---
title: "Variable-rate feedback versus fixed-rate basal PCA: effect on 48-hour cumulative opioid consumption"
id: "bmj-open-7-comparison-of-cumulative-opioid-consumption-between-variable-rate-feedback"
canonical_url: "https://medichelpline.com/clinical-feed/bmj-open-7-comparison-of-cumulative-opioid-consumption-between-variable-rate-feedback"
content_type: "clinical_feed_article"
specialty: "General"
source_name: "BMJ Open"
source_url: "http://bmjopen.bmj.com/cgi/content/short/16/8/e117278?rss=1"
published_at: "2026-08-28T09:38:04.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Variable-rate feedback versus fixed-rate basal PCA: effect on 48-hour cumulative opioid consumption
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/bmj-open-7-comparison-of-cumulative-opioid-consumption-between-variable-rate-feedback
- **Specialty:** [General](https://medichelpline.com/clinical-feed/general.md)
- **Primary Source:** BMJ Open
- **Source URL:** [Original Journal Publication](http://bmjopen.bmj.com/cgi/content/short/16/8/e117278?rss=1)
- **Published At:** 2026-08-28T09:38:04.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- Postoperative pain that is poorly controlled can delay mobilisation and increase complications; intravenous patient-controlled analgesia (PCA) is widely used but conventional fixed-rate basal infusion may not match fluctuating postoperative pain patterns. - New network-integrated pumps can run a **variable-rate feedback infusion** that adjusts the background infusion based on real-time patient demand to potentially reduce opioid exposure while maintaining analgesia. - This multicentre, randomised, double-blind controlled trial in China will enrol 1,170 adults (age 18–65, ASA I–III) undergoing elective mixed surgery under general anaesthesia, including thoracic, abdominal, spinal, orthopaedic and cranial procedures. - Participants are randomised 1:1 to a **fixed-rate basal infusion** group or a **variable-rate feedback infusion** group; both use a standardised PCA solution of **sufentanil**. - The variable-rate algorithm increases background infusion by 0.5 mL/hour on demand boluses during lockout and decreases by 0.5 mL/hour after 1 hour without demands. - The primary endpoint is total cumulative **opioid consumption** at 48 hours postoperatively, including PCA-delivered sufentanil and opioid-equivalent rescue analgesics. - Key secondary outcomes: resting and movement pain scores, cumulative PCA volume, number and dose of rescue analgesia, and postoperative quality of recovery. - Exploratory outcomes include sleep quality, sedation and agitation, degree of nausea and vomiting, and patient satisfaction with PCA; outcomes are measured at predefined postoperative time points. - The trial is approved by three institutional review boards and will follow the Declaration of Helsinki and Good Clinical Practice; written informed consent will be obtained. Results will be published and summarised for participants. Trial registration: NCT07361822.
## Clinical Analysis & Structured Key Points
Introduction Inadequately managed postoperative pain remains a significant clinical challenge, often leading to delayed mobilisation and increased complications. While intravenous patient-controlled analgesia (PCA) is a mainstay of treatment, conventional fixed-rate basal infusion modes may not align with the fluctuating biphasic nature of postoperative pain. This often results in either insufficient analgesia or unnecessary opioid overexposure. Advanced network-integrated PCA pumps now allow for 'variable-rate feedback infusion,' which dynamically adjusts the background rate based on real-time patient demand. This study aims to determine whether a variable-rate feedback infusion mode reduces total cumulative opioid consumption at 48 hours postoperatively while providing non-inferior analgesic efficacy compared with a fixed-rate basal infusion mode. Methods and analysis This is a multicentre, randomised, double-blind, controlled trial to be conducted at three hospitals in China. A total of 1170 patients (aged 18 - 65 years, American Society of Anaesthesiologists I-III) undergoing elective mixed surgery under general anaesthesia, including thoracic, abdominal, spinal, orthopaedic and cranial procedures performed using either minimally invasive or open approaches, will be recruited and randomised in a 1:1 ratio to either the fixed-rate basal infusion group or the variable-rate feedback infusion group. Both groups will receive a standardised PCA solution of sufentanil. In the variable-rate feedback infusion group, the background infusion rate will automatically increase by 0.5 mL/hour on demand boluses during lockout intervals and decrease by 0.5 mL/hour after 1 hour of inactivity. The primary outcome is the total cumulative opioid consumption at 48 hours postoperatively, including sufentanil delivered via PCA and opioid-equivalent rescue analgesics. Key secondary outcomes include resting and movement pain scores, cumulative PCA volume consumption, number and dosage of additional rescue analgesia and postoperative quality of recovery. Exploratory outcomes include sleep quality, sedation and agitation levels, and the degree of nausea and vomiting, patient's satisfaction with PCA. These outcomes are assessed at predefined postoperative time points. Ethics and dissemination The study has been approved by the Institutional Review Board of Beijing Tiantan Hospital (KY2025-387-02) and the Affiliated Hospital of Youjiang Medical University for Nationalities (YYFY-LL-2026-006), and the Second Affiliated Hospital of Hainan Medical University (2026-K140-01). The study will be conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. Written informed consent will be obtained from all participants before enrolment. Findings from this study will be disseminated through peer-reviewed journals and at scientific conferences. A summary of the findings will also be made available to participants on request. Trial registration number NCT07361822 .
## Related Clinical Research

- [Nursing undergraduates’ willingness to work in long-term care: qualitative insights from a geriatr](https://medichelpline.com/clinical-feed/plos-one-16-willingness-of-nursing-undergraduates-to-work-in-long-term-care-facilities-a.md)
- [Cropland type determines arbuscular mycorrhizal fungi (AMF) density and diversity in Northwest Eth](https://medichelpline.com/clinical-feed/plos-one-23-cropland-type-shapes-arbuscular-mycorrhizal-fungi-amf-population-density-and.md)
- [Patient and Public Engagement in Clinical Trials: CTO’s Decade of Co‑production Lessons](https://medichelpline.com/clinical-feed/bmj-open-0-partnering-with-patients-and-the-public-in-the-clinical-trials-ecosystem-a.md)
- [Cost-effectiveness of telephone motivational interviewing (MAPS) for veterans with musculoskeletal](https://medichelpline.com/clinical-feed/bmj-open-11-the-cost-effectiveness-of-motivational-interviewing-to-activate-pain-support-in.md)
- [FRACTURE-ML: Nationwide machine-learning tool for population hip fracture prediction](https://medichelpline.com/clinical-feed/plos-medicine-2-a-clinical-decision-support-tool-for-accurate-hip-fracture-prediction-a.md)

## Navigation
- [← Back to General Feed](https://medichelpline.com/clinical-feed/general.md)
- [← All Clinical Specialties](https://medichelpline.com/clinical-feed.md)
## Medical & Regulatory Disclaimer

> [!CAUTION]
> MedicHelpline content is structured for research, educational, and professional discovery purposes. It does not constitute individual medical advice, clinical diagnosis, or treatment recommendations.
> Always verify dosing, contraindications, and regulatory alerts against official product labeling and primary regulatory sources before clinical decision-making.