[The therapy of diabetic coma: quantitative value of insulin loss on the infusion instruments]

The loss of insulin due to adsorption to glass and tubing has been quantitatively determined. The properties of albumin, plasma protein, gelatin, heparin and Rheomacrodex in the prevention of insulin adsorption have been tested. The loss of insulin given by intravenous infusion is reproducible and constant for any given situation. The loss of insulin increases as the ratio of volume to glass surface decreases and as the time of contact between insulin and glass is prolonged. There is an almost linear relationship between insulin loss and insulin concentration, as would be expected if insulin binding by glass was an unspecific phenomenon. Albumin and plasma protein almost completely prevent insulin adsorption. In most clinical situations the loss of insulin through adsorption to glass and tubing can be ignored, and hence no albumin or plasma protein needs to be added to the solution.