Objectives Postoperative pain is characterized by a wide variability of patients' pain perception and analgesic requirement. The study investigated the extent to which demographic and psychologic variables may influence postoperative pain intensity and tramadol consumption using patient-controlled analgesia (PCA) after cholecystectomy. Methods Eighty patients, aged 18 to 70 years, with an American Society of Anesthesiologists physical status I or II and a body mass index between 18.5 and 24.9, undergoing laparoscopic cholecystectomy were enrolled. Self-rating anxiety scale (SAS) and self-rating questionnaire for depression (SRQ-D) were used—1 day before surgery—to assess patients' psychologic status. General anesthesia was standardized. PCA pump with intravenous tramadol was used for a 24-hour postoperative analgesia. Visual analog scale at rest (VASr) and after coughing (VASi) and tramadol consumption were registered. Pearson's and point biserial correlations, analysis of variance, and step-wise regression were used for statistical analysis. Results Pearson r showed positive correlations between anxiety, depression, and pain indicators (P<0.05). Moreover, female patients had higher pain indicators (P<0.05). Analysis of variance showed that anxious (P<0.05) and depressed (P<0.001) patients had higher pain indicators, which significantly decreased during the postoperative 24 hours (P<0.00001). Regression analysis revealed that tramadol consumption was predicted by preoperative depression (P<0.001). VASr was predicted by sex and SRQ-D (P<0.05). VASi was predicted by sex and SAS (P<0.05). Discussion Pain perception intensity was primarily predicted by sex with an additional role of depression and anxiety in determining VASr and VASi, respectively. Patients with high depression levels required a larger amount of tramadol.

Chronic pain represents a major public health problem worldwide. Current pharmacological treatments for chronic pain syndromes, including neuropathic pain, are only partially effective, with significant pain relief achieved in 40–60% of patients. Recent studies suggest that the mammalian target of rapamycin (mTOR) kinase and downstream effectors may be implicated in the development of chronic inflammatory, neuropathic, and cancer pain. The expression and activity of mTOR have been detected in peripheral and central regions involved in pain transmission. mTOR immunoreactivity was found in primary sensory axons, in dorsal root ganglia (DRG), and in dorsal horn neurons. This kinase is a master regulator of protein synthesis, and it is critically involved in the regulation of several neuronal functions, including the synaptic plasticity that is a major mechanism leading to the development of chronic pain. Enhanced activation of this pathway is present in different experimental models of chronic pain. Consistently, pharmacological inhibition of the kinase activity turned out to have significant antinociceptive effects in several experimental models of inflammatory and neuropathic pain. We will review the main evidence from animal and human studies supporting the hypothesis that mTOR may be a novel pharmacological target for the management of chronic pain.

Summary Background and objectives: The aim of this prospective, observational study was to evaluate changes in regional cerebral oxygen saturation (rSO2) and incidence of intraoperative cerebral desaturation in a cohort of elderly patients undergoing major abdominal surgery. Methods: rSO2 was continuously monitored on the left and right sides of the forehead in 60 patients older than 65 yr (35 males and 25 females; ASA II–III; age: 72 ± 5 yr; without pre-existing cerebral pathology, and baseline Mini Mental State Examination (MMSE) score >23) undergoing sevoflurane anaesthesia for major abdominal, non-vascular surgery >2 h. Results: Baseline rSO2 was 63 ± 8%; cerebral desaturation (rSO2 decrease <75% of baseline or <80% in case of baseline rSO2 <50%) occurred in 16 patients (26%). The MMSE decreased from 28 ± 1 before surgery to 27 ± 2 on 7th postoperative day (P = 0.05). A decline in cognitive function (decrease in MMSE score ≥ 2 points one week after surgery as compared to baseline value) was observed in six patients without intraoperative cerebral desaturation (13.6%) and six patients who had intraoperative cerebral desaturation (40%) (P = 0.057) (odds ratio: 4.22; CI95%: 1.1–16). Median (range) hospital stay was 14 (5–41) days in patients with an area under the curve of rSO2 <50% (AUCrSO2<50%) >10 min%, and 10 (4–30) days in those with an AUCrSO2<50% <10 min% (P = 0.0005). Conclusions: In a population of healthy elderly patients, undergoing non-vascular abdominal surgery cerebral desaturation can occur in up to one in every four patients, and the occurrence of cerebral desaturation is associated with a higher incidence of early postoperative cognitive decline and longer hospital stay.