Frail patients having vascular surgery during the early COVID-19 pandemic experienced high rates of adverse perioperative events and amputation.

BACKGROUND: Frailty predicts adverse perioperative outcomes and increased mortality in patients having vascular surgery. Frailty assessment is a potential tool to inform resource allocation, and shared decision-making about vascular surgery in the resource constrained COVID-19 pandemic environment. This cohort study describes the prevalence of frailty in patients having vascular surgery and the association between frailty, mortality and perioperative outcomes. METHODS: The COVID-19 Vascular Service in Australia (COVER-AU) prospective cohort study evaluates 30-day and six-month outcomes for consecutive patients having vascular surgery in 11 Australian vascular units, March-July 2020. The primary outcome was mortality, with secondary outcomes procedure-related outcomes and hospital utilization. Frailty was assessed using the nine-point visual Clinical Frailty Score, scores of 5 or more considered frail. RESULTS: Of the 917 patients enrolled, 203 were frail (22.1%). The 30 day and 6 month mortality was 2.0% (n = 20) and 5.9% (n = 35) respectively with no significant difference between frail and non-frail patients (OR 1.68, 95%CI 0.79-3.54). However, frail patients stayed longer in hospital, had more perioperative complications, and were more likely to be readmitted or have a reoperation when compared to non-frail patients. At 6 months, frail patients had twice the odds of major amputation compared to non-frail patients, after adjustment (OR 2.01; 95% CI 1.17-3.78), driven by a high rate of amputation during the period of reduced surgical activity. CONCLUSION: Our findings highlight that older, frail patients, experience potentially preventable adverse outcomes and there is a need for targeted interventions to optimize care, especially in times of healthcare stress.

Effect of enriched oxygen inhalation on lower limb skin temperatures in diabetic and healthy humans: a pilot study.

INTRODUCTION: Measurement of skin temperature with infrared thermometry has been utilised for assessing metabolic activity and may be useful in identifying patients with ulcers suitable for hyperbaric oxygen treatment and monitoring their treatment progress. Since oxygen promotes vasoconstriction in the peripheral circulation, we hypothesised that oxygen administration may lower skin temperature and complicate the interpretation of temperatures obtained. This pilot study investigated the effect of oxygen administration on lower limb skin temperature in healthy subjects and diabetic patients. METHODS: Volunteers were recruited from healthy staff members (n = 10) and from patients with diabetic foot ulcers (n = 10) at our facility. Foot skin surface temperatures were measured by infra-red thermometry while breathing three different concentrations of oxygen (21%, 50% and 100%). RESULTS: Skin temperature changes were observed with increasing partial pressure of oxygen in both groups. The mean (SD) foot temperatures of diabetic patients and healthy controls at air-breathing baseline were 30.1°C (3.6) versus 29.0°C (3.7) respectively, at FiO2 0.5 were 30.1°C (3.6) versus 28.5°C (4.1) and at FiO2 1.0 were 28.3°C (3.2) versus 29.2°C (4.3). None of these differences between groups were statistically significant. CONCLUSIONS: Data from this small study may indicate a difference in thermal responses between healthy subjects and diabetic patients when inhaling oxygen; however, none of the results were statistically significant. Further investigations on a larger scale are warranted in order to draw firm conclusions.

Synthesis and characterization of synthetic sand by geopolymerization of industrial wastes (fly ash and GGBS) replacing the natural river sand.

The diminution of the natural sources in the form of dredging the riverbanks and blasting the mountain ranges has always dented the balance of the ecosystem which in turn results in disasters as well at times. This alarming situation accelerates the global warming, threatens the biota life in riverbanks, diminishes the ground water level, harms the aquatic life, and affects the growth of agriculture. This study is an attempt to synthesis fine aggregates from the industrial byproducts, namely, fly ash and GGBS through the process of geopolymerization. This enables the formation of aluminosilicate networks upon the addition of the alkaline activator solution (Na2 SiO3 + NaOH) into the byproducts. The dry mix is then allowed for oven drying as well as air drying to accelerate the geopolymerization process. The fly ash-geopolymerized fine aggregate (F-GFA) and the GGBS-geopolymerized fine aggregate (G-GFA) were noted to exhibit adequate physiochemical and mechanical properties in par with the natural sand. The production of GFA is considered eco-friendly process since it ceases the extensive usage of river sand and incorporates the effective usage of industrial byproducts (fly ash and GGBS), thereby minimizing the land pollution and its consequent harmful hazards. Though the F-GFA and G-GFA showcased higher water absorption ratio than the natural sand due to the presence of unreacted fly ash and GGBS particles, the complete replacement of fine aggregate with geopolymerized sand initiated the adequate compressive strength attainment up to 90% of natural sand, by reacting with the lime expelled out of the hydration process of cement in the mortar specimens developed in this experimental study. The geopolymer itself is hydrophilic in nature, and it will also aid for the higher water absorption ratio of the polymer sand. The microstructure of the samples was further examined through optical microscope, scanning electron microscope, and X-ray diffraction analysis in order to corroborate the experimental results of this study. The results thus obtained strongly recommend the potential of the F-GFA and G-GFA as an ideal replacement material for natural sand.