Effect of clonidine on heart rate variability during spinal anesthesia: randomized clinical trial
Bibliographic record
Abstract
Abstract Introduction:All anesthetic techniques act, in some way, in the Autonomic Nervous System. In spinal anesthesia this effect is well described. The administration of local anesthetics in the subarachnoid space produces sensitive and sympathetic motor block, however, with latencies and variable and independent block levels. Adjuvants administered in association with local anesthetics have the potential to prolong the duration of spinal anesthesia, increasing the incidence of side effects. The recovery of spinal anesthesia is based solely on the return of motor function and does not take into account the recovery of Autonomic Nervous System activity.Objective:To analyze the autonomic modulation of heart rate in patients undergoing surgical procedures under spinal anesthesia at the moment of recovery of motor function and to compare the autonomic function in patients who received bupivacaine in subarachnoid anesthesia with patients who recover bupivacaine associated with clonidine. Method:randomized, double-blind clinical trial. The sample consisted initially of 71 patients ASA I to III, submitted to surgery under spinal anesthesia. Patients were divided into 2 groups. Group B received only bupivacaine and group C received bupivacaine with clonidine. The Heart Rate Variability was evaluated during 10 min in three moments: (T1) rest, before the anesthesia; (T2) 20 min after the installation of the anesthetic block, and (T3) at the time of recovery of motor function. Linear methods, frequency domain and non-linear methods in the Chaos domain were used. Results:The approximate entropy in the clonidine group showed a elevation, which may suggest a protective effect on the cardiovascular system of the addition of clonidine in spinal anesthesia. Conclusion:The approximate entropy values at the moment of recovery of motor function in patients receiving spinal anesthesia with bupivacaine and clonidine present a reduction when compared to the values obtained at rest. This data suggests that motor and autonomic block recovery occurs at different times when clonidine is used in spinal anesthesia. This data brings a question about the safety of the discharge criteria of the post anesthetic recovery room using only the return of the motor function after spinal anesthesia.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.005 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.006 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.008 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".