Electrical injury: mechanisms, manifestations, and therapy

Human contact with strong electrical power sources often results in complex injury patterns which have been difficult to explain and even more difficult for survivors to overcome. Fundamentally, there are two basic modes of tissue injury: direct effects of strong electric fields on proteins and cellular structures and indirect effects related to joule heating. Historically, tissue injury due to direct effects of electric forces have received no consideration with respect to understanding electrical injury. Recently, substantial progress has been made in understanding this aspect. The structural characteristics of nerve and skeletal muscle tissue renders them particularly vulnerable to injury by supraphysiological electric fields. How the injury manifests from the combination of thermal and electric effects depends on several variables including the tissue field strength, duration of exposure, frequency, and current path. This review describes the destructive changes to cellular structure resulting from exposure to commercial electrical power sources and the resulting manifestations at the organ system level. Finally, several important new therapeutic approaches to treat and possibly reverse the molecular alterations of electrical shock are discussed.