Role of heart-rate variability in preoperative assessment of physiological reserves in patients undergoing major abdominal surgery

Petr Reimer,1 Jan Máca,1 Pavel Szturz,1 OndÅ™ej Jor,1 Roman Kula,1 Pavel Ševčík,1 Michal Burda,2 Milan Adamus3 1Department of Anesthesiology and Intensive Care Medicine, University Hospital Ostrava, 2Institute for Research and Applications of Fuzzy Modeling, Centre of Excellence IT4Innovations, University of Ostrava, Ostrava, 3Department of Anesthesiology and Intensive Care Medicine, University Hospital Olomouc, Olomouc, Czech Republic Background: Major abdominal surgery (MAS) is associated with increased morbidity and mortality. The main objective of our study was to evaluate the predictive value of heart-rate variability (HRV) concerning development of postoperative complications in patients undergoing MAS. The secondary objectives were to identify the relationship of HRV and use of vasoactive drugs during anesthesia, intensive care unit length of stay (ICU-LOS), and hospital length of stay (H-LOS). Patients and methods: Sixty-five patients scheduled for elective MAS were enrolled in a prospective, single-center, observational study. HRV was measured by spectral analysis (SA) preoperatively during orthostatic load. Patients were divided according to cardiac autonomic reactivity (CAR; n=23) and non-cardiac autonomic reactivity (NCAR; n=30). Results: The final analysis included 53 patients. No significant difference was observed between the two groups regarding type of surgery, use of minimally invasive techniques or epidural catheter, duration of surgery and anesthesia, or the amount of fluid administered intraoperatively. The NCAR group had significantly greater intraoperative blood loss than the CAR group (541.7±541.9 mL vs 269.6±174.3 mL, p<0.05). In the NCAR group, vasoactive drugs were used during anesthesia more frequently (n=21 vs n=4; p<0.001), and more patients had at least one postoperative complication compared to the CAR group (n=19 vs n=4; p<0.01). Furthermore, the NCAR group