Pain
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Comparative Study Clinical Trial
Age is the best predictor of postoperative morphine requirements.
The dose of opioid prescribed for postoperative pain relief has traditionally been based on the weight of the patient. Although a reduction in dose is often suggested for elderly patients over 70 years of age, age-related alterations to dose are generally not considered for younger patients. The records of 1010 patients, under 70 years old, prescribed morphine via patient-controlled analgesia (PCA) after major operations were examined to see what factors might best predict the amount of morphine used in the first 24 h after surgery. ⋯ Although previous studies have noted a correlation between patient age and the amount of opioid needed, this study quantifies this correlation and provides guidelines for opioid dosing. Prescriptions for conventional analgesic regimens should include a dose range centred on values obtained from the above formula to allow for the large interpatient variation in each age group. While initial morphine dose should be guided by patient age and not weight, subsequent doses must still be titrated according to effect.
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Randomized Controlled Trial Clinical Trial
The influence of low back pain on muscle activity and coordination during gait: a clinical and experimental study.
Chronic low back pain (CLBP) is a major clinical problem with a substantial socio-economical impact. Today, diagnosis and therapy are insufficient, and knowledge concerning interaction between musculoskeletal pain and motor performance is lacking. Most studies in this field have been performed under static conditions which may not represent CLBP patients' daily-life routines. ⋯ The clinical and experimental findings indicate that musculoskeletal pain modulates motor performance during gait probably via reflex pathways. Initially, these EMG changes may be interpreted as a functional adaptation to muscle pain, but the consequences of chronic altered muscle performance are not known. New possibilities to monitor and investigate altered motor performance may help to develop more rational therapies for CLBP patients.
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Randomized Controlled Trial Comparative Study Clinical Trial
A double-blind randomised comparison of the effects of epidural clonidine, lignocaine and the combination of clonidine and lignocaine in patients with chronic pain.
Twenty patients with chronic pain who previously had obtained analgesia from epidural clonidine and lignocaine agreed to participate in a double-blind crossover study of lumbar epidural clonidine (150 micrograms), lignocaine (40 mg) and the combination of clonidine (150 microgram) and lignocaine (40 mg), all drugs were given in a volume of 3 ml. There were 11 women and 9 men with a mean age 53 years (range: 23-78 years); 9 patients had low back and leg pain, 9 had neuropathic pain, 1 had pelvic pain and 1 Wegner's granulomatosis. Pain intensity and pain relief, as well as sensory and motor blockade, were assessed for 3 h following each injection. ⋯ Overall there was no relationship between neurological blockade and analgesia. The reported side effects appeared to be related to clonidine. These data indicate that in these patients with chronic pain epidural clonidine had a supra-additive effect and behaved more like a co-analgesic than a pure analgesic.
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Nerve growth factor (NGF) is known to produce hyperalgesia as well as to stimulate synthesis of neuropeptides in dorsal root ganglia (DRG). In the present study, we wanted to determine the effects of local NGF administration and assess to which extent mast cell-dependent factors are mediating NGF responses. Rats received 1 daily unilateral intraplantar injection for 3 days. ⋯ We suggest therefore that NGF-induced local edema was caused by mast cell-derived vasoactive compounds which act together with afferent neuron-derived CGRP to increase vascular permeability. NGF-induced thermal hyperalgesia most likely was caused by an increased sensitivity of peripheral endings of capsaicin sensitive afferents. This effect of NGF was not mediated by products of the cyclooxygenase pathway, and was also observed in mast cell-depleted rats.
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Clinical Trial
Sensory-motor interactions of human experimental unilateral jaw muscle pain: a quantitative analysis.
Experimental muscle pain was elicited by bolus injection of 0.15 ml of 5% hypertonic saline into the human masseter muscle. The sensory experience was described using 10-cm visual analogue scales (VAS) and the McGill Pain Questionnaires (MPQ) on 10 subjects. Effects of pain on deliberately unilateral mastication were quantitatively assessed in 13 other male subjects using kinematic recordings of the mandible and jaw muscle electromyography (EMG). ⋯ Moreover, agonist EMG activity during pain was significantly lower in the ipsilateral masseter muscle (20.3 +/- 25.4%, P < 0.05) as compared to pre-pain root-mean-square (RMS) values. The observed sensory-motor interactions can be explained by a facilitatory effect of activity in nociceptive muscle afferents on inhibitory brain-stem interneurons during agonist action. Thus, generated movements have smaller amplitudes and they are slower which most likely represents a functional adaptation to experimental jaw muscle pain.