Evaluation of the perfusion index according to the visual analog scale in postoperative patients

OBJECTIVES: To evaluate the possible value of the perfusion index (PI) as a tool for pain assessment. Methods: This prospective, observational study was performed with 89 patients underwent surgery with general anesthesia. The patients with visual analog scale (VAS) greater than 3 were grouped as M1, and patients with VAS≤3 and performed morphine were grouped as M2. After surgery patients with VAS greater than 3 were given 2mg morphine. Patients with VAS greater than 3 were given increments of intravenous morphine (2 mg) at 20 minute intervals until VAS less than 3. The correlation and difference between PI and VAS score values were evaluated before and after analgesic administration. Results: Significant changes were found in both PI values and VAS scores between M1 and M2 groups (2.80±0.77, 3.97±0.94, p less than 0.001; 6.60±1.20, 2.74±0.46, p less than 0.001) Despite no correlation was found between PI values and VAS scores of M1 and M2 groups, weak negative correlation was detected between differences in PI values and VAS scores among groups (r=-0.255, p=0.016). Conclusion: Perfusion index is a parameter that can be used in the assessment of postoperative pain and responses to analgesics.