Relationship Between Anesthesia Depth and Quality of Seizures: New Study in JECT
Out on PubMed, from investigators in Austria, is this study:
Relationship Between Anesthesia Depth and Quality of Seizures in Patients Undergoing Electroconvulsive Therapy: A Prospective Observational Study.
J ECT. 2021 Sep 13. doi: 10.1097/YCT.0000000000000792. Online ahead of print.PMID: 34519686
The abstract is copied below:
Objectives: Electroconvulsive therapy under general anesthesia is an established treatment for mood disorders, such as therapy-resistant depression. As most anesthetic drugs used for induction of anesthesia increase the seizure threshold, adequate depth of anesthesia without diminishing the therapeutic efficacy of interventions is crucial. The aim of this study was to investigate whether anesthesia depth as assessed by Narcotrend (NCT) monitoring correlates with maximum seizure quality.
Methods: An observational study was performed in psychiatric patients undergoing multiple interventions of electroconvulsive therapy. Seizure quality of each attendance was assessed evaluating electroencephalogram end point, electromyogram end point, postictal suppression index, the midictal amplitude, and a 3-step overall graduation. Narcotrend was used to assess anesthesia depth according to index-based electroencephalogram findings. Measurements were obtained before induction of anesthesia, before stimulation, and after arousal. Data were analyzed by means of linear mixed models and generalized estimating equations models.
Results: A total of 105 interventions in 12 patients were analyzed. Anesthesia depth before stimulation was significantly associated with seizure quality (standardized β = 0.244, P = 0.010), maximum sustained coherence (β = 0.207, P = 0.022), and electroencephalogram duration (β = 0.215, P = 0.012). A cutoff value of 41 or greater versus 40 or less for the NCT index was found appropriate to differentiate between good and less satisfactory overall seizure quality.
Conclusions: Anesthesia depth index assessed by NCT monitoring was positively associated with seizure quality. Narcotrend monitoring may be useful in assessment of optimal anesthesia depth before stimulation.
From the introduction:
Narcotrend (NCT) is another device to recognize EEG patterns
and assess the depths of anesthesia using a dimensionless index
(100–0) to specify stages from A (awake) to F (burst suppression).18–20
In this observational study, we evaluated the depth of anesthesia using NCT monitoring before, during, and after ECTapplications. The aim was to investigate whether NCT values before
electric stimulation correlate with seizure quality
And some tables:
This study holds some interest, but in the end, is really quantification of the obvious, and complicating something that does not need to be complicated.
Okay, too deep anesthesia leads to poorer seizure quality: this is well known, but additional data to confirm this are useful to increase the evidence base.
But the idea that the Narcotrend device or a BIS monitor is necessary to monitor anesthesia depth is surely overkill.
The sentence in the introduction, Currently, the assessment of anesthetic dosages in clinical practice depends on the individual experience of the anesthetist... is a red flag. Well, the dose of anesthetics is standardized (within fairly narrow ranges), and should not be at the whim of the anesthesiologist. Furthermore it should be pretty simple in almost all cases to tell if the patient is unconscious by speaking to them and examining them, no fancy instrumentation required.
But there is enough interesting detailed data here for followers of the anesthesia literature to want to read it in full, ~15 minutes.
Comments
Post a Comment