Metabolism after injury. 1: Effects of severity, nutrition, and environmental temperature on protein potassium, zinc, and creatine

Abstract

The effect of an environmental temperature of 28–30°C. and a relative humidity of 35–45 per cent on the protein metabolic response to injury of one or more major long bones of the lower limbs has been studied in 29 male patients and 28 similar controls housed at 20–22°C. The metabolic response was reduced at the higher temperature compared with the controls, the more severely injured showed a greater metabolic response than the less severely injured, and the ameliorating influence of environmental temperature was more noticeable in the former. The metabolic response seems to be principally one of catabolism of muscle, with increased urinary excretions of potassium, creatine, and zinc in the urine correlating well with those of nitrogen at 20°C. but not at 30°C. The response (i.e., catabolism of muscle) was not affected by post-injury diet at 20°C. ambient temperature. There was a reduction in the disturbance of the plasma proteins. In general, the patients tolerated the warm drier conditions. Owing to the intrinsic difficult in assessing minor changes in bone healing it was not possible to assess what, if any, beneficial change occurred in the fracture site. From our experimental observations on the rat and the work of others on burned patients the reduction in heat production at the higher ambient temperature is accompanied by an enhanced rate of healing of surface wounds.