Pain
-
Recently it has been shown that placement of 4 loose chromic gut sutures around the rat sciatic nerve produces hyperalgesia. A possible mechanism underlying this hyperalgesia is a preferential loss of large myelinated fibers. A difficulty, however, is that neuropathic symptoms are not static and the time course of the axon loss has not been determined. ⋯ In addition, at 28 days post surgery there are essentially no large myelinated axons in the distal segment, but the signs of hyperalgesia have almost resolved. These findings indicate that the onset of the hyperalgesia is accompanied by a preferential loss of large fibers and by a lesser but still substantial loss of small myelinated and unmyelinated axons. The subsequent course of the hyperalgesia, however, is not in any obvious way related to the proportions of large myelinated fibers in the affected nerve.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Efficacy of cognitive therapy for chronic low back pain.
The effects of outpatient group cognitive therapy, relaxation training, and cognitive therapy in combination with relaxation training on chronic low back pain and associated physical and psychosocial disability were evaluated and compared. One-hundred and two mildly disabled chronic low back pain patients were assigned randomly to a waiting-list (WL) control condition and the 3 treatments. ⋯ Depressive symptoms and disability improved significantly in all conditions (including the waiting list) from pretreatment to post-treatment, with no statistically significant differences among treatments. At both follow-ups, all 3 treatment groups remained significantly improved from pretreatment, with no statistically significant differences between treatments.
-
A 3 x 6 factorial design with a double blind and placebo control was employed to investigate the effect of TENS treatment on pain produced by venipuncture. The three treatment groups consisted of TENS, placebo-TENS and control. Subjects were blocked into six 2-year age groups (ages: 5-17 years). ⋯ Pain intensity and affect were lowest for the TENS group and highest for the control group. The pain scores were greatest for lower age groups and lowest for higher age groups. The results of this study support the use of TENS for children's pain and the need for interventions for children's procedural pain.
-
Comparative Study
Developmental changes in pain expression in premature, full-term, two- and four-month-old infants.
The purpose of this study was to examine the behavioural responses of infants to pain stimuli across different developmental ages. Eighty infants were included in this cross-sectional design. Four subsamples of 20 infants each included: (1) premature infants between 32 and 34 weeks gestational age undergoing heel-stick procedure; (2) full-term infants receiving intramuscular vitamin K injection; (3) 2-month-old infants receiving subcutaneous injection for immunisation against DPT; and (4) 4-month-old infants receiving subcutaneous injection for immunisation against DPT. ⋯ The results imply that the premature infant has the basis for communicating pain via facial actions but that these are not well developed. The full-term newborn is better equipped to interact with his caretakers and express his distress through specific facial actions. The cries of the premature infant, however, have more of the characteristics that are arousing to the listener which serve to alert the caregiver of the state of distress from pain.
-
Thirty-five cancer patients, treated with chronic epidural morphine, were assayed for plasma and cerebrospinal fluid (CSF) minimum steady-state concentrations (Css min) of morphine (M), morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) by high performance liquid chromatography (HPLC). A linear dose-concentration relationship was found for the 3 substances in plasma and for morphine and M3G in CSF. The mean +/- S. ⋯ CSF M6G concentrations were low and did not contribute to any detectable analgesia. We conclude that after epidural administration of morphine, the M3G and M6G metabolites in CSF are low compared to unchanged morphine and seem to have little influence on analgesia. However, the fact that a significant passage of the glucuronide metabolites occurs to the CSF may indicate a role in morphine analgesia after other routes of administration.