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Biomedical subjects

K A Mitchell

Publications and source records attributed to K A Mitchell.

26 records · Page 2Linked to original sources
PubMed1991

The effects of recombinant desulphatohirudin on arterial thrombosis in rats.

The role of thrombin in the formation of arterial thrombi is poorly understood. With the new availability of the specific thrombin inhibitor, recombinant desulphatohirudin, in large quantities this is now under investigation. A new model of arterial thrombosis in rats is described where a thrombus is formed on a mechanically injured vessel in vivo. Both platelet and fibrin deposition is inhibited by a recombinant hirudin (CGP 39393) at doses which prolong the activated partial thromboplastin time (APTT) to no more than 3-4 times the control level. In contrast, both unfractionated heparin and Fragmin only inhibit thrombosis when the APTT is excessively prolonged (i.e. to greater than 15 times the control value). It is concluded that CGP 39393 is an effective antithrombotic in arterial thrombosis at lower levels of anticoagulation than either heparin or Fragmin.

Animals↗
PubMed1990

The Royal Naval Medical Stores for Service Afloat: a prospective quantitative study.

The contents of the scale of Medical Stores for Service Afloat must provide adequate quantities of drugs to allow proper patient care in a variety of situations often remote from specialist support. The overall make up of the scale is difficult to envisage outside the context for which it was conceived. This study was designed to assess the accuracy of the make up of the scale in three RN ships over a six-month period during a detached deployment. During this time the usage of all consumable items was specifically recorded and the outcome subjected to rigorous analysis in relation to the present scale. The results of the study indicate that in the case of both HMS Ark Royal (AR) and the two smaller ships HMS Edinburgh and HMS Sirius (ES) the quantities of drugs in the majority of cases are in excess of requirements. Of the 290 (AR) and 266 (ES) individual drugs 68% and 40% respectively could safely be reduced by varying amounts, whereas only 7.6% and 4.9% respectively needed to be increased. Furthermore, when these changes are costed the savings that result are 7806 pounds for the AR scale and 1532 pounds for the ES scale. Extrapolation of these figures across the surface fleet produces an overall saving on the costs of drugs of over 87,000 pounds.

Cost Control↗
PubMed1989

Recombinant desulphatohirudin (CGP 39393) anticoagulant and antithrombotic properties in vivo.

The effects of the newly available biotechnology product, recombinant desulphatohirudin (CGP 39393) have been investigated in rats. This highly potent and selective thrombin inhibitor exhibited marked anticoagulant properties with controllable titration of anticoagulant effect, as measured by activated partial thromboplastin time (APTT), up to nearly four times control values. Furthermore, CGP 39393 exhibited impressive antithrombotic activity in vivo. In an arteriovenous shunt model of thrombus formation on a cotton-thread, the compound was capable of complete inhibition of thrombus development (ED50 = 0.3 mg/kg i.v. and 1.0 mg/kg s.c.). Venous stasis thrombosis was also highly susceptible to inhibition by CGP 39393 (ED50 = 0.01 mg/kg i.v. and 0.45 mg/kg s.c.). Comparison of the anticoagulant and antithrombotic activities of the compound shows that potent antithrombotic effects (83-97% inhibition in the rat shunt model) are achieved within the generally acceptable range of anticoagulation. These results suggest a clear potential for this new agent in the clinical treatment of thrombotic disease.

Animals↗
PubMed1985

Prospective randomized evaluation of two methods of drawing coagulation studies from heparinized arterial lines.

To establish a standardized protocol of obtaining coagulation studies from arterial lines without heparin contamination, two methods were evaluated in a prospective randomized fashion for accuracy by comparing PT and aPTT results with simultaneous samples drawn by venipuncture. Fifty paired samples were obtained, 25 by method A and 25 by method B, from critically ill patients in the surgical intensive care unit at City of Memphis Hospital. Analyses of PT and aPTT from these samples revealed a close statistical correlation with the venous controls and no clinically significant difference between the samples.

Blood Coagulation Tests↗
PubMedDate not supplied

Mortality in patients with bilateral femoral fractures.

OBJECTIVES: To determine and compare the mortality rates of patients with bilateral versus unilateral femoral fractures and to determine the contribution of the femoral fracture to, and identify risk factors for, such mortality. STUDY DESIGN: Retrospective analysis using trauma registry data on consecutive blunt trauma patients with unilateral (800 patients, group I) or bilateral (eighty-five patients, group II) femoral fractures. METHODS: Univariate data analysis was performed to compare the groups' ages, Injury Severity Scores, Glasgow Coma Scale values, mortality, and the presence of adult respiratory distress syndrome (ARDS). Logistic regression analysis was performed to determine variables statistically associated with mortality. RESULTS: Group II patients had a significantly higher Injury Severity Score (30.2 versus 24.5, p < 0.001), lower Glasgow Coma Scale value (12.3 versus 13.1, p = 0.05), higher mortality rate (25.9 vs 11.7%, p < 0.001), and higher incidence of ARDS (15.7 versus 7.27%, p = 0.014) than group I patients. Group II patients also had significantly more closed head injuries, open skull fractures, intraabdominal injuries requiring surgical intervention, and pelvic fractures; the rates of thoracic injury were similar. Regression analysis of variables evident on admission revealed a significant correlation between bilateral femoral fractures and death; however, other factors (shock, closed head injury, and thoracic injury) had much stronger correlations with mortality. CONCLUSIONS: Patients with bilateral femoral fractures have a significantly higher risk of death, ARDS, and associated injuries than patients with unilateral femoral fractures. This increase in mortality is more closely related to associated injuries and physiologic parameters than to the presence of bilateral femoral fractures. The presence of bilateral femoral fractures should alert the clinician to the likelihood of associated injuries, a higher Injury Severity Score, and the potential for a more serious prognosis.

Adult↗
PubMedDate not supplied

Standardized TPN order form reduces staff time and potential for error.

The Nutrition Support Team developed a standardized parenteral nutrition (PN) order form for the newly introduced total nutritional admixture (TNA) system. The new order form (TNA-Form) is oriented toward the physician, providing prescription guidelines and standing orders for the initiation and discontinuation of PN. The form replaced an older one (TPN-Form) originally designed for pharmacy use. Over two 4-month periods, the usefulness of the new TNA-Form was compared with that of the old TPN-Form, with reviews of the completeness and safety of all PN prescriptions. When prescription errors, errors of dosage, or errors of omission occurred, the pharmacist queried the physician. The number and the nature of the prescription errors per PN order were recorded daily for each patient. With the old TPN-Form, there were 634 prescription errors in 682 patients (93% total error rate). This rate decreased to 116 prescription errors in 1017 patients (11% total error rate) with the new TNA-Form. There were fewer errors in all categories concerning glucose and lipid concentrations, trace elements and vitamins, the use of heparin, infusion rate, and electrolyte concentrations. It was concluded that the new TNA-Form led to a substantial decrease in overall PN prescription errors, particularly errors of omission, resulting in safer, more efficacious, and more uniform provision of PN. The new TNA-Form provided the secondary benefit of an educational tool for housestaff. Because of its broad-based benefits, it was subsequently adopted by two other hospitals in the community.

Drug Prescriptions↗
PubMedDate not supplied

Partners in nursing education.

In this article, the authors present the efforts of several hospitals in a large southern city to collaborate on continuing education projects to meet the needs of the nursing staff. In 1985, four hospitals formed a health maintenance organization. An outgrowth was the formation of a critical care consortium whose main objective was to develop an entry level critical care course. The authors discuss the development of this course, the advantages and disadvantages of a partnership, and the results of 7 years of experience.

Critical Care↗