A prospective randomized trial on heart rate variability of the surgical team during laparoscopic and conventional sigmoid resection

Hypothesis: Mental strain measured by heart rate variability differs during laparoscopic and conventional sigmoid resections. Design: Prospective randomized study. Setting: University hospital. Participants: 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. Intervention: 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: 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. Conclusion: Performing laparoscopic colorectal surgery causes higher mental strain in surgeons than performing conventional surgery.