Effects of volume therapy with different doses of 6% hydroxyethyl starch 130/0.4 on lung injury in a rat model of hemorrhagic shock

Objective To evaluate the effects of volume therapy with different doses of 6% hydroxyethyl starch 130/0.4 (6% HES 130/0.4) on lung injury in a rat model of hemonhagic shock.Methods Twenty-four male SD rats weighing 220-300 g were randomly divided into 4 groups ( n = 6 each) : group I sham operation (group S); group II Ringer's solution (group RS); group HI and IV 2 HES groups (group H1, H2 ). The animals were anesthetized with intraperitoneal 1% sodium pentobarbital 45 ing/kg. Right common carotid artery (CCA) and left femoral vein were cannulated for blood letting, MAP monitoring, fluid administration and blood sampling. Hemonhagic shock was induced by withdrawing blood from right CCA in group II , III and IV . MAP was reduced to 35-45 mmHg which was maintained for 90 min. In group RS, hemorrhagic shock was resuscitated with Ringer's solution 3 times of the volume of blood withdrawn, while group H1 and H2 received HES 33 and 50 ml/kg respectively and Ringer' s solution (the total volume was equal to 3 times of the volume of blood removed) . Arterial blood samples were taken before blood letting (T0 , baseline), and at 2, 3 h after volume therapy (T1,2) for blood gas analysis and PaO2/FiO2 was calculated. The animals were then sacrificed by exsanguination and the lungs were immediately removed for microscopic examination and determination of protein concentration in broncho-alveolar lavage fuid (BALF), W/D lung weight ratio and TNF-α, IL-1 β and IL-10 contents in the lung.Results TNF-α, IL-1β and IL-10 content in the lung, protein concentration in BALF and W/D ratio were significantly higher in group RS, H1 and H2, while PaO2/FiO2 was significantly lower at T,2 in group RS and at T2 in group H2 than in group S (P < 0.05). TNF-α and IL-1β contents in the lung, protein concentration in BALF and W/D ratio were significantly lower in group H1 and H2 , while PaO2/FiO2 was significantly higher at T,i2 in group H1 and at T1 in group H2 than in group RS (P <0.05) . PaO2/FiO2 at T2 and IL-10 content in the lung were significantly lower in group H2 than in group H, ( P < 0.05) . The lung damage was significantly ameliorated in group H1 and H2 especially in group H, as compared with group RS. Conclusion Volume therapy with 6% HES 130/0.4 33 or 50 ml/kg can attenuate lung injury in a rat model of hemorrhagic shock and the efficacy of 33 ml/kg is better. Key words: Hetastarch; Shock,hemorrhagic; Respiratory distress syndrome,adult