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To avoid the risk of R-on-T incident and the unnecessary decrease of cardiac output, we devised an algorithm consisting of six steps for choosing the most appropriate intraoperative pacemaker (PM) mode, which is modified from Heart Rhythm Society and the American Society of Anesthesiologists expert consensus statement. Following this algorithm, we reviewed previous operations at our hospital to evaluate the appropriateness of the choices. Six of 78 cases (7.7%) were unfit to the algorithm because of an inappropriate mode change. The PM mode was changed preoperatively in four patients, even though the surgical site was under the umbilicus. In one case of the two other cases, the PM mode was changed from AAI to VOO. This case could not be avoided by the previous algorithm of the expert clinical statements. In another case, the anesthesiologist did not change PM mode even though the patient underwent parotidectomy and his heart rate depended on PM. Prospective research on this algorithm could clarify its usefulness in the future. Moreover, discussions about this algorithm could help develop this field of study and improve the intraoperative management of PMs., Author(s): Yusaku Terada [sup.1], Tetsuya Miyashita [sup.1], Yusuke Nagamine [sup.1], Takahisa Goto [sup.1] Author Affiliations: (1) grid.470126.6, 0000 0004 1767 0473, Department of Anesthesiology, Yokohama City University Hospital, , 3-9 [...]

Purpose Severe hypotension caused by anesthetic administration for anesthesia induction, which might cause ischemic stroke, myocardial injury, acute kidney injury and postoperative mortality, should be prevented. Anesthesiologists are familiar with ultrasound examination of the internal jugular vein (IJV). This study aimed to clarify whether ultrasonographic IJV evaluation just before induction could predict the occurrence of such hypotension. Methods Adult patients undergoing surgery under general anesthesia were enrolled after excluding patients with cardiovascular disease or ASA-PS [greater than or equal to] III. Ultrasonographic IJV images were recorded in both the supine and 10° Trendelenburg positions immediately before induction. Using these images, IJV area (IJV-A), diameter and change rate with posture were measured. Hypotension during induction was defined as mean BP 30% decrease from baseline. Results Hypotension during induction was observed in 37 of 82 patients. IJV-A in the Trendelenburg position was 2.02 ± 0.86 and 1.72 ± 0.68 in the hypotensive and non-hypotensive groups, respectively (P = 0.08). Logistic regression analysis performed using age, use of calcium antagonists, angiotensin converting enzyme inhibitors/angiotensin receptor blockers, baseline mean BP and IJV-A in the Trendelenburg position as variables showed that IJV-A in the Trendelenburg position was an independent predictor of hypotension, with an adjusted odds ratio of 3.11 (95% CI 1.07-9.03, P = 0.04). Area under the curve was 0.595 (95% CI 0.469-0.722) for IJV-A in the Trendelenburg position. Conclusion IJV-A in the Trendelenburg position was an independent predictor of hypotension during induction. Further study is required to examine the diagnostic accuracy of IJV-A as a predictor for hypotension during induction., Author(s): Kenta Okamura [sup.1], Takeshi Nomura [sup.2], Yusuke Mizuno [sup.2], Tetsuya Miyashita [sup.2], Takahisa Goto [sup.2] Author Affiliations: (1) grid.470126.6, 0000 0004 1767 0473, Department of Anesthesiology, Yokohama City University [...]

Image sticking can be observed in some cases and it degrades the image quality of liquid crystal (LC) display. The image sticking is considered to be induced by generation of residual direct current voltage (Vrdc), which would be caused by the presence of ion in a LC cell. We clarified the generation mechanism of Vrdc based on a model of adsorption and desorption of the ion to and from the surface of an alignment layer at various temperatures. The experimental results indicate that these processes can be explained by the Boltzmann distribution. The analysis based on Arrehnius plots shows that the ion adsorbs to the surface of the alignment layer with weak binding such as van der Waals interaction or hydrogen bonding. This finding is effective for development of high image quality LC displays. [ABSTRACT FROM AUTHOR]

The presence of ionic charges in a liquid crystal layer causes the generation of residual direct current (dc) voltage (Vrdc) in a liquid crystal cell. Vrdc is one of the most important factors governing the image quality of liquid crystal displays, because the existence of Vrdc causes the image sticking phenomenon. We studied the generation mechanism of Vrdc based on a model of the adsorption and desorption of the ionic charges at the interface between the liquid crystal and alignment layer. In this paper, we propose three evaluation parameters, (i) saturated residual dc voltage, (ii) time to reach its saturation state, and (iii) relaxation time during the open circuit state after applying the external dc voltage, for effective evaluation of liquid crystal and alignment layer materials from the viewpoint of the improvement of the image sticking. [ABSTRACT FROM AUTHOR]

In this paper, the liquid crystal (LC) order parameters of the interface layers at rubbed polymer surfaces were studied. The LC films in this study were made with either polyvinyl alcohol or polyimide and the test LCs were filled into wedge-shaped cells for various measurements. The real distribution of order parameters from LC bulk to the interface was obtained by measuring the anisotropic infrared absorbance of sample films. It was found that the order parameters start to decrease where the LC layer thickness is smaller than 10 nm, and the order parameter of LC monolayer at the rubbed polymer surface is only 1/3–1/2 of that of the LC bulk even in a strong rubbing condition. When the temperature was increased to the transition point, the LC interface layer (excluding the adsorption monolayer) completed the phase transition while the bulk layer remained in LC phase. This was a further evidence that the order parameter of the interface layer is lower than that of the bulk. [ABSTRACT FROM AUTHOR]