The Monitoring of the Autonomic Nervous System: Myth or Reality

Every physiological or pathological change of the body is mirrored in a parameter alteration, but still there are elements that cannot be measured. In literature, authors tried to find a way to monitor the Autonomic Nervous System activity through different algorithms. A pleth-wave derived parameter, the Perfusion Index, could be helpful in monitoring the Autonomic Nervous System modifications. The Perfusion Index is modified by any vasoconstrictor or vasodilatative stimuli. In literature, there are studies that correlate the Perfusion Index with several external influences. As anesthesiologists, there are many situations where this index may be useful. In our department, we observed and noted the Perfusion Indexmodifications on 20 patients (15 scheduled for elective surgery and 5 from the ICU) before and after induction, laryngoscopy, incision, emergence from anesthesia, regional anesthesia, vasoactive drug administration and body temperature changes. In these situations, Perfusion Index modifications occurred.