BACKGROUND: Hematic protective has arisen widely attention in China and abroad due to the serious blood contamination and transfusion related diseases.  
OBJECTIVE: To observe hematic protective effect of hypertonic solution chloride hydroxyethyl 40 injection (HSH) on acute hypervolemic hemodilution (AHH) in maxilla Lefort Ⅰ osteotomy.
METHODS: Totally 40 patients were randomly divided into the experimental and control groups, with 20 patients in each group. All patients were operated under tracheal intubation general anesthesia. In the experimental group, 4 mL/kg HSH was infused with speed of 10 mL/min, and the infusion was finished within 30 minutes. There was no treatment in the control group. Blood routine examination (including hematocrit, hemoglobin, blood platelets count) and routine coagulation test (including platelet, partial thromboplastin time, fibrinogen) was performed at the points of before AHH (T0), at the end of AHH (T1), 30 min after AHH (T2),  60 min after AHH (T3), 3 hours after AHH (T4), 1 day after operation (T5), and 3 days after operation (T6), respectively. Simultaneously, the capacities of blood transfusion, liquor transfusion, hemorrhage and urine during operation was recorded.
RESULTS AND CONCLUSION: All the patients were included in the final analysis. Compared to the control group, the capacity of blood transfusion in the experimental group was smaller than that of the control group (P < 0.05), with greater urine volume (P < 0.05). However, the differences of liquor transfusion and hemorrhage had no significance (P > 0.05). After controlled hypotension, the heart rates of patients at T2 and T3 were obvious increased than that of T1 (P < 0.05), the systolic pressure, diastolic pressure, and mean arterial pressure were significantly decreased (P < 0.05). At T1, T2 and T3 points, the heart rates of patients in the experimental group were greater than that of the control group (P < 0.05). The systolic pressure, diastolic pressure, and mean arterial pressure had no dramatically differences between two groups (P > 0.05). After AHH, the hematocrit and hemoglobin were obviously decreased in the experimental group at T1, T2, T3 and T4 points (P < 0.05), with more blood platelets count and prolonged partial thromboplastin time (P < 0.05). Compared to the control group, the Na⁺ , Cl^- was increased in the experimental group at T1 and T2 points (P < 0.05), with greater hematocrit and hemoglobin at the T5 and T6 points (P < 0.05). The results demonstrated that HSH can decrease or avoid transfusing blood in maxilla Lefort Ⅰ osteotomy.