Application of a protective sleeve is associated with decreased occupational anxiety during endotracheal intubation: a randomized controlled trial

Background The high risk of cross-infection during tracheal intubation has caused excessive occupational anxiety for anaesthesiologists amid the novel coronavirus disease 2019 (COVID-19) pandemic. Currently, there is no effective way to attenuate their anxiety in clinical practice. We found that anaesthesiologist with better protective equipment might experience decreased levels of anxiety during intubation. Methods In this study, 60 patients who underwent intubation and extubation in the operating room were enrolled, and then randomized 1:1 to either wear protective sleeves (protective sleeve group) or not (control group). Visual analogue scale (VAS) was used to measure the anxiety level of anaesthesiologists during intubation. The respiratory droplets of patients on the sleeve, and the anaesthesiologists’ perception including the patient’s oral malodour, exertion, satisfaction degree, waist discomfort and shoulder discomfort were recorded. The patients’ anxiety, oppressed feelings and hypoxia and postoperative complications were all measured and recorded. Results Compared with the control group, the anaesthesiologists in protective sleeve group achieved lower anxiety scores and better satisfaction degrees during the process of intubation and extubation (all P < 0.05). Respiratory droplets were observed only on the inner side, but not the external side, of the protective sleeves (P < 0.001). The incidence of the anaesthesiologists’ perception of patients’ oral malodour was significantly lower in the protective sleeve group (P = 0.02) and no patients developed hypoxemia or intubation-related complications in the protective sleeve group. Conclusion Using protective devices for intubation might eliminate droplet transmission from patients to anaesthesiologists, while also decreasing their anxiety in a controlled operating room environment. Trial registration Chinese Clinical Trial. no. ChiCTR2000030705. Registry at www.chictr.org.cn on 10/03/2020.

Application Research on Testing Efficiency of Main Drainage Pump in Coal Mine Using Thermodynamic Theories

The efficiency of a drainage pump should be tested at regular intervals to master the status of the drainage pump in real time and thus achieve the goal of saving energy. The ultrasonic flowmeter method is traditionally used to measure the flow of the pump. But there are some defects in this kind of method of underground coal mine. This paper first introduces the principle of testing the main drainage pump efficiency in coal mine using thermodynamic theories, then analyzes the energy transformation during the process of draining water, and finally derives the calculation formulae of the pump efficiency, which meet the on-site precision of engineering. On the basis of analyzing the theories, the protective sleeve and the base of the temperature sensor are designed to measure the water temperature at inlet and outlet of the pump. The efficiencies of pumps with two specifications are measured, respectively, by using the thermodynamic method and ultrasonic flowmeter method. By contrast, the results show that thermodynamic method can satisfy the precision of the testing requirements accuracy for high-flow and high-lift drainage pump under normal temperatures. Moreover, some measures are summed up to improve the accuracy of testing the pump efficiency, which are of guiding significance for on-site testing of the main drainage pump efficiency in coal mine.

The Research about the Strength of Composite Riser Pipes Based on Finite Element Method

Composite riser pipes are being paid more and more attention because of its lightweight and high strength comparing with the steel riser pipes. It mainly includes internal liner, elastic shear layer, structural composite overlap layers, external protective sleeve and additional composite layer and so on. In this paper, the mechanical analytical model of composite riser pipe is constructed. The equivalent material properties are obtained in the globe analysis, and from the local analysis, it found that the helical layers mainly bear bend loadings, and the hoop layers mainly bear internal pressures from the simplified composite joint local analysis. It is proved that the composite riser pipe has the excellent designability.