Risk stratification models fail to predict hospital costs of cardiac surgery patients.

BACKGROUND: The aim of this prospective study was to determine if commonly used risk stratification models can predict total hospital costs in cardiac surgical patients. METHODS: Between October 1st and December 31st 2003, all consecutive adult patients undergoing cardiac surgery on CPB at our institution were classified using seven risk stratification scoring systems: EuroSCORE, Cleveland, Parsonnet, Ontario, French, Pons, and CABDEAL. Total hospital costs for each patient were calculated on a daily basis including preoperative diagnostic tests, operating room costs, disposable materials, drugs, blood components, costs for personnel, and hospital fixed-costs. Linear regression analysis was used to determine the correlation between costs and the seven risk stratifications models as well as length of stay (LOS) on ICU. The Spearman correlation coefficient was calculated from the regression line, and an analysis of residuals was performed to determine the quality of the regression. RESULTS: A total of 252 patients were operated for CABG (n=175), valve (n=39), CABG plus valve (n=21), thoracic aorta (n=13) and miscellaneous (2 myxoma, 1 ASD, 1 pulmonary embolism). Mean age of the patients was 66.0+/-11.4 years, 29.4% were female. LOS on ICU was 3.3+/-6.3 days and the 30-day mortality rate was 6.7%. Spearman correlation between the seven risk stratification models and hospital costs was below r=0.32 (p=0.0001), but was r=0.94 (p=0.0001) between ICU LOS and costs. CONCLUSIONS: Total hospital costs can be identified by length of ICU stay. None of the common risk stratification models accurately predicted total hospital costs in cardiac surgical patients.

The effects of long-term cadmium exposure on the growth and survival of juvenile bull trout (Salvelinus confluentus).

Bull trout (Salvelinus confluentus) have been listed recently as threatened in the United States under the federal Endangered Species Act. This species currently resides, or historically resided, in several waterways that either are impacted or are under threat of impact from metals mining activities. We conducted a 55-day sub-chronic (i.e. sublethal) cadmium (Cd) exposure in water at 30 mg l(-1) (as CaCO(3)) hardness, pH 7.5, and 8 degrees C. Exposures were conducted using six replicate exposure tanks for each of the six treatments (five Cd concentrations and one control). Measured Cd concentrations were <0.013 (control), 0.052, 0.089, 0.197, 0.383, and 0.786 microg Cd l(-1). Exposure to 0.786 microg Cd l(-1) caused increased mortality (37%) and reduced growth (28% reduction in weight change) in fish exposed for 55 days. All Cd exposure concentrations caused significant whole body accumulation of Cd compared with controls. Our results indicate that even though fish are significantly accumulating Cd in each non-control treatment, growth reductions in bull trout occurred only at Cd concentrations that also caused significant mortality. The Cd concentration that reduced growth and survival in this long-term exposure (0.786 microg Cd l(-1)) is greater than the recently-revised US federal aquatic life criteria (ALC) value for the corresponding hardness concentration (ALC=0.62 microg Cd l(-1) for acute effects and 0.11 microg Cd l(-1) for chronic effects).

Relationship between exposure duration, tissue residues, growth, and mortality in rainbow trout (Oncorhynchus mykiss) juveniles sub-chronically exposed to copper.

We conducted a 56-day sub-chronic test on the effects of Cu on rainbow trout (Oncorhynchus mykiss) fry at a nominal water hardness of 100 mg l(-1) (as CaCO(3)). Response measures were growth, whole body Cu concentrations, and mortality. Significant mortality was observed in fish exposed to 54.1 microg Cu l(-1) (47.8%) and 35.7 microg Cu l(-1) (11.7%). Growth was dose-dependent over the range of Cu treatments (0-54 microg Cu l(-1)), and was modeled as a function of Cu exposure concentration and exposure duration. Calculated inhibition concentrations (based on change in wet weight through a 56-day Cu exposure) were IC(50)=54.0 microg Cu l(-1), IC(20)=21.6 microg Cu l(-1), IC(10)=10.8 microg Cu l(-1), and IC(01)=1.1 microg Cu l(-1). Measured whole body Cu was also dose-dependent, and growth of trout fry was readily modeled as a function of tissue Cu and exposure duration. This model was virtually identical to a model previously developed for rainbow trout exposed to Cu at a hardness of 25 mg l(-1). Following the 56-day exposure period, we performed a 96-h acute challenge to Cu and Cd to evaluate the effects of Cu acclimation on acute Cu and Cd toxicity. Sensitivity to Cu was dependent on the 'acclimation dose'; trout previously held in control aquaria (i.e. not acclimated to Cu) suffered over 80% mortality, whereas trout previously exposed to 35.7 microg Cu l(-1) for 56 day suffered 20% mortality. These fish also showed somewhat reduced sensitivity to Cd, suggesting acclimation to Cu can enhance tolerance to other metals. Finally, the relationship between growth response and hardness (derived from several studies) appeared to have a different slope than the hardness relationship previously observed for lethality responses.

