Pupillometry-guided anesthesia associated with reduced intraoperative opioid consumption, finds study

Recent systematic review and network meta-analysis aimed to compare different nociception monitors in quantifying nociception during general anesthesia. The primary outcomes focused on intraoperative opioid consumption, while secondary outcomes included postoperative opioid use, extubation time, and postoperative pain scores. Five monitors were studied: NOL, ANI, pupillometry, SPI, and CARDEAN.

Results indicated that pupillometry-guided anesthesia led to reduced intraoperative opioid consumption compared to standard care and SPI-guided anesthesia. However, no significant differences were observed in postoperative pain scores, postoperative opioid use, or PONV incidence among the monitors studied. NOL-guided anesthesia showed shorter extubation times compared to standard care and ANI. The study included 38 papers involving 3412 patients undergoing general anesthesia. Most studies focused on abdominal surgeries, with various anesthetics and analgesics used. The risk of bias assessment per study showed some concerns, with few studies at low risk.

The analysis methods involved Bayesian network meta-analysis and sensitivity analyses to assess the impact of prior distributions and individual study exclusion. The findings highlighted pupillometry-guided anesthesia as beneficial for reducing opioid consumption, while other monitors showed no significant effects on intraoperative opioid usage. Notably, inconsistencies in methodological approaches and various surgical procedures across studies were identified as limitations.

The discussion emphasized the importance of nociception monitoring during anesthesia and the evolving field of dedicated techniques for assessing nociception. Although the study provided insights into the behavior of different monitors, the clinical benefits of these monitors remain limited. The authors recommended focusing on clinical outcomes in future well-designed studies to determine the true impact of nociception monitors on patient care.

Conclusion

In conclusion, the network meta-analysis demonstrated that pupillometry-guided anesthesia was associated with reduced intraoperative opioid consumption, while the other monitors did not significantly affect opioid usage. The study highlighted the need for further research to establish the clinical benefits of nociception monitoring during general anesthesia.

Key Points

- The systematic review and network meta-analysis compared five nociception monitors (NOL, ANI, pupillometry, SPI, and CARDEAN) in quantifying nociception during general anesthesia, with primary outcomes focusing on intraoperative opioid consumption and secondary outcomes on postoperative opioid use, extubation time, and postoperative pain scores.

- Results showed that pupillometry-guided anesthesia resulted in decreased intraoperative opioid consumption compared to standard care and SPI-guided anesthesia. NOL-guided anesthesia also exhibited shorter extubation times than standard care and ANI. However, no significant differences were observed in postoperative pain scores, postoperative opioid use, or PONV incidence across the monitors studied.

- The study included 38 papers involving 3412 patients undergoing general anesthesia, primarily for abdominal surgeries using various anesthetics and analgesics. Risk of bias assessment per study indicated some concerns, with few studies at low risk.

- Analysis methods employed Bayesian network meta-analysis and sensitivity analyses to evaluate the impact of prior distributions and individual study exclusion. The findings suggested the benefits of pupillometry-guided anesthesia in reducing opioid consumption, while other monitors did not significantly affect intraoperative opioid usage. Methodological inconsistencies and variations in surgical procedures were recognized as study limitations.

- The discussion underscored the significance of nociception monitoring during anesthesia and the emergence of specialized techniques for assessing nociception. Although the study provided insights into different monitors' performance, the clinical benefits of these monitors were deemed limited. Future well-designed studies were recommended to focus on clinical outcomes to ascertain the true impact of nociception monitors on patient care.

- In conclusion, the network meta-analysis indicated that pupillometry-guided anesthesia was linked to decreased intraoperative opioid consumption, while the other monitors did not have a significant impact on opioid usage. Further research was advocated to establish the clinical advantages of nociception monitoring in general anesthesia.

Reference –

Merel A J Snoek et al. (2024). Comparison Of Different Monitors For Measurement Of Nociception During General Anaesthesia: A Network Meta-Analysis Of Randomised Controlled Trials.. *British Journal Of Anaesthesia*. https://doi.org/10.1016/j.bja.2024.09.020.