380
P. Martínez-Vázquez et al.
24.5 Advantages and Challenges in Depth of Anaesthesia
Monitoring
The DoA monitoring is a relatively recent technology in constant development, updating to the newer research findings in neuroscience, pharmacology and anaesthesiology. The main advantages of these technologies are: (1) Reduction the incidence of
AWR [11, 31, 36, 57]. (2) Tailoring the anaesthetic agents to the present patient‘s
condition and surgical context, optimizing drug consumption [46, 50], attenuating
potential adverse effects from overdose and facilitating faster recovery [17, 27].
(3) Potential reduction of anaesthetic exposure decreasing the risk of postoperative
delirium and cognitive declines [8]. Yet, the limitations of processed EEG monitoring
come basically from the lack of complete knowledge of all the complex mechanisms
involved during the anaesthesia procedure, and the lack of a gold standard. Some of
the current challenges in the depth of anaesthesia monitoring are: (1) Attenuation
of the electromyographic (EMG) interference activity present in all EEG recordings. (2) Enhancement of the discrimination between the different components of
the balanced anaesthesia: the hypnosis, the analgesia and the areflexia as well as the
interaction between their different associated drugs. (3) Currently, there is no reliable
solution to deal with ketamine , and some volatile agents as the nitrous oxide and
halothane among others. (4) Development of robust closed-loop control system to
titrate the anaesthetics, to continuously optimize automatically the drug-delivering
according to the patient‘s context.
24.6 Conclusions
In this chapter, we introduced the basic changes and patterns of the EEG oscillations induced by anaesthetics. Due to the complexity of the EEG oscillations, their
characterization followed multiple distinct perspectives, from linear system theory
to non-linear methods. Despite there is no gold standard on the estimation of the
patient state, the different perspectives point to similar estimations. Independently
of the taken approach any EEG based DoA index must agree with the pharmacological and clinical assessment information. Processed EEG, for DoA monitoring,
is a multidisciplinary field in constant research and development for newer methods
to support for preventing AWR episodes and reduce other adverse effects such as
postoperative cognitive declines in elderly and new-borns.
P. Martínez-Vázquez et al.
24.5 Advantages and Challenges in Depth of Anaesthesia
Monitoring
The DoA monitoring is a relatively recent technology in constant development, updating to the newer research findings in neuroscience, pharmacology and anaesthesiology. The main advantages of these technologies are: (1) Reduction the incidence of
AWR [11, 31, 36, 57]. (2) Tailoring the anaesthetic agents to the present patient‘s
condition and surgical context, optimizing drug consumption [46, 50], attenuating
potential adverse effects from overdose and facilitating faster recovery [17, 27].
(3) Potential reduction of anaesthetic exposure decreasing the risk of postoperative
delirium and cognitive declines [8]. Yet, the limitations of processed EEG monitoring
come basically from the lack of complete knowledge of all the complex mechanisms
involved during the anaesthesia procedure, and the lack of a gold standard. Some of
the current challenges in the depth of anaesthesia monitoring are: (1) Attenuation
of the electromyographic (EMG) interference activity present in all EEG recordings. (2) Enhancement of the discrimination between the different components of
the balanced anaesthesia: the hypnosis, the analgesia and the areflexia as well as the
interaction between their different associated drugs. (3) Currently, there is no reliable
solution to deal with ketamine , and some volatile agents as the nitrous oxide and
halothane among others. (4) Development of robust closed-loop control system to
titrate the anaesthetics, to continuously optimize automatically the drug-delivering
according to the patient‘s context.
24.6 Conclusions
In this chapter, we introduced the basic changes and patterns of the EEG oscillations induced by anaesthetics. Due to the complexity of the EEG oscillations, their
characterization followed multiple distinct perspectives, from linear system theory
to non-linear methods. Despite there is no gold standard on the estimation of the
patient state, the different perspectives point to similar estimations. Independently
of the taken approach any EEG based DoA index must agree with the pharmacological and clinical assessment information. Processed EEG, for DoA monitoring,
is a multidisciplinary field in constant research and development for newer methods
to support for preventing AWR episodes and reduce other adverse effects such as
postoperative cognitive declines in elderly and new-borns.