The Effect Of Acute Hypervolemic Hemodilution On Intrapulmonary Shunt During One Lung Ventilation

Objective This study evaluates the effect of hypervolemic hemodilution on hypoxic pulmonary vasoconstriction(HPV)and intrapulmonary shunt(Qs/Qt)during one lung ventilation(OLV).Mdthods 20 patients scheduled for thoracic operation were randomly divided into hypervolemic hemodilution (group I )and control ( group II)groups. They all did not have cardiac, liver and kidney diseases. Before operation, Voluven was infused fastly by 15ml/kg in the group I .The infusion was divided into two stages: In the first stage , the injection was infused by 10ml/kg in 15 min;In the second stage ,the injection was infused by 5ml/kg in 10—15 min. The patients' blood volume increased 20%. The operation begin after infusion. In the group II, Ringer's was infused normaly by 10ml/kg. h. In two groups, the quantity of losed blood was replenished with equal amounts of Voluven.The moisture of urine, evaporate from the surface of wound and transferred to the third gap were replenished with Ringer's by 8ml/kg. h. If the losed blood volume in excess of 600ml or Hct<25%, concentrate RBC need infused. The patients were forbidden to eat and drink before operation for 8 hours, so the quantity of losed body fluid need to replenish in Ringer's by 20ml/kg. Half the injection was infused fastly before anesthesia induction, 50% of the remaining was replenished in 1 hour after anesthesia. 25% of the remaining was infused in the second and the third hours respectively. The PaO₂, PvO₂ PaCO₂ SvO₂ and PH were observed and Qs/Qt were calculated.Results Qs/Qt increased, PaO₂ and PvO₂ decreased significantly during OLV compared with that during TLV in two groups(P<0. 01). SvO₂...