Pseudocholinesterase activity increases and heart rate variability decreases with preoperative anxiety.

ABSTRACT

BACKGROUND AND OBJECTIVE: The objective of this study was to determine the influence of preoperative anxiety on the activity of plasma cholinesterase and heart rate (HR) variability. METHODS: A total of 50 subjects were studied, 25 male patients one day preoperatively and 25 male volunteers without surgical intervention as a control group. Blood samples were taken to determine plasma cholinesterase activity. HR variability was recorded for a period of 256 beat-to-beat intervals and analysed by frequency domain analysis into very low frequency (VLF 0.02-0.04 Hz), low frequency (LF 0.04-0.15 Hz) and high frequency (HF 0.15-0.4 Hz). LF/HF ratio and total power over the 0.02-0.4 Hz range were calculated. Anxiety levels were assessed using the hospital anxiety and depression scale, the self-rating anxiety scale and a visual analogue scale. RESULTS: The patient group had significantly higher anxiety scores. Plasma cholinesterase activity was significantly higher in patients vs. controls (6646 vs. 5324 units L(-1)). Total power, LF and HF were significantly lower in the patients (1489 vs. 2581 ms2; 656 vs. 1186 ms2; 491 vs. 964 ms2, respectively). CONCLUSIONS: Preoperative anxiety increases plasma cholinesterase activity and decreases HR variability.