Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Effect of heat treatment on wear resistance of a grinding plate

The effects of heat treatment on the hardness and by extension the wear resistance of locally produced grinding plate of known composition were investigated. Specimens were prepared from the grinding plate and were heat treated at 840°C, 860°C and 880°C and quenched at different rate. Some of the specimens were quenched in water and palm oil, while some of the quenched specimens were tempered at 200°C. The results obtained were corroborated with the microstructure of the specimens examined under an optical microscope. The hardness values of the grinding plate specimens quenched in various media increased with increased heat treatment temperatures, and are higher than that of the as-cast specimen. Water quenched tempered specimens (WT) displayed higher hardness values than the as-cast, whereas oil quenched tempered specimens (OT) possessed lower hardness values. The presence of carbide was evident on the micrographs of the water quenched specimens at all the exposure temperatures, which corroborated the observed increased in the hardness values with increased heat treatment temperatures. However, there was significant reduction in the hardness value of the water quenched tempered specimens compared with the quenched specimens, which indicates a significant improvement in toughness. Thus, water quenched and tempered specimen with relatively high hardness value and improved toughness, will be suitable for use as grinding plate because of its relatively better wear resistance. The hardness of the specimens was found to depend on the formation of carbide precipitates within the matrix structure. There is also possibility of production of structure consisting of graphite embedded in a martensitic matrix through the heat treatment.Keyword: carbide, heat treatment, hardness, microstructure, wear resistanc

Comparación de la termometría digital infrarroja y electrónica en pollos de engorde

Se utilizaron datos de la temperatura corporal (BT) obtenidos de 150 pollos de engorde no envejecidos de 28 d de edad para comparar la exactitud de los diferentes termómetros. Se utilizaron simultáneamente termómetros digitales electrónicos (ED) e infrarrojos (IR) para medir BT. La termometría de ED se realizó a través del recto (TEMPd) mientras que el termómetro IR se usó en la apertura del recto (TEMPiR), la frente (TEMPiH) y bajo las alas (TEMPiW). Los datos se sometieron a análisis de correlación de ANOVA y Pearson. Diagramas de dispersión se representaron para generar R2 para las relaciones entre las lecturas del termómetro. El tipo de termómetro tuvo un efecto significativo (P 0,001) a TEMPiW, pero el dúo fue significativamente mayor que TEMPiR y TEMPiH. TEMPiH no fue significativamente diferente de la de la apertura del recto. Existe correlación positiva entre TEMPd y TEMPiW (r = 0.327) mientras que la correlación entre TEMPd y TEMPiH es negativa (r = -0.250). TEMPiR no tuvo correlación significativa (P> 0,05) con TEMPd (r = 0,061). Regresión lineal de TEMPd con TEMPiR, TEMPiH y TEMPiW rindió R2 valores de 0,003, 0,062 y 0,106, respectivamente. Las desviaciones de TEMPd obtenidas fueron de 3,63, 3,79 y -0,12oC para TEMPiR, TEMPiH y TEMPiW, respectivamente. TEMPiR y TEMPiH en pollos de engorde no produjeron lecturas similares en comparación con los termómetros ED. La termometría con IR debajo de las alas dio una lectura más cercana con el termómetro ED. La precisión del termómetro IR en los pollos de engorde depende del punto en la superficie del cuerpo del que se toma la lectura. Las lecturas con IR debajo de las alas imitan la temperatura corporal central