The effects of midazolam on the EEG during sedation of critically ill patients Journal Article
| Authors: | Veselis, R. A.; Reinsel, R.; Marino, P.; Sommer, S.; Carlon, G. C. |
| Article Title: | The effects of midazolam on the EEG during sedation of critically ill patients |
| Abstract: | Patients who require mechanical ventilation are often sedated with midazolam. As clinical signs of sedation are often confusing or nonexistent, and there are few adverse side effects when large doses are infused over a period of days, substantial drug accumulation can result in these critically ill patients, despite the short half‐life of midazolam. An objective monitor of sedation would help maintain sedation at a constant level despite changing pharmacokinetic values in patients. We undertook this study to describe the electroencephalographic changes which occur with intravenous midazolam in critically ill patients, and to determine if a relationship exists between these changes and the depth of sedation as measured using a clinical scoring method. A series of 31 critically ill patients who required intravenous midazolam during mechanical ventilation were studied. Four different levels of sedation were defined ranging from execution of verbal commands to no response to suctioning through the tracheal tube or sternal rub. Electroencephalographic recordings were obtained in patients on a daily basis and a concurrent sedation level was determined. High frequency electroencephalogram activity decreased as sedation level increased. This was reflected in decreases in the spectral edge (17.61 to 10.56 Hz (p = 0.0024)), the median frequency (4.27 to 2.56 Hz (p = 0.0278)), and the logarithm of the absolute power in the beta, (p = 0.0012), and beta2 (p < 0.0001) bands. An incidental finding of asymmetry in power between right and left frontal electrodes was observed, with right‐sided power being 9–18% greater (p < 0.001). This form of monitoring of midazolam sedation in critically ill patients, which may allow better discrimination of different sedation levels than clinical examination alone, may be useful in guiding administration of midazolam to produce a constant sedative effect. Changes in electroencephalogram power, a useful sign of cerebral ischaemia, may be affected by the use of midazolam, which appears to cause asymmetry in power. Copyright © 1993, Wiley Blackwell. All rights reserved |
| Keywords: | adult; clinical article; aged; midazolam; sedation; drug accumulation; brain; scoring system; drug half life; dose calculation; speech; electroencephalogram; critical care; intravenous drug administration; clinical examination; artificial ventilation; hypnotics and sedatives; critical illness; electroencephalography; suction; middle age; respiration, artificial; power spectrum; human; male; female; priority journal; article; hypnotics benzodiazepines; intensive care. |
| Journal Title: | Anaesthesia |
| Volume: | 48 |
| Issue: | 6 |
| ISSN: | 0003-2409 |
| Publisher: | Wiley-Blackwell Publishing Ltd. |
| Date Published: | 1993-06-01 |
| Start Page: | 463 |
| End Page: | 470 |
| Language: | English |
| DOI: | 10.1111/j.1365-2044.1993.tb07063.x |
| PUBMED: | 8322985 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | Source: Scopus |
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