BACKGROUND: Studies on pregnant @entity1 undergoing cesarean delivery or elderly @entity1 scheduled for prostate brachytherapy have demonstrated the predictive value of heart rate variability (HRV) analysis for @entity551 during spinal anaesthesia. We conducted a prospective observational study to investigate if preoperative HRV analysis may have a role in identifying the risk of @entity551 following spinal anaesthesia in otherwise healthy @entity1 . METHODS: The study investigated 47 ASA physical status I--II @entity1 aged between 18--50 years that underwent subarachnoid anaesthesia for lower abdominal or orthopaedic scheduled surgery. ECG was recorded from all subjects before the @entity510 . We analysed the autonomic nervous system modulation, measured by HRV analysis. The variables that were be considered were preoperative HRV total power, low frequency (LF) and high frequency (HF) heart beat oscillations and LF/HF ratio. The LF/HF ratio was dichotomized according to the median for sensitivity analysis. The lowest arterial pressure value between spinal anaesthesia and the end of surgery was recorded. RESULTS: The median LF/HF before anaesthesia was 2.3. We considered two groups of 23 (LF/HF<2.3, group LOW) and 24 (LF/HF>2.3, group HIGH) @entity1 respectively. Both groups had similar baseline demographic and haemodynamic variables. A high preoperative sympathetic outflow and loss of vagal modulation, as stated by LF/HF>2.3, was correlated with a relative risk of 7.7 (95%CI 1.04 to 56.6, p=0.023) of post--spinal @entity551 . CONCLUSIONS: Preoperative analysis of autonomic nervous system modulation might be useful to stratify the risk of post--spinal @entity551 and it might indicate the need for careful monitoring or prophylactic fluids.

Preoperative autonomic nervous system analysis may stratify the risk of XXXX after spinal anaesthesia.

@entity1 :: ('9606', 'Species') :: ['women', 'patients', 'men'] @entity551 :: ('MESH:D007022', 'Disease') :: ['hypotension'] @entity510 :: ('MESH:D013345', 'Disease') :: ['subarachnoid block']
@entity551 :: (MESH:D007022,Disease) :: ['hypotension']
