Anesthesia and analgesia
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Anesthesia and analgesia · May 2011
Propofol depresses the cytotoxicity of X-ray irradiation through inhibition of gap junctions.
General anesthetics (e.g., propofol) influence the therapeutic activity of intraoperative radiotherapy but the mechanism of the effects is largely unknown. It has been reported that propofol inhibits gap junction (GJ) function briefly, and a functional GJ enhances the efficacy of radiotherapy in some cancer cells. Yet the mechanisms underlying the inhibition of GJ function by propofol and the influence of propofol on therapeutic activity of intraoperative radiotherapy are unknown. ⋯ These results suggest that propofol inhibits the function of the GJ through the reduction of Cx32 protein levels by a transcription-independent mechanism. They further indicate that propofol depresses the cytotoxicity of radiograph irradiation through inhibition of GJ activity.
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Anesthesia and analgesia · May 2011
The association between obesity and difficult prehospital tracheal intubation.
Nonphysician advanced life support (ALS) providers often perform tracheal intubation (TI) for cardiac arrest or other life-threatening indications in the prehospital setting, where airway assessment and airway management tools are limited. However, the frequency of difficult TI in obese patients in this setting is unclear. In this study we determined factors associated with TI success, and determined TI difficulty as a function of body mass index (BMI) in a system of ALS providers experienced in TI, to guide future prehospital education efforts. ⋯ Among prehospital ALS providers with previously documented and published successful TI performance, increased difficulty with TI was observed in patients with extreme obesity, but not in patients with lesser degrees of obesity. Because extreme obesity is an easily identifiable patient characteristic, didactic and clinical (e.g., operating room) airway management education for such providers should emphasize airway management challenges and strategies associated with obesity, including specific equipment, patient positioning, and practice recommendations that may facilitate both TI and alternative airway management techniques in this population.
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Anesthesia and analgesia · May 2011
Differential roles of fibrinogen and von Willebrand factor on clot formation and platelet adhesion in reconstituted and immune thrombocytopenia.
Bleeding tendencies in immune thrombocytopenia (ITP) do not always correlate with the number of platelets, suggesting platelet function variation. We used a model of normal whole blood thrombocytopenia to compare platelet function and other hemostatic variables with ITP patients. We further investigated the effect of in vitro spiking with von Willebrand factor (vWF) and fibrinogen on platelet function and hemostatic variables. ⋯ Using a model of whole blood thrombocytopenia enables us to establish reference variables for the Cone and Plate(let) Analyzer and rotational thromboelastometry and to assess platelet function and clot formation in the presence of severe thrombocytopenia. We demonstrated that in most cases of ITP, platelet function is comparable to normal platelets. This work also suggests that vWF and fibrinogen differentially affect primary and secondary hemostasis and therefore both may perform a function in the bleeding phenotype and possibly may be considered for treatment in patients with ITP.