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Biomedical subjects

K Kumon

Publications and source records attributed to K Kumon.

At least 55 records · Page 3Linked to original sources
PubMed1994

Subcutaneous administration of recombinant human erythropoietin before cardiac surgery: a double-blind, multicenter trial in Japan.

BACKGROUND: Dose and injection times have not previously been determined for subcutaneously administered recombinant human erythropoietin that would allow sufficient deposition of blood for autologous use in cardiac surgery. STUDY DESIGN AND METHODS: A double-blind, multicenter trial of placebo (Group 1) and recombinant human erythropoietin at 12,000 IU (Group 2) and at 24,000 IU (Group 3) was performed on 114 patients at 26 institutions to determine the dosage that would permit an 800-g preoperative deposit of blood for autologous use. The test drug was administered subcutaneously on Days 21, 14, and 7 prior to operation, and oral iron preparations at 200 mg per day were given for 21 days. There were 28 patients in Group 1, 28 in Group 2, and 30 in Group 3, with 28 excluded for a violation of the protocol. RESULTS: Blood was safely drawn 14 and 7 days before operation from 22 patients in Group 1 (78.6%), from 26 in Group 2 (92.9%), and from all patients in Group 3 (p = 0.018). The hemoglobin level on the day before operation decreased by 1.1 +/- 1.1 g per dL (11 +/- 11 g/L) in Group 1 and by 0.9 +/- 0.9 g per dL (9 +/- 9 g/L) in Group 2 and rose by 0.1 +/- 0.8 g per dL (1 +/- 8 g/L) in Group 3, compared to initial levels. Allogeneic blood transfusion could be avoided in 62, 89, and 90 percent of Group 1, 2, and 3 patients, respectively (p = 0.013). CONCLUSION: The present study shows that subcutaneously administered recombinant human erythropoietin at a dose of 24,000 IU per week for 3 weeks is effective and sufficient to allow the safe deposition of 800 g of blood for autologous use in cardiac surgery.

Blood Donors↗
PubMed1994

[Inhaled nitric oxide after Fontan type operation].

The indication of Fontan type operation has been extending, but some cases on the boundary of the indication resulted in low cardiac output syndrome (LOS) postoperatively. Recently the inhalation of nitric oxide (NO) has been revealed to produce selective pulmonary vasodilatation, and it has come to be applied in the clinical setting. We experienced a case of 6-year-old boy with complex cardiac anomaly in whom the inhalation of nitric oxide was remarkably effective for the LOS caused by increased pulmonary vascular resistance after Fontan type operation. In the case various conventional treatments failed to improve his LOS during the weaning from a respirator on the second postoperative day. After the initiation of the inhalation of nitric oxide at a concentration of 6ppm, a rapid decreasing of pulmonary artery pressure concomitant with an improvement of hemodynamics were obtained. We concluded that the inhalation of nitric oxide is an effective strategy for the increased pulmonary resistance after Fontan type operation.

Administration, Inhalation↗
PubMed1993

Pericardial clot after open heart surgery: its specific localization and haemodynamics.

Transoesophageal echocardiography disclosed a localized pericardial blood clot compressing the right atrium (RA) and/or right ventricle (RV) in 15 patients suffering from low cardiac output failure soon after open-heart surgery. The left ventricular end-diastolic diameter was small (38.4 +/- 10.1 mm) and its fractional shortening normal (34.9 +/- 10.2%). These findings suggested cardiac tamponade as a result of pericardial clot. However, the 'y' trough of the RA pressure tracing was prominent, which is not characteristic of typical cardiac tamponade, but rather of constrictive pericarditis. This implies therefore that the pathophysiology of cardiac tamponade by pericardial clot differs from that of tamponade by fluid. Emergency open-chest removal of the pericardial clot was performed in seven patients, with good results. Pericardial clot produces low cardiac output soon after open-heart surgery, but its location is specific and its haemodynamics are not characteristic of cardiac tamponade.

Adult↗
PubMed1993

[Multiple organ failure related to disseminated intravascular coagulation].

This paper describes the main pathophysiological events leading to multiple organ failure (MOF) related to disseminated intravascular coagulation (DIC), caused by circulatory failure or infection. The main mechanisms responsible for the development of MOF in DIC are discussed, as are both the organ ischemia due to stasis and/or obstruction and the close interrelated reactions between inflammatory reaction, immune system and coagulation systems, especially focused on the close connection between the endothelium and superimposed mediators.

Capillary Permeability↗
PubMed1992

[High incidence of left ventricular thrombosis and systemic embolism in patients with left ventricular assist system].

