Trial reportBMC anesthesiology2018
Intrathecal morphine administration reduces postoperative pain and peripheral endocannabinoid levels in total knee arthroplasty patients: a randomized clinical trial.
Trial report in BMC anesthesiology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT02620631 (Prospective, Randomized, Double-blinded, Placebo-controlled Study to Examine Pain Relief and the Need for Supplementary Analgesics With Intra-thecal Morphine Sulfate), which is not on this map. Cited by 13 papers, 2 of them syntheses that pooled 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.
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.
Prospective, Randomized, Double-blinded, Placebo-controlled Study to Examine Pain Relief and the Need for Supplementary Analgesics With Intra-thecal Morphine Sulfate (0.2 mg) in Patients Undergoing Total Knee Arthroplasty (TKA)
Who cites it
13 citing papers in PubMed, 2 syntheses or guidelines pooled it, 22 citations in OpenAlex.
- Pooled it
- Pooled it
- Combined intrathecal fentanyl and morphine for postoperative analgesia after total knee arthroplasty: a randomised controlled trial.BMC anesthesiology · 2026Trial
- Trial
- Endocannabinoids, perioperative pain, and acetaminophen in patients undergoing total knee arthroplasty: a prospective cohort study.Pain reports · 2026Article
- Review
- Enhanced recovery after surgery (ERAS) in sacral tumour surgery and comprehensive description of a multidisciplinary program: a prospective study in a specialized hospital in China.International orthopaedics · 2024Article
- Effect of multiple analgesic pathways including local infiltration analgesia, peripheral nerve blocks, and intrathecal morphine for controlling pain after total knee arthroplasty.European journal of orthopaedic surgery & traumatology : orthopedie traumatologie · 2023Article
- Circulating endocannabinoids and genetic polymorphisms as predictors of posttraumatic stress disorder symptom severity: heterogeneity in a community-based cohort.Translational psychiatry · 2022Article
- Toward Composite Pain Biomarkers of Neuropathic Pain-Focus on Peripheral Neuropathic Pain.Frontiers in pain research (Lausanne, Switzerland) · 2022Review
- Escalating morphine dosing in HIV-1 Tat transgenic mice with sustained Tat exposure reveals an allostatic shift in neuroinflammatory regulation accompanied by increased neuroprotective non-endocannabinoid lipid signaling molecules and amino acids.Journal of neuroinflammation · 2020Article
- Combined spinal and general anaesthesia in 58 cats undergoing various surgical procedures: description of technique and retrospective perioperative evaluation.Journal of feline medicine and surgery · 2019Article
- Cancer- and Non-cancer Related Chronic Pain: From the Physiopathological Basics to Management.Open medicine (Warsaw, Poland) · 2019Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
12 authors at 4 institutions in 1 country.
Funding
Abstract
backgroundThe primary goal of this study was to determine whether administration of intrathecal morphine reduces postoperative pain. The secondary goal was to determine the effect of intrathecal morphine upon circulating levels of the weakly analgesic endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and the related lipids palmitoylethanolamide (PEA) and oleoylethanolamide (OEA).
methodsForty two total knee arthroplasty (TKA) patients were enrolled in a prospective, double-blinded, randomized study. The intervention consisted of intrathecal morphine (200 μg) or placebo administered at the time of the spinal anesthesia. Postoperative pain was measured during the first 4 h after surgery while serum levels of AEA, 2-AG, PEA, OEA, and cortisol were measured at baseline and 4 h after surgery.
resultsAdministration of intrathecal morphine reduced postoperative pain 4 h after TKA surgery compared to placebo (p = 0.005) and reduced postoperative systemic opioid consumption (p = 0.001). At baseline, intrathecal morphine led to a significant reduction in AEA, 2-AG, and OEA levels but did not affect PEA or cortisol levels. In patients administered intrathecal placebo, 2-AG levels were elevated 4 h after surgery; whereas patients receiving intrathecal morphine showed reductions in AEA, PEA, and OEA when compared to placebo. At 4 h after TKA surgery cortisol levels were significantly elevated in the placebo group and reduced in those receiving morphine.
conclusionsThese results indicate that intrathecal morphine reduces postoperative pain in TKA patients. Furthermore, activation of central opioid receptors negatively modulates the endocannabinoid tone, suggesting that potent analgesics may reduce the stimulus for production of peripheral endocannabinoids. This study is the first to document the existence of rapid communication between the central opioid and peripheral endocannabinoid systems in humans.
trial registrationThis trial was registered retrospectively. TRIAL REGISTRY: NCT02620631 . Study to Examine Pain Relief With Supplemental Intrathecal Morphine in TKA Patients, NCT02620631 , 12/03/2015.
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Registered trials
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.