Evidence map›Paper›PMID 39855933›Full record

Trial reportBritish journal of anaesthesia2025

Qnox index for quantification of intraoperative nociception and analgesia: a prospective single-centre validation study.

Hao Kong, Dan-Dan Ma, Jia-Hui Ma, Yu-Xiu Zhang, Hong Zhang, Dong-Xin Wang

Registry-linked trialAbstract readClinical TrialValidation Study
PubMed Full text at PMC Publisher
In one paragraph

Trial report in British journal of anaesthesia, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT07479719 (Anesthesia Maintenance With Target-controlled Infusion of Propofol and Remifentanil at Fixed Ratio on Neurocognitive Recovery in Older Patients After Surgery), which is not on this map. Cited by 6 papers.

0numbers the graph read from it
0cells of the map it votes in
6citing papers in PubMed
–field-weighted citation impact
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.

NCT07479719 phase4not yet recruitingnot on this mapstarted 2026, after this paper: background citation

Anesthesia Maintenance With Target-controlled Infusion of Propofol and Remifentanil at Fixed Ratio on Neurocognitive Recovery in Older Patients After Surgery: a Randomized Trial

TypeinterventionalSponsorPeking University First HospitalRan2026 to 2027Enrolled200ConditionsElderly, Surgery, Depth of Anesthesia, Total Intravenous AnesthesiaArmsLight anesthesia, Deep anesthesia
3 · Its place in the literature

Who cites it

6 citing papers in PubMed.

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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

6 authors.

Hao KongDepartment of Anaesthesiology, Peking University First Hospital, Beijing, China.
Dan-Dan MaDepartment of Anaesthesiology, Yidu Central Hospital, Qingzhou, China.
Jia-Hui MaDepartment of Anaesthesiology, Peking University First Hospital, Beijing, China.
Yu-Xiu ZhangDepartment of Anaesthesiology, Peking University First Hospital, Beijing, China.
Hong ZhangDepartment of Anaesthesiology, Peking University First Hospital, Beijing, China. Electronic address: zhanghong40@hotmail.com.
Dong-Xin WangDepartment of Anaesthesiology, Peking University First Hospital, Beijing, China; Outcomes Research Consortium, Cleveland, OH, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe Qnox index is a novel monitor to quantify intraoperative nociception based on an electroencephalographic algorithm. We evaluated the ability of the Qnox index to discriminate noxious from non-noxious stimuli, respond to stimuli, and discriminate different levels of analgesia in patients under propofol anaesthesia with neuromuscular block.

methodsQnox was compared with heart rate and mean arterial pressure with five designated stimuli: tetanic stimulations without (tetanic 1) and with sufentanil (tetanic 2), skin incision, tracheal intubation, and a non-noxious period. The response around the skin incision was also evaluated at two target remifentanil concentrations.

resultsIn 83 adult patients scheduled for elective surgery, Qnox performed worse than heart rate and mean arterial pressure in discriminating tetanic 2, tetanic 1, skin incision, and tracheal intubation noxious stimuli from the non-noxious period, with an area under curve of 0.52 (95% confidence interval 0.43-0.61), 0.54 (0.45-0.62), 0.67 (0.58-0.75), and 0.65 (0.57-0.73), respectively. The post-stimulus values of Qnox increased significantly after tracheal intubation and skin incision, but not after tetanic 1 or tetanic 2. Qnox values after skin incision were similar between the low- and high-remifentanil-concentration groups.

conclusionsQnox had a poor ability to discriminate noxious stimuli from non-noxious stimuli. Although Qnox responded to tracheal intubation and skin incision, it did not respond to tetanic stimulations and failed to discriminate different levels of analgesia. The Qnox index was not superior to heart rate or mean arterial pressure in assessing nociception during general anaesthesia. CLINICAL

trial registrationChinese Clinical Trial Registry (ChiCTR2100046063).

Indexed as

AnalgesiaElectroencephalographyMonitoring, IntraoperativeNociceptionAdultAgedAlgorithmsFemaleHeart RateHumansIntubation, IntratrachealMaleMiddle AgedNeuromuscular BlockadePropofolProspective StudiesPropofolRemifentanilSufentanilanalgesiaheart rateintraoperative nociceptionmean arterial pressurenoxious stimuliQnox index

Identifiers

PMID39855933
PMCPMC11867073

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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.