Mental strain measured by heart rate variability differs during laparoscopic and conventional sigmoid resections.
Prospective randomized study.
Two surgeons performed 10 conventional and 10 laparoscopic sigmoid resections, alternating roles as primary surgeon and assistant. The kind of technique was randomly chosen each time.
Electrocardiograms of the surgeon and assistant were continuously recorded during the procedures and heart rate variability was analyzed off-line. The first 10 procedures (5 laparoscopic and 5 conventional) were performed by the more experienced and the next 10 by the less experienced surgeon.
Main Outcome Measures
Heart rate variability was determined by power spectral analysis as heart rate in beats per minute, high frequency (HF) and low frequency (LF) components in normalized units, and LF/HF ratio.
Results are given for heart rate, HF, LF, and LF/HF ratio for the following variables: laparoscopic surgery: 87.9, 14.7, 90.1, 7.5; conventional surgery: 90.2, 17.1, 87.6, 6.4; surgeon: 94.0, 13.5, 91.4, 8.4; first assistant: 84.1, 17.8, 86.3, 5.6; more experienced surgeon: 93.1, 16.5, 87.8, 6.4; and less experienced surgeon: 85.0, 14.8, 90.0, 7.5. The LF/HF ratio was significantly higher (P<.05) for laparoscopic compared with conventional surgery and for the surgeon compared with the assistant (P<.001), but not between the less and the more experienced surgeons.
Performing laparoscopic colorectal surgery causes higher mental strain in surgeons than performing conventional surgery.