Intrathecal Hydromorphone Versus Intrathecal Morphine for Postcesarean Delivery Analgesia: A Randomized Noninferiority Trial
Bibliographic record
Abstract
BACKGROUND: Spinal anesthesia with intrathecal morphine is often the preferred anesthetic modality for elective cesarean delivery. Side effects and drug shortages, however, prompted researchers to look into intrathecal hydromorphone as an alternative. These studies established the effective analgesic dose for 90% of patients (ED90) for both opioids for postcesarean analgesia, yet failed to demonstrate the superiority of morphine over hydromorphone. Nonetheless, the noninferiority of hydromorphone has yet to be determined. METHODS: In this noninferiority randomized blinded clinical trial, 126 patients undergoing elective cesarean delivery under spinal anesthesia received either morphine 150 µg or hydromorphone 75 µg (ED90). The primary outcome was the between-group difference of the mean Numeric Rating Scale (NRS) pain score (0-10) for the first 24 hours after cesarean delivery, with a preestablished threshold for noninferiority of 1. This 24-hour NRS pain score was defined as a single number obtained at the 24 hours postcesarean delivery interview, based on participant's recall of their overall pain experience during this period. Secondary outcomes included differences in NRS pain scores every 6 hours, cumulative 24 hour opioid consumption, time-to-first opioid request, quality of recovery as measured by the Obstetric Quality of Recovery Score-11 (ObsQoR-11), frequency of interventions for side effects, and Apgar scores. RESULTS: The mean (standard deviation [SD]) of the 24-hour NRS pain score was 4.0 (1.7) for morphine and 3.6 (1.5) for hydromorphone (between-group difference -0.46 (95% confidence interval [CI], -1.0 to 0.1). Given that the upper limit of the 95% CI did not exceed 1, noninferiority of hydromorphone was established. No statistically significant differences were found in mean (SD) 24 hour oral morphine consumption (morphine: 4.2 mg (6.5) vs hydromorphone: 4.1 (8.0) mg; P = .98), median [interquartile range {IQR}] ObsQoR-11 score (morphine: score 87 [75-97.5] vs hydromorphone: score 90 [80-96.5]; P = .51), median [IQR] time to first opioid request (morphine: 10.2 [3.2-15.5] h versus hydromorphone: 6.2 [3.1-12.4] h; P = .35), or proportion of patients requiring interventions for opioid-related pruritus (morphine: 0.316 (variance 0.216) vs hydromorphone: 0.321 (variance 0.218) ( P = .96) and opioid-related nausea and vomiting (morphine: 0.333 (variance 0.222) vs hydromorphone: 0.393 (variance 0.238) ( P = .51). CONCLUSIONS: Intrathecally, hydromorphone is noninferior to morphine for analgesia after elective cesarean delivery when using the previously established ED90 for both opioids (morphine: 150 µg versus hydromorphone: 75 µg); hydromorphone provides effective analgesia and may be a suitable alternative to morphine.
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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 | 0.006 | 0.009 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.005 | 0.003 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.005 | 0.004 |
| Insufficient payload (model declined to judge) | 0.010 | 0.002 |
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".