Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2007
Randomized Controlled Trial Comparative StudyThe influence of neck flexion and extension on the distribution of contrast medium in the high thoracic epidural space.
For safe and effective thoracic epidural analgesia (TEA), it is important to control the level of TEA and to identify factors that influence its spread. In this study, we observed the distribution of contrast injected into the high thoracic epidural space during neck flexion and extension. ⋯ Cranial spread of contrast in the high thoracic epidural space is limited. However, neck flexion increases cranial spread. These results suggest that when TEA is high, the tip of the epidural catheter should be located at the upper part of the level to be blocked and that neck flexion may cause an unwanted cervical block.
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Anesthesia and analgesia · Jun 2007
Randomized Controlled Trial Comparative StudyThe coagulation changes induced by rapid in vivo crystalloid infusion are attenuated when magnesium is kept at the upper limit of normal.
Rapid crystalloid infusion enhances coagulation, regardless of electrolytes, pH or osmolality, an effect thought to be related to deep vein thrombosis and other clot formations. Altered serum magnesium may play a role in the balance of coagulation. In this in vivo study we investigated the coagulation response to rapid hemodilution when serum magnesium is maintained or partially increased. ⋯ Rapid hemodilution-induced coagulation may be partially due to decreased magnesium, and the effect is attenuated by maintaining magnesium at the upper limit of normal. Crystalloid resuscitation fluids should possibly contain higher magnesium levels, around 3 mmol/L.
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Anesthesia and analgesia · Jun 2007
Comparative StudyComplications and adverse effects associated with continuous peripheral nerve blocks in orthopedic patients.
The increasing popularity of continuous peripheral nerve blocks (CPNBs) warrants further study of their adverse effects and complications. ⋯ Our results add to the evidence that major complications from CPNBs are rare. However, minor adverse effects associated with CPNBs may be more common.
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Anesthesia and analgesia · Jun 2007
Comparative StudyThe effects of the local anesthetics lidocaine and procaine on glycine and gamma-aminobutyric acid receptors expressed in Xenopus oocytes.
The voltage-dependent sodium channel is the primary site of action for local anesthetics (LAs). Although systemically administered low-dose LAs have been shown to exert antihyperalgesic effects, the molecular targets responsible for these effects are not fully known and their functional effects on inhibitory neurotransmitter receptors associated with antinociception have not been sufficiently studied. ⋯ Lidocaine and procaine enhanced glycine receptor function at low concentrations and inhibited the functions of glycine and GABA(A) receptors at high concentrations. The mechanism of the LA-induced enhancement of glycine receptor function probably differs from that of general anesthetics. These findings may explain the pharmacological effects of LAs, such as antinociception and convulsion.
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Anesthesia and analgesia · Jun 2007
Comparative StudyExperimental neuropathy in mice is associated with delayed behavioral changes related to anxiety and depression.
Patients with chronic pain frequently suffer affective disorders, particularly anxiety and depression. Although clinical research on the relationship between pain and depressive symptoms has been done, it is not clear whether pain causes depression or depression exaggerates pain. To investigate the relation between pain and affect, we measured anxiety and depression-related behaviors in mice after spinal nerve ligation using classical behavioral tests. ⋯ Nerve injury can trigger affective disturbances in mice that appear much later than sensory hypersensitivity.