Background: Anesthesia per se results in atelectasis development in the dependent regions of the lungs. The effect of pneumoperitoneum on atelectasis formation is not known. The aim of the current study was to measure by spiral computed tomography the effect of carbon dioxide pneumoperitoneum for laparoscopic surgery on the development of atelectasis, overall lung volume, and regional tissue volumes of gas and tissue.
Methods: Seven patients (American Society of Anesthesiologists physical status I), scheduled to undergo laparoscopic cholecystectomy, were observed. After induction of anesthesia, the patients were mechanically ventilated and positioned supine on the computed tomography table. Tomography of the lungs (10 mm spiral) was performed before and 10 min after induction of carbon dioxide pneumoperitoneum at an intraabdominal pressure of 11-13 mmHg. The Student t test was used for statistical analysis. A P value less than 0.05 was considered significant.
Results: Induction of pneumoperitoneum increased the mean atelectasis volume in the dependent lung regions by 66% (range, 11-170%). The overall lung volume and gas as well as tissue volume significantly decreased. Relative to the total lung volume, lung tissue volume increased, while gas volume decreased significantly. Both upper and lower lobes reacted the same way. A cranial displacement of the diaphragm between 1 and 3 cm (mean, 1.9 cm) was registered.
Conclusion: Pneumoperitoneum at an intraabdominal pressure level of 11-13 mmHg increased the volume of atelectasis. Because lung tissue volume increased in the lung, there may have been an opening of previously closed vessels, which could explain previously seen increase in arterial oxygenation after induction of pneumoperitoneum.
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http://dx.doi.org/10.1097/00000542-200502000-00009 | DOI Listing |
PLoS One
January 2025
Department of Anesthesiology, The Second Affiliated Hospital, The Army Military Medical University, Chongqing, China.
Background: Rapid sequence induction intubation (RSII) is commonly used in emergency surgeries for patients at high risk of aspiration. However, these patients are more susceptible to hypoxemia during the RSII process. High-flow nasal cannula (HFNC) oxygen therapy has emerged as a potential alternative to traditional face mask (FM) ventilation pre- and apneic oxygenation.
View Article and Find Full Text PDFPLoS One
January 2025
Cooperative Agricultural Research Center, College of Agriculture, Food and Natural Resources, Prairie View A&M University, Prairie View, TX, United States of America.
The significance of forests in absorbing and storing carbon plays a crucial role in international greenhouse gas policies outlined by the United Nations Framework Convention for Climate Change (UNFCC). This study was conducted in a typical tropical moist forest of Ethiopia to assess its carbon stock, a critical issue in climate policy. The study domain was divided into six strata using elevation criteria.
View Article and Find Full Text PDFGlob Chang Biol
January 2025
Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China.
The carbon sink function performed by the different vegetation types along the environmental gradient in coastal zones plays a vital role in mitigating climate change. However, inadequate understanding of its spatiotemporal variations across different vegetation types and associated regulatory mechanisms hampers determining its potential shifts in a changing climate. Here, we present long-term (2011-2022) eddy covariance measurements of the net ecosystem exchange (NEE) of CO at three sites with different vegetation types (tidal wetland, nontidal wetland, and cropland) in a coastal zone to examine the role of vegetation type on annual carbon sink strength.
View Article and Find Full Text PDFACS Nano
January 2025
Songshan Lake Materials Laboratory (SLAB), Dongguan 523808, P. R. China.
Electrocatalytic CO reduction into high-value multicarbon products offers a sustainable approach to closing the anthropogenic carbon cycle and contributing to carbon neutrality, particularly when renewable electricity is used to power the reaction. However, the lack of efficient and durable electrocatalysts with high selectivity for multicarbons severely hinders the practical application of this promising technology. Herein, a nanoporous defective AuCu single-atom alloy (De-AuCu SAA) catalyst is developed through facile low-temperature thermal reduction in hydrogen and a subsequent dealloying process, which shows high selectivity toward ethylene (CH), with a Faradaic efficiency of 52% at the current density of 252 mA cm under a potential of -1.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132, USA.
The electrochemical oxidation of alcohol molecules has gained significance as a key anode reaction, offering an alternative to the oxygen evolution reaction (OER) for hydrogen (H) production and carbon dioxide (CO) reduction. The (photo)electrochemical oxidation of benzyl alcohol and its derivatives serves as an important model system, not only because benzyl alcohol oxidation is a critical industrial process, but also because it offers valuable insights into electrocatalytic biomass conversion. Tailoring this reaction through electrochemical and photoelectrochemical methods using heterogeneous noble and transition metal electrocatalysts presents a green approach and the potential for uncovering new reaction mechanisms.
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