Extra Mortality Research Articles

Extra Mortality of Nosocomial Infections in Neonatal ICUs at Eight Hospitals of Argentina, Colombia, Mexico, Peru and Turkey. Findings of the International Nosocomial Infection Control Consortium (INICC)

BACKGROUND/OBJECTIVES: Our goal was to determine the extra mortality (EM) of the health care associated infections (HAI) at Neonatal intensive care units (ICU) of hospitals members of the INICC in Argentina, Colombia, Mexico, Peru and Turkey. METHODS: We conducted a case control analysis nested in a prospective cohort study in 8 Neonatal ICUs at 8 hospitals members of the INICC, between 2003 and 2005 (3 years) to analyze the extra mortality of patients with central vascular catheter associated blood stream infection (CVC-BSI), mechanical ventilator associated pneumonia (VAP), and catheter associated urinary tract infection (CA-UTI). All patients were assessed for mortality. Patients who died were called cases, while those who did not die, were called controls. RESULTS: From 2003 to 2005, we enrolled 1,529 patients, representing 14,800 bed days. The overall HAI rate was 7.8 per 100 patients and 8.0 per 1000 bed days. The CVC-BSI rate was 16.1 per 1000 CVC days, the VAP rate was 10.6 per 1000 device days, and CA-UTI rate was 5.3 per catheter days. 201 out of 1,529 (13.1%) patients without HAI died; 22 out of 65 patients (33.8%) with CVC-BSI died, the extra mortality of CVC-BSI was 22.1%, (RR, 2.89; 95% CI, 1.85-4.51; P, 0.0000); 7 out of 29 patients (24.1%) with VAP died, the extra mortality of VAP was 12.4%, (RR, 2.06; 95% CI, 0.97-4.39; P, 0.0557); 0 out of 1 patients (0.0%) with CA-UTI died, the extra mortality of CA-UTI was −11.7%, (RR, 0.00; 95% CI, -undef-; P, 0.7321). CONCLUSIONS: This study has identified that CVC-BSI is significantly associated with higher mortality.

Effekter av oljeutsläpp på övervintrande alfågel Clangula hyemalis vid Hoburgs bank i centrala Östersjön mellan 1996/97 och 2003/04

The Baltic Sea is an important marine area for wintering birds. Surveys in the 1990s showed that more than 25% of the European Long-tailed Duck Clangula hyemalis population wintered at Hoburgs bank and east of Gotland. A shipping route with very frequent traffic goes from southwest Baltic Sea via Öland, Hoburgs bank and east of Gotland to the Gulf of Finland. In year 2000 about 58,500 ships passed east of Öland along this route. Hundreds of oils spills are registered along the route each year. Weekly surveys of oiled birds at southern Gotland and analyses of birds that had drown in fish nets showed that tens of thousands of Long-tailed Ducks were injured by oil each year in central Baltic Sea. Of 998 birds that drowned in fish nets at Hoburgs bank 11.8% were found to have oil in the plumage. There was no clear relationship between the number of oiled birds observed and the number of registered oil spills in different years. Many sea duck have a life history in which variable or low productivity is compensated for by relatively high adult survival. This makes sea duck populations very susceptible to extra adult mortality caused by oil spills.

The attributable cost and length of hospital stay because of nosocomial pneumonia in intensive care units in 3 hospitals in Argentina: A prospective, matched analysis

No information is available on the financial impact of nosocomial pneumonia in Argentina. To calculate the cost of nosocomial pneumonia in intensive care units, a 5-year, matched cohort study was undertaken at 3 hospitals in Argentina. Six adult intensive care units (ICU). Three hundred seven patients with nosocomial pneumonia (exposed) and 307 patients without nosocomial pneumonia (unexposed) were matched for hospital, ICU type, year admitted to study, length of stay more than 7 days, sex, age, antibiotic use, and average severity of illness score (ASIS). The patient's length of stay (LOS) in the ICU was obtained prospectively in daily rounds, the cost of a day was provided by the hospital's finance department, and the cost of antibiotics prescribed for nosocomial pneumonia was provided by the hospital's pharmacy department. The mean extra LOS for 307 cases (compared with controls) was 8.95 days, the mean extra antibiotic defined daily doses (DDD) was 15, the mean extra antibiotic cost was $996, the mean extra total cost was $2255, and the extra mortality was 30.3%. Nosocomial pneumonia results in significant patient morbidity and consumes considerable resources. In the present study, patients with nosocomial pneumonia had significant prolongation of hospitalization, cost, and a high extra mortality. The present study illustrates the potential cost savings of introducing interventions to reduce nosocomial pneumonia. To our knowledge, this is the first study evaluating this issue in Argentina.

