TIIE history and application of intravenious therapy and medicationl especially as to the use of salinie, glucose and acacia solutions has been completely an(l well reviewed in a recent article by Norman Keith of the Mayo Clinic.The value of infusionis has generally become well accepted, but their effectiveness is often nmarred by utntowar(l reactions, often at most inopportunle times.It is the purpose of this paper to clear up the causes of these reactions .and demonstrate practical methodls to eliminate them. Reactions, as we know them, embody a variable extent of damage to the body physiology from mere elevation of temperature to chills, cyanosis, diarrhwea, nausea, vomiting, collapse and death. Even the mildest are uncomfortable to the patient and severe reactions are always (langerous., especially so in very ill cases, which are often, incidentally, the very cases wherein intravenous therapy can be of greatest value.Many things have been suggested as causes for reactions, and( to comprehensively study the problem each of the suggested factors was considered and either proven or disproven to be active factors in the situation. Thus rubber tubing, heat of solution, speed of injection, individual susceptilbility, disease itself, hydrogen ion concentration of solution, absorption from. glassware all these have been suggested as possible causes. Of these, the first and seemingly most likely factor to be studied was the effect of hydrogen ion concentration. A portable quinhydrone Unlit was designed as illustrated (Fig. i) using a Micslowitzer quinhydrone cup against standard saturated calomel electrode, and a Leeds and Northrup potentiometer. The temperature coefficient was placed on a graph in the top of the box so that readings made after equilibrium of the solution could be directly transposed to pH and corrected for changes in temperature. This method gave readings of comparatively great accuracy within a few minutes' time. The accuracy of the method was challenged, however, because the solutions studied were unbuffered. It was therefore carefully checked with a colorimetric method, using brom-thymol blue. Fig. 2 illustrates in graphical form the result of this check. It is to be noted that there is an average variation of some 0.25 pI1 between the two methods. This is, however, constant, and "salt action" of the indicator used in itself introduces a possibility of error, so that the true p1 probably lies somewhere between the two. \We feel that the quinhydrone method is much the more accurate for relative differences of pEI and the observations made are therefore recorded in quinhydrone figures.* Read before the Philadelphia Academy of Surgery, April 7, I930.195
