Evidence map›Paper›PMID 42058549›Full record

ArticleCureus2026

Comparison of Postoperative Analgesic Efficacy of Two Intrathecal Morphine Doses (75 μg vs 100 μg) for Cesarean Delivery: A Double-Blind Randomized Study.

Joseph A Veraza, Mariam A Martinez, Pedro Angulo, Mabel Z Almeida

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Article in Cureus, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Joseph A VerazaAnesthesiology, Clínica Andes Salud Puerto Montt, Puerto Montt, CHL.
Mariam A MartinezAnesthesiology, Hospital Universitario de Caracas, Caracas, VEN.
Pedro AnguloAnesthesiology, Hospital Universitario de Caracas, Caracas, VEN.
Mabel Z AlmeidaBiostatistics, Hospital Universitario de Caracas, Caracas, VEN.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundIntrathecal morphine remains a cornerstone of post-cesarean analgesia due to its prolonged spinal effect; however, its use is limited by dose-dependent adverse effects. Contemporary practice trends favor dose minimization, yet the lowest dose that reliably maintains effective analgesia remains unclear. This study aimed to evaluate whether a reduced dose of 75 μg provides analgesic efficacy comparable to a standard 100 μg dose.

methodsIn this prospective, randomized, double-blind trial, 240 ASA II women undergoing elective cesarean delivery under spinal anesthesia were allocated to receive either 75 μg or 100 μg of preservative-free intrathecal morphine combined with 7.5 mg of 0.5% isobaric bupivacaine. Postoperative pain intensity was assessed using the Visual Analog Scale (VAS, 0-10) at 0, 4, 8, 12, and 24 hours. Secondary outcomes included rescue analgesic requirements, maternal adverse effects, and neonatal Apgar scores.

resultsAll 240 enrolled participants completed the study protocol. At the primary 12-hour endpoint, pain intensity did not differ significantly between groups, with median VAS scores of 0.0 (IQR 1.0) in the 75 μg group and 1.0 (IQR 1.75) in the 100 μg group (p = 0.224); no significant differences were observed at 4, 8, or 24 hours. Non-opioid rescue analgesia was required in 50/120 (41.7%) patients in the 75 μg group and 45/120 (37.5%) in the 100 μg group (p = 0.509), with no patients requiring opioid rescue. Maternal adverse effects were comparable between groups, including pruritus in 30/120 (25.0%) patients in the 75 μg group and 25/120 (20.8%) in the 100 μg group (p = 0.442), and nausea in 20/120 (16.7%) and 10/120 (8.3%) patients, respectively (p = 0.051). Neonatal outcomes were favorable, with all neonates achieving Apgar scores ≥8 at five minutes. Although statistically significant differences were observed between groups, these differences were not clinically meaningful.

conclusionsA 75 μg dose of intrathecal morphine was associated with comparable 24-hour postoperative analgesia to 100 μg, with no statistically significant differences observed between groups in pain scores or adverse effects. These findings suggest that lower doses may provide adequate analgesia while maintaining a similar safety profile. However, further studies specifically designed as non-inferiority or equivalence trials are required to confirm these observations.

Indexed as

anesthesia spinalelective cesarean deliveryintrathecal morphineobstetric anesthesiapostoperative pain

Identifiers

PMID42058549
PMCPMC13123135

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.