Changes in Plasma and Buffy Layer Vitamin C Concentrations following Major Surgery: What Do They Reflect?

Abstract

Plasma and buffy layer vitamin C concentrations have been measured in 19 patients before and following major surgery, and falls of 36% and 43% respectively were recorded on the first post-operative day. However, the change in the buffy layer could not be accounted for by a change in the concentration of vitamin C in platelets, mononuclear cells or polymorphonuclear leucocytes, the cell types which form the buffy layer. The buffy layer change could be explained by a post-surgical increase in the number of polymorphonuclear leucocytes which, when the buffy layer vitamin C is expressed per 108 white cells, dilutes the platelet and mononuclear cell contribution to the buffy layer vitamin C concentration. The fall in buffy layer vitamin C does not, therefore, reflect any increased demand for white cell vitamin C in the immediate post-operative period, although the decrease in plasma vitamin C could imply some increased utilisation or redistribution of the non-cellular compartment.