Purpose: The concept of the second gas effect is well known, however, there have been no studies that showed the relationship between alveolar oxygen concentration and arterial oxygen tension (PaO2) after the inhalation of nitrous oxide (N2O) in humans. The purpose of this study was to examine the changes in both end-tidal oxygen fraction (F(ET)O2) and PaO2 after N2O inhalation in patients under general anesthesia.
Methods: Fifteen patients scheduled for elective orthopedic surgery were enrolled in this study. Anesthesia was maintained with the continuous infusion of propofol and with nitrogen (N2) and oxygen (O2) (6 L x min(-1), F1O2, 0.33). In all patients, the lungs were ventilated with a Servo 900C ventilator equipped with a gas mixer for O2, N2O, and N2. After obtaining baseline data, N2 was replaced with N2O maintaining FIO2 constant at 0.33. The changes in fractional concentration of O2, N2O, and N2 were continuously measured using mass spectrometer in a breath-by-breath basis. PaO2 and hemodynamic data were obtained at 1, 5, 10, 30 and 60 min after the start of N2O inhalation.
Results: Five minutes after N2O inhalation, F(ET)O2 increased from 0.27+/-0.01 to 0.31+/-0.02 (P<0.01) and PaO2 increased from 172.0+/-22.5 mm Hg to 201.0+/-10.3 mm Hg (P<0.01). These effects produced by N2O were observed for 30 min.
Conclusions: These results confirm the concept of second gas effect of N2O on oxygen uptake in humans and provide evidence that the PaO2 increase correlated with the increase in F(ET)O2 after N2O inhalation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/BF03018940 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
[Analysis of phthalate esters and their novel alternatives in indoor dust using comprehensive two-dimensional gas chromatography-time of flight mass spectrometry].
Se Pu
February 2025
Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100214, China.
A comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF-MS) method was developed to analyze 25 traditional phthalate esters (PAEs) and 19 novel alternatives in indoor dust samples. PAEs are ubiquitous in indoor environments because they are widely used as plasticizers in a variety of consumer products, and potential health concerns have prompted the need for effective monitoring methods. In this study, dust samples were collected from various indoor settings in a university campus, including classrooms, cafeterias, laboratories, and dormitories, and were subsequently ultrasonically extracted with hexane-dichloromethane (1∶1, v/v) solution for 30 min.
View Article and Find Full Text PDFEffect of neuromuscular electrical stimulation combined with respiratory rehabilitation training on pulmonary rehabilitation in patients with chronic obstructive pulmonary disease.
J Cardiothorac Surg
January 2025
Department of Cardiac Rehabilitation, Zhejiang Hospital, Hangzhou, Zhejiang Province, 310007, China.
Objective: the study aimed to analyze the therapeutic effects of neuromuscular electrical stimulation (NMES) combined with respiratory muscle training (RMT) on patients with moderate-to-severe chronic obstructive pulmonary disease (COPD).
Methods: 135 patients with moderate/severe chronic obstructive pulmonary disease were selected as the research object and randomly selected. 72 cases were divided into rehabilitation group and 63 cases in control group.
Short-term modification of breathprint by Elexacaftor/Tezacaftor/Ivacaftor in a paediatric cohort.
J Cyst Fibros
January 2025
INSERM U1151, Institut Necker Enfants Malades, Paris, France; Hôpital Necker Enfants Malades, Centre de Référence Maladies Rares Mucoviscidose et Maladies apparentées, Paris, France; Université Paris-Cité, Paris, France; European Reference Network-Lung. Frankfurt, Germany. Electronic address:
Background: The triple combination Elexacaftor/Tezacaftor/Ivacaftor (ETI) translates into major respiratory improvements in adults; yet current clinical endpoints may prove insufficiently sensitive in young children. We hypothesised that ETI rapidly modifies the lungs' metabolism, resulting in changes in breath composition.
Methods: Eleven children with CF were enrolled in a longitudinal pilot study at the paediatric Necker hospital.
Assessing microplastic and nanoplastic contamination in bird lungs: evidence of ecological risks and bioindicator potential.
J Hazard Mater
January 2025
Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China. Electronic address:
Microplastics (MPs, 1 µm-5 mm) and nanoplastics (NPs, < 1 µm), collectively termed micro(nano)plastics (MNPs), are pervasive airborne pollutants with significant ecological risks. Birds, recognized as bioindicators, are particularly vulnerable to MNP exposure, yet the extent and risks of MNP pollution in bird lungs remain largely unexplored. This study assessed MP exposure in bird lungs of 51 species and NP exposure in the lungs of five representative species using laser direct infrared (LDIR) and pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) techniques, respectively.
View Article and Find Full Text PDFComparison of outcomes following prepectoral and subpectoral implants for breast reconstruction in patients with breast cancer.
Front Oncol
January 2025
Thyroid and Breast Medical Center, Weifang People's Hospital, Shandong Second Medical University, Weifang, Shandong, China.
Background: In recent years, different approaches to implant-based breast reconstruction have increasingly become an important option to meet both the treatment and postoperative aesthetic needs of breast cancer patients. This study selected two commonly used techniques for the prepectoral approach: single-incision, gas-inflated endoscopic prepectoral breast reconstruction (SIE-BR) and open prepectoral implant-based breast reconstruction (C-BR), as well as a commonly used technique for the subpectoral approach: open subpectoral implant-based breast reconstruction (SI-BR). By comparing the clinical efficacy and aesthetic outcomes of these three techniques in the treatment of breast cancer patients, this study aims to summarize the advantages of the prepectoral approach.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!