Small-volume hypertonic saline dextran resuscitation from canine endotoxin shock

Abstract

This study evaluated resuscitation of endotoxin shock with 7.5% hypertonic saline dextran (HSD 2400 mOsm) by measuring hemodynamic and regional blood flow responses. Endotoxin challenge (1 mg/kg) in adult dogs caused a significant decrease in mean arterial blood pressure (MABP), cardiac output (CO), left ventricular +/- dP/dt max, and regional blood flow (radioactive microspheres). Cardiocirculatory dysfunction and acid-base derangements persisted throughout the experimental period in untreated endotoxin shock (group 1, n = 10). In contrast both regimens of fluid resuscitation (group 2, n = 11: bolus of 4 mL/kg HSD followed by a constant infusion of lactated Ringer's [LR] to maintain MABP and CO at baseline values; group 3, n = 10; LR alone given as described for group 2) improved regional perfusion and corrected acid-base disturbances similarly in all dogs. Hypertonic saline dextran enhanced all indices of cardiac contraction and relaxation more than LR alone. The total volume of LR required to maintain MABP and CO at baseline values was less in the HSD group (59.2 +/- 6.8 mL/kg) than in the LR alone group (158 +/- 16 mL/kg, p = 0.01). The net fluid gain (infused volume minus urine output and normalized for kilogram body weight) was five times greater in the LR (24.8 +/- 6.2 mL/kg) than in the HSD group (4.6 +/- 1.2 mL/kg, p = 0.01). Lung water was similar in all dogs, regardless of the regimen of fluid resuscitation. Hypertonic saline dextran effectively resuscitates endotoxin shock in this canine model.