Evolving clinical and scientific concepts of upper extremity electrical trauma.
In conclusion, the pathogenesis of electrical injury is more complex than previously thought. Cellular damage occurs both by heating and electroporation. The relative contributions of heat and electroporation depend on the duration of electric current passage, the orientation of the cells, their location, and other factors. If the contact is brief, nonthermal mechanisms of cell damage may be most important. If the contact is much longer, heat damage will be most destructive. The characteristic time before heat damage predominates is probably a function of the electrical field strength in the tissue. If heat damage predominates, the injury may not be limited just to the plasma membrane but to other cell membranes as well. This is unlikely to be reversible. These parameters should also determine the pattern of injury. Damage by Joule heating is not known to be dependent on cell size, whereas larger cells are more vulnerable to membrane breakdown by electroporation. Cells do survive transient plasma membrane rupture under appropriate circumstances. Thus, if electroporation is the mechanism of damage, injured tissue may be salvageable; the challenge is to identify a technique that promptly reseals the damaged membranes. Current therapy requires a fully staffed and equipped intensive care unit, available operating suites, and the full range of available medical specialists. Major teaching hospitals are usually the prime candidates for operating an electric trauma unit. After initial resuscitation, efforts should be directed primarily toward preventing additional tissue loss mediated through a compartment syndrome. Renal and cardiac failure resulting from the release of intracellular muscle contents into the circulation must be prevented. Attention can then be directed toward maximizing tissue salvage and preventing late skeletal and neuromuscular complications. Finally, complex reconstructive procedures are needed to optimize the functional value of the remaining tissue. The eventual reconstructive goals should be kept in mind throughout the acute care of the patient.
Department of Surgery, University of Chicago Pritzker School of Medicine, Illinois.
L M
LM
Zachary
R C
RC
Lee
L J
LJ
Gottlieb
D001134:Arm Injuries / Q000209:etiology / Q000628:therapy; D002058:Burns, Electric / Q000209:etiology / Q000628:therapy; D006801:Humans