Evidence map›Paper›PMID 36581811›Full record

Trial reportBMC anesthesiology2022

The minimum effective concentration (MEC90) of ropivacaine for ultrasound-guided quadratus lumborum block for analgesia after cesarean delivery: a dose finding study.

Rong Cao, Xuehan Li, Jing Yang, Lingmei Deng, Yu Cui

Open access · goldAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in BMC anesthesiology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
1.1field-weighted citation impact, top 22% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed, 5 citations in OpenAlex.

  1. The MECDrug design, development and therapy · 2026
    Trial
  2. Trial
  3. Trial
  4. Local anesthetic dosing for fascial plane blocks to avoid systemic toxicity: a narrative review.Canadian journal of anaesthesia = Journal canadien d'anesthesie · 2025
    Review
  5. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 3 institutions in 1 country.

Rong CaoDepartment of Anesthesiology, The Affiliated Hospital, School of Medicine, UESTC Chengdu Women's and Children's Central Hospital, Chengdu, 610091, China.
Xuehan LiDepartment of Anesthesiology, and Laboratory of Anesthesia and Intensive Care Medicine, West China Hospital of Sichuan University, Chengdu, China.
Jing YangDepartment of Anesthesiology, The Affiliated Hospital, School of Medicine, UESTC Chengdu Women's and Children's Central Hospital, Chengdu, 610091, China.
Lingmei DengDepartment of Anesthesiology, The Affiliated Hospital, School of Medicine, UESTC Chengdu Women's and Children's Central Hospital, Chengdu, 610091, China.
Yu CuiDepartment of Anesthesiology, The Affiliated Hospital, School of Medicine, UESTC Chengdu Women's and Children's Central Hospital, Chengdu, 610091, China. cuiyu19831001@163.com.
Chengdu Women's and Children's Central Hospital · CNSichuan University · CNUniversity of Electronic Science and Technology of China · CN

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundQuadratus lumborum block was recently proposed as an alternative technique for post-cesarean delivery analgesia. However, there is not a definite optimum concentration of local anesthetics. A biased coin design up-and-down method was used to explore the minimum effective concentration of ropivacaine in quadratus lumborum block for satisfactory analgesia after cesarean delivery.

methodsFifty-six patients weighing 60-80 kg after cesarean section and with ages between 18 and 40 years were recruited. For the posterior quadratus lumborum block, a volume of 25 ml of the assigned concentration of ropivacaine was injected bilaterally. The concentration administered to each patient depended on the response to the previous dose. The first patient received 0.25%. If a successful block was observed, the next patient was randomized to receive the same ropivacaine concentration (with a probability of 0.89) or 0.025% less (with a probability of 0.11). After any block failure, the concentration was always increased by 0.025% for the next. The study ended when 45 successful blocks were obtained. We defined effective quadratus lumborum block as a resting visual analog score ≤ 3 and the absence of a need for rescue anesthetics.

resultsThe 90% minimum effective concentration of ropivacaine was 0.335% (95% CI 0.306 to 0.375%), and the 99% minimum effective concentration was 0.371% (95% CI 0.355 to 0.375%). The sufentanil consumption was 11 (11,13) and 24 (22,27) μg at 12 and 24 hours after quadratus lumborum block, respectively.

conclusionsThe optimum dosage of ropivacaine is a 25 ml volume of 0.335% for quadratus lumborum block after cesarean delivery.

trial registrationThe study was registered in the Chinese Clinical Trial Registry (No. ChiCTR2000040415 ).

Indexed as

AnalgesiaCesarean SectionAdolescentAdultAnalgesics, OpioidAnesthetics, LocalFemaleHumansPostoperative PainPregnancyRopivacaineUltrasonography, InterventionalYoung AdultAnalgesics, OpioidAnesthetics, LocalRopivacaineCesarean deliveryMinimum effective concentrationPostoperative painQuadratus lumborum block

Identifiers

PMID36581811
PMCPMC9798625
OpenAlexW4313331704

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

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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.