Pain
-
Noxious stimulation of the rat's face evokes intense face grooming with face wash strokes almost exclusively directed to the stimulated area (e.g. Clavelou et al., Neurosci. Lett., 14 (1989) 3263-3270). ⋯ Only formalin-injected rats displayed significantly more face grooming activity directed to the affected infraorbital nerve territory than unstimulated control rats. Non-painful sensory disturbances (especially mineral oil application) induced an initial bout of directed face grooming; this response was transient and short-lasting. These observations suggest that directed face grooming can be used as a sign of unilateral facial pain in freely moving rodents; unilateral non-painful facial sensory disturbances do not lead to intense and persistent directed face grooming.
-
A prospective observational study of cohorts of patients undergoing hip replacement (30), knee replacement (31), and spinal nerve root decompressive surgery (30) were interviewed pre-operatively to identify factors which might correlate with and potentially predict severe post-operative pain and dissatisfaction with analgesic management. The hip patients comprised 33% females and averaged 64 years, while the knee patients were 45% female and older (mean 71 years) and the spinal patients were 43% female and averaged 50 years. The three groups were similar with respect to all other pre-operative variables. ⋯ Significant (P < or = 0.01) multivariate correlates of severe post-operative pain assessed by logistic regression analysis of 11 variables were female gender, high pre-operative pain severity, and younger age. Significant (P < or = 0.01) multivariate correlates of both worse than expected pain experience and low satisfaction were female gender, high pre-operative pain severity, high anxiety about risks and problems, low expected pain severity, age (younger) and high willingness to report pain. These variables may reasonably be tested in further studies as potential predictors of adverse post-operative pain experience.
-
Styles of catastrophic thinking about pain have been related to an inability to divert attention away from pain. We investigated whether pain catastrophizers displayed high attentional interference during a threatening low-intensity electrocutaneous stimulus (ES). In Experiment 1, 44 undergraduates performed a tone discrimination task whilst experiencing several times an ES on the left or right arms. ⋯ In Experiment 2, threat was induced in 36 undergraduates by informing them that an ES excites pain fibres. Again, catastrophizers had marked interference immediately after onset. The results are discussed in terms of how catastrophizing amplifies somatosensory information and primes fear mechanisms.
-
Case Reports
Epileptic seizure associated with intracerebroventricular and intrathecal morphine bolus.
We report on two patients with morphine-related seizures associated with either intrathecal or intracerebroventricular administration. Both patients had a history of malignant tumor and both experienced the seizures following bolus application of morphine, while even higher dosages were well tolerated when continuously infused. ⋯ Initiation of intrathecal morphine therapy and bolus application should be performed carefully and only when constant monitoring is provided for at least 12 h. Animal data and possible mechanisms for morphine-related seizures are discussed.
-
The compatibility of ketamine and morphine mixture was studied. In addition, pH adjustment to minimise local tissue irritation led to no change in stability of the mixture up to pH 5.9. It appears that ketamine and morphine mixtures are stable over a 24 h period.