Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2011
ReviewBrief preoperative smoking abstinence: is there a dilemma?
The concern that stopping smoking shortly (<8 weeks) before surgery increases postoperative pulmonary complications poses a barrier to tobacco use interventions in surgical patients. We show how this concern arose from a misinterpretation of initial studies and has remained in the medical literature despite the accumulation of later evidence. The persistence of unsubstantiated concepts is not uncommon and can have a significant impact on medical practice. Although it may take several weeks to derive pulmonary benefit from quitting, fear of an increase in pulmonary complications should not be a barrier for clinicians to help their patients quit smoking at any time before surgery.
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Anesthesia and analgesia · Dec 2011
ReviewPharmacogenomics of β-adrenergic receptor physiology and response to β-blockade.
Myocardial β-adrenergic receptors (βARs) are important in altering heart rate, inotropic state, and myocardial relaxation (lusitropy). The β1AR and β2AR stimulation increases cyclic adenosine monophosphate concentration with the net result of myocyte contraction, whereas β3AR stimulation results in decreased inotropy. Downregulation of β1ARs in heart failure, as well as an increased β3AR activity and density, lead to decreased cyclic adenosine monophosphate production and reduced inotropy. ⋯ Although βAR SNPs may not directly cause disease, they appear to be risk factors for, and modifiers of, disease and the response to stress and drugs. In the perioperative setting, this has specifically been demonstrated for the Arg389Gly β1AR polymorphism with which patients with the Gly variant had a higher incidence of adverse perioperative events. Knowing that genetic variants play an important role, perioperative medicine will likely change from simple therapeutic intervention to a more personalized way of adrenergic receptor modulation.
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Anesthesia and analgesia · Dec 2011
Comparative StudyMorphine-induced epidermal growth factor pathway activation in non-small cell lung cancer.
Epidermal growth factor receptor (EGFR) is coactivated by the μ-opioid receptor (MOR), expressed on non-small cell lung cancer (NSCLC) cells and human lung cancer. We hypothesized that clinically used opioid analgesics that are MOR agonists coactivate EGFR, resulting in growth- and survival-promoting signaling. ⋯ Morphine-induced phosphorylation of EGFR occurs via ORs, leading to downstream MAPK/ERK, Akt phosphorylation, cell proliferation, and increased invasion. Notably, ORs are also associated with EGF-induced phosphorylation of EGFR. Increased coexpression of MOR and EGFR in human lung cancer suggests that morphine may have a growth-promoting effect in lung cancer.
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Anesthesia and analgesia · Dec 2011
Comparative StudyBupivacaine destabilizes action potential duration in cellular and computational models of long QT syndrome 1.
The effects of the local anesthetic bupivacaine on cardiac action potentials (APs) are mainly attributed to inhibition of cardiac Na(+) channels. The relevance of its ability to also induce high-affinity blockade of human ether-à-gogo-related gene (hERG) channels is unclear. We investigated whether this interaction may functionally become more significant in cellular and computational models of long (L)QT syndromes. ⋯ This study provides evidence that bupivacaine induces inhibition of hERG channels, which is functionally silent under normal conditions but will become more relevant in LQT1-like states in which repolarization relies to a larger degree on hERG channels. Interactions with ion channels other than cardiac Na(+) channels may, therefore, determine the net cardiac effects of bupivacaine when the normal balance of ionic currents is altered.