Recording and analyzing electroencephalogram (EEG) and continuous pain monitor data under anesthesia in order to investigating the pharmacodynamic effects of opioids and sedatives.
The Patient State Index (PSI) is the main instrument used for monitoring brain waves during anesthesia. By using conductive patches to detect frontal lobe brainwave patterns, PSI helps assess the patient's depth of anesthesia. The Analgesia Nociception Index (ANI) is a heart rate variability (HRV)-based indicator that evaluates the activity of the autonomic nervous system (sympathetic and parasympathetic), thereby reflecting the patient's pain or stress response. PSI and ANI are often used together in anesthetized patients to avoid drug overdose. Since opioids and sedative drugs interact with each other, different doses of opioids and sedatives have varying effects on brain waves, PSI, and ANI. This interaction has recently become a focus in anesthesiology and critical care medicine. The purpose of this study is to use target-controlled infusion (TCI) to continuously administer opioids and sedative drugs, and to observe changes in the Patient State Index (PSI), raw EEG, and ANI data during the anesthesia process, in order to identify the effects of opioids and sedatives on PSI, EEG, and ANI.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
DOUBLE
Enrollment
20
The initial dose is alfentanil cet 10ng/mL and propofol 1ug/mL. Dose of alfentanil will be increased by 10ng/mL each until PSI reach to 25-50. If alfentail has been adjusted to 50 but PSI is still too high, increase propofol cet by 0.5-1ug/mL till target PSI is reached. If propofol is adjusted to 0 but PSI is still too low, decrease alfetanil by 10ng/mL The range of dosage of alfentanil is 0-50ng/mL while propofol is 0-5ug/mL.
Adjust dose of propofol to the upper limit before adjusting dose of alfentanil. Increase dose of propofol 0.5-1 ug/mL in order to have PSI valued 25-50. The initial dose of propofol is 1ug/mL, alfentanil 10 ng/mL. If propofol was adjusted to cet=5 ug/mL but PSI is still too high, increase alfentanil by 10 ng/mL instead. If alfentanil was adjusted to 0 but PSI is still too low, decrease propofol by 0.5-1 ug/mL instead . The range of dosage of propofol is 0-5 ug/mL while alfentanil is 0-50ng/mL.
EEG alpha power to beta power ratio
Time frame: Baseline and periprocedural
EEG alpha ratio
Time frame: baseline and periprocedural
EEG delta ratio
Time frame: baseline and periprocedural
EEG beta ratio
Time frame: baseline and periprocedural
Patient State Index (PSI)
A processed electroencephalogram (EEG) parameter derived from frontal EEG signals. It is being measured continuously by a EEG monitor.
Time frame: baseline and periprocedural
Analgesia Nociception Index (ANI)
The Analgesia Nociception Index is measured by a continuous analgesia monitoring system . It is a numeric index (range from 0-100) indicating patients' nociception.
Time frame: Baseline and periprocedural
Blood pressure
Time frame: baseline and periprocedural
Non-invasive cardiac output
Cardiac output measured continuously by non-invasive monitoring (e.g., electrical cardiometry or equivalent device). The unit of measure is liters per minute (L/min)
Time frame: during the whole sedation
Heart rate
Time frame: baseline and periprocedural
Peripheral Capillary Oxygen Saturation (SpO₂)
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Continuous non-invasive measured by pulse oximetry,
Time frame: baseline and periprocedural
Non-invasive cardiac index
Cardiac index calculated as cardiac output normalized to body surface area, measured non-invasively. The unit of measure is liters per minute per square meter (L/min/m²)
Time frame: baseline and periprocedural
Non-invasive Stroke Volume (SV)
Stroke volume measured non-invasively, defined as the volume of blood ejected from the left ventricle per heartbeat.
Time frame: baseline and periprocedural