Mathematical model describing erythrocyte sedimentation rate. Implications for blood viscosity changes in traumatic shock and crush syndrome

BACKGROUND: The erythrocyte sedimentation rate (ESR) is a simple and inexpensive laboratory test, which is widespread in clinical practice, for assessing the inflammatory or acute response. This work addresses the theoretical and experimental investigation of sedimentation a single and multiple particles in homogeneous and heterogeneous (multiphase) medium, as it relates to their internal structure (aggregation of solid or deformed particles). METHODS: The equation system has been solved numerically. To choose finite analogs of derivatives we used the schemes of directional differences. RESULTS: (1) Our model takes into account the influence of the vessel wall on group aggregation of particles in tubes as well as the effects of rotation of particles, the constraint coefficient, and viscosity of a mixture as a function of the volume fraction. (2) This model can describe ESR as a function of the velocity of adhesion of erythrocytes; (3) Determination of the ESR is best conducted at certain time intervals, i.e. in a series of periods not exceeding 5 minutes each; (4) Differential diagnosis of various diseases by means of ESR should be performed using the aforementioned timed measurement of ESR; (5) An increase in blood viscosity during trauma results from an increase in rouleaux formation and the time-course method of ESR will be useful in patients with trauma, in particular, with traumatic shock and crush syndrome. CONCLUSION: The mathematical model created in this study used the most fundamental differential equations that have ever been derived to estimate ESR. It may further our understanding of its complex mechanism

Injury in China: a systematic review of injury surveillance studies conducted in Chinese hospital emergency departments

<p>Abstract</p> <p>Background</p> <p>Injuries represent a significant and growing public health concern in China. This <it>Review </it>was conducted to document the characteristics of injured patients presenting to the emergency department of Chinese hospitals and to assess of the nature of information collected and reported in published surveillance studies.</p> <p>Methods</p> <p>A systematic search of MEDLINE and China Academic Journals supplemented with a hand search of journals was performed. Studies published in the period 1997 to 2007 were included and research published in Chinese was the focus. Search terms included emergency, injury, medical care.</p> <p>Results</p> <p>Of the 268 studies identified, 13 were injury surveillance studies set in the emergency department. Nine were collaborative studies of which eight were prospective studies. Of the five single centre studies only one was of a prospective design. Transport, falls and industrial injuries were common mechanisms of injury. Study strengths were large patient sample sizes and for the collaborative studies a large number of participating hospitals. There was however limited use of internationally recognised injury classification and severity coding indices.</p> <p>Conclusion</p> <p>Despite the limited number of studies identified, the scope of each highlights the willingness and the capacity to conduct surveillance studies in the emergency department. This <it>Review </it>highlights the need for the adoption of standardized injury coding indices in the collection and reporting of patient health data. While high level injury surveillance systems focus on population-based priority setting, this <it>Review </it>demonstrates the need to establish an internationally comparable trauma registry that would permit monitoring of the trauma system and would by extension facilitate the optimal care of the injured patient through the development of informed quality assurance programs and the implementation of evidence-based health policy.</p

Temperature and Resource Availability May Interactively Affect Over-Wintering Success of Juvenile Fish in a Changing Climate

The predicted global warming may affect freshwater systems at several organizational levels, from organism to ecosystem. Specifically, in temperate regions, the projected increase of winter temperatures may have important effects on the over-winter biology of a range of organisms and especially for fish and other ectothermic animals. However, temperature effects on organisms may be directed strongly by resource availability. Here, we investigated whether over-winter loss of biomass and lipid content of juvenile roach (Rutilus rutilus) was affected by the physiologically relatively small (2-5°C) changes of winter temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC), under both natural and experimental conditions. This was investigated in combination with the effects of food availability. Finally, we explored the potential for a correlation between lake temperature and resource levels for planktivorous fish, i.e., zooplankton biomass, during five consecutive winters in a south Swedish lake. We show that small increases in temperature (+2°C) affected fish biomass loss in both presence and absence of food, but negatively and positively respectively. Temperature alone explained only a minor part of the variation when food availability was not taken into account. In contrast to other studies, lipid analyses of experimental fish suggest that critical somatic condition rather than critical lipid content determined starvation induced mortality. Our results illustrate the importance of considering not only changes in temperature when predicting organism response to climate change but also food-web interactions, such as resource availability and predation. However, as exemplified by our finding that zooplankton over-winter biomass in the lake was not related to over-winter temperature, this may not be a straightforward task

Risk factors for recurrence after repair of enterocutaneous fistula.

