AIM:To evaluate the inhibitory effects of carbon dioxide (CO2) insufflation on pneumoperitoneum and bowel distension after percutaneous endoscopic gastrostomy (PEG).METHODS:A total of 73 consecutive patients who were ...AIM:To evaluate the inhibitory effects of carbon dioxide (CO2) insufflation on pneumoperitoneum and bowel distension after percutaneous endoscopic gastrostomy (PEG).METHODS:A total of 73 consecutive patients who were undergoing PEG were enrolled in our study.After eliminating 13 patients who fitted our exclusion criteria,60 patients were randomly assigned to either CO2 (30 patients) or air insufflation (30 patients) groups.PEG was performed by pull-through technique after threepoint fixation of the gastric wall to the abdominal wall using a gastropexy device.Arterial blood gas analysis was performed immediately before and after the procedure.Abdominal X-ray was performed at 10 min and at 24 h after PEG to assess the extent of bowel distension.Abdominal computed tomography was performed at 24 h after the procedure to detect the presence of pneumoperitoneum.The outcomes of PEG for 7 d postprocedure were also investigated.RESULTS:Among 30 patients each for the air and the CO2 groups,PEG could not be conducted in 2 patients of the CO2 group,thus they were excluded.Analyses of the remaining 58 patients showed that the patients' backgrounds were not significantly different between the two groups.The elevation values of arterial partial pressure of CO2 in the air group and the CO2 group were 2.67 mmHg and 3.32 mmHg,respectively (P = 0.408).The evaluation of bowel distension on abdominal X ray revealed a significant decrease of small bowel distension in the CO2 group compared to the air group (P < 0.001) at 10 min and 24 h after PEG,whereas there was no significant difference in large bowel distension between the two groups.Pneumoperitoneum was observed only in the air group but not in the CO2 group (P = 0.003).There were no obvious differences in the laboratory data and clinical outcomes after PEG between the two groups.CONCLUSION:There was no adverse event associated with CO2 insufflation.CO2 insufflation is considered to be safer and more comfortable for PEG patients because of the lower incidence of pneumoperitoneum and less distension of the small bowel.展开更多
Isoprene emissions emitted from vegetation are one of the most important precursors for tropospheric ozone and secondary organic aerosol formation. The authors estimate the biogenic isoprene emissions in China over 20...Isoprene emissions emitted from vegetation are one of the most important precursors for tropospheric ozone and secondary organic aerosol formation. The authors estimate the biogenic isoprene emissions in China over 2006-2011 using a global chemical transport model （GEOS- Chem） driven by meteorological fields from the assimilated meteorological data from MERRA. The authors incorporate three different parameterizations of isoprene-CO2 interaction into the model, and perform three sensitivity simulations to investigate the effect of CO2 inhibition on isoprene emissions for the period 2006-2011 in China. The annual isoprene emissions rate across China is simulated to be 12.62 Tg C yr-1, averaged over 2006-2011, and decreases by about 2.7%-7.4% when the CO2 inhibition schemes are included. The CO2 inhibition effect might be significant in regions where the CO2 concentration and isoprene emissions are high. Estimates of isoprene emissions can differ depending on the scheme of CO2 inhibition. According to the results obtained from the sensitivity simulations, the authors find that the CO2 inhibition effect leads to 5.6% ±2.3% reductions in annual isoprene emissions over China. The authors also find that inclusion of CO2 inhibition can substantially alter the sensitivity of isoprene emissions to the changes in meteorological conditions during the study period.展开更多
文摘AIM:To evaluate the inhibitory effects of carbon dioxide (CO2) insufflation on pneumoperitoneum and bowel distension after percutaneous endoscopic gastrostomy (PEG).METHODS:A total of 73 consecutive patients who were undergoing PEG were enrolled in our study.After eliminating 13 patients who fitted our exclusion criteria,60 patients were randomly assigned to either CO2 (30 patients) or air insufflation (30 patients) groups.PEG was performed by pull-through technique after threepoint fixation of the gastric wall to the abdominal wall using a gastropexy device.Arterial blood gas analysis was performed immediately before and after the procedure.Abdominal X-ray was performed at 10 min and at 24 h after PEG to assess the extent of bowel distension.Abdominal computed tomography was performed at 24 h after the procedure to detect the presence of pneumoperitoneum.The outcomes of PEG for 7 d postprocedure were also investigated.RESULTS:Among 30 patients each for the air and the CO2 groups,PEG could not be conducted in 2 patients of the CO2 group,thus they were excluded.Analyses of the remaining 58 patients showed that the patients' backgrounds were not significantly different between the two groups.The elevation values of arterial partial pressure of CO2 in the air group and the CO2 group were 2.67 mmHg and 3.32 mmHg,respectively (P = 0.408).The evaluation of bowel distension on abdominal X ray revealed a significant decrease of small bowel distension in the CO2 group compared to the air group (P < 0.001) at 10 min and 24 h after PEG,whereas there was no significant difference in large bowel distension between the two groups.Pneumoperitoneum was observed only in the air group but not in the CO2 group (P = 0.003).There were no obvious differences in the laboratory data and clinical outcomes after PEG between the two groups.CONCLUSION:There was no adverse event associated with CO2 insufflation.CO2 insufflation is considered to be safer and more comfortable for PEG patients because of the lower incidence of pneumoperitoneum and less distension of the small bowel.
基金supported by the National Natural Science Foundation of China[grant number 41405138]the National High Technology Research and Development Program of China[grant number 2013AA122002]
文摘Isoprene emissions emitted from vegetation are one of the most important precursors for tropospheric ozone and secondary organic aerosol formation. The authors estimate the biogenic isoprene emissions in China over 2006-2011 using a global chemical transport model （GEOS- Chem） driven by meteorological fields from the assimilated meteorological data from MERRA. The authors incorporate three different parameterizations of isoprene-CO2 interaction into the model, and perform three sensitivity simulations to investigate the effect of CO2 inhibition on isoprene emissions for the period 2006-2011 in China. The annual isoprene emissions rate across China is simulated to be 12.62 Tg C yr-1, averaged over 2006-2011, and decreases by about 2.7%-7.4% when the CO2 inhibition schemes are included. The CO2 inhibition effect might be significant in regions where the CO2 concentration and isoprene emissions are high. Estimates of isoprene emissions can differ depending on the scheme of CO2 inhibition. According to the results obtained from the sensitivity simulations, the authors find that the CO2 inhibition effect leads to 5.6% ±2.3% reductions in annual isoprene emissions over China. The authors also find that inclusion of CO2 inhibition can substantially alter the sensitivity of isoprene emissions to the changes in meteorological conditions during the study period.
