Peritoneal inflammation and fatigue experiences following colorectal surgery: a pilot study

The effect of post-surgical inflammation, as indicated by peritoneal cytokines and neopterin, was assessed on the duration and characteristics of post-surgical fatigue (PSF) experiences.

During the weeks following major colorectal surgery, many patients report experiencing substantial fatigue but the physiological factors contributing to this are not well understood. Because cytokines, particularly pro-inflammatory cytokines, have been found to be important in fatigue-related experiences in experimental systems, they may well be important mediators of PSF.

In 27 patients following colorectal surgery, cytokines and neopterin (a relatively stable immune activation marker) were measured in 24-h peritoneal drain fluid and in serum 2, 5 and 14 days post-operatively. Patient fatigue was assessed using the Identity-Consequence Fatigue Scale questionnaire pre-operatively and 2, 5, 14, 30 and 60 days after surgery.

Using linear mixed model analysis controlling for age, gender and ASA score, the trajectory of fatigue experience during the first 2 months of surgical recovery was significantly related to intra-peritoneal concentrations of IL-6, IL-10 and TNF-alpha during the first 24h after surgery, while the trajectory of fatigue impacts was related only to IL-6 and TNF-alpha concentrations. Moreover, correlations between neopterin, and post-operative peritoneal (within 24h of surgery) and serum cytokine concentrations permitted neopterin to be used as a surrogate inflammation marker. Patients with elevated neopterin concentrations during the initial weeks following surgery reported significantly more severe and sustained PSF.

Locally occurring inflammatory responses may influence reports of fatigue following major surgery in a sustained manner, and, as a consequence, reducing inflammation may be effective in reducing PSF.