The nature and detection of diabetic acidosis

Abstract

Simultaneous determinations by the following three methods were made on diabetics in various stages of acidosis.

1. The alveolar carbon dioxide, by Fredericia's method.

2. The carbon dioxide capacity of the oxalate plasma. The plasma is shaken with air containing 6 per cent. CO₂, and the CO₂ content of the plasma is then determined. A simple apparatus was devised which permits, in three or four minutes, a determination of the CO₂ content, with an accuracy within one per cent. It consists essentially of a 50 c.c. pipette, provided with three-way stopcocks at the top and bottom, and connected with a mercury bulb. The pipette being full of mercury, 1 c.c. of plasma, washed in with 1 c.c. of water and 0.5 c.c. of N/1 acid, is introduced through the upper cock. The mercury is then drawn out from below by lowering the mercury bulb until a Torricellian vacuum is obtained in the pipette. The carbon dioxide escapes from the solution as the result of a few seconds shaking, and the water solution is drawn out of the pipette at the bottom. The mercury is then let in again through the other entrance of the 3-way cock at the bottom, and the volume of the carbon dioxide is read in the upper stem of the pipette, which is calibrated in 0.02 c.c. divisions. Normal serum binds about 75 per cent. of its volume of CO₂. In acidosis we have seen the figure as low as 20 per cent.

3. The H+ concentration of the plasma after addition of known amounts of HCZ. The H+ concentration of the untreated plasma itself is about the same in normal condition and in acidosis. In the latter condition, however, as follows from the reasoning of L. J. Henderson, the ability of the blood to maintain its reaction when treated with acid must be lowered.