Comparison of Pain Assessment Using The Numeric Rating Scale And Qnox Index in Postoperative Patients Undergoing General Anesthesia at The Main Teaching Hospital in North Sumatera

Abstract

Introduction: Postoperative pain affects many patients undergoing surgery, and while the Numeric Rating Scale (NRS) is commonly used for pain assessment, it lacks objectivity. The qNOX index, an alternative based on EEG signals, may offer a more objective measure. This study aims to compare the effectiveness of the qNOX index and NRS in assessing postoperative pain in patients with general anesthesia.

Methods: A cross-sectional analysis was conducted in the recovery room of patients undergoing general anesthesia. Pain was assessed at 15 and 60 minutes post-surgery using both NRS and the qNOX index. A sample size of 38 patients was determined using G*Power. Data were analyzed with paired t-tests and the Wilcoxon test, with significance defined as p < 0.05.

Results: The mean age of the sample was 43.03 ± 13.56 years, with 68.4% experiencing moderate pain. Both NRS and qNOX scores were lower at 60 minutes compared to 15 minutes (NRS: 6.26 ± 1.54 vs. 4.79 ± 1.58, p < 0.001; qNOX: 87.08 ± 8.67 vs. 82.29 ± 11.23, p < 0.001). NRS showed greater sensitivity to changes in pain over time compared to qNOX (r -0.68 vs. -0.77).

Conclusion: NRS proved more effective than the qNOX index in assessing postoperative pain.