Surgical repair of right-atrial aneurysm.

Atrial fibrillation and embolic events are the most common clinical symptoms of congenital right- or left-atrial aneurysms. We report an a case of righ-atrial aneurysm, in a patient with typical history of atrial fibrillation and history of stroke. The aneurysm was resected, but the patient suffered from acute embolic occlusion of the left anterior descending coronary artery on the fourth postoperative day despite of systemic heparinization with 300 IU/kg bw per 24 hours.

Cardiac surgery in patients with end-stage renal disease: 10-year experience.

BACKGROUND: End-stage renal disease is known to be an important risk factor complex for cardiac operations performed with cardiopulmonary bypass. METHODS: To investigate the influence of preoperative status on perioperative mortality and morbidity, we retrospectively analyzed data from 65 patients (20 women and 45 men with a mean age of 58.8+/-10.0 years [+/-standard deviation]) with end-stage renal disease who were on dialysis and who underwent a cardiac surgical procedure between 1988 and 1998. RESULTS: Fifty-one percent of the patients had isolated coronary artery bypass grafting, 35% had replacement or reconstruction of one valve or two valves, and 14% underwent combined coronary artery bypass grafting and valve replacement. The perioperative mortality rate was 13.8% with 78% (7 of 9) of deaths occurring in patients having a valve procedure. Six of the 9 patients who died had compromised left ventricular function preoperatively, and all 9 were in New York Heart Association class III or IV. Mean preoperative duration of dialysis was longer (80+/-70 months) in the 9 patients who died compared with that in the surviving 56 patients (45+/-49 months) (p = 0.05). We found dyspnea at rest, duration of dialysis of 60 months or more, combined procedures (coronary artery bypass grafting and valve operation), and New York Heart Association class IV to be associated with a higher relative risk for perioperative death. Neither angina pectoris nor isolated coronary artery bypass grafting was associated with increased relative risk for perioperative death. However, after a cardiac operation, mortality in patients with end-stage renal disease was substantially higher than in those with normal renal function. CONCLUSIONS: These data are comparable with those in the literature and possibly suggest that both indications and referral for surgical intervention have been delayed in patients who have end-stage renal disease combined with coronary artery disease, valve disease, or both. The delay may contribute to the relatively high perioperative mortality.

Cardiac myocytes of hearts from patients with end-stage dilated cardiomyopathy do not contain Borrelia burgdorferi DNA.

OBJECTIVE: To determine if end-stage dilated cardiomyopathy (DCM) is associated with the presence of Lyme disease causing spirochete Borrelia burgdorferi in the myocardium, we used nested polymerase chain reaction to detect B burgdorferi DNA in myocardial samples from explanted hearts of patients with end-stage DCM. Patients originated from endemic areas for Lyme disease (Bavaria, Lower Saxony, Germany). METHODS AND RESULTS: This was a retrospective study. Polymerase chain reaction was used to detect the specific B burgdorferi recombinant outer surface protein A (OspA) gene in myocardial tissue from 68 patients with end-stage DCM who had undergone heart transplantation. The clinical history of Lyme disease, the presence of Borrelia burgdorferi OspA, and antibodies against OspA in myocardial tissue and serum were investigated. B burgdorferi DNA was not detected in any of the 68 human hearts. Immunoglobulin G antibodies against specific B burgdorferi antigens were observed in 3 (12.5%) of 24 patients. In contrast, 4 hearts from rats experimentally infected with B burgdorferi were all positive for OspA DNA as measured by polymerase chain reaction. CONCLUSION: Our data show that cardiac myocytes of hearts obtained from subjects with end-stage DCM did not contain B burgdorferi DNA as investigated by polymerase chain reaction. However, B burgdorferi shows a high affinity for myocardial tissue as shown by the animal studies, indicating that myocardial infections are nevertheless possible.

An improved postembedding technique for ultrastructural studies of lectin binding sites in bone marrow: a critical evaluation.

Little is known about the ultrastructural localization of lectin binding sites in human bone marrow tissue. This is probably due to the lack of suitable methods yielding both satisfactory tissue preservation and optimal labelling results. For this reason, we developed a modified postembedding technique for electron-microscopic studies of the glycosylation pattern of haematopoietic cells. Fixation with a 2.5% glutardialdehyde solution was shown to be an important prerequisite and could be even improved by postfixation with tannic acid and uranyl acetate. In particular, embedding with the acrylic resin UnicrylR (Bioacryl) resulted in an optimal ultrastructural preservation of bone marrow tissue. Employment of this hydrophilic resin in combination with a two-step labelling method which included digoxigenin-conjugated Concanavalin A (Con A) followed by ultrasmall anti-digoxigenin-gold and silver amplification, delivered a highly specific staining pattern. Our results with this lectin in different bone marrow cells revealed nuclear and cytoplasmic membranes, rough endoplasmic reticulum as well as granules to display reactivity of varying intensity. These findings underline the validity of our method, for they confirm and extend formerly reported histochemical and biochemical evaluations on the cellular binding sites of Con A.