Abdominal Wall Block Decreases Intraoperative Opioid Con-Sumption by Surgical Pleth Index-Guided Remifentanil Administration in Single-Port Laparoscopic Herniorrhaphy: A Prospective Randomized Controlled Trial

Surgical pleth index monitoring in perioperative pain management: usefulness and limitations

Surgical pleth index (SPI) monitoring is a representative, objective nociception-monitoring device that measures nociception using photoplethysmographic signals. It is easy to apply to patients and the numerical calculation formula is intuitively easy to understand; therefore, its clinical interpretation is simple. Several studies have demonstrated its efficacy and utility. Compared with hemodynamic parameters, the SPI can detect the degree of nociception during surgery under general anesthesia with greater accuracy, and therefore can provide better guidance for the administration of various opioids, including remifentanil, fentanyl, and sufentanil. Indeed, SPI-guided analgesia is associated with lower intraoperative opioid consumption, faster patient recovery, and comparable or lower levels of postoperative pain and rates of adverse events compared with conventional analgesia. In addition, SPI monitoring allows for the degree of postoperative pain and analgesic requirements to be predicted through the SPI values immediately before patient arousal. However, because patient age, effective circulating volume, position, concomitant medication and anesthetic regimen and level of consciousness may be confounding factors in SPI monitoring, clinicians must be careful when interpreting SPI values. In addition, as SPI values can differ depending on anesthetic and analgesic regimens and the underlying disease, an awareness of the effects of these variables with an understanding of the advantages and disadvantages of SPI monitoring compared to other nociception monitoring devices is essential. Therefore, this review aimed to help clinicians perform optimal SPI-guided analgesia and to assist with the establishment of future research designs through clarifying current usefulness and limitations of SPI monitoring in perioperative pain management.

Application of surgical pleth index in the opioid-free anesthesia: A randomized controlled trial

BACKGROUND

Currently, there is no gold standard for monitoring noxious stimulation during surgery, and the surgical pleth index (SPI) is only one of many monitoring methods. It is commonly used in the monitoring of conventional opiate anesthesia, but its effectiveness in opioid-free anesthesia (OFA) has not been evaluated. Therefore, the aim of this study was to observe the guidance value of the surgical pleth index in opioid-free anesthesia for patients undergoing lower abdominal or pelvic surgery.

METHODS

A total of 122 patients who underwent lower abdominal or pelvic surgery in our hospital between March 2021 and July 2022 were selected and equally divided into OFA (F) and control (C) groups according to the random number table method. Both groups underwent ultrasound-guided unilateral/bilateral quadratus lumborum block in the supine position according to the surgical field. In group F, 0.50% lidocaine and 0.20% ropivacaine (in 20 mL of 0.9% normal saline) were injected on each side. In group C, 20 mL 0.9% normal saline was injected on each side. Group F received general anesthesia without opioids and group C received general anesthesia with opioids. BP, pulse oxygen saturation, PETCO2, reactionentropy, stateentropy, and SPI values; Steward score; dosage of propofol, dexmedetomidine, rocuronium, and diltiazem; extubation time; and awake time were monitored in both groups.

RESULTS

There were no significant differences in the general data between the 2 groups (P > .05). There were no significant differences in SPI values at T0, T1, T2, T3, T4, and T5 or the number of cases requiring additional remifentanil, propofol, and diltiazem between the 2 groups (P > .05). The stateentropy, reactionentropy, and Steward scores were higher in group F than in group C at T4 and T5, while the extubation and awake times were lower in group F than in group C (P < .05). The heart rate and SPI of group F were lower than that of group C at T3 (P < .05).

CONCLUSION

The guiding value of SPI in OFA was similar to its use in opiated anesthesia. Its clinical efficacy is exact, vital signs are stable, enabling rapid, and complete regaining of consciousness.