Background: Despite advances in the techniques and perioperative management of cancer surgery, postoperative pain is a drawback and continues to be a clinical issue. Pain caused by surgical procedures impacts the postoperative rehabilitation and quality of life. Surgical incisions activate peripheral and central sensitizations, so the pain status should be identified early to prevent persistent postoperative pain. However, there are no objective methods to assess pain intraoperatively. The perfusion index is a metric for monitoring the peripheral perfusion status. This study evaluated the correlation between intraoperative perfusion index change and acute postoperative pain after laparoscopic colorectal cancer surgery.

Methods: We retrospectively analyzed the data of 65 patients who underwent laparoscopic colorectal surgery. We recorded the perfusion index before intubation, at the start and end of the surgery, and after extubation. We defined groups N and P as those with <7 and ≥7 pain score at postoperative anesthesia care unit (PACU) arrival time, respectively. Clinical data and perfusion index of the groups were analyzed. To minimize individual variance of perfusion index absolute values, we calculated perfusion index change ratio.

Results: A total of 60 patients were examined, of whom 28 (46.7%) and 32 (53.3%) reported <7 and ≥7 pain score at PACU arrival time, respectively. Age, sex, body mass index (BMI), ASA status, diagnosis, preoperative chemoradiotherapy, surgery type, pathological stage, anesthesia and surgery time, and preoperative pain score did not differ between the groups. Group P had a significantly higher fentanyl consumption in the intraoperative and PACU periods. A perfusion index change ratio was not different between the groups.

Conclusions: A perfusion index change ratio in the intraoperative period does not predict the acute postoperative pain following laparoscopic colorectal surgery.

Reference
1. Correlation of perfusion index change and analgesic efficacy in transforaminal block for lumbosacral radicular pain. J Clin Med 2019
2. Transition from acute to chronic pain after surgery. Lancet 2019