Does surgical plethysmographic index-guided analgesia affect opioid requirement and extubation time? A systematic review and meta-analysis.

PURPOSE: This meta-analysis of all relevant clinical trials investigated surgical plethysmographic index (SPI)-guided analgesia's efficacy under general anesthesia for perioperative opioid requirement and emergence time after anesthesia.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched up to January 2022 to identify clinical trials comparing SPI-guided and conventional clinical practice for patients who underwent general anesthesia. With the random-effects model, we compared intraoperative opioid consumption, emergence time, postoperative pain, analgesia requirement, and incidence of postoperative nausea and vomiting (PONV).

RESULTS

Thirteen randomized controlled trials (RCTs) (n = 1314) met our selection criteria. The overall pooled effect sizes of all RCTs indicated that SPI-guided analgesia could not significantly reduce opioid consumption during general anesthesia. SPI-guided analgesia accompanied with hypnosis monitoring could decrease intraoperative opioid consumption (standardized mean difference [SMD] - 0.31, 95% confidence interval [CI] - 0.63 to 0.00) more effectively than SPI without hypnosis monitoring (SMD 1.03, 95% CI 0.53-1.53), showing a significant difference (p < 0.001). SPI-guided analgesia could significantly shorten the emergence time, whether assessed by extubation time (SMD - 0.36, 95% CI - 0.70 to - 0.03, p < 0.05, I2 = 67%) or eye-opening time (SMD - 0.40, 95% CI - 0.63 to - 0.18, p < 0.001, I2 = 54%). SPI-guided analgesia did not affect the incidence of PONV, postoperative pain, and analgesia management.

CONCLUSION

SPI-guided analgesia under general anesthesia could enhance recovery after surgery without increasing the postoperative complication risk. However, it did not affect intraoperative opioid requirement. Notably, SPI-guided analgesia with hypnosis monitoring could effectively reduce intraoperative opioid requirement.