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Respiration rates and drowning times after complete submergence were observed in diapausing Heliothis zea (Boddie) pupae at 5, 10, 15, 20, and 27°C. Respiration rate in pupae 2.5–12 weeks in diapause increased as an exponential function of temperature. The respiration rate of post-diapause pupae at 27°C increased over 10-fold in an approximately linear fashion during 12 days of pharate adult development. Time to 50% drowning in diapausing pupae decreased with increasing temperature, varying from 22.9 to 4.1 days at 5 and 27°C, respectively. Drowning rates in these pupae increased approximately exponentially with temperature. Diapausing and post-diapause pupae at 27°C had similar times to 50% drowning. An empirical model of drowning fitted the results well at all five temperatures, but a mechanistic model based on respiration predicted drowning considerably before it was observed. When the latter model was modified to allow withdrawal of dissolved oxygen from the water, it predicted longer survival periods, as observed. Our evidence suggests that respiration and drowning rates are closely correlated. Given the long survival times under complete submergence at 5–20°C, we speculate that pupae overwintering in the field in deep diapause are relatively resistant to drowning, whereas pre- and post-diapause pupae, with higher respiration rates, are at much greater risk.

The purpose of this study was to determine the relationship between frailty and poverty in burn patients >50 years-old, and their association with patient outcomes. This was a single-center retrospective chart review from 2009-2018 of patients >50 years old admitted with acute burn injuries. Frailty was assigned using the Canadian Study of Health and Aging Clinical Frailty Scale. Poverty was defined as a patient from a zip code that had >20% of people living in poverty. The relationship between frailty and poverty, as well as each variable independently on mortality, length of stay (LOS), and disposition location was examined. Of 953 patients, the median age was 61 years, 70.8% were male, and median total body surface area burn was 6.6%. Upon admission, 26.4% and 35.2% patients were frail and from impoverished neighborhoods, respectively. The mortality rate was 8.8%. Univariate analysis demonstrated that non-survivors had significantly higher chances of living in poverty (p=0.02) and were more likely to be frail compared to survivors. There was no significant correlation between poverty and frailty (p=0.08). Multivariate logistic regression confirmed the relationship between lack of poverty and mortality (OR 0.47 95% CI 0.25-0.89) and frailty and mortality OR 1.62 95%CI 1.24-2.12). Neither poverty (p=0.26) nor frailty (p=0.52) was associated with LOS. Both poverty and frailty were associated with a patient’s discharge location (p=0.03; p<0.0001). Poverty and frailty each independently predict mortality and discharge destination in burn patients >50, but they are not associated with LOS nor each other.

Introduction Previous work has demonstrated that frailty predicts mortality and patient disposition in burn patients >50 years old. It is unknown to what extent poverty contributes to these outcomes. There has been no work demonstrating the interplay of these two variables on patients with burn injuries. The purpose of this study was to determine the relationship of frailty and poverty in burn patients over the age of 50, and their association with patient outcomes. Methods A 9-year retrospective chart review from 2009-2018 of patients >50 years old admitted to an ABA verified burn center with acute burn injuries was completed. Patient demographics, burn characteristics, frailty scores and poverty levels were collected. Frailty scores were assigned using the Canadian Study of Health and Aging Clinical Frailty Scale (scored 1-7). Frailty was dichotomized with scores >5 being frail. Poverty data were obtained using zip code and US census data. Poverty level was categorized according to whether a patient came from a zip code that had >20% of people living in poverty. Descriptive statistics, univariate analysis, and multivariate analysis were completed to examine the relationship between frailty and poverty, as well as each variable independently on mortality and length of stay (LOS). Results A total of 953 patients were included. Mean age was 63.5 + 10.4 years and 675 (70.8%) were male. Mean %TBSA was 11.4%+14.2% and mean frailty score was 3.8 + 1.2. Upon admission, mean poverty score was 17.3+ 8.7. The overall mortality rate was 8.8%. Univariate analysis demonstrated that non-survivors had significantly higher chances of living in poverty (p=0.02). Similarly, univariate analysis showed that non-survivors were more likely to have frailty scores of 5 or greater compared to survivors. Multivariate logistic regression confirmed relationship between poverty and mortality (<20% vs >20%, OR 0.47 95% CI 0.25-0.89) and frailty and mortality ( >5 vs 1-4, OR 2.9 95%CI 1.4-5.8). It also demonstrated that the combined variable of frailty and poverty was not significantly associated with mortality (Wald χ2 2.0, p=0.15). Neither poverty (< 20% vs >20%, p=0.26) nor frailty (1-4 vs >5, p=0.52) were associated with LOS. Both poverty and frailty were associated with a patient’s disposition destination (p=0.03; p< 0.0001). Univariate analysis did not show a significant correlation between poverty and frailty (p=0.08), though there was a trend towards significance. Conclusions Poverty and frailty each independently predict mortality and discharge destination in burn patients >50, but they are not associated with LOS, and do not show a significant association with each other, nor a combined effect on mortality.