Objective To compare the effects of high and low positive end-expiratory pressure( PEEP) levels on mortality and risk of barotrauma in patients with acute respiratory distress syndrome ( ARDS) . Methods Randomized controlled trials ( RCTs) were recruited from PubMed( 1966-2008. 9) ,EMBASE( 1980-2008. 9) , Cochrane Database ( Issue 2, 2008) , Chinese Cochrane Centre Database and CBMdisc ( 1978-2008. 9) . Related published and unpublished data and attached references were hand searched. All RCTs about ventilation with PEEP for patients with ARDS were included, then a systematic review were performed. Results Five eligible trials were enrolled in the systematic review. According to ventilation strategy, all trials were divided into subgroup A( low tidal volumes + high PEEP vs traditional tidal volumes + low PEEP) and subgroup B( low tidal volumes + high PEEP vs low tidal volumes + low PEEP) . In subgroup A, high PEEP was associated with a lower mortality[ RR 0. 59, 95%CI( 0. 43, 0. 82) ] and a lower prevalence of barotraumas [ RR 0. 24, 95% CI( 0. 09, 0. 70) ] in patients with ARDS. In subgroup B, the difference in mortality[ RR 0. 97, 95%CI( 0. 83, 1. 13) ] and barotraumas[ RR 1. 13, 95% CI( 0. 78, 1. 63) ]were not significant. Conclusions As compared with conventional ventilation, low tidal volumes and high PEEP ventilation strategy is associated with improved survival and a lower prevalence of barotraumas in patients with ARDS. It is necessary to further confirm the role of sole high PEEP in the ventilation strategy.
Objective To summarize the surgical experiences of ventricular septal rupture (VSR) after acute myocardial infarction (AMI) and investigate the time and methods of surgery. Methods From January 1999 to December 2008, 22 patients with VSR after AMI underwent surgical procedures. There were 17 male and 5 female with a age of 3978 years (mean age of 61.77 years). There were 18 cases with anterior VSR and 4 cases with posterior VSR, all of them combined with left ventricular aneurysm. Twentytwo cases underwent ventricular septal repair and aneurysm resection, 16 cases underwent coronary artery bypass grafting concomitantly with a graft of 2.11±1.57. Results There were 2 perioperative deaths (9.09%), 1 died of severe low cardiac output syndrome and 1 died of massive cerebral embolism. The other 20 cases were all cured and discharged. According to cardiac function classification from New York Heart Association（NYHA）, there were 4 cases in grade Ⅲ, 12 cases in grade Ⅱ and 4 cases in grade Ⅰ. Echocardiography showed that there were no VSR shunt and 2 cases with mild mitral valve regurgitation. Postoperative left ventricular enddiastolic diameter (LVEDD) reduced significantly compared with that before operation (50.27±5.33 mm vs. 57.94±6.79 mm, t=4.437, P=0.000). Sixteen cases were followed up, and the follow-up time was 3.24 months (13.9±6.5 months). Four cases were lost. There was no late death and cardiovascular event during following up. There were 11 cases in cardiac function classification (NYHA) grade Ⅱ and 5 in grade Ⅰ. Echocardiography showed that LVEDD reduced significantly (49.50±4.66 mm vs. 57.94±6.79 mm, t=5.041, P=0.000) and left ventricular ejection fraction (LVEF) increased significantly (55.08%±6.72% vs. 45.57%±11.31%, t=2.719, P=0.013)compared with those before operation. Conclusion VSR after AMI is one of the serious complications of AMI. Proper operation timing, perfect preoperative preparation, appropriate perioperative treatment, right surgical method and the avoidance of complications can effectively reduce the mortality and improve the prognosis.
Abstract: Objective To examine the cell viability and hemodynamic functions of the stented homograft valves preserved in liquid nitrogen. Methods Cell viability of the stented homograft valve preserved in liquid nitrogen after 3 months of preservation (experimental group，n=6) was examined using flow cytometer. Fresh homografts served as control group (n=6). We prepared three sorts of stented homograft valve(21#, 23#, 25#) preserved by liquid nitrogen. In vitro pulsatile flow tests were performed on valves of two groups. Effective opening area EOA),transvalve pressure gradient and regurgitation ratio were recorded at various flow volume, and compare with Perfect bioprosthetic valve. Results The results revealed that the death ratio of endothelial cell was 10.24%±1.71% in the experimental group, and 9.09%±2.72% in the control group (P=0.441). The death ratio of smooth muscle cell was 8.76%±1.82% in the experimental group, and 7.84%±0.59% (P=0.178) in the control group. The death ratio of total cell was 8.79%±1.44% in the experimental group, and 7.40%±0.49% in the control group (P=0.072). There were no significantly differences between two groups. The transvalve pressure gradient of two groups of valve depended on the flow volume, and increased with the flow volume increasing. The transvalve pressure gradient of the stented homograft valve was higher than that of Perfect valve. Regurgitation ratio of the stented homograft valve was bigger than Perfect valve’s. EOA had an increasing character when flow volume increased. EOA of the stented homograft valve was smaller than that of Perfect valve’s. Conclusion Liquid nitrogen can offer the benefit of cell viability of the stented homograft bioprosthetic valves. The stented homograft valve has salisfactory hemodynamic functions.