New Tool Measures Stress to Predict Level of Postoperative Pain

New research published in Br J Anaesth tested a brief measure of emotional preoperative stress (B-MEPS) designed to predict moderate to intense postoperative pain (MIAPP).¹

Previous findings suggest that psychological factors could influence the extent of postoperative pain. A 2009 review showed anxiety to be the top predictor of such pain, and a positive correlation between anxiety and postsurgical pain intensity was observed in 15 studies covering a range of specialties and surgery types.² In addition, depression and other types of psychological distress have been found to have a positive correlation with postoperative pain in various studies.³

In the current study, researchers at the Federal University of Rio Grande do Sul in Brazil developed the B-MEPS questionnaire, which could help predict the risk of higher-intensity postoperative pain. The tool was created with a sample of 863 adult surgery patients, using items from various psychometric instruments that have previously been used to assess preoperative psychological status: the short-form State-Trait Anxiety Inventory (STAI-S-T), the Montgomery- Äsberg Depression Rating Scale (MADRS), the World Health Organization’s (WHO) Self-reporting Questionnaire (SRQ-20) to assess minor psychiatric disorders, and the Future Self-perception Questionnaire (FSPQ).

After the final 15 items of the B-MEPS were validated in a pilot study of 100 patients, the authors tested it in a prospective cohort of 150 women undergoing abdominal hysterectomy for uterine myomatosis. One day prior to surgery, an anesthetist advised patients regarding the course of surgery and the use of patient-controlled analgesia (PCA). With the facilitation of 4 training evaluators, patients also completed the B-MEPS, the Brazilian Portuguese Pain Catastrophizing Scale (BP-PCS), the STAI-S-T, and a pain evaluation; they then received anxiolytics following the psychological assessments.

All patients received epidural anesthesia via a catheter inserted at lumbar segments L2 to L4, and the postoperative analgesia (morphine via PCA) was available for 24 hours following surgery. Patients whose pain was uncontrolled after the 24-hour postsurgical period were given 1000 mg of dipyrone every 6 hours. Pain was assessed with a 10-cm visual analog scale (VAS), on which scores ranged from 0 (no pain) to 10 cm (worst possible pain). Patients were classified into 2 groups based on the average pain ratings recorded at 6, 12, 18, and 24 hours following surgery: Scores below 4 cm indicated an absence of pain or mild pain, while scores above 4 cm indicated moderate, intense, or worst possible pain.  

The results show that the B-MEPS independently predicted MIAPP with an odds ratio of 1.20 (confidence interval [CI] 95%, 1.05-1.43). These findings may have important implications in helping to identify patients most at risk for MIAPP with the aim of improving postoperative outcomes. Other studies have found, for example, that psychological preparation before surgery leads to improved outcomes, reduced length of stay in the hospital, and lower rates of complication.^4,5  

The results show that the B-MEPS independently predicted MIAPP with an odds ratio of 1.20 (confidence interval [CI] 95%, 1.05-1.43). These findings may have important implications in helping to identify patients most at risk for MIAPP with the aim of improving postoperative outcomes. Other studies have found, for example, that psychological preparation before surgery leads to improved outcomes, reduced length of stay in the hospital, and lower rates of complication.^4,5

References

1. Caumo W, Nazare Furtado da Cunha M, Camey S, Maris de Jezus Castro S, Torres IL, Cadore Stefani L. Development, psychometric evaluation and validation of a brief measure of emotional preoperative stress (B-MEPS) to predict moderate to intense postoperative acute pain. Br J Anaesth. 2016;117(5):642-649.
2. Ip HY, Abrishami A, Peng PW, Wong J, Chung F. Predictors of postoperative pain and analgesic consumption: a qualitative systematic review. Anesthesiology. 2009; 111(3):657-677.
3. Hariharan S. Do patient psychological factors influence postoperative pain? Pain Manag. 2016; 6(6):511-513.
4. Johnston M, Voegele C. Benefits of psychological preparation for surgery: a meta-analysis. Ann Behav Med. 1993;15:245-256.
5. Bolton V, Brittain M. Patient information provision: its effect on patient anxiety and the role of health information services and libraries. Health Libr Rev. 1994;11:117-132.