Skeletal muscle microcirculation and oxygenation in experimental intestinal shock: A study on the efficacy of different plasma substitutes.

Shock was induced in 60 dogs by exteriorization of the small intestine for three hours. The relative effectiveness of various hemodiluting agents on the microcirculation was measured as skeletal muscle capillary blood flow (QXe) and capillary permeability (P) surface area (S) for plasma (PSp), as calculated from the clearances of two locally injected isotopes, 133 Xenon and 131 Iodide. Skeletal muscle oxygen tension (Pm(2) was measured with a tissue PO2 electrode. During shock QZe decreased to 26%, PSp to 31% of the initial values, and PmO2 dropped from 51 to 18 mmHg. The degree of recovery from shock was assessed after reposition of the intestine and the infusion of different plasma substitutes (albumin, dextran 40, dextran 70, gelatin, ACD-plasma, and Ringer's acetate). Return of the intestine to the abdominal cavity did not in itself improve the shock condition. Dextran 40 and dextran 70 infusion increased QXe, PSp, and PmO2 to or above control levels, PSp to 60%, and QXe to 40% of the control values. Ringer's acetate gelatin, and ACD-plasma did not improve QXe but increased PSq to 62-67% of control values. Albumin and dextran increased PmO2 significantly in relation to no-fluid infusion. Only dextran 40 and dextran 70 increased both QXe and PSp significantly in relation to no -fluid infusion.