Glucose kinetics in haemorrhagic shock

Sir: I read with much interest the article by Shimodate et al. about the use of glucose as an indicator for haemorrhagic shock [1]. Rapid infusions of glucose and sucrose were given to dogs and their distribution volumes were proposed as an indication of haemorrhage. This approach is simple and attractive, but the hyperglycaemic effect of haemorrhagic shock is likely to impose certain limitations on its usefulness. Haemorrhage mobilizes glucose by means of gluconeogenesis and the glucose level may double or, if glycogen stores are filled, even triple [2-4]. In the cat and in the rat, this effect is fully developed within 1 h after a severe bleeding event. It is thought to be a defence mechanism - the increase in glucose level raises the osmolality of the extracellular fluid, which redistributes water from the cells. A progressive increase in endogenous blood glucose acts to decrease the apparent distribution volume for the glucose when calculated by Shimodate et al. I believe that the safe use of glucose for dilution volumetry in haemorrhage requires that this possible confounder is addressed. R. G.