• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.575-583
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• 1993

Background: Mediastinal masses are not uncommon, and an overall incidence of one case per 100,000 population per year in individuals of all ages and with no difference in sex incidence may be a reasonable estimation. At least half of all mediastinal masses are asymptomatic and this proportion has increased in recent decades with wider use of screening chest roentgenography. Symptoms in patients with mediastinal mass lesions are usually due to compression or invasion of nearby intrathoracic structures. Most mediastinal mass lesions have characteristic predilectional locations. The basic focus of diagnostic evaluation is an orderly preparation for obtaining a tissue diagnosis but even lesions discovered to be benign must generally be removed. Seldom is this status known for certain preoperatively. In additaion, benign tumors may continue to enlarge, thus compromising vital organs; they may rupture, hemorrhage, become infected or have the possibility of various malignant degeneration. Therefore, all mediastinal masses must be surgically removed whether they are malignant or benign. Methods: We reviewed the medical records of 344 cases previously confirmed as mediastinal tumors or cysts from January, 1960 to August, 1992 and investigated the clinical findings. Results: Neurogenic tumors were the most common(24.7%) and thymomas were distinctively increased recently. Overall ratio between males and females was 1.1:1 and age distribution was relatively even among all age groups. Predilectional sites were posterior for neurogenic tumors, and anterior for teratodermoid tumors, thymomas and lymphomas. Dyspnea was the most common symptom in the patients of the mediastinal tumors and asymptomatic patients were 19.5%, Benign mediastinal mass lesions were 66.0% and malignant, 34.0%, Complete or partial resection was done in 42.4%. Conclusion: We could find the increasing incidence and the tendency of aggressive resection as possible in the mediastinal tumors. We expect the discovery of more mediastinal tumors with wider use of regular check-up and development of diagnostic methods.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.206-215
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• 2007

Background : The prone position is often used for operations involving the spine and provides excellent surgical access. The complications associated with the prone position include ocular and auricular injuries, and musculoskeletal injuries. In particular, the prone position during general anesthesia causes hemodynamic changes. To evaluate the cardiovascular effects of the prone position in surgical patients during general anesthesia, we investigated the effects on hemodynamic change of the prone position with the Jackson spinal surgery table. Materials and Methods : Thirty patients undergoing spine surgery in the prone position were randomly selected. After induction of general anesthesia, intra-arterial and central venous pressures (CVP) were monitored and cardiac output was measured by $NICO^{(R)}$. We measured stroke volume, cardiac index, cardiac output, mean arterial pressure, heart rate, CVP and systemic vascular resistance (SVR) before changing the position. The same measurements were performed after changing to the prone position with the patient on the Jackson spinal surgery table. Results : In the prone position, there was a significant reduction in stroke volume, cardiac index and cardiac output. The heart rate, mean arterial pressure and CVP were also decreased in the prone position but not significantly. However, the SVR was increased significantly. Conclusion : The degree of a reduced cardiac index was less on the Jackson spinal surgery table than other conditions of the prone position. The reduced epidural pressure caused by free abdominal movement may decrease intraoperative blood loss. Therefore, the Jackson spinal surgery table provides a convenient and stable method for maintaining patients in the prone position during spinal surgery.