Lightning injuries

A major source of injury and death from the environment, lightning is one of the top 3 causes of death from environmental origins. (The other top environmental killers are floods and extreme temperatures.) Lightning is neither a direct current nor an alternating current. It is a unidirectional, massive, current impulse with several return strokes back to the cloud. Once connection from the cloud is made, a tremendously large current impulsively flows for an incredibly short time. Uniqueness of lightning — The most important difference between lightning and high-voltage electrical injuries is the duration of exposure to the current. Lightning has only brief contact with the skin. There is not enough time to allow skin burns. Internal burns and renal failure play a small part in the injury pattern from lightning. Cardiac and respiratory arrest, vascular spasm, and neurologic damage play a much greater role. Immediate effects — The immediate effect of a lightning strike tends to be ventricular asystole rather than fibrillation. While the heart rhythm will often pick up again, the respiratory arrest that accompanies the cardiac arrest may be prolonged and result in a secondary cardiac arrest. Other injuries caused by blunt trauma or ischemia from vascular spasm, such as myocardial infarction or spinal artery syndromes, occasionally may occur. Long-term effects — The number of survivors of lightning injury is estimated to be between 10-20 times larger than the number of fatalities. Survivors may have ongoing problems that are not easy to quantify or treat, including neuropsychological and neurocognitive changes, chronic pain syndromes, chest pain, sympathetic nervous system dysfunction, sleep disorders, severe continuing headaches, and cardiac effects. The survivors tend to be young, employed, family people who suffer loss of income and disability and become a large cost for the community. Place and time — In addition to outdoor fatalities caused by lightning, there are a number of people injured indoors every year, including victims of telephone-mediated strikes. While recreational pursuits predominate in the injuries and fatalities, nearly one-third of the injuries are work-related, on-the-job injuries. The most common days of injury are Sundays, Saturdays, and Wednesdays, probably reflecting the recreational activities on the weekends. The most common time of day to be injured by lightning is from noon to 6 PM, with 6-12 PM following, related not only to when thunderstorms occur but also to when people are most likely to be outdoors. The most dangerous times for lightning injury are those in which the victim underestimates the likelihood of being hit — before the storm (lightning may hit as far as 10 miles in front of a thunderstorm) or after the storm appears over (but is not). Gender — In the US, males were found to be 4 to 5 times more likely to be injured and killed by lightning than females. This is not because of any physiologic differences, but purely is related to males' increased exposure, due to outdoor activities or work. Age — The highest number of incidence tends to occur in people under 16 years and in people aged 26-35 years. Few people over 50 years are injured since they are less often engaged outdoors.