THE EFFECTS OF PROPOFOL, ISOFLURANE, AND SEVOFLURANE ON OXYGENATION AND SHUNT FRACTION DURING ONE-LUNG VENTILATION

Propofol's effect on hypoxic pulmonary vasoconstriction during one-lun g ventilation (OLV) has not been determined. Twenty patients who had l ong-term OLV for esophageal surgery were allocated randomly to one of two study groups; one in which isoflurane administration preceded prop ofol, and another in which sevoflurane administration preceded propofo l. Arterial and mixed venous blood samples and hemodynamics were measu red as follows: before OLV, during OLV, OLV at 4 cm of positive end-ex piratory pressure (PEEP), OLV after conversion from volatile anestheti cs to propofol, OLV at 4 cm of PEEP, and after OLV. After the applicat ion of 4 cm of PEEP during propofol anesthesia, Pao, increased signifi cantly in both groups. The shunt fraction (Qs/Qt) increased significan tly after the initiation of OLV in both groups and decreased significa ntly after the conversion from volatile anesthetics to propofol in bot h groups. Propofol can be used safely during OLV because Pao, increase d after the application of 4 cm of PEEP during propofol anesthesia, an d Qs/Qt decreased significantly after the conversion from inhaled anes thetics to propofol anesthesia. Implications: During one-lung ventilat ion, the arterial partial pressure of oxygen values with propofol were greater than these with isoflurane and sevoflurane, and shunt fractio n values with propofol were lower than these with both volatile anesth etics. Propofol improved oxygenation and shunt fraction during one-hmg ventilation compared with volatile anesthetics.