The purpose of this study was to determine the incidence of left ventricular (LV) thrombosis and systemic embolism in 14 patients with LV assist systems. Echocardiography was used to detect LV wall motion abnormalities, intracavitary smoke-like echoes and thrombosis, and the effect of anticoagulant therapy was serially examined. During full assist of the circulation, the aortic valve did not open in any patient. Smoke-like echoes were observed in 9 patients (64%) and thrombi in 8 (57%). The thrombus developed within the first 3 assist days. Systemic anticoagulant therapy decreased the thrombus size in only 3 patients, but there was a possibility of intracranial or mediastinal bleeding in other 3 patients. Systemic embolism was noted in 7 of 11 autopsy patients (64%). The characteristic finding was that there were multiple embolized organs, such as the brain, kidneys, spleen and liver, in all patients. Development of a thrombus is a serious complication in all patients with LV assist systems. However, the problem does not lie in the assist system but in the left ventricle of the patient's own heart. It is also noteworthy that systemic anticoagulation is not effective for an LV thrombus. A new method of assisting the failing heart, or a new anticoagulant delivery technique for the LV cavity to prevent LV thrombus development is needed.

Adult↗
PubMed1991

[Coagula tamponade as a complication of open heart surgery: the clinical significance and diagnostic value of transesophageal echocardiography].

The pathogenesis of low cardiac output failure (LOF) immediately after open heart surgery was studied in 41 patients with LOF and 15 control patients without LOF using echocardiography. In 35 patients, transesophageal echocardiography was also performed. Left ventricular (LV) contraction was impaired in 28 of the 41 LOF patients, in whom LV fractional shortening was less than 25%. In the other 13 LOF patients, however, it was greater than 25%. In 12 of these 13 patients, transesophageal echocardiography revealed that accumulating pericardial coagula were localized in the right side of the heart, deforming the right atrial and ventricular chambers. The LV end-diastolic diameter was significantly less than the control, indicating that the pericardial coagula disrupted the distension of the heart. Emergent coagulotomy was performed in 5 patients, and hemodynamic conditions were improved. In spite of "cardiac tamponade", the wall motion and pressure tracings of the right atrium and right ventricle in these patients differed from those in fluid tamponade. Therefore, this condition should be designated "coagula tamponade." In the other 22 patients in whom transesophageal echocardiography was employed, no coagula were observed. Since pericardial coagula can hardly be detected by transthoracic echocardiography, transesophageal echocardiography is indispensable for diagnosing pericardial coagula noted immediately after open heart surgery.

Adult↗
PubMed1991

[Human heart recovery during weaning from a left ventricular assist system: time course and outcome prediction].

To investigate the time course of recovery of a failing heart using the left ventricular assist system (LVAS) and to predict the outcome of weaning from the LVAS, 14 patients with a failing heart were studied. Among them, 5 had recovered and survived for more than 2 weeks after weaning from the LVAS (recovered group), while 9 could not be weaned or died within 2 weeks after weaning (unrecovered group). All patients were gradually weaned from the LVAS with adequate support for systemic circulation for 3 days. In the recovered group, indices of systolic time intervals (STIs) showed improvement within a week. However, improvement of STIs was slow reaching a plateau around the 10th day in the unrecovered group. On weaning from the LVAS, aortic systolic pressure and ejection time were regulated by the patients' own hearts and were nearly the same between the 2 groups. However, left atrial pressure was significantly higher in the unrecovered group than in the recovered group. These hemodynamic features were first present on the 7th day. Therefore, hemodynamic data on the 7th assistant day can be a reliable factor in predicting the possibility of successful weaning from the LVAS and recovery in patients with a failing heart.

Adult↗
PubMed1991

[Efficacy of transesophageal echocardiography immediately after open heart surgery: diagnosis of coagula tamponade].

Massive pericardial coagula were detected by transesophageal echocardiography in some patients with low cardiac output failure immediately after open heart surgery. Characteristically, the coagula were localized anterior to the right atrium and right ventricle in all patients. The coagula could not be detected by transthoracic echocardiography. Despite of low output, absence of wall motion abnormality of the left ventricle, tachycardia, elevated atrial pressure and small left ventricular cavity lead to diagnose cardiac tamponade by pericardial coagula. Neither the right atrial nor the right ventricular wall showed collapsing motion except the area with pericardial effusion. Massive coagula in the anterior mediastinum produced similar clinical manifestation, but could be differentiated from pericardial coagula by echographic identification of the anterior pericardium. Pericardial coagula were also observed in patients with superior vena cava syndrome, but low right atrial pressure differentiated it from coagula tamponade. In all of the present patients, usual transthoracic echocardiography did not offer any sufficient images for diagnosing pericardial coagula. Transesophageal echocardiography was indispensable for detecting pericardial coagula soon after open heart surgery.

Adult↗
PubMed1991

[Effects of nitroglycerin upon myocardial metabolism after open heart surgery].

The effects of intravenous administration of nitroglycerin (TNG) on hemodynamics and myocardial metabolism after open heart surgery were evaluated in 22 patients without ischemic heart disease. On 12 hours after starting the continuous infusion of TNG at a rate of 0.2 micrograms/kg/min on 10 patients (TNG group), coronary blood flow (CBF) increased (p less than 0.01) and myocardial oxygen metabolism improved remarkably. However, anaerobic metabolism still existed in TNG group and no significant difference between TNG group and Control group even after 12 hour continuous drug infusion. From these studies, it was concluded that the intravenous administration of TNG at a rate of 0.2 microgram/kg/min increased CBF, however did not improve myocardial metabolism after open heart surgery possively probably because of changes in coronary collateral function.

