Search

Massage is analgesic for some people with pain-inducing massage (PIM) resulting in greater pain sensitivity changes compared to pain-free massage (PFM). However, the underlying neurobiological mechanisms are not well-understood. Given that the experience of pain and analgesia rely on the functioning of pain inhibitory systems, PIM may exert analgesia via mechanisms consistent with conditioned pain modulation (CPM). Thus, we aimed to determine if PIM used as a conditioning stimulus would result in comparable self-reported and experimental pain sensitivity changes as a cold pressor task or a PFM control. Fifty healthy participants (68% female, mean age 22 years (SD=4.72)) were randomly assigned to four, one-minute exposures to a cold pressor to the hand, a PIM or PFM to the neck. Pressure pain thresholds (PPT) were assessed on the contralateral foot before and after each intervention period. Cold pressor pain ratings (M=39.78, SD=24.43)) exceeded PIM pain reports (M=22.04, SD= 14.54, p<0.01) and both exceeded the PFM (M=0.02, SD=0.11, p<0.01). A 2-way repeated measures ANCOVA with baseline PPT as a covariate indicated a group by time interaction in PPT (p<0.01). Cold pressor resulted in increased PPT compared to PFM after 1, 2, and 3 minutes (p's<0.05) but not following the fourth minute (p=0.09). PIM resulted in higher PPT compared to PFM after 3 and 4 minutes (p's<0.05). PIM and cold pressor did not differ at any time point (p>0.05). Pearson correlation revealed that greater intervention-related pain was associated with increases in PPT (r=0.29, p=0.04). Although PIM resulted in less self-reported pain than a cold pressor task, both resulted in similar magnitude of the CPM response suggesting shared underlying mechanisms. Future studies are needed to elucidate the neurobiological substrates of PIM that can help identify therapeutic outcomes. [ABSTRACT FROM AUTHOR]

The incidence of chronic pain following thoracic surgery (∼50%) is greater than most other surgeries. The goal of this retrospective study was to detect the incidence of prolonged opioid use at 1 year after surgery among those veterans who were chronic opioid users versus not chronic users during the one year prior to their thoracic surgery, separately. In addition, predictors of prolonged opioid use at 1 year after surgery from demographic, surgical, and comorbid medical and psychiatric factors were assessed for each of the two groups separately. Veterans Health Administration sample of 19,240 patients who had thoracotomy or video assisted thoracoscopy between 2006 and 2015 and were alive at one year after surgery were included. "Chronic opioid use" was defined as consistent opioid prescription for more than 90 days during the year (1). Veterans' opioid use during the 1-year prior to surgery was used to determine whether they were "preoperative chronic opioid users" at the time of surgery. Similarly, the opioid use information during the first year after the surgery was used to determine whether they become "prolonged opioid users" during the 1-year following surgery. Out of 2,370 preoperative opioid users at the time of surgery, 61% (95% CI: 59% to 63%) continued prolonged opioid use at 1 year after their thoracic surgery. Only younger age and the presence of pre-existing chronic pain were associated with the prolonged opioid use at 1 year after surgery. Out of 16,870 patients who were not preoperative chronic opioid users during the year prior to their surgery, 6.8% (95% CI: 6.4% to 7.2%) became prolonged opioid users. At the 0.01 type I error level, the presence of pre-existing chronic pain, longer duration of hospital stay, antidepressant use and benzodiazepine use were associated with prolonged opioid use at one year after thoracic surgery. [ABSTRACT FROM AUTHOR]