Cardiovascular disease as a late complication of end-stage renal disease in children

As in older adults, cardiovascular disease is the most important cause of death in adolescents and young adult patients with end-stage renal disease (ESRD) since childhood. This concerns patients on dialysis as well as transplant patients, despite the fact that a long duration of dialysis during childhood is an extra mortality risk factor. Left ventricular hypertrophy (LVH), aortic valve calcification, and increased arterial stiffness, but not increased arterial intima media thickening, are the most frequently observed alterations in young adult survivors with childhood ESRD. In transplanted patients a concentric LVH as a result of chronic hypertension is mostly observed; in dialysis patients a more asymmetric septal LVH is found as a result of chronic volume overload. These results suggest that in children and young adults with ESRD chronic pressure and volume overload, a high calcium-phosphate product, and chronic inflammation, but not dyslipidemia, play a role in the development of cardiovascular disease.

Ecological importance of snappers in the stability of modeled coastal ecosystems

Based on mass-balanced Ecopath models from tropical shelves and lagoons, the importance of snappers (Family: Lutjanidae) on the ecosystem stability was analyzed. Using ECOSIM software, extra mortality of snappers was simulated and the effects of this mortality on the stability of the whole ecosystem was measured as persistence (time without changes), resilience (recovery capability), and resistance (absorption of disturbance). Simulation of extra mortality lasted 3, 6, and 9 years, and results were analyzed through the next 90 years. Stability showed different patterns for persistence, resilience, and resistance. Resistance decreased when mortality level and disturbance time was increased, persistence only decreased when mortality level was increased, and resilience sometimes decreased when mortality level was increased and other times increased. Reasons of this behavior are discussed. In general, rates of change were larger when the disturbance factor was lower. Lagoons were more resistant and persistent than shelves, however shelves were more resilient. Importance of trophic level, biomass, and consumption rate of snappers as responsible for these results are also discussed.

Chaos to order: preliminary experiments with a population dynamics models of three trophic levels

Hastings and Powell [Ecology 72(3) (1991) 896] produced a new example of a chaotic population system in a simple tri-trophic food chain with Holling type II functional response. Toxin producing phytoplankton (TPP) reduces the grazing pressure of zooplankton. The present note modifies Hastings and Powell model by introducing an extra mortality term in zooplankton population. Our result suggests that chaotic behaviour less likely occurs in a real food chain dynamics.

The Burry shellfishery and oystercatchers: using a behaviour-based model to advise on shellfishery management policy

The Burry inlet, South Wales, supports a licensed cockle Cerastoderma edule fishery and occasional mussel Mytilus edulis fishery. It is also an important overwintering ground for oystercatchers Haematopus ostralegus. In recent years mussels have settled over parts of some cockle beds, preventing cockle fishery there and leading to a request by shellfishers to remove this 'mussel crumble'. Conservation managers, however, were concerned that the mussel crumble might be providing a high-quality food source for the oystercatchers, making its removal detrimental to the birds. A behaviour-based model of oystercatcher feeding on cockles and mussels was parameterised for the inlet and its predictions tested against the distribution of birds across the shellfish beds and the amount of time they spent feeding. The model was then used to explore whether the birds were currently food-limited and what would be the effects on their mortality rate and body condition if the mussel crumble were to be removed, thereby re-exposing underlying cockle beds. The model predicted successfully the proportion of birds feeding on the different types of food and the number of hours birds spent feeding on neap tides. It was predicted that, at current bird population sizes, there would have to be a 50% reduction in shellfish stocks and the areas of shellfish beds from 2000-01 levels to cause noticeable extra emigration or mortality. A given area of mussel bed was predicted to be able to support more birds than the same area of cockle bed, but the greater area of the cockle beds meant that they were more important than mussels in determining the number of birds supported by the inlet. The simulated removal of mussel crumble to expose underlying cockles had no effect on predicted bird mortality and body condition at 2000-01 shellfish stock levels. However, there were circumstances under which the mussel crumble was predicted to increase the inlet's capacity to support birds, particularly when the area of existing cockle and mussel beds was substantially reduced.

