We aimed to evaluate the effects of resuscitation with different ratios of fresh frozen plasma (FFP) to red blood cells (RBCs) on pulmonary inflammatory injury and to illuminate the beneficial effects of FFP on lung protection compared with lactated ringers (LR) using a rat model of hemorrhagic shock.

Rats underwent pressure-controlled hemorrhage for 60 minutes and were then transfused with LR for initial resuscitation. Thereafter, the rats were transfused with varying ratios of FFP:RBC (1:4, 1:2, 1:1, and 2:1) or LR:RBC (1:1) to hold their mean arterial pressure (MAP) at 100 ± 3 mm Hg for 30 minutes. After 4 hours of observation, lung tissue was harvested to determine the wet/dry weight, myeloperoxidase levels, tumor necrosis factor α levels, macrophage inflammatory protein 2 (MIP-2) levels, inducible nitric oxide synthase activity, and the nuclear factor κB p65 DNA-binding activity.

With an increase in the FFP:RBC ratio, the volume of required RBC to maintain the target MAP decreased. The MAP value in each group was not significantly different during the whole experiment period. The values of the wet/dry weights and MIP-2 were significantly lower in the FFP:RBC = 1:1 group than the other groups (P < .05). All parameters detected above were predominantly lower in the FFP:RBC = 1:1 group than the FFP:RBC = 1:2 group and the LR:RBC = 1:1 group (P < .05). In addition, all parameter values were lower in the FFP:RBC = 1:1 group than in the FFP:RBC = 2:1 group, but only the wet/dry weight, myeloperoxidase, and MIP-2 values were significantly different (P < .05).

Resuscitation with a 1:1 ratio of FFP to RBC results in decreased lung inflammation. Compared with LR, FFP could further mitigate lung inflammatory injury.