Assessment of hemodynamic and gastric mucosal acidosis with modified fluid gelatin versus 6% hydroxyethyl starch:: a prospective, randomized study

Objective:To investigate the effect of 4% succinylated modified fluid gelatin (MFG) versus mean weight, highly substituted 6% hydroxyethyl starch (HES) on hemodynamic and gastric mucosal acidosis variables, in septic hypovolemic patients. Design: Prospective, randomized, clinical investigation. Setting: University hospital intensive care unit. Patients: Thirty-four septic hypovolemic ventilated and hemodynamically controlled patients. Interventions: Invasive hemodynamic and gastric tonometric measurements. Measurements and results: Hemodynamic and tonometric parameters were recorded at baseline and 60 min after infusion of 500 ml of each colloid. In all patients central venous pressure, pulmonary artery occlusion pressure, cardiac index and mean arterial pressure increased significantly with both colloids, and hemoglobin concentration decreased by the same amount while oxygen delivery remained stable. Gastric intramucosal pH increased from 7.27 +/- 0.08 to 7.31 +/- 0.07 (p < 0.001) with MFG and decreased non-significantly from 7.26 +/- 0.11 to 7.22 +/- 0.08 (ns) with HES. Carbon dioxide gastric mucosal arterial gradient decreased from 18 +/- 9 to 13 +/- 9 mmHg (p < 0.0005) in the MFG group and rose non-significantly from 18 +/- 11 to 21 +/- 11 mmHg with HES. Conclusions: Although MFG and 6% HES have the same hemodynamic effects, their physicochemical properties induce different responses on gastric mucosal acidosis in septic, hypovolemic and ventilated patients. These effects of MFG and HES on gastric mucosa need to be considered in patient management.