Prevalence of 90-days postoperative wound infections after cardiac surgery.

Postoperative wound infections generally cause considerable extra morbidity, mortality and costs. As nowadays length of hospitalization shortens, post-discharge surveillance is important to get reliable information on the prevalence of postoperative wound infections. In this study, the prevalences of sternal wound (SWI) and donor site infections (DSI) during hospitalization as well as, 30 and 90 days after cardiac surgery were studied paying special attention to the contribution of post-discharge surveillance. A total of 1885 patients who underwent cardiac surgery were included in the study and were followed for the prevalence of SWI or DSI up to 90 days postoperatively. Infection data during hospitalization were collected using medical records, bacteriological results and systematic observations of infection control nurses. After discharge from the hospital, data were collected with the help of the out-patient clinic and the family physician. After cardiac surgery, SWI and DSI were diagnosed in 4.7 and 1.5% of patients during hospitalization, in 6.8 and 4.6% at 30 days postoperatively, and in 9.0 and 7.3% of patients at 90 days postoperatively. Of the 90-days postoperative infections rates almost half of SWI and 80% of DSI were diagnosed post-discharge, a result predominantly achieved by the active participation of the family physicians. After 30 and 90 days follow-up of patients after cardiac surgery, additional sternal wound and donor site infections were diagnosed compared with the in-hospital infection rate. Post-discharge surveillance is essential for a reliable assessment of surgical wound infections.

Bet-hedging for variability in life cycle duration: bigger and later-emerging chestnut weevils have increased probability of a prolonged diapause.

Diversified bet-hedging for life cycle duration is defined as within-generation variability in cycle length expressed by a single genotype maximising mean geometric fitness. Such plasticity is not predictive, i.e. it is not a response to cues from the environment that has a predictive value for the decision at hand. In evolutionary terms, diversified bet-hedging is perceived as an adaptation to environmental stochasticity. However, clear evidence of bet-hedging is scarce and exists only for a few desert plant species and one desert bee. In temperate insects, diversified bet-hedging for life cycle duration has been suspected in the chestnut weevil, but proximate factors responsible for individual variation are still unknown. From field experiments, we show that the frequency of the long cycle depends on larval weight and on the date when a larva abandons the fruit, but not on larval burying depth in the soil. Since the two first factors are known to depend on food and temperature and cannot lead to predictive plasticity, we give evidence of bet hedging in this temperate species. Indeed, despite a cost associated with prolonged diapause (extra mortality and loss of reproductive opportunity), a previous study showed that plasticity for life cycle duration, such as discussed in this paper, maximises mean geometric fitness and persistence probability in the chestnut weevil. We propose the hypothesis that the variation in life cycle duration depends on individual variability of metabolic resources such as lipids.

Low birth weight-associated adult hypertension in the rat.

Epidemiological surveys have suggested that intrauterine growth retardation is a risk factor for the development of hypertension in later life. A rat model of intrauterine growth retardation, induced by maternal low-protein diet during the second half of pregnancy, was used to study the relationship between birth weight and adult hypertension. The offspring were born at term and were allowed to nurse normally until weaned to standard chow at 4 weeks of age. They had 15% lower birth weights than control offspring, with complete catch-up growth by age 4 weeks. Both females and males developed progressively worsening hypertension beginning at 8 weeks. The 11-month survival rate was 69% versus 100% in control animals. During the early stages of the hypertension, plasma creatinine was normal, plasma sodium concentration was slightly higher than that of control animals, plasma renin activity was suppressed, and the males had mild proteinuria. Renal function remained normal throughout the 11-month observation period, but plasma renin activity gradually rose above control values. Angiotensin-converting enzyme inhibition by enalapril, begun at 8 weeks of age, was effective in completely normalizing the blood pressure, but did not totally prevent the extra mortality. Sprague-Dawley and Wistar rat strains developed equally severe hypertension after maternal protein deprivation, despite their different susceptibilities to nephrosclerosis with aging. In conclusion, maternal low-protein diet resulted in low birth weight and adult hypertension in the rat. Primary sodium retention and expanded extracellular volume may be critical factors during the development of the hypertension.

