In this study, we investigated the phlebitic potentials of several infusion solutions for peripheral
parenteral nutrition to clarify the effects of pH and osmolality on the development of infusion
phlebitis.
A 10%
glucose solution with
electrolytes (GE, pH 4.93, 727 mOsm/kg),
a 10%
amino acid solution (AA, pH 6.95, 929 mOsm/kg), or a 5:2 admixture of GE and AA (GEAA, pH 6.46, 779 mOsm/kg) was infused into the rabbit ear vein for 6 hr
at 10 mL/kg/hr, and the infused veins were examined histopathologically. Both GE and AA caused phlebitic changes, such as loss of venous endothelial cells, inflammatory cell infiltration, and perivascular
edema. However, their admixture, GEAA, caused scant phlebitic changes. These results were as follows: 1) rabbit peripheral veins could tolerate the pH (6.46) and the osmolality (779 mOsm/kg) of GEAA under the conditions of this study; 2) GE caused
phlebitis due to its acidity (pH 4.93); 3) AA caused
phlebitis due to its hyperosmolality (929 mOsm/kg); and 4) mixing GE and AA eliminated the factors causing
phlebitis in each
solution. The admixture of GE and another 10%
amino acid solution (AB, pH 6.04) at the ratio of 5:2 (GEAB, pH 5.76, 758 mOsm/kg) caused phlebitic changes. Since its osmolality was lower than that of GEAA, it was considered that GEAB caused phlebitic changes due to its acidity (pH 5.76), which was attributed to the
acidic amino acid solution used as a component.