Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2009
Comparative Study Clinical TrialArteriovenous differences in plasma dilution and the distribution kinetics of lactated ringer's solution.
Conventional concept suggests that infused crystalloid fluid is first distributed in the plasma volume and then, since the capillary permeability for fluid is very high, almost instantly equilibrates with the extracellular fluid space. We challenge whether this view is consistent with findings based on volume kinetic analysis. ⋯ The relatively slow whole-body distribution of lactated Ringer's solution, which boosts the plasma volume expansion during and for up to 30 min after an infusion, is probably governed by a joint effect of capillary permeability and differences in tissue perfusion between body regions.
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Anesthesia and analgesia · Jan 2009
Randomized Controlled Trial Comparative StudyThe influence of head and neck position on the oropharyngeal leak pressure and cuff position of three supraglottic airway devices.
With supraglottic airway devices, such as the laryngeal tube suction (LTS), ProSeal laryngeal mask airway (PLMA) and Cobra perilaryngeal airway (CobraPLA), oropharyngeal leak pressure or cuff position may vary according to changes in the position of the head and neck. We evaluated oropharyngeal leak pressure and cuff pressure of the PLMA, LTS, and CobraPLA in different head and neck positions. ⋯ The PLMA showed significantly lower oropharyngeal leak pressures than did the LTS or CobraPLA in the neck extension and rotation positions. Caution is warranted when changing the position of the head and neck when using the Cobra-PLA or LTS as gastric insufflation or ventilatory difficulty may occur.
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Anesthesia and analgesia · Jan 2009
Comparative StudyIntrathecal morphine preconditioning induces cardioprotection via activation of delta, kappa, and mu opioid receptors in rats.
Small doses of intrathecal morphine provide cardioprotection similar to that conferred by IV morphine. However, the extent of intrathecal morphine preconditioning (IT-MPC) relative to that resulting from ischemic preconditioning (IPC) is unknown. Further, it is uncertain whether IT-MPC is mediated by opioid receptor dependent pathways. In this study, we compared the extent of cardioprotection conferred by IT-MPC with IPC and investigated the role of opioid receptors in this effect. ⋯ IT-MPC produced comparable cardioprotection to myocardial IPC and IV morphine. Myocardial preconditioning from intrathecal morphine seems to involve delta, kappa, and mu opioid receptors.
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Anesthesia and analgesia · Jan 2009
Competitive substrates for P-glycoprotein and organic anion protein transporters differentially reduce blood organ transport of fentanyl and loperamide: pharmacokinetics and pharmacodynamics in Sprague-Dawley rats.
Drug transport proteins may be instrumental in controlling the concentration of fentanyl at mu receptors in the brain and may provide potential therapeutic targets for controlling an individual response to opioid administration. P-glycoprotein (P-gp) efflux transporter and organic anion transport protein inward transporters (OATP, human; Oatp, rat) have been implicated in fentanyl and verapamil (only P-gp) transport across the blood-brain barrier. We hypothesized that transport proteins P-gp and Oatp mediate opioid uptake in a drug and organ-specific manner, making them excellent potential targets for therapeutic intervention. ⋯ Protein transporters appear to be organ and drug-specific in vivo, affecting first-pass pulmonary uptake and CNS response to opioid administration. Further, data suggest that transport protein inhibition may prove useful for normalizing an individual response to opioids.