Effects of spraying the herbicides 2,4-D and 2,4,5-T on a population of the tortoise Testudo hermanni in southern Greece

A population of the tortoise Testudo hermanni near Olympia in southern Greece was studied by mark-recapture from 1975 to 1984. Part of the site was sprayed with the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) each year from 1980, producing symptoms of poisoning (swollen eyes, fluid discharge from the nose and immobility) in tortoises. Survival rates of tortoises 10 cm or larger were significantly lower in the affected areas, with extra mortality of about 34% year −1, against an annual survival rate of 0.85–0.90 in unaffected areas. Changing population structures showed that juveniles were even more strongly affected, with the proportion of juveniles in samples decreased by half. The population in the sprayed area declined to near zero by 1984, due to mortality rather than to emigration, since more movements were recorded into than out of the affected area. There was no difference in body mass condition between sprayed and unsprayed areas, showing that effects were acute; mortality was not due to starvation from loss of food plants. The scale and pattern of mortality was similar to that from a severe scrub fire; spraying is potentially more catastrophic since often repeated at shorter intervals than burning. Possible physiological mechanisms of death are discussed. The susceptibility of tortoises to 2,4-D and 2,4,5-T (or to associated dioxin impurities) presents a warning for conservation of these late-maturing animals.

Life history elasticity and the population‐level effect of p‐nonylphenol on Daphnia galeata

In order to evaluate population‐level effects of p‐nonylphenol on a cladoceran zooplankton (Daphnia galeata), the chronic effects on survival and reproduction were estimated with partial life table tests, which examined responses in life history characters until 3 weeks after birth. The observed responses in survival and reproduction were converted to reductions of the intrinsic rate of natural increase r. The population level EC50, which is defined as the exposure concentration that reduces r by 50%, was estimated as 16.1 μg l−1. In order to examine the extent to which the population‐level effect in terms of r is influenced by extra mortality in nature, which is induced by predation, starvation, etc., sensitivity (elasticity) measures of the intrinsic rate of natural increase to reductions in age‐specific survival and reproduction were calculated under hypothetical predation schemes. The sensitivities of the intrinsic rate to changes in survival and reproduction invariably decline rapidly after the onset of reproduction irrespective of predation schemes. This implies that partial life cycle tests until 21 days after birth can provide reliable estimates of the population‐level effects.

Do host‐plant requirements and mortality from soil cultivation determine the distribution of graminivorous sawflies on farmland?

1. There are many arthropod species on farmland that are not economic pests but which have an important role in the wider ecology of agricultural ecosystems. Few of these have been studied in detail. This study investigated the factors underlying the distribution of one such group, graminivorous sawflies (Hymenoptera: Tenthredinidae). 2. In a farm survey, sawfly larvae of the genera Dolerus and Pachynematus were over six times more abundant in fields of sown perennial rye‐grass Lolium perenne L. than in fields of spring barley, winter wheat or long‐established grazing pastures. 3. In rearing trials the growth rates and survival of larvae of the two genera were high on L. perenne and low on two cereals, spring barley and winter wheat. Differences were sufficiently marked to have had a strong influence on the distribution of larvae between crops in the field. 4. In an experimental study, nearly twice as many adults emerged from uncultivated as from cultivated ground, suggesting that disturbance of the overwintering prepupae and pupae in the soil caused about 50% extra mortality. This mortality will have reinforced the effects of host‐plant requirements, suppressing sawfly numbers in annually cultivated cereal fields whilst numbers built up in less‐frequently cultivated grass fields. 5. Sawfly abundance is known to have declined on farmland. Our results suggest that changes in patterns of crop rotation have been the main cause of this decline. Farming practice in Britain has moved away from mixed rotations alternating cereals with undersown grass fields. Modern intensive farms grow monocultures of cereal crops or of heavily grazed grass, both poor habitats for sawflies. 6. Increasing insecticide use in cereals has probably been only a minor influence on population abundance of sawflies as wheat and barley fields are not high‐quality habitats. 7. Provision of undisturbed grassy habitats would promote the conservation of graminivorous sawflies on farmland.

