Propofol Overdose, EEG
Conditions
Keywords
Propofol, General anesthesia, EEG, Burst suppression
Brief summary
In the world, 230 million surgeries are performed per year and a significant part is performed in patients over 65 years of age. These patients are more labile, especially from the neurocognitive point of view with a high risk to develop neurocognitive complications, such as postoperative delirium. Recent studies have linked this type of complication with an overdose of general anesthetics during surgery. For this reason, in recent years, the use of brain function monitors during the intraoperative period has been recommended to adapt the dosage of the drugs to each patient and thus to avoid overdosing of general anesthetics. However, to date, the available monitors that process the electroencephalographic signal are not able to adequately discriminate gradual changes in anesthetic depth. Also, no systematic studies have been performed that analyze changes that occur in the electroencephalogram (EEG) signal secondary to increases in complications from general anesthetics. Thus, the investigators design this study with the main aim to determine the changes in electroencephalographic patterns induced by a stepped increase of propofol until the burst suppression is reached.
Detailed description
The investigators will carry out a prospective analytical observational clinical study at the Clinical Hospital of the University of Chile. In total 15 patients will be recruited, in who a frontal electroencephalographic signal will be recorded using a SedLine® monitor, and propofol concentration will be estimated using the Marsh model. First, the concentration of propofol at the loss of consciousness (LOS) will be recorded in the presence of remifentanil (7.5 ng/mL). Then, patients will be intubated and remifentanil will be decreased to 4 ng/mL. After that, the concentration of propofol that caused the LOS will be maintained for 20 minutes. Finally, propofol will be increased in steps of 0.3 mcg/mL for 7 min, until an episode of burst suppression will be observed. In the complete protocol, EEG activity will be acquired using a SedLine® monitor.
Interventions
DRUGPropofol
Stepped propofol concentration after 20 min of LOS
Acquisition of EEG activity
Sponsors
University of Chile
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists (ASA) Physical Status 1 or 2 * Low-risk surgery
Exclusion criteria
* BMI \> 35 kg/m2 * Benzodiazepines use * Epilepsy * Psychiatric disorder * Kidney disease * Liver disease * Brain damage
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in the alpha power of EEG Spectrogram | Change between baseline time (0 minutes) and burst suppression time (35 minutes) | % of change |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in the delta power of EEG Spectrogram | Change between baseline time (0 minutes) and burst suppression time (35 minutes) | % of change |
| Change in the coherence | Change between baseline time (0 minutes) and burst suppression time (35 minutes) | % of change |
| Change in the propofol concentration | Change between baseline time (0 minutes) and burst suppression time (35 minutes) | concentration in mcg/mL |
Countries
Chile
Outcome results
None listed