Effects of different durations of severe acute hypervolemic hemodilution on acute lung injury in rabbits

Abstract

Objective To evaluate the effects of different durations of severe acute hypervolemic hemodilution (AHH) on acute lung injury in rabbits. Methods Thirty-six healthy adult rabbits of both sexes, weighing 2.7-3.1 kg, were randomly divided into 2 groups (n=18 each) using a random number table: control group (C group) and AHH group.AHH was performed with 6% hydroxyethyl starch 130/0.4 until the target hematocrit of 20% was achieved in group AHH.Immediately before AHH (T0), and at 1, 2 and 4 h after AHH (T1-3), blood samples were taken from the right femoral artery for blood gas analysis.The oxygenation index was calculated.The occurrence of acute lung injury (oxygenation index ≤ 300 mmHg) was recorded.After blood samples were collected at T1-3, 6 rabbits in each group were sacrificed, and lungs were removed for determination of wet/dry lung weight ratio (W/D ratio) and aquaporin-1 (AQP-1) expression (by immuno-histochemistry). Results In group AHH, 1 rabbit developed acute lung injury at 1-2 h after AHH, and 4 rabbits developed acute lung injury at 2-4 h after AHH.Compared with group C, W/D ratio was significantly increased at T1-3, and the expression of AQP-1 was down-regulated at T2, 3 in group AHH (P<0.05 or 0.01). Conclusion Severe AHH performed with 6% hydroxyethyl starch 130/0.4 with the target hematocrit reduced to 20% and the duration > 1 h induces acute lung injury in rabbits. Key words: Hemodilution; Respiratory distress syndrome, adult