[A survey on clinical practice of tracheostomy decannulation in medical institutions at all levels across the country]

Objective: A questionnaire survey was conducted on the clinical practice of tracheostomy decannulation among medical staff in medical institutions at all levels across the country. Methods: The questionnaire was determined by literature review and expert consultation to investigate the clinical practice of tracheostomy decannulation among medical staff in comprehensive and rehabilitation hospitals of different levels across the country and the factors considered when deciding to decannulate. Statistical methods used χ² test and one-way ANOVA. Results: A total of 570 questionnaires were collected from all over the country, with 463 valid questionnaires. The survey results showed that the most important factors in clinical practice to determine the decannulation of the tracheostomy tube were upper airway patency, cough effectiveness, level of consciousness and oxygenation. Before decannulation, 220 (47.50%) would choose to change to metal cannula, and 384 (82.90%) would routinely occlude the tube. 294 (63.50%) thought that re-intubation within 24 hours after decannulation of the tracheostomy tube was failure of decannulation. The decannulation failure rate was mostly 2%-5%. Conclusions: Upper airway patency, cough effectiveness, level of consciousness and oxygenation were important factors when considering decannulation. Reintubation within 24 hours of decannulation was defined as failure by the majority of respondents.

Microstructure Evolution and Nanotribological Properties of Different Heat-Treated AISI 420 Stainless Steels after Proton Irradiation

In this paper, low-energy proton irradiation experiments with different cumulative fluences were performed on samples of AISI 420 stainless steel that were either annealed or tempered at 600 or 700 °C. The effects of the cumulative proton irradiation fluence on the evolution of the microstructure of AISI 420 were studied by transmission electron microscopy (TEM). Scratch tests were performed using a Tribo Indenter nanomechanical tester, in order to investigate the effects of the cumulative fluence on the tribological properties of the AISI 420 stainless steel. The results indicate that the dislocation density of the microstructure near the surface of the AISI 420 stainless steel increases with higher cumulative proton irradiation fluences. Under the same load, the nanoscale friction coefficient and wear rate both decreased with increasing cumulative proton irradiation fluence. This indicates that the surface hardening effect induced by proton irradiation can diminish the nanoscale friction coefficient and wear rate.