[Hemorrheological changes in irreversible hemorrhagic shock].

OBJECTIVE

To observe the characteristics of changes in hemorheology at the early stage of irreversible hemorrhagic shock in a rodent model.

METHODS

Rodent model of irreversible hemorrhagic shock was reproduced. Animals were randomized into 4 groups. In the first group, survival rate and mean arterial pressure (MAP) in 180 minutes were observed after hemorrhagic shock (S group). In the second group, animals were sacrificed soon after hemorrhagic shock (S0 group). In the third group, animals were sacrificed 60 minutes after hemorrhagic shock (S1 group). In the fourth group, animals were sacrificed 120 minutes after hemorrhagic shock (S2 group). Blood samples of animals of S0, S1 and S2 were all obtained before hemorrhagic shock. Blood lactate, hemorheological parameters, red blood cell (RBC) deformability and RBC aggregation index were determined.

RESULTS

Mean blood loss of S group was (22.9+/-3.8) ml/kg, constituting about (38.1+/-6.3)% of total blood volume. At 60, 120 and 180 minutes after hemorrhagic shock, survival rates were 100%, 72% and 64%, respectively. Compared with baseline, 0, 60 and 120 minutes after hemorrhagic shock, blood lactate increased significantly (all P<0.01), but 120 minutes after hemorrhagic shock, it decreased significantly compared with 0 minute after hemorrhagic shock (P<0.05). Compared with baseline, 0 minute and 60 minutes after hemorrhagic shock, blood viscosity was found to be decreased at shear rate of 10 s(-1), 60 s(-1) and 100 s(-1) (all P<0.01); 120 minutes after hemorrhagic shock, at shear rate of 10 s-1 and 60 s(-1), blood viscosity decreased significantly (both P<0.01); 0, 60 and 120 minutes after hemorrhagic shock, plasma viscosity, RBC deformability and RBC aggregation index at shear rates of 600 s(-1), 800 s(-1) and 1 000 s(-1) decreased significantly (all P<0.01).

CONCLUSION

At the early stage of irreversible hemorrhagic shock, blood lactate increased significantly, and decreased afterwards. These indicate reversal of deterioration of metabolism. At different time after the early stage of irreversible hemorrhagic shock, blood and plasma viscosity, RBC deformability and aggregation index lowered significantly and did not improve. Changes in viscosity and RBC aggregation are different from the changes in late stage, and this indicates that hemorheological disorders should be corrected in the treatment at the early stage after hemorrhagic shock.