ObjectivesTo assess outcomes after repair of enterocutaneous fistulae (ECF) and identify factors that predict mortality and recurrence.DesignRetrospective study.SettingUniversity hospital.PatientsOne hundred thirty-five patients undergoing ECF repair between 1989 and 2005.Main outcome measuresMortality and recurrence of ECF.ResultsDefinitive operation for ECF was attempted in 135 patients. Mortality was 8%, recurrence was 17%, and 84% of patients eventually survived with a closed fistula. The primary determinant of mortality was ECF recurrence (odds ratio [OR], 6.7; 95% confidence interval [CI], 1.9-23.4). Factors independently associated with ECF recurrence by multivariate logistic regression included the presence of inflammatory bowel disease (OR, 4.9; 95% CI, 1.5-16.1), interval between diagnosis and operation of 36 weeks or longer (OR, 5.4; 95% CI, 1.8-16.4), location of fistulae in the small intestine (OR, 9.8; 95% CI, 1.7-57.6), and resection with stapled anastomosis (OR, 4.1; 95% CI, 1.3-13.2). Recurrence of ECF was 35% with resection and stapled anastomosis, 22% with simple oversew, and 11% with resection and hand-sewn anastomosis. Recurrence of ECF was 12% when operation was performed prior to 36 weeks from diagnosis, compared with 36% if performed at or beyond 36 weeks.ConclusionsThe primary determinant of mortality after ECF repair is a failed operation leading to recurrence of the fistula. Risk factors for ECF recurrence include inflammatory bowel disease, fistula located in the small intestine, an interval of 36 weeks or longer between diagnosis and operation, and resection with stapled anastomosis

Risk factors for recurrence after repair of enterocutaneous fistula.

ObjectivesTo assess outcomes after repair of enterocutaneous fistulae (ECF) and identify factors that predict mortality and recurrence.DesignRetrospective study.SettingUniversity hospital.PatientsOne hundred thirty-five patients undergoing ECF repair between 1989 and 2005.Main outcome measuresMortality and recurrence of ECF.ResultsDefinitive operation for ECF was attempted in 135 patients. Mortality was 8%, recurrence was 17%, and 84% of patients eventually survived with a closed fistula. The primary determinant of mortality was ECF recurrence (odds ratio [OR], 6.7; 95% confidence interval [CI], 1.9-23.4). Factors independently associated with ECF recurrence by multivariate logistic regression included the presence of inflammatory bowel disease (OR, 4.9; 95% CI, 1.5-16.1), interval between diagnosis and operation of 36 weeks or longer (OR, 5.4; 95% CI, 1.8-16.4), location of fistulae in the small intestine (OR, 9.8; 95% CI, 1.7-57.6), and resection with stapled anastomosis (OR, 4.1; 95% CI, 1.3-13.2). Recurrence of ECF was 35% with resection and stapled anastomosis, 22% with simple oversew, and 11% with resection and hand-sewn anastomosis. Recurrence of ECF was 12% when operation was performed prior to 36 weeks from diagnosis, compared with 36% if performed at or beyond 36 weeks.ConclusionsThe primary determinant of mortality after ECF repair is a failed operation leading to recurrence of the fistula. Risk factors for ECF recurrence include inflammatory bowel disease, fistula located in the small intestine, an interval of 36 weeks or longer between diagnosis and operation, and resection with stapled anastomosis