Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2011
The accuracy of noninvasive hemoglobin measurement by multiwavelength pulse oximetry after cardiac surgery.
In March 2008, a new multiwavelength pulse oximeter, the Radical 7 (Rad7; Masimo Corp., Irvine, CA), was developed that offers noninvasive measurement of hemoglobin concentration. Accuracy has been established in healthy adults and some surgical patients, but not in cardiac surgery intensive care patients, a group at high risk of postoperative bleeding events and anemia in whom early diagnosis could improve management. ⋯ Our study demonstrates poor correlation between hemoglobin measured noninvasively by multiwavelength pulse oximetry and a laboratory hematology analyzer. The difference was greater when the pulse oximetry perfusion index was low, as may occur in shock, hypothermia, or vasoconstriction patients. The multiwavelength pulse oximetry is not sufficiently accurate for clinical use in a cardiovascular intensive care unit.
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Anesthesia and analgesia · Nov 2011
Editorial CommentAnesthetic neurotoxicity: a difficult dragon to slay.
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Anesthesia and analgesia · Nov 2011
Validation and insights of anesthetic action in an early vertebrate network: the isolated lamprey spinal cord.
The lamprey spinal cord is a well-characterized vertebrate network that could facilitate our understanding of anesthetic action. We tested several hypotheses concerning the lamprey's clinical application to anesthesia, and the sites/mechanisms of anesthetic action. ⋯ The lamprey spinal cord is a relevant and tractable vertebrate network model for anesthetic action. Isoflurane disrupts interneuronal locomotor networks. γ-Aminobutyric acid A and glycine receptors have marginal roles in isoflurane-induced immobility in lampreys. Propofol's selective γ-aminobutyric acid A receptor-mediated immobilizing mechanism is conserved in lampreys. The differential immobilizing mechanisms of isoflurane versus propofol reflect those in mammals, and further suggest different network modes of immobilizing action.
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Anesthesia and analgesia · Nov 2011
The etomidate requirement is decreased in patients with obstructive jaundice.
Patients with obstructive jaundice have increased sensitivity to inhaled anesthetics. In rodent brain, bilirubin can enhance γ-aminobutyric acid A/glycinergic synaptic transmission. Etomidate is a nonbarbiturate hypnotic that induces sedation through γ-aminobutyric acid A receptors in the central nervous system. We tested the hypothesis that patients with obstructive jaundice have an altered sensitivity to etomidate. ⋯ Etomidate requirements to reach a level of anesthesia defined by a Bispectral Index of 50 are reduced in patients with obstructive jaundice.