The journal of pain : official journal of the American Pain Society
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Few studies have examined the underlying psychosocial mechanisms of pain in Asian Americans. Using the biopsychosocial model, we sought to determine whether variations in depression contribute to racial group differences in symptomatic knee osteoarthritis pain between Asian Americans and non-Hispanic white Americans. The sample consisted of 100 participants, including 50 Asian Americans (28 Korean Americans, 9 Chinese Americans, 7 Japanese Americans, 5 Filipino Americans, and 1 Indian American) and 50 age- and sex-matched non-Hispanic white Americans with symptomatic knee osteoarthritis pain. The Centers for Epidemiologic Studies Depression Scale was used to assess symptoms of depression, and the Western Ontario and McMaster Universities Osteoarthritis Index and the Graded Chronic Pain Scale were used to measure clinical pain. In addition, quantitative sensory testing was used to measure experimental sensitivity to heat- and mechanically-induced pain. The results indicated that higher levels of depression in Asian Americans may contribute to greater clinical pain and experimental pain sensitivity. These findings add to the growing literature regarding ethnic and racial differences in pain and its associated psychological conditions, and additional research is warranted to strengthen these findings. ⋯ This article shows the contribution of depression to clinical pain and experimental pain sensitivity in Asian Americans with knee osteoarthritis. Our results suggest that Asian Americans have higher levels of depressive symptoms and that depression plays a relevant role in greater clinical pain and experimental pain sensitivity in Asian Americans.
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Upon systemic administration in rats, the prodrug L-4-chlorokynurenine (4-Cl-KYN; AV-101; VistaGen Therapeutics, Inc, South San Francisco, CA) is rapidly absorbed, actively transported across the blood-brain barrier, and converted in astrocytes to 7-chlorokynurenic acid (7-Cl-KYNA), a potent and specific antagonist of the glycine B coagonist site of the N-methyl-D-aspartate (NMDA) receptor. We examined the effects of 4-Cl-KYN in several rat models of hyperalgesia and allodynia and determined the concentrations of 4-Cl-KYN and newly produced 7-Cl-KYNA in serum, brain, and spinal cord. ⋯ Our conclusions show that after systemic delivery, the highest 2 doses (167 and 500 mg/kg) of 4-Cl-KYN yielded brain concentrations of 7-Cl-KYNA exceeding its half maximal inhibitory concentration (IC50) at the glycine B site and resulted in dose-dependent antihyperalgesia in the 4 models of facilitated processing associated with tissue inflammation and nerve injury. On the basis of the relative dose requirements for analgesic actions and side effect profiles from these experiments, 4-Cl-KYN is predicted to have antihyperalgesic efficacy and a therapeutic ratio equal to gabapentin and superior to MK-801.
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Pain after surgery remains a problem worldwide, although there are no published data on postoperative outcomes in Spain. We evaluated 2,922 patients on the first day after surgery in 13 tertiary care Spanish hospitals, using the PAIN-OUT questionnaire. The aims were to: assess postoperative outcomes and anesthetic/analgesic management in Orthopedics (ORT) and General Surgery (GEN) patients; explore the influence of the analgesic therapy on outcomes and opioid requirements; evaluate and compare outcomes and analgesic management according to surgical procedure. ⋯ Presurgical chronic pain (>7) and/or chronic opioid consumption, were associated with worsened pain outcomes; the latter with a 50% increase in postoperative opioid requirements. Tibia/fibula and foot surgeries (ORT), and gastric, small intestine, and anterior abdominal wall procedures (GEN) were the most painful. Rigorous control of chronic pain before surgery, and combining opioids with adjuvants and other analgesics perioperatively, might improve postoperative outcomes.
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This study aimed to describe utilization of opioid medications among infants, children, and adolescents on the inpatient setting. These data are needed to guide clinical trials and improve research methodologies, as well as to inform more about possible sources of opioid misuse in the United States. A retrospective chart review was conducted covering a span of 1 year, with a special focus on the prescription of opioids for long-term treatment of chronic pain. ⋯ Among those who were prescribed opioids for >14 days, the focus was often for reasons other than pain. These data indicate that models of chronic pain that may be utilized in clinical trials of longer-term opioid usage in pediatrics are exceedingly limited. In addition, the patterns of utilization indicate that opioid administration among pediatric inpatients is not a likely contributory factor to concerns about opioid misuse in the United States.
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Sickle cell disease (SCD) is associated with episodes of severe vaso-occlusive pain beginning in infancy with a subset of patients with SCD transitioning to chronic pain. Response to experimental pain using quantitative sensory testing in these patients suggests altered pain processing. The objectives of this study were to characterize sensitivity to multiple modalities of experimental pain stimuli and to interrogate the relationship of psychological covariates, clinical pain burden, and pain-related outcomes to experimental pain sensitivity in children with SCD compared with healthy individuals of similar age and sex. ⋯ Anxiety, depressive symptoms, catastrophizing, and somatization were found to be associated with increased sensitivity to experimental pain stimuli. Increased frequency of painful episodes in SCD was associated with decreased sensitivity to heat pain and decreased mechanical temporal summation. These data suggest that careful consideration be given to psychological factors, age, sex, and clinical burden of pain when studying response to experimental pain in SCD.