Perioperative psychotherapy for persistent post-surgical pain and physical impairment: a meta-analysis of randomised trials.

BACKGROUND: Persistent post-surgical pain affects 10-80% of individuals after common operations, and is more common among patients with psychological factors such as depression, anxiety, or catastrophising. METHODS: We conducted a systematic review and meta-analysis of randomised, controlled trials to evaluate the efficacy of perioperative psychotherapy for persistent post-surgical pain and physical impairment. Paired independent reviewers identified studies, extracted data, and assessed risk of bias. The Grading of Recommendations, Assessment, Development and Evaluation system was used to assess the quality of evidence. RESULTS: Our search of five electronic databases, up to September 1, 2016, found 15 trials (2220 patients) that were eligible for review. For both persistent post-surgical pain and physical impairment, perioperative education was ineffective, while active psychotherapy suggested a benefit (test of interaction P=0.01 for both outcomes). Moderate quality evidence showed that active perioperative psychotherapy (cognitive-behaviour therapy, relaxation therapy, or both) significantly reduced persistent post-surgical pain [weighted mean difference (WMD) -1.06 cm on a 10 cm visual analogue scale for pain, 95% confidence interval (CI) -1.56 to -0.55 cm; risk difference (RD) for achieving no more than mild pain (≤3 cm) 14%, 95% CI 8-21%] and physical impairment [WMD -9.87% on the 0-100% Oswestry Disability Index, 95% CI -13.42 to -6.32%, RD for achieving no more than mild disability (≤20%) 21%, 95% CI 13-29%]. CONCLUSIONS: Perioperative cognitive behavioural therapy and relaxation therapy are effective for reducing persistent pain and physical impairment after surgery. Future studies should explore targeted psychotherapy for surgical patients at higher risk for poor outcome. CLINICAL TRIAL REGISTRATION: PROSPERO CRD42016047335.

[Investigation on the changing regularity of the relationship between retention index and temperature of the GDX series stationary phases].

A systematical measure of the polarity scale of the Chinese porous polymer beads of this series of stationary phase has been carried out, including the McReynolds constant at 120 degrees C by using squalane as non-polar stationary phase and the relative constant to GDX-103 at 180 degrees C. Based on the above work, two kinds stationary phases GDX-101 and GDX-103 were selected, on which the changing regularity of the relationship between retention index and temperature of the five "probes" of stationary polarity determination, including benzene, butanol, 1-nitropropane, 2-pentanone and pyridine were investigated. At the same time, the changing regularity with temperature of the relative McReynolds constant delta I of GDX-101 to GDX-103 was studied. It is found that Ip-theta c curve and delta I-theta c curve all showed a turning point at the temperature of 180 degrees C and that there was a maximum value of delta I at the temperature of 180 degrees C. So we think that the retention mechanism of this kind of stationary phase changed at 180 degrees C.