Overweight Is Risking Fate

In this paper I have defined obesity and indicated its prevalence, as well as its risks. Body fat and its relation to other body components can be quantitated in many ways. From a practical point of view, the use of body mass or Quetelet index, defined as the ratio of weight (kg) divided by the square of the height (m2) is the most useful. Overweight is defined as a BMI of 25 to 30 kg/m2 and obesity as a BMI above 30 kg/m2. The WHR can provide additional information about the risk of obesity. Using BMI, the prevalence of overweight in the English-speaking countries of Australia, Great Britain, and the United States is almost identical at 24% of women and 31 to 34% of men. In the obese category, there are more Americans (12%) than in the other two countries (6-8%). There is a U-shaped relationship between weight and risk of death. When body weight is increased 20% above average, the extra mortality rises to 20% for men and 10% for women. This extra mortality is associated with an increased death rate from heart disease, hypertension, diabetes mellitus, digestive diseases, and cancer. In addition to an increased risk of death, overweight individuals demand more from their heart, lungs, and musculoskeletal and digestive systems.

Overweight Is Risking Fate

In this paper I have defined obesity and indicated its prevalence, as well as its risks. Body fat and its relation to other body components can be quantitated in many ways. From a practical point of view, the use of body mass or Quetelet index, defined as the ratio of weight (kg) divided by the square of the height (m2) is the most useful. Overweight is defined as a BMI of 25 to 30 kg/m2 and obesity as a BMI above 30 kg/m2. The WHR can provide additional information about the risk of obesity. Using BMI, the prevalence of overweight in the English-speaking countries of Australia, Great Britain, and the United States is almost identical at 24% of women and 31 to 34% of men. In the obese category, there are more Americans (12%) than in the other two countries (6-8%). There is a U-shaped relationship between weight and risk of death. When body weight is increased 20% above average, the extra mortality rises to 20% for men and 10% for women. This extra mortality is associated with an increased death rate from heart disease, hypertension, diabetes mellitus, digestive diseases, and cancer. In addition to an increased risk of death, overweight individuals demand more from their heart, lungs, and musculoskeletal and digestive systems.

The effect of flooding on the recruitment of reed marsh and tall forb plant species

Recruitment of plant species in wetlands dominated by Phragmites australis often results in a zonation of two vegetation types. A development of reed marshes takes place in the shallow flooded parts where the dominant P. australis becomes accompanied by interstitial marsh species. The vegetation on higher elevations becomes dominated by tall forbs. We investigated whether this zonation is related to the effects of flooding on the recruitment of component species of both vegetation types. All but one species had maximum germination at field capacity and germination was strongly reduced in drier soils and flooded soils. Nearly all seedlings of reed marsh species, irrespective of whether they initially supported two or six true leaves, survived eight weeks of total inundation. Survival of tall forbs was however significantly decreased by inundation. At both seedling stages a considerable number of Cirsium arvense lost their leaves when submerged, but all plants were able to recover when drained. Eupatorium cannabinum suffered extra mortality when transferred from flooded to drained conditions, whereas only young seedlings of Epilobium hirsutum died. Of all investigated species E. hirsutum was the only one with a significantly increased stem length after one week of submergence. Root porosities did not differ between reed marsh species and tall forbs but stem porosities of the reed marsh species Mentha aquatica and Lycopus europaeus were significantly higher than those of the tall forbs C. arvense and E. cannabinum. It was concluded that both reed marsh species and tall forbs require lowered water levels for germination. Flooding during the seedling stage will assign species to their position on the elevation gradient. Reed marsh species establish at lower elevations because they are best able to survive flooding and because their higher stem porosities allows them to withstand higher levels of partial submergence.

A nosocomial infection surveillance network in Belgian ICUs: methodology and feedback

The risk for nosocomial infections (NI) in ICUs is five to 10 times higher than in other hospital care units, causing extra morbidity, mortality and costs. Previous studies have shown a significant decrease in NI after the set up of effective surveillance programs. If this surveillance is performed in a multicentric setting, the results from the aggregate database can offer an added value to the local results. The most important element is the production of meaningful feedback reports, allowing each ICU to evaluate its own situation as compared with the aggregate results of the whole studied group.

