Microcirculatory, leucocyte/endothelium interaction and survival time effects of dobutamine in nonhypotensive endotoxemia

Introduction

Microcirculatory, leucocyte/endothelium interaction and survival time effects of dobutamine in the dose of 5 μg/kg/minute associated or not with volume resuscitation were studied in the hamster window chamber model during resuscitation from nonhypotensive endotoxemia [1, 2].

Methods

Awake hamsters were submitted to endotoxemia with intravenous injection of lipopolysaccharide (LPS) in the dose of 2 mg/kg. After 3 hours of LPS injection they were divided into four groups: LPS (n = 6): received no treatment; VR (n = 6): resuscitated with 40 ml/kg body weight of NaCl 0.9% in 1 hour followed by 20 ml/kg body weight during the remaining 4 hours; Dobuta (n = 6): received dobutamine infusion in the dose of 5 μg/kg/minute for 3 hours; Dobuta/VR (n = 6): resuscitated with 40 ml/kg body weight of NaCl 0.9% in the first hour followed by 20 ml/kg body weight during the remaining 2 hours, the last combined with dobutamine in the dose of 5 μg/kg/minute. The groups were compared with Control (n = 7): no treatment. Arteriolar and venular diameters, functional capillary density (FCD), leukocyte rolling and adhesion, and 72-hour survival time were evaluated.

Results

Dobuta had lower arteriolar diameter than Control (51 ± 10 and 114 ± 10% from baseline). LPS and Dobuta had lower FCD than Control and baseline values (18 ± 15; 16 ± 18; and 88 ± 6% from baseline, in LPS, Dobuta and Control, respectively). VR and VR/Dobuta restored FCD from baseline (382 ± 19 and 476 ± 30% from baseline in VR and VR/Dobuta, respectively). FCD in VR and VR/Dobuta were lower than Control. LPS and Dobuta had higher leucocytes adhesion than Control (42.2 ± 10; 32.2 ± 31; and 4.0 ± 7.1 leucocytes/mm² in LPS, Dobuta and Control groups, respectively). There was no significant difference in survival time between VR and Control, and VR/Dobuta and Control. Survival time was significantly lower in LPS and Dobuta than Control.

Conclusion

Dobutamine associated or not with volume resuscitation did not improve microcirculatory parameters, leucocyte adhesion or survival time during resuscitation from nonhypotensive endotoxemia while volume resuscitation restored microcirculatory parameters and improved survival time.