Effects Of Acute Normovolemic Hemodilution Combined With Controlled Hypotension On Elderly Surgical Patients’ Extravascular Lung Water And Oxygenation

Objective: To observe the effect of acute normovolemic hemodilution(ANH) and ANH combined with controlled hypotension on the extravascular lung water(EVLW) and oxygenation in elderly patientsMethods: Forty-five ASA I~II elderly patients of either sex, aged 65-75 years included in the study. The patients were randomly divided into 3 groups(n=15 each): Group A was control group, regular in the routine transfusion and intraoperative crystalloid fluids and colloidal liquid to add volume. Group B were ANH group, the target Hct of ANH were 30% respectively after induction of anesthesia. Group C were ANH combined with CH group, the target Hct of ANH were 30% respectively after induction of anesthesia. And the patients were continued to pump infusion of nitroglycerin combined with esmolol for controlled hypotension before major steps. The target mean arterial pressure controlled below the basic value of 30% the left and right sides. The patient was monitoring of vital signs after entered the operation room, The HR, BP, MAP, Extravascular Lung Water Index(EVLWI) and Cardiac index(CI) were monitored by Pi CCO, and detected arterial blood gases and recorded at 5 points: before before induction of anesthesia(T1), immediately after ANH(T2), 30 min after ANH(T3), 30 min after CH(T4), immediately after surgery(T5). Recorded urine output and blood loss after surgery.Results: The 3 group were comparable with Sex ratio, age, body weight, length of operation time and urine output had no significant differences(P>0.05). Group B and group C’s volumes of autoblood removed had no significant difference(P>0.05). The amount of blood loss in group C was reduced significantly(P<0.05). MAP of three groups had significant differences(P<0.05), group C was lower than the other groups in T4. The MAP of T1 was higher than time points After induction of anesthesia in each groups. The HR ofT1 was higher than the other time points in each groups(P<0.05). The CI of group A was lower than the other groups in T2(P<0.05). The CI of T1 was lower After induction of anesthesia. The SVI of group A was lower than the other groups in T2. EVLWI、p H of three groups had no significant differences(P>0.05). The Pa O2, SPO2 of three groups had no significant differences(P>0.05), The T1 was lower than other time points in each groups. The Hct of three groups had significant differences(P<0.05), Group A was higher than other two groups in T2, T3 and T4. In the study, there were 6 cases in group A need homologous Allogeneic blood transfusion, there were 1 case in group B, while group C without homologous Allogeneic blood transfusion.Conclusion: acute normovolemic hemodilution combined with controlled hypotension has the exact effect of saving blood in elderly patients, and without any influence on the extravascular lung water and oxygenation.