Five-year evolution of drug prescribing in a university adult intensive care unit

Introduction: Drug prescription is difficult in ICUs as prescribers are many, drugs expensive and decisions complex. In our ICU, specialist clinicians (SC) are entitled to prescribe a list of specific drugs, negotiated with intensive care physicians (ICP). The objective of this investigation was to assess the 5-year evolution of quantity and costs of drug prescription in our adult ICU and identify the relative costs generated by ICP or SC. Methods: Quantities and costs of drugs delivered on a quarterly basis to the adult ICU of our hospital between 2004 and 2008 were extracted from the pharmacy database by ATC code, an international five-level classification system. Within each ATC first level, drugs with either high level of consumption, high costs or large variations in quantities and costs were singled out and split by type of prescriber, ICP or SC. Cost figures used were drug purchase prices by the hospital pharmacy. Results: Over the 5-year period, both quantities and costs of drugs increased, following a nonsteady, nonparallel pattern. Four ATC codes accounted for 80% of both quantities and costs, with ATC code B (blood and haematopoietic organs) amounting to 63% in quantities and 41% in costs, followed by ATC code J (systemic anti-infective, 20% of the costs), ATC code N (nervous system, 11% of the costs) and ATC code C (cardiovascular system, 8% of the costs). Prescription by SC amounted to 1% in drug quantities, but 19% in drug costs. The rate of increase in quantities and costs was seven times larger for ICP than for SC (Figure 1 overleaf ). Some peak values in costs and quantities were related to a very limited number of patients. Conclusions: A 5-year increase in quantities and costs of drug prescription in an ICU is a matter of concern. Rather unexpectedly, total costs and cost increases were generated mainly by ICP. A careful follow-up is necessary to try influencing this evolution through an institutional policy co-opted by all professional categories involved in the process.

Evolution of insulin sensitivity and its variability in out-of-hospital cardiac arrest (OHCA) patients treated with hypothermia.

INTRODUCTION: Therapeutic hypothermia (TH) is often used to treat out-of-hospital cardiac arrest (OHCA) patients who also often simultaneously receive insulin for stress-induced hyperglycaemia. However, the impact of TH on systemic metabolism and insulin resistance in critical illness is unknown. This study analyses the impact of TH on metabolism, including the evolution of insulin sensitivity (SI) and its variability, in patients with coma after OHCA. METHODS: This study uses a clinically validated, model-based measure of SI. Insulin sensitivity was identified hourly using retrospective data from 200 post-cardiac arrest patients (8,522 hours) treated with TH, shortly after admission to the intensive care unit (ICU). Blood glucose and body temperature readings were taken every one to two hours. Data were divided into three periods: 1) cool (T <35°C); 2) an idle period of two hours as normothermia was re-established; and 3) warm (T >37°C). A maximum of 24 hours each for the cool and warm periods was considered. The impact of each condition on SI is analysed per cohort and per patient for both level and hour-to-hour variability, between periods and in six-hour blocks. RESULTS: Cohort and per-patient median SI levels increase consistently by 35% to 70% and 26% to 59% (P <0.001) respectively from cool to warm. Conversely, cohort and per-patient SI variability decreased by 11.1% to 33.6% (P <0.001) for the first 12 hours of treatment. However, SI variability increases between the 18th and 30th hours over the cool to warm transition, before continuing to decrease afterward. CONCLUSIONS: OCHA patients treated with TH have significantly lower and more variable SI during the cool period, compared to the later warm period. As treatment continues, SI level rises, and variability decreases consistently except for a large, significant increase during the cool to warm transition. These results demonstrate increased resistance to insulin during mild induced hypothermia. Our study might have important implications for glycaemic control during targeted temperature management.

Separating Myth from Probability: the Origins and Evolution of QWERTY

We use basic probability theory and simple replicable electronic search experiments to evaluate some reported “myths” surrounding the origins and evolution of the QWERTY standard. The resulting evidence is strongly supportive of arguments put forward by Paul A. David (1985) and W. Brian Arthur (1989) that QWERTY was path dependent with its course of development strongly influenced by specific historical circumstances. The results also include the unexpected finding that QWERTY was as close to an optimal solution to a serious but transient problem as could be expected with the resources at the disposal of its designers in 1873.

The evolution of inbred social systems in spiders and other organisms: from short-term gains to long-term evolutionary dead-ends?

The question of why some social systems have evolved close inbreeding is particularly intriguing given expected short- and long-term negative effects of this breeding system. Using social spiders as a case study, we quantitatively show that the potential costs of avoiding inbreeding through dispersal and solitary living could have outweighed the costs of inbreeding depression in the origin of inbred spider sociality. We further review the evidence that despite being favored in the short term, inbred spider sociality may constitute in the long run an evolutionary dead end. We also review other cases, such as the naked mole rats and some bark and ambrosia beetles, mites, psocids, thrips, parasitic ants, and termites, in which inbreeding and sociality are associated and the evidence for and against this breeding system being, in general, an evolutionary dead end.

Estimating patterns of leaf herbivory along an altitudinal transect in NE Queensland rainforests: might global warming increase leaf herbivory in tropical rainforests?

Climate change has been taking place at unprecedented rates over the past decades. These fast alterations caused by human activities are leading to a global warming of the planet. Warmer temperatures are going to have important effects on vegetation and especially on tropical forests. Insects as well will be affected by climate change. This study tested the hypothesis that higher temperatures lead to a higher insect pressure on vegetation. Visual estimations of leaf damage were recorded and used to assess the extent of herbivory in nine 0.1ha plots along an altitudinal gradient, and therefore a temperature gradient. These estimations were made at both a community level and a species level, on 2 target species. Leaf toughness tests were performed on samples from the target species from each plot. Results showed a strong evidence of increasing insect damage along increasing temperature, with no significant effect from the leaf toughness.