Adult↗
PubMed1991

[Non-occlusive mesenteric infarction following cardiovascular surgery].

In the majority of patients with intestinal infarction, it is generally agreed that the occlusion of mesenteric arteries or vein is the primary etiologic factor; however, some showed no evidence of thrombosis, embolization or vasculitis as the causative factor. In many patients, this particular type of infarction is the terminal event of the episode. From October 1977 to December 1986, 24 patients with mesenteric infarction were investigated following cardiovascular surgery in our institute. Among them, 15 were diagnosed with organic vascular occlusion; however, the other 9 showed no evidence of thromboembolism or any other organic vascular occlusive lesion of mesenteric vessels and were diagnosed as non-occlusive mesenteric infarctions. All of these patients were in severe cardiac failure (LOS) postoperatively. There was no typical symptom, although abdominal fullness and diarrhea were the major and consistent findings. In blood chemical analysis, the enzymatic levels such as serum GOT, LDH and CPK were significantly elevated and discrepancy between serum GOT and serum GPT was observed. In this clinical situation, it was difficult to establish a correct diagnosis mainly because of the few signs and symptoms present relating to the mesenteric infarction. On the other hand, when the correct diagnosis was made, these patients were too critically ill to be treated conservatively. The outcome of these patients was grave and all of them died which showed 100% of mortality rate. The conservative management did not produce favorable progress, which accelerated LOS and prevented patients from recovering from cardiac failure. The aggressive surgical approach to this particular type of acute mesenteric ischemia might have offered an improved prognosis from these catastrophic events.

Adult↗
PubMed1990

[Effects of intra-aortic balloon pumping on mitral flow dynamics after aortocoronary bypass surgery].

Improvement in left ventricular function following intra-aortic balloon pumping (IABP) in 15 patients (aged 51 to 86 years) after coronary artery bypass grafting was evaluated. Using transesophageal atrial echocardiography, the mitral flow velocity integrals in the rapid filling phase (IntR) and in the contraction phase (IntA) were measured from transmitral flow patterns, and the sum of IntR and IntA (IntR + IntA), and the ratios of IntA to IntR (IntA/IntR) were calculated for ON and OFF states of balloon pumping (IABP OFF test). The same parameters were determined during 1:2 assist balloon pumping (IABP 1:2 test); the cardiac cycle with balloon assist was defined as "ON", and that without balloon assist as "OFF". 1. IABP OFF test: IABP increased IntR from 6.4 +/- 1.6 cm to 7.6 +/- 1.9 cm (p less than 0.01), suggesting that a decreased afterload improves left ventricular relaxation. IntA did not change with balloon assist (ON 3.5 +/- 1.2 cm, OFF 3.7 +/- 1.2 cm). IntR + IntA increased from 10.0 +/- 2.0 cm to 11.1 +/- 2.4 cm during IABP (p less than 0.01). IABP reduced the IntA/IntR from 0.62 +/- 0.25 to 0.50 +/- 0.20 (p less than 0.01). The increment in the IntA/IntR without IABP suggests that impaired diastolic filling of the left ventricle due to an increased afterload may be compensated for by enhanced left atrial contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Influences of intra-aortic balloon pumping on superior mesenteric flow dynamics].

The influences of intra-aortic balloon pumping (IABP) on arterial flow of the superior mesenteric artery were assessed by Doppler echocardiography. The subjects were 13 patients postoperatively, requiring IABP support to control low cardiac output state, in which distal aspects of balloons were distal to the superior mesenteric artery. Superior mesenteric flow velocity integral in systole (IntS) and that in diastole (IntD) were measured from superior mesenteric flow pattern, and the sum of IntS and IntD (IntS + IntD) was calculated ON and OFF balloon pumping (IABP ON-OFF test). The same parameters were obtained with balloon inflating on every other beat (IABP 1:2 test); the cardic cycle with balloon assist was defined as "1:2 ON", and that without balloon assist was defined as "1:2 OFF". 1) IABP ON-OFF test. IABP increased IntS from 7.07 +/- 2.56 cm to 9.20 +/- 3.19 cm (p less than 0.05), IntD from 3.00 +/- 1.18 cm to 3.62 +/- 1.40 cm (p less than 0.05), and IntS + IntD from 10.07 +/- 3.48 cm to 12.82 +/- 4.04 cm. Cardiac output increased from 3.89 +/- 1.34 l/min to 4.24 +/- 1.64 l/min with IABP support. The increments in IntS, IntD and IntS + IntD with IABP are attributed, to a large extent, to an increase in cardiac output. 2) IABP 1:2 test. Without balloon inflation, IntS increased (1:2 ON; 7.16 +/- 2.91 cm, 1:2 OFF; 8.41 +/- 3.30 cm, p less than 0.05), and IntD decreased (1:2 ON; 3.51 +/- 1.60 cm, 1:2 OFF; 2.33 +/- 1.25 cm, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