• The Korean Journal of Pharmacology
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• v.14 no.1_2
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• pp.13-23
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• 1978

1) It was attempted to clarify the sites of action of central (either intraventricular or intracisternal) norepinephrine(NE) and clonidine to cause cardiac slowing and hypotension in urethane-anesthetized rabbits. 2) NE produced cardiac slowing but indistinct effect on blood pressure. Clonidine produced cardiac slowing and hypotension. 3) Intraventricular and intracisternal administration of NE, clonidine, phenylephrine and isoproterenol did not make difference in their effects, except that the onset of cardiac slowing by intracisternal NE was more rapid than intraventricular NE. 4) Upon repeated administration of NE at the intervals of about two hours, blood pressure responses changed to the pressor ones, the cardiac slowing unchanged. By this procedure the cardiac slowing as well as the hypotension by clonidine were gradually diminished. 5) Clonidine, when given during the NE effects were persisting, did not produce the lowering of blood pressure and further decrease of heart rate. NE, when given during the clonidine effects were persisting, produced marked elevation of blood pressure but did not produce further decrease of heart rate. 6) After intraventricular administration of regitine or desmethylimipramine, the cardiac slowing effect of NE and the clonidine effects were not observed, whereas NE produced marked elevation of blood pressure. 7) Reserpinized rabbits showed pressor and cardiac accelerating responses to NE; slight pressor, and little cardiac responses to clonidine. 8) It seems that the cardiac slowing by both clonidine and NE as well as the hypotetsion by clonidine are mediated by the presynaptic ${\alpha}$-adrenoceptor in the brain but the pressor responses to NE and clonidine are mediated by other site(s) than the presynaptic ones.

• Journal of Chest Surgery
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• v.34 no.6
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• pp.485-489
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• 2001

Background: The most important factor in preventing sternal complications is stable sternal approximation. We have tried to find the most effective sternal closure method by examining the incidence of sternal dehiscence with or without infection in patients with cardiac surgery through median sternotomy. Material and Method: This study was performed in 489 patients over 45 years of age with median sternotomy for open cardiac surgery. Simple closure with interrupted 6 wires was performed in 159 patients, figure-of-8 closure technique in 119, overlapping interrupted closure using 10 wires in 150, and combined closure technique of interrupted simple closure and figure-of-8 suture closure in 61. Two hundred thirty-four patients underwent valve and aortic operations and 213 patients coronary artery bypass surgery. Result: Sternal dehiscence with or without infection occurred in 12 (2.5 %) patients. The complication developed in 5 of 159 patients (3.1%) with six interrupted simple closure, in 4 of 119 patients (3.4%) with figure-of-8 closure, and in 3 of 150 patients (2.0%) with overlapping interrupted closure using 10 wires, but there was no complication in 61 patients with combined closure technique (relative risk for other closure techniques, p<0.05). There was no significant difference in the incidence of the sternal complication between valve and aortic operation group and coronary artery bypass group (3.0% vs 2.3%, not significant), but diabetes mellitus was a significant independent risk factor (odds ratio and multivariate analysis, p<0.05). Conclusion: The sternal closure technique that combines simple interrupted suture closure and figure-of-8 suture closure may be a more useful technique to enhance sternal stabilization compared to other closure techniques, such as simple interrupted closure, 8-figure closure, and overlapping interrupted closure.