Objective To explore the clinical application of adaptive support ventilation (ASV) in elderly patients with acute respiratory failure.Methods A total of 46 mechanically ventilated patients aged over 65 years with acute respiratory failure admitted from January 2013 to June 2015 were enrolled.Comparison between the ASV mode and synchronized intermittent mandatory ventilation (SIMV) mode was carried out in respects of the impacts of both modes on respiratory mechanics, hemodynamics, oxygen availability and comfort rate.Results Difference between ASV and SIMV in respiratory rate was [(20.84 ±4.04) vs.(24.50 ±4.60) cycles/min, t =4.04, P ＜0.05], in inspiratory resistance was [(13.24 ±4.76) vs.(16.54±5.25) cmH2O/ (L·s), t=3.16, P＜0.05], in mean airway pressure was [(13.58±2.58) vs.(16.63 ±1.57) mmHg, t =6.84, P＜0.05], in peak airway pressure was [(25.96 ± 3.69) vs.(27.87 ± 2.45) mmHg, t =2.92, P ＜ 0.05], and tidal volume was [(378.41 ± 85.61) vs.(341.52 ± 86.84) mL, t =2.05, P ＜ 0.05], and comfort rate of patients was increased in ASV mode.There were no statistically significant differences in arterial oxygen partial pressure, carbon dioxide partial pressure, lactate, heart rate, mean arterial pressure and central venous pressure between the two modes (PP ＞ 0.05).Conclusions Compared with the synchronized intermittent mandatory ventilation mode, the adaptive support ventilation mode can improve the respiratory mechanics and can increase the comfort rate in the elderly patients with mechanical ventilation.

OBJECTIVETo explore the biomarkers for monitoring trinitrotoluene (TNT) exposure, the relationship between TNT hemoglobin adducts and TNT exposed level.

METHODHemoglobin adducts (4A-Hb and 2A-Hb) were determined by GC-MS in 25 TNT exposed workers. TNT exposed level was evaluated by determining skin contaminated and inhaled TNT levels. The correlation between hemoglobin adducts level and TNT exposed level was analyzed.

RESULTSThere was a correlation between total TNT exposure level, especially skin exposure level, and 4A-Hb or 2A-Hb content. No significant difference was found between the slopes and intercepts of lin ear equation of (4A-Hb) vs TNT exposed level and linear equation of (4A-Hb +2A-Hb) vs TNT exposed level (P > 0.05).

CONCLUSIONSkin contamination is the major role of TNT exposure. TNT exposed level can be evaluated by determining the content of both 4A-Hb and 2A-Hb, and 4A-Hb is more suitable for monitoring TNT exposure.

Environmental Monitoring ; methods ; Hemoglobins ; metabolism ; Humans ; Occupational Exposure ; Skin ; drug effects ; Trinitrotoluene ; metabolism