Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a tot...Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800 cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492 female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38± 40.64) min, the average clamping time of the vena cava was (77.87±27.99) min and the average mechanical ventilation time was (17.78±12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststernal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375%), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case (0.125%). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation. Pump-beating heart technique offers a safe and practical option especially in patients with severe critical valvular disorder.展开更多
To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperatu...To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China： No.4 by volume 3,200 m3 of “Jinan Iron ＆ Steel Company” in Jinan （683 thermocouples）, No.2 by volume 1,080 m3 of “Henan Jiyuan Iron ＆ Steel （Group） Company” in Jiyuan （212 thermocouples）, No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron ＆ Steel （Group） Company” in Liuzhou （383 thermocouples）, No.3 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）; No.1 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）.展开更多
文摘Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800 cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492 female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38± 40.64) min, the average clamping time of the vena cava was (77.87±27.99) min and the average mechanical ventilation time was (17.78±12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststernal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375%), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case (0.125%). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation. Pump-beating heart technique offers a safe and practical option especially in patients with severe critical valvular disorder.
文摘To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China： No.4 by volume 3,200 m3 of “Jinan Iron ＆ Steel Company” in Jinan （683 thermocouples）, No.2 by volume 1,080 m3 of “Henan Jiyuan Iron ＆ Steel （Group） Company” in Jiyuan （212 thermocouples）, No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron ＆ Steel （Group） Company” in Liuzhou （383 thermocouples）, No.3 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）; No.1 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）.
