Pain
-
A number of studies have shown that catastrophizing is an important predictor of pain and disability in persons having persistent pain conditions. The newly developed communal model of catastrophizing maintains that catastrophizing is a part of broader, interpersonal style of coping in which coping efforts are directed at interpersonal goals, rather than solely at pain reduction. This study examined the potential interpersonal correlates of pain catastrophizing in a sample of 70 patients having gastrointestinal cancers and their caregivers. ⋯ Caregivers of patients who catastrophized, rated the patient as having more pain and engaging in more pain behavior. Caregivers of patients who catastrophized, also reported higher levels of caregiver stress and critical behaviors. Taken together, these preliminary findings suggest that pain catastrophizing has interpersonal correlates and support the need for additional research examining the social context of pain catastrophizing.
-
The posterior zygo-apophyseal joints (facet joints) may be a significant source of back pain. Invasive treatment typically consists of injecting the joints with local anaesthetic and steroid or by radiofrequency ablation of the nerve supply to the joint. Facet joint injection is generally considered to be a very safe procedure with few significant side effects reported. ⋯ Most cases occur spontaneously but the condition may complicate epidural anaesthesia, spinal anaesthesia or epidural steroid injection. We report a case in which facet joint injections resulted in epidural abscess formation. To our knowledge this has not previously been reported.
-
Comparative Study
A cannabinoid agonist differentially attenuates deep tissue hyperalgesia in animal models of cancer and inflammatory muscle pain.
Pain associated with cancer and chronic musculoskeletal disorders can be difficult to control. We used murine models of cancer and inflammatory muscle pain to examine whether the cannabinoid receptor agonist WIN55,212-2 reduces hyperalgesia originating in deep tissues. C3H/He mice were anesthetized and implanted with osteolytic NCTC clone 2472 cells into the humeri or injected with 4% carrageenan into the triceps muscles of both forelimbs. ⋯ Catalepsy and loss of motor coordination, known side effects of cannabinoids, did not account for the antihyperalgesia produced by WIN55,212-2. These data show that cannabinoids attenuate deep tissue hyperalgesia produced by both cancer and inflammatory conditions. Interestingly, cannabinoids differentially modulated carrageenan- and tumor-evoked hyperalgesia in terms of potency and receptor subtypes involved suggesting that differences in underlying mechanisms may exist between these two models of deep tissue pain.
-
Amitriptyline, nortriptyline, imipramine, doxepin, desipramine, protriptyline, trimipramine, and maprotiline are tricyclic antidepressants (TCAs) used orally in treating major depressive disorders. Recent studies showed that amitriptyline is more potent in blocking the sciatic nerve functions in vivo by local injection than bupivacaine, a long-acting local anesthetic. We therefore tested whether various TCAs could likewise act as local anesthetics in vivo after single injection via the rat sciatic notch. ⋯ With this in vitro expression system, TCAs appear more potent than bupivacaine as Na(+) channel blockers in Nav1.5 Na(+) channels. We suggest that the ability of TCAs to pass through various membrane barriers within peripheral nerve trunks is crucial to their local anesthetic efficacy in vivo. TCAs with a tertiary amine appear more effective in penetrating these membrane barriers than TCAs with a secondary amine.
-
A 47-year-old patient with cancer pain underwent implantation of an intrathecal drug delivery device. When the patient suffered from an infection with fever, pain on injection into the catheter and an elevated number of granulocytes in the cerebrospinal fluid 7 weeks later, radiologic examination showed an encapsulation of the catheter tip. Concentrations of morphine and morphine-6-glucuronide in the cerebrospinal fluid suggested transport of morphine into the systemic circulation via the vascularisation of the encapsulating membrane. After antibiotic therapy and removal of the catheter, morphine was administered intravenously with a one to one conversion ratio.