Hypertonic saline-dextran improves intestinal perfusion and survival in porcine endotoxin shock

Objective: To examine the effects of hypertonic (7.5%) saline-6% dextran 70 (HSD) and isotonic (0.9%) saline-6% dextran 70 (ISD) on cardiovascular function and intestinal perfusion in experimental endotoxin shock. Design: Experimental, randomized, unblinded, interventional study. Setting: University experimental animal laboratory. Subjects: Anesthetized and mechanically ventilated landrace pigs (n = 24). Interventions: Induction of endotoxin (ET) shock by infusion of Escherichia coli lipopolysaccharide endotoxin (serotype 0111: B4) followed by no fluid treatment (control; C) or small-volume (4 mL/kg) treatment with HSD or ISD. Measurements and Main Results: Mean arterial pressure, central venous pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, cardiac output, portal vein blood flow, intestinal microcirculation, intramucosal (regional) PCO₂, intestinal-arterial gap of CO₂, and intramucosal pH were monitored, and blood gases were analyzed. Infusion of ET resulted in hypokinetic shock, which in untreated animals led to cardiovascular deterioration and a survival rate of only 33% at 300 mins after start of ET infusion. ISD treatment transiently improved hemodynamic variables and mucosal blood flow but did not affect the survival rate vs. C. Significant beneficial, long-lasting effects of HSD infusion on hemodynamics, especially on mucosal blood flow and intramucosal pH, were demonstrable, resulting in a survival rate of 86%. The relative risk of death at 300 mins was 1.20 for ISD vs. C and 0.17 for HSD vs. C. Conclusion: Small-volume HSD resuscitation is much more effective than ISD resuscitation. Variables that were improved include cardiac output, portal blood flow, and intestinal mucosal blood flow in ET shock, all of which improve survival. Such beneficial effects of HSD on splanchnic perfusion may be of value in treating critically ill septic patients in the intensive care unit.