Sex-dependent selection on an autosomal melanic female ornament promotes the evolution of sex ratio bias.

Sex-dependent selection often leads to spectacularly different phenotypes in males and females. In species in which sexual dimorphism is not complete, it is unclear which benefits females and males derive from displaying a trait that is typical of the other sex. In barn owls (Tyto alba), females exhibit on average larger black eumelanic spots than males but members of the two sexes display this trait in the same range of possible values. In a 12-year study, we show that selection exerted on spot size directly or on genetically correlated traits strongly favoured females with large spots and weakly favoured males with small spots. Intense directional selection on females caused an increase in spot diameter in the population over the study period. This increase is due to a change in the autosomal genes underlying the expression of eumelanic spots but not of sex-linked genes. Female-like males produced more daughters than sons, while male-like females produced more sons than daughters when mated to a small-spotted male. These sex ratio biases appear adaptive because sons of male-like females and daughters of female-like males had above-average survival. This demonstrates that selection exerted against individuals displaying a trait that is typical of the other sex promoted the evolution of specific life history strategies that enhance their fitness. This may explain why in many organisms sexual dimorphism is often not complete.

Evolution of endurance during a multidisciplinary treatment of chronic low back pain and its influence of work capacity

Introduction: Low back pain is a common disorder touching up to 80% of the population, with redundancies of up to 70%. A small proportion would go on to develop chronic low back pain (LBP) with reduced work capacity and they would count for the majority of the costs. Up to day, a multi-disciplinary treatment program is one of the best approaches. In the program one of the mile-stones is restoration of function. The aim of this study was to follow patients, according to the endurance change after the program and its influence on workability during one year after inclusion in a such program. Method: Patients were following a multidisciplinary treatment for 3 weeks including physiotherapy, occupation measures combined with an educational program with behavioural and psychological interventions on an outpatient program. We studied the endurance with the help of the Bruce test, accomplished at the beginning and at the end of the program. On the other hand the patients filled out pain questionnaires and PACT score according their own impression on workability. Results: There were a clear relation between the increase in the cardiovascular endurance and the increased workability. Almost every patient presented an increase in the VO2 max, even though the workability did not follow. This increase were associated with a decrease in pain apprehension. Conclusion: A multidisciplinary treatment program, teaching the patients how to care with their pain and to accept it even if it persist is successful in lowering the global pain. If the program allows the patients to strengthen the endurance, the workability will increase in parallel. In this way the patients were able to reduce the consummation of medicaments and to increase the work capacity.

A cohort-based analysis of the evolution of lifetime prevalence of recourse to prostitution by men in the general population of Switzerland, 1987-2000

Background: Despite their relevance to the prevention of sexually transmitted infections, there are few data on the frequency of recourse to prostitution in the male population in Switzerland. Using data gathered for the evaluation of the Swiss AIDS prevention strategy, we analysed net aggregate change and cohort-based change in lifetime prevalence of recourse to prostitution. Methods: Seven repeated cross-sectional telephone surveys of the general population aged 17-45 years (17-30 years only for the 1987 and 1988 surveys) were undertaken from 1987 to 2000 providing information on sexual behaviour including men's recourse to prostitution (total n¼9318). Age categories were: 17-20, 21-25, 26-30, 31-35, 36-40 and 41-45 years. Prevalence at 17-30 years was available in all surveys and prevalence at 41-45 was available for 1989-2000, though not for the same cohorts. Intra-cohort increase in prevalence over 10 years was analysed using truncated information for cohorts aged 21-25 and 26-30 years in 1987 and 1990. Population estimates were computed with 95% confidence intervals (CI). Results: No net change occurred in the 17-45 years male population prevalence between 1989 (17.6%, CI ¼ 15.4; 20.0) and 2000 (17.7%, CI ¼ 15.6; 20.0). The median starting prevalence of recourse to prostitution at age 17-20 was 4.8% (in 1989, CI ¼ 2.0; 9.7) and the range was from 1.8 (in 1994) to 10.4% (in 1990). The median ending prevalence at age 41-45 was 21.9% (in 1994, CI 16.7; 27.9) and the range was from 17.9 (in 2000) to 26.1% (in 1992). No clear trend was observed in either starting or ending prevalence. Intra-cohort evolution of the 1997 and 1990 cohorts was very similar. Conclusions: Based on available data, there was no net (aggregate) change in the prevalence of recourse to prostitution by males in Switzerland between 1989 and 2000. Within the time frame available, intra-cohort evolution was also very similar.

Cultural transmission can inhibit the evolution of altruistic helping.

The study of culturally inherited traits has led to the suggestion that the evolution of helping behaviors is more likely with cultural transmission than without. Here we evaluate this idea through a comparative analysis of selection on helping under both genetic and cultural inheritance. We develop two simple models for the evolution of helping through cultural group selection: one in which selection on the trait depends solely on Darwinian fitness effects and one in which selection is driven by nonreproductive factors, specifically imitation of strategies achieving higher payoffs. We show that when cultural variants affect Darwinian fitness, the selection pressure on helping can be markedly increased relative to that under genetic transmission. By contrast, when variants are driven by nonreproductive factors, the selection pressure on helping may be reduced relative to that under genetic inheritance. This occurs because, unlike biological offspring, the spread of cultural variants from one group to another through imitation does not reduce the number of these variants in the source group. As a consequence, there is increased within-group competition associated with traits increasing group productivity, which reduces the benefits of helping. In these cases, selection for harming behavior (decreasing the payoff to neighbors) may occur rather than selection for helping.