Procedure-specific pain intensity four days after day surgery and the relationship with preoperative pain: A prospective cohort study

Background: Identification of painful procedures is essential for the development of procedure-specific pain-treatment schedules. The aim of this study was firstly, to analyze the prevalence of acute postsurgical pain (APSP) after various types of day surgery on the fourth postoperative day, and secondly, to assess the predictive value of preoperative pain for the development of APSP after different types of surgical procedures. Methods: From November 2008 to April 2010, patients scheduled for elective day surgery were enrolled in this prospective cohort study. Data were collected one week preoperatively and four days postoperatively. The 11-point Numeric Rating Scale (NRS) was used for pain measurement. Moderate pain was defined as an NRS 4 to 5, and severe pain as an NRS > 5. The predictive value of preoperative pain for development of APSP was analyzed using a univariate logistic regression, stratified for the surgical procedure. Results: From a total of 1123 included patients, 182 patients experienced moderate pain (16.3%) and 136 patients experienced severe pain (12.1%) on the fourth postoperative day. A large procedure-specific variability in APSP was observed, with shoulder, anal and dental surgery associated with the highest pain levels. Overall, preoperative pain significantly predicted postoperative pain on the fourth day (OR 4.45). This predictive value showed a procedure-specific variation and was not noted after various well-defined procedures. Conclusions: The prevalence of moderate to severe APSP was high four days after day surgery and showed a significant procedure-specific variation. Furthermore, there was a strong relationship between preoperative and postoperative pain, likewise characterized by a significant procedure-specific variation.