The Effect of Propofol Concentration on Dispersion of Myocardial Repolarization in Children
Bibliographic record
Abstract
BACKGROUND: QT interval prolongation on the electrocardiogram (ECG) may be drug-induced and is traditionally associated with torsades des pointes. A better predictor of torsades des pointes is the time interval between the peak and the end of the T-wave (Tp-e). Older studies of propofol's effect on the corrected interval (QTc) are conflicting and confounded by polypharmacy. It was recently shown that target-controlled infusion of propofol at 3 microg/mL has no effect on QTc or Tp-e. This plasma concentration of propofol is at the extreme lower end of the range for surgical anesthesia. In this randomized, double-blind, clinical study, we investigated the dose-response relationship between propofol, QTc, and Tp-e in a range of doses clinically relevant for surgical anesthesia. METHODS: Sixty healthy unpremedicated children, aged 3-10 yr, were recruited. Subjects were randomized to receive target-controlled infusions of propofol, to achieve 1 of 3 plasma concentrations: 3, 4.5, and 6 microg/mL. A preoperative 12 lead ECG was performed and repeated 5 min after induction. Two investigators, blinded to group allocation and to the timing of the ECG traces, independently measured QTc and Tp-e within and between each group. Paired t-tests were used to compare QTc and Tp-e within groups. One-way analysis of variance was used for intergroup analysis. The primary outcome measure was a change of >25 ms in Tp-e both within and between groups. RESULTS: ECG recordings were obtained in 51 children. There were no demographic or ECG differences at baseline, at which time QTc and Tp-e values were within normal limits. There were no differences in QTc or Tp-e after induction within or between the three different groups. DISCUSSION: Propofol has no effect on myocardial repolarization in healthy children at clinically relevant doses. This suggests that propofol would be a rational choice for children with a preexisting repolarization abnormality.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".