The Measurement of Neurovegetative Activity During Anesthesia and Surgery in Swine: An Evaluation of Different Techniques

• Published in: Anesthesia and analgesia Vol. 102; no. 5; pp. 1333 - 1340
• Main Authors: Martín Cancho, María F, Carrasco-Jiménez, María S, Lima, Juan R, Luis, Laura, Crisóstomo, Verónica, Usón-Gargallo, Jesús
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD International Anesthesia Research Society 01.05.2006; Lippincott
• Subjects: Anesthesia; Anesthesia, General - methods; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Autonomic Nervous System - drug effects; Autonomic Nervous System - physiology; Biological and medical sciences; Blood Pressure - drug effects; Blood Pressure - physiology; Female; Heart Rate - drug effects; Heart Rate - physiology; Hemodynamics - drug effects; Hemodynamics - physiology; Hydrocortisone - blood; Medical sciences; Methyl Ethers - administration & dosage; Ovariectomy; Swine; Anesthesia; Surgery
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1213/01.ane.0000202464.06660.66

In this study we evaluated, in 10 sevoflurane-anesthetized pigs undergoing abdominal surgery, different techniques for measuring autonomic nervous system (ANS) activityANSiscope™ index, spectral analysis of heart-rate variability, hemodynamic variables, and plasma catecholamines and cortisol levels. Animals underwent a 120-min anesthesia during which unilateral ovariectomy was performed. Cardiovascular and respiratory responses were monitored. ANSiscope™ indices (ANSindex™ sympathetic, ANSindex™ parasympathetic and balANSindex™) were used to monitor ANS activity. Spectral analysis was performed using an autoregressive model with a parametric method. The low frequency (LF) and high frequency (HF) components were used to interpret the power spectral density of short-term electrocardiograms (ECGs). The relationship LF/(LF+HF) reflects sympathetic activity, HF/(LF+HF) indicates parasympathetic activity, and the LF/HF ratio gives the predominance of the system. Plasma concentrations of adrenaline, noradrenaline, and cortisol were determined at different times. Correlation (P < 0.01) was found between the balANSindex™ and adrenaline levels and between LF/HF ratio and plasma adrenaline concentrations. Moreover, a significant (P < 0.01) correlation was found between the balANSindex™ and LF/HF ratio. However, no correlation was seen between the registered ANSiscope indices and hemodynamic variables. The correlation seen in this study suggests that the balANSindex™ could be a useful tool to monitor ANS activity during anesthesia and surgery.