Surgical Pleth Index for Predicting Postoperative Moderate-to-Severe Pain: A Systematic Review and Meta-Analysis

BACKGROUND Conventional vital signs lack the specificity for intraoperative nociception. The Surgical Pleth Index (SPI), calculated from photoplethysmographic waveforms, provides a quantitative measure of nociceptive status ranging from 0 to 100. Elevated SPI values correspond to increased nociceptive intensity. While some evidence suggests that SPI may help predict pain, its accuracy in forecasting postoperative pain requires further validation. AIM This study aimed to assess the capacity of the Surgical Pleth Index (SPI) to predict moderate to severe pain following surgery.

We conducted a systematic literature search across three databases to identify studies investigating SPI’s predictive value for postoperative pain. A random-effects model was applied to pool summary estimates of sensitivity, specificity, and the area under the summary receiver operating characteristic curve (SROC-AUC).

Analysis included ten studies encompassing 1,042 patients. Pooled sensitivity and specificity were 0.74 (95% CI: 0.67–0.80) and 0.65 (95% CI: 0.55–0.74), respectively. The SROC-AUC reached 0.76, suggesting a moderate level of predictive accuracy. Significant heterogeneity was observed and not explained by differences in SPI cutoff values.

The SPI demonstrates moderate accuracy in forecasting moderate-to-severe postoperative pain and may serve as a useful adjunct to conventional clinical assessment. What is known?The Surgical Pleth Index has been suggested as a reliable monitor for nociceptive states. What new information does this article contribute?The Surgical Pleth Index (SPI) demonstrated moderate accuracy in predicting moderate-to-severe postoperative pain. Current evidence supports its role as a validated supplementary instrument to guide analgesic administration during surgery. Core Tip:This meta-analysis confirms that the Surgical Pleth Index (SPI) provides moderate predictive accuracy for moderate-to-severe postoperative pain and, as such, has a complementary role in guiding intraoperative analgesia, provided its outputs are interpreted within the context of a comprehensive clinical assessment. Competing Interest Statement The authors have declared no competing interest. Clinical Protocols https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=250756 Funding Statement The author(s) received no specific funding for this work. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study is a systematic review and meta-analysis of previously published literature and did not require ethical approval from an institutional review board (IRB). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Footnotes First author: Wei Liu Data availability statement Data are available upon reasonable request. Ethical approval: Not applicable.