ration.

Factors affecting calcium, phosphorus, and magnesium status of dairy cattle on the Oregon coast.

Blood plasma from 126 milking cows in 21 herds was analyzed for calcium, phosphorus, and magnesium in October, 1974, and in the following April. For all three minerals, time of sampling, herds, and time of sampling by herd differed. Mean values in October and April were calcium, 10.1 and 9.0; phosphorus, 5.96 and 4.88; magnesium, 1.98 and 1.85 mg/100 ml. Calcium also differed between stages of lactation. Mean calcium for cows milking less than 100 days, 101 to 200 days, and greater than 200 days and dry was: 9.41, 9.70, and 9.80 mg/100 ml. Differences in winter feeding practices among herds were responsible for time of sampling, herd, and time of sampling-by-herd differences.