Increased Daily Work Precipitates Natural Death in the Kestrel

1. Costs of reproduction have been assessed experimentally by measuring subsequent survival and reproduction of parent animals raising enlarged and reduced numbers of offspring. Reported effects on survival have so far always referred to local survival of marked individuals in the study population. They do not provide definitive proof of a cost of reproduction, since reduced local survival may be due either to reduced survival or to an increased tendency to emigrate from the study area. Therefore, it is important to assess mortality rates in connection with brood size experiments. 2. We report an analysis of the time of death in 63 cases where kestrels, Falco tinnunculus L. had raised broods of manipulated size and were subsequently reported freshly dead. 60% of the parents raising two extra nestlings were reported dead before the end of the first winter, compared to 29% of those raising control or reduced broods. This result confirms our interpretation of the manipulation effects on local survival as due to mortality rather than emigration. The extra mortality occurred in the winter following the brood enlargement. 3. Kestrel parents in these experiments have been shown to adjust their daily energy expenditure to the modified brood size. Increased parental effort in this species thus entails an increased risk of death half a year later.

Long-term health risk of primary hyperparathyroidism: the effect of surgery.

Primary hyperparathyroidism is a common disease but 90% of sufferers remain undetected. In elderly women its prevalence is about 1%. The disease can cause severe hypercalcaemia and lead to life-threatening symptoms. However, the majority of cases represent milder forms of hyperparathyroidism with minimal symptoms or no symptoms at all, and slight hypercalcaemia which does not progress during follow-up. Surgery is the only effective treatment of primary hyperparathyroidism and most of the symptoms respond favourably to surgery. Nevertheless, the role of surgery has been controversial in the treatment of mini-symptomatic patients. Recently it has become evident that primary hyperparathyroidism is associated with increased mortality due mainly to cardiovascular diseases, and it has been shown that surgical treatment is able to diminish or even eliminate this risk of premature death. The extra mortality is connected also to the mild and nonprogressive forms of the disease, and it seems to have a strong correlation with the duration of the disease. This aspect favours active treatment at an early stage of the disease. Conservative treatment can be considered only in old patients with mild and stable clinical course. Primary hyperparathyroidism is an important risk factor causing morbidity and mortality.

Usefulness of continuous transesophageal echocardiographic (TEE) monitoring during the weaning period from cardiopulmonary bypass in children

The arterial switch operation (ASO) has become the procedure of choice for the transposition of great arteries (TGA) and double outlet right ventricle (DORV) Taussig – Bing anomaly. The improvement in diagnosis, surgical techniques, and peri-operative management resulted in improvement in mortality and morbidity. The objective of this study was to evaluate the preoperative demographic, morphological and operative variables that affect the early outcome of the arterial switch procedure.This is a retrospective study of 85 patients who underwent ASO in children's cardiovascular program (Deutsches Herzzentrum, Berlin) between august 2012 and October 2015. It included all patients underwent ASO for D-TGA or DORV. Preoperative, operative and postoperative variable were studied and analyzed for their correlation to unfavorable early postoperative outcome [mortality or high morbidity such as need for extra-corporeal membrane oxygenation (ECMO), occurrence of coronary events and reoperation or catheter intervention].There were 3 (3,5%) early deaths in our study; 2 due to coronary ischemic events and one due to low cardiac output. Five coronary events and 17 early reoperations or catheter interventions were recorded. Several risk factors were associated with unfavorable outcome as low birth weight patients (P-value = 0.03), preoperative corticosteroid intake (P-value = 0,046), intramural course of coronary arteries (P-value = 0.04), but retropulmonary course and mono-coronary ostium had no correlation to unfavorable outcome. There was no correlation between having simultaneous operative procedure and the unfavorable outcome (P-value = 0.9). The predictors of unfavourable outcome included prolonged ischemic time (P-value = 0.000), prolonged cardiopulmonary bypass time, prolongation of the ventilation time and increasing amount of postoperative bleeding (P-value = 0,000). The increase in the ischemic time had a strong statistical correlation with the increased inotropic support in the postoperative period (P-value = 0.002).ASO can be performed without excess mortality. Simultaneous aortic arch repair can be done with no extra mortality. Prematurity, low birth weight, Taussig-Bing anomaly, intramural coronary artery course and some other coronary abnormalities, aortic cross clamp time and bypass time were risk factors for unfavourable outcome.