[Relationship between antacid therapy and hospital acquired pneumonia in critically ill patients: a meta-analysis].

OBJECTIVE: To systematically review the effect of antacid medication on stress-related mucosal disease (SRMD) bleeding, hospital acquired pneumonia (HAP), and hospital mortality in critically ill patients admitted to intensive care unit (ICU). METHODS: Related articles were retrieved from Medline Database (from January 1980 to December 2012). Randomized control trials (RCTs) focused on comparison between antacid and sucralfate were collected, and then a meta-analysis was performed. RESULTS: Twelve studies including a total of 2537 patients admitted to ICU were qualified for analysis. Antacid medication significantly increased the incidence of HAP when compared with sucralfate in 11 trials [19.36% (249/1286) vs. 15.23% (184/1208), odds ratio (OR)=1.27, 95% confidence interval (95%CI): 1.03-1.57, P=0.02]. Subgroup analyses showed that antacid therapy significantly reduce the incidence of clinically significant bleeding compared with sucralfate [1.80% (12/667) vs. 3.86% (26/673), OR=0.46, 95%CI: 0.23-0.91, P=0.03], however, it did not lower the incidence of overt bleeding [7.09% (40/564) vs. 7.35% (36/490), OR=1.00, 95%CI: 0.62-1.62, P=0.99]. There was no significant difference between antacid group and sucralfate group on neither ICU mortality nor hospitalization mortality in 11 studies [25.58% (288/1126) vs. 23.65% (268/1133), OR=1.11, 95%CI: 0.92-1.35, P=0.28]. CONCLUSIONS: Antacid therapy used in critically ill patients may increase the incidence of HAP while reduce the rate of upper gastrointestinal bleeding, while it exerts no influence on mortality rate when compared with sucralfate treatment in this meta-analysis. It is imperative to restrict the overuse of such medication, and further RCTs focused on indication and withdrawal should be encouraged.

Kinetic process of UV Cu(+) laser in Ne-CuBr longitudinal pulsed discharge.

The kinetic process of Cu(+) UV laser in Ne-CuBr longitudinal pulsed discharge is analyzed and a comprehensive self-consistent physical model is developed. The temporal evolutions of discharge parameters, main particle densities, the electron temperature, and the laser pulse intensity are numerically calculated. The model results illustrate the process of population inversion and the lasing mechanism. The calculations on the influences of the tube radius and Br atoms on the laser output characteristic well explain the experimental results.