Relatively little is known about the effects of general anesthesia on blood pressure variability (BPV). This study was designed to evaluate the changes of high frequency (HF) and low frequency (LF) of BPV before and during general anesthesia with sevoflurane.

Beat-to-beat blood pressure was recorded at conscious baseline and during general anesthesia at 2% end-tidal sevoflurane in 17 healthy living-liver transplantation donors. BPV estimated by power spectra of systolic (SBP) and mean blood pressure (MBP) was calculated.

Both LF power of SBP and MBP were diminished to 96.2% and 97.1% during sevoflurane anesthesia (5.5 ± 2.8 to 0.2 ± 0.2 mmHg², 6.6 ± 3.7 to 0.2 ± 0.2 mmHg², P < 0.001 for both). However, there were no significant changes of HF power of SBP and MBP during sevoflurane anesthesia.

Sevoflurane anesthesia reduced noticeably LF power, which was associated with sympathetic vasomotor activity, but not HF power, which represents mostly the mechanical effect of respiration on blood pressure, of BPV.