Our research group recently published a positive association between early postoperative pain and 30-day postoperative complications in a broad surgical population. To investigate whether... Show moreOur research group recently published a positive association between early postoperative pain and 30-day postoperative complications in a broad surgical population. To investigate whether heterogeneity of the population and surgical procedures influenced these results, we explored this association in a homogenous surgical population. A secondary analysis of the LEOPARD-2 (NCT02146417) and RELAX-1 study (NCT02838134) in laparoscopic donor nephrectomy patients (n = 160) was performed. Pain scores on the postanesthesia care unit and postoperative day (POD) 1 and 2 were compared between patients with infectious, noninfectious, and no complications 30 days after surgery. Patients who developed infectious complications had significantly higher pain scores on POD1 and 2 (6.7 +/- 2.1 and 6.4 +/- 2.8) than patients without complications (4.9 +/- 2.2 and 4.1 +/- 1.9), respectively (P= 0.006 andP= 0.000). Unacceptable pain (numeric rating scale [NRS] >= 6) on POD1 was reported by 72% of patients who developed infectious complications, compared to 38% with noninfectious complications and 30% without complications (P= 0.018). This difference was still present on POD2 at 67% with infectious complications, 21% with noninfectious, and 40% without complications (P= 0.000). Multiple regression analysis identified unacceptable pain (numeric rating scale >= 6) on POD2 as a significant predictor for 30-day infectious complications (odds ratio 6.09,P= 0.001). Results confirm the association between early postoperative pain and 30-day infectious complications in a separate, homogenous surgical population. Further clinical trials should focus on finetuning of postoperative analgesia to elucidate the effects on the endocrine and immune response, preserve immune homeostasis, and prevent postoperative infectious complications. Show less
In contrast to classical conditioning of physiological responses such as immune responses and drug effects, only a limited number of studies investigated classical conditioning of endocrine... Show moreIn contrast to classical conditioning of physiological responses such as immune responses and drug effects, only a limited number of studies investigated classical conditioning of endocrine responses. The present paper is the first systematic review that integrates evidence from animal and human trials regarding the possibility to condition the endocrine responses. Twenty-six animal and eight human studies were included in the review. We demonstrated that there is accumulating evidence that classical conditioning processes are able to influence specific endocrine responses, such as cortocosterone/cortisol and insulin, while more limited evidence exists for other hormones. Animal and human studies were generally consistent in their findings; however, the limited number of human studies makes it difficult to generalize and translate the results of animal research to humans. Next to methodological recommendations for future studies, we suggest several ways how classically conditioned endocrine responses can be used in clinical practice. Show less
