Lower limb intracast pressures generated by different types of immobilisation casts

AIM To determine if complete, split casts and backslabs [plaster of Paris(POP) and fiberglass] generate different intracast pressures and pain. METHODS Increased swelling within casts was modeled by a closed water system attached to an expandable bag placed directly under different types of casts applied to a healthy lower limb. Complete fiberglass and POP casts, split casts and backslabs were applied. Twenty-five milliliter aliquots of saline were injected into the system and the generated intracast pressures were measured using a sphygmomanometer. The subject was blinded to the pressure scores to avoid bias. All casts were applied to the same right limb on the same subject to avoid the effects of variations in anatomy or physiology on intracast pressures. Pain levels were evaluated using the Visual Analogue Score after each sequential saline injection. Each type of cast was reapplied four times and the measurements were repeated on four separate occasions. Sample sizes were determined by a pre-study 90% power calculation to detect a 20% difference in intracast pressures between cast groups. RESULTS A significant difference between the various types of casts was noted when the saline volume was greater than 100 mL(P = 0.009). The greatest intracast pressure was generated by complete fiberglass casts, which were significantly higher than complete POP casts or backslabs(P = 0.018 and P = 0.008 respectively) at intracast saline volumes of 100 mL and higher. Backslabs produced a significantly lower intracast pressure compared to complete POP only once the saline volume within casts exceeded 225 mL(P = 0.009). Intracast pressures were significantly lower in split casts(P = 0.003). Split POP and fiberglass casts produced the lowest intracast pressures, even compared to backslabs(P = 0.009). Complete fiberglass casts generated the highest pain levels at manometer pressures of 75 mm Hg and greater(P = 0.001). Split fiberglass casts had significantly reduced pain levels(P = 0.001). In contrast, a split complete POP cast did not produce significantly reduced pain levels at pressures between 25-150 mmH g. There was no difference in pain generated by complete POP and backslabs at manometer pressures of 200 mm Hg and lower. CONCLUSION Fibreglass casts generate significantly higher intracast pressures and pain than POP casts. Split casts cause lower intracast pressures regardless of material, than complete casts and backslabs.

Impact of Australia’s catastrophic 2019/20 bushfire season on communities and environment.Retrospective analysis and current trends

2019/20 Australia’s bushfire season(Black Summer fires)occurred during a period of record breaking tempera-tures and extremely low rainfall.To understand the impact of these climatic values we conducted a preliminary analysis of the 2019/20 bushfire season and compared it with the fire seasons between March 2000 and March 2020 in the states of New South Wales(NSW),Victoria,and South Australia(SA).Forest and fire management in Australia were asked to provide data on the number of fires,burned area,life and house loss,as well as weather conditions.By March 2020 Black Summer fires burnt almost 19 million hectares,destroyed over 3,000 houses,and killed 33 people.Data showed that they were unprecedented in terms of impact on all areas.A number of mega-fires occurred in NSW resulting in more burned area than in any fire season during the last 20 years.One of them was the largest recorded forest fire in Australian history.Victoria had a season with the highest number of fires,area burned,and second highest numbers of houses lost for the same period.SA had the highest number of houses lost in the last 20 years.Black Summer fires confirmed existing trends of impact categories during the last two decades for NSW and Victoria.It showed that the smoke from the bushfires may be a significant concern in the future for the global community,as it travels to other countries and continents.Based on preliminary data,it will take many years to restore the economy and infrastructure in impacted areas,and to recover animal and vegetation biodiversity.