The effect of renal impairment and obesity on anti-Xa peak and trough levels in patients receiving therapeutic doses of nadroparin: a comparison with control patients

PURPOSE

Anti-Xa peak level monitoring is recommended during LMWH treatment in renal impairment or obesity. The trough level has been proposed as marker for bleeding. We studied the influence of renal impairment and obesity on anti-Xa levels.

METHODS

Peak and trough levels were collected during therapeutic nadroparin treatment in patients with renal impairment, obese patients, and controls. 27 patients (n = 68 samples) were evaluated and combined with published data (n = 319 samples from 35 patients) using population pharmacokinetic (popPK) modelling.

RESULTS

Median peak level was 0.44 and 0.95 IU/mL in renal impairment with and without dose reduction and 0.60 and 0.43 IU/mL in obesity and controls, respectively. Trough levels were < 0.5 IU/mL in all patients with renal impairment with dose reduction and in 5/6 control patients. In the popPK model, total body weight and eGFR were covariates for clearance and lean body weight for distribution volume. Model-based evaluations demonstrated peak levels below the therapeutic window in controls and increased levels in renal impairment. Dose reductions resulted in a different effect on peak and trough levels. Obese patients (BMI up to 32 kg/m2) had similar levels upon weight-based dosing.

CONCLUSION

In renal impairment, anti-Xa peak levels after dose reduction are comparable to those in controls. Weight-based dosing is suitable for obese patients. Aiming for peak levels between 0.6 and 1.0 IU/mL in these patients would result in overexposure compared to controls. Considering the association of trough levels and bleeding risk and our findings, trough monitoring seems to be a suitable parameter to identify nadroparin accumulation.

Hypothyroidism in the rat results in decreased soleus motoneurone soma size

Adult female rats were thyroidectomized. After an average of 17 weeks, horseradish peroxidase (HRP) was injected into the right side soleus muscle. Two days later, left side soleus muscle properties were recorded and muscles and spinal cord were removed for further histological measurements. Soleus muscles from hypothyroid rats no longer contained type IIA fibers. Contraction and half-relaxation times of twitches had increased significantly compared to control rats. The average cross-sectional surface areas of HRP-labeled soleus motoneurones from hypothyroid rats were slightly but significantly smaller than those of control rats. A similar decrease in size was found for other (presumed moto-) neurones lying ventrolaterally to the soleus motor nucleus. It is concluded that changes in the soleus muscle fiber composition, as caused by lowered levels of thyroid hormone, are paralleled by corresponding changes in the size of its motoneurones and also of other spinal (moto)neurones.

Application of the problem-based learning model for continuing professional education: a continuing medical education program on managed care issues--Part II

Physicians must incorporate concepts of practice management and knowledge of managed care into their practices. Managed care presents an immediate and challenging opportunity to providers of continuing medical education to offer effective educational programs for physicians on managed care issues. In this exploratory research, the problem-based learning model was used to develop a continuing medical education program that would offer an interactive and effective method for teaching physicians about managed care. Problem-based learning is a departure from the traditional lecture format of continuing medical education programs because it is designed for small groups of self-directed learners who are guided by a faculty facilitator. Although only a small number of participants participated in this program, the findings offer important considerations for providers of continuing medical education. For example, participants reported increased confidence in their knowledge about managed care issues. Participants also clearly indicated a preference for the small group, interactive format of the problem-based learning model.

Theoretical framework for implementing a managed care curriculum for continuing medical education--Part I

Healthcare reform has created a new working environment for practicing physicians, as economic issues have become inseparably intertwined with clinical practice. Although physicians have recognized this change, and some are returning to school for formal education in business and healthcare administration, formal education may not be practical or desirable for the majority of practicing physicians. Other curriculum models to meet the needs of these professionals should be considered, particularly given the growing interest in continuing education for physicians in the areas of managed care and related aspects of practice management. Currently, no theory-based models for implementing a managed care curriculum specifically for working physicians have been developed. This paper will integrate diffusion theory, instructional systems design theory, and learning theory as they apply to the implementation of a managed care curriculum for continuing medical education. Through integration of theory with practical application, a CME curriculum for practicing physicians can be both innovative as well as effective. This integration offers the benefit of educational programs within the context of realistic situations that physicians can apply to their own work settings.

Staining myelin and myelin-like degradation products in the spinal cords of chronic experimental allergic encephalomyelitis (Cr-EAE) rats using Sudan black B staining of glycol methacrylate-embedded material

A high-resolution light-microscopical (HRLM) technique is described to visualize myelin, and macrophages containing degradation products of myelin, in the spinal cords of chronic relapsing experimental allergic encephalomyelitis (Cr-EAE) rats. This HRLM technique was developed to optimalize the correlation between nuclear magnetic resonance (NMR) characteristics and histopathological images in this well-established animal model for multiple sclerosis (MS). Spinal cords were fixed by perfusion with a combination of cacodylate-buffered glutaraldehyde and formaldehyde, post-fixed in Dalton's fixative (containing osmium tetroxide), rinsed in water, processed in ethanol, acetone, and embedded in glycol methacrylate resin (Technovit 7100/HistoResin). Semi-thin sections were stained with Sudan Black B and counterstained with Cresyl Fast Violet, resulting in black staining of myelin and its degradation products, with blue/violet staining of demyelinated axons and other tissue elements. These dyes were selected with the aid of a numerical model of staining, which took both access and lipophilicity into account. The staining procedure is simple and highly reproducible. The resulting images are contrast rich, and combine excellent morphology with a high degree of lipid retention.