Anesthesiology
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Clinical Trial
Accelerometry of adductor pollicis muscle predicts recovery of respiratory function from neuromuscular blockade.
Residual paralysis increases the risk of pulmonary complications but is difficult to detect. To test the hypothesis that accelerometry predicts effects of residual paralysis on pulmonary and upper airway function, the authors related tests of pulmonary and pharyngeal function to accelerometry of adductor pollicis muscle in 12 partially paralyzed volunteers. ⋯ Impaired inspiratory flow and upper airway obstruction frequently occur during minimal neuromuscular blockade (TOF ratio 0.8), and extubation may put the patient at risk. Although a TOF ratio of unity predicts a high probability of adequate recovery from neuromuscular blockade, respiratory function can still be impaired.
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Comparative Study
Antihyperalgesic and side effects of intrathecal clonidine and tizanidine in a rat model of neuropathic pain.
Although intrathecal clonidine produces pronounced analgesia, antinociceptive doses of intrathecal clonidine produce several side effects, including hypotension, bradycardia, and sedation. Intrathecal tizanidine, another alpha(2)-adrenergic agonist, has provided antinociception without producing pronounced hemodynamic changes in animal studies. However, it has been unclear whether antihyperalgesic doses of intrathecal clonidine and tizanidine produce hypotension and bradycardia in a neuropathic pain state. This study was designed to evaluate the antihyperalgesic effects and side effects of intrathecal clonidine and tizanidine in a rat model of neuropathic pain. ⋯ The antihyperalgesic dose of intrathecal clonidine and the antinociceptive doses produced several side effects. Intrathecal tizanidine at the dose that reversed hyperalgesia would be preferable for neuropathic pain management because of absence of hypotension and bradycardia and lower incidence of sedation.
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Although intravenous morphine titration is widely used to obtain rapid and complete postoperative pain relief, the relationship between measurement of pain and morphine requirements varies, and the evolution of pain during titration is poorly understood. ⋯ A VAS score of 70 or greater should be considered indicative of severe pain. The relationship between the initial VAS score and morphine requirements is not linear, and the evolution of the VAS score during the pain relief process is described by a sigmoid curve.
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Gabapentin, a gamma-aminobutyric acid analog anticonvulsant, has been shown to possess antinociceptive effects in animal models and clinical trials. An endogenous binding site of [3H]gabapentin has been revealed to be the alpha(2)delta subunit of voltage-dependent Ca2+ channels. Magnesium chloride, ruthenium red, and spermine have been shown to modulate [3H]gabapentin binding to this binding site in vitro. In this study, the authors examined whether intrathecal magnesium chloride, ruthenium red, or spermine could affect the antiallodynic effect of intrathecal gabapentin in a rat model of postoperative pain. ⋯ These results provide behavioral evidence to support that the alpha(2)delta subunit of Ca2+ channels may be involved in the antiallodynic action of intrathecal gabapentin in the postoperative pain model.
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Letter Comparative Study
Can choice of vasopressor therapy affect rostral spread of spinal anaesthetic?