[Changes in urine oxygen tension (PuO2) during anesthesia with isoflurane and sevoflurane]

Leonhardt and coworkers have suggested that PuO2 may indicate degree of renal medullary perfusion and function. The changes in PuO2 during N2O-O2-isoflurane anesthesia (GOI) and N2O-O2-sevoflurane anesthesia (GOS) were studied in 20 patients (GOI group: 10 cases, GOS group: 10 cases) who underwent elective surgeries. In the GOI group, PuO2 decreased significantly 30 and 60 minutes after the beginning of surgical incision, and it returned to the previous value immediately after the cessation of isoflurane. In the GOS group PuO2 decreased starting 30 minutes after the beginning of surgical incision until 10 minutes after the cessation of sevoflurane. These results suggest that isoflurane and sevoflurane administration caused a reduction in renal medullary perfusion, and that the low perfusion during sevoflurane anesthesia lasted longer than during isoflurane anesthesia. Measurement of PuO2 has a number of problems, but we believe that PuO2 is useful as an indicator of renal medullary blood flow.