Traumatically induced hypophosphataemia in anaesthetized pigs.

Clinical studies in severely injured patients have regularly shown hypophosphataemia probably directly related to the humoral response to trauma. In this study 72 anaesthetized pigs were exposed to a standardized missile trauma to find out whether the same type of change could be induced in an experimental animal as far as possible in the absence of other factors known to cause hypophosphataemia. The serum phosphate, calcium, and albumin concentrations and the fractional excretion of phosphate were recorded for 72 hours after inflicting the injury. The fall in serum phosphate after trauma follows a biphasic pattern, with a rapid drop immediately after the injury, a brief increase, and then a gradual slow decrease with a minimum at the end of the experimental period. This decrease was not caused by glucose infusion or phosphaturia due to haemodilution and increase in extracellular volume. The results support the hypothesis that hypophosphataemia in the posttraumatic period is caused by the humoral response to trauma. A new experimental model has been developed for the study of posttraumatic metabolic events.