Increased variation of the response index of nociception during noxious stimulation in patients during general anaesthesia

Tia J.M. Sarén-Koivuniemi, Arvi M. Yli-Hankala, Mark van Gils (Corresponding Author)

    Research output: Contribution to journalArticleScientificpeer-review

    5 Citations (Scopus)


    Objective: Analgesia is an important part of general anaesthesia, but no direct indicators of nociceptive–anti-nociceptive balance have been validated in detail. The Response Index of Nociception (RN) is a multiparameter approach which combines photoplethysmographic waveform (PPG), State Entropy (SE), Response Entropy (RE), and heart rate variability (HRV). We aimed at evaluating RN during general anaesthesia; especially we wanted to compare pre- and post-index values of certain noxious stimuli to the average index values. Our assumption was that RN could be a useful indicator of nociceptive–anti-nociceptive balance during the surgery.

    Methods: Sixty women undergoing gynaecological or breast surgery participated in the study. All patients had elective surgery and anaesthesia was maintained with propofol–remifentanil target controlled infusion. Neuromuscular blocking agent rocuronium was used at the beginning of the surgery. Electrocardiography (ECG), photoplethysmography (PPG) and electroencelophalography (EEG) were registered and extracted off-line. An index, reflecting amplitude and frequency of occurrence of abrupt increases (“peaks”) in the RN was evaluated during surgery in general and around occurrences of predefined noxious stimuli in particular.

    Results: Fifty-four patients were eligible for analysis. Patient movement was associated with increased index values, both before and after the event. Post-event values of the index for intubation and skin incision were higher than its intra-surgery baseline, while pre-event values remained unchanged.

    Conclusion: Changes in RN can be used to detect noxious stimuli during surgery. RN also predicted movement in our patients under propofol–remifentanil anaesthesia.
    Original languageEnglish
    Pages (from-to)154-160
    JournalComputer Methods and Programs in Biomedicine
    Issue number2
    Publication statusPublished - 2011
    MoE publication typeA1 Journal article-refereed
    Event7th IFAC Symposium on Modelling and Control in Biomedical Systems - Aalborg, Denmark
    Duration: 12 Aug 200914 Aug 2009


    • Nociception
    • monitoring
    • electroencephalography
    • entropy
    • photoplethysmography
    • movement
    • electrocardiograph


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