Search results for "Gas analysis"
showing 10 items of 71 documents
Differential contribution of dead space ventilation and low arterial pCO2 to exercise hyperpnea in patients with chronic heart failure secondary to i…
2003
In chronic heart failure (CHF), the abnormally large ventilatory response to exercise (VE/VCO(2) slope) has 2 conceptual elements: the requirement of restraining arterial partial pressure of carbon dioxide (pCO(2)) from increasing (because of an increased ratio between increased physiologic dead space and tidal volume [VD/VT]) and the depression of arterial pCO(2) by further increased ventilation, which necessarily implies an important non-carbon dioxide stimulus to ventilation. We aimed to assess the contribution of these 2 factors in determining the elevated VE/VCO(2) slope in CHF. Thirty patients with CHF underwent cardiopulmonary exercise testing (age 65 +/- 11 years, left ventricular e…
Cavity ring down spectrometry for disease diagnostics using exhaled air
2017
In this paper we report the current stage of the development of a cavity ring-down spectrometer (CRDS) system using exhaled human breath analysis for the diagnostics of different diseases like diabetes and later lung cancer. The portable CRDS system is made in ultraviolet spectral region using Nd:Yag laser 266 nm pulsed light. Calibration of the CRDS system was performed using generated samples by KinTek automated permeation tube system and self-prepared mixtures with known concentration of benzene and acetone in air. First experiments showed that the limits of detection for benzene and acetone are several tens of ppb.
Multi frequency phase fluorimetry (MFPF) for oxygen partial pressure measurement: ex vivo validation by polarographic clark-type electrode.
2013
BACKGROUND: Measurement of partial pressure of oxygen (PO2) at high temporal resolution remains a technological challenge. This study introduces a novel PO2 sensing technology based on Multi-Frequency Phase Fluorimetry (MFPF). The aim was to validate MFPF against polarographic Clark-type electrode (CTE) PO2 measurements. METHODOLOGY/PRINCIPAL FINDINGS: MFPF technology was first investigated in N = 8 anaesthetised pigs at FIO2 of 0.21, 0.4, 0.6, 0.8 and 1.0. At each FIO2 level, blood samples were withdrawn and PO2 was measured in vitro with MFPF using two FOXY-AL300 probes immediately followed by CTE measurement. Secondly, MFPF-PO2 readings were compared to CTE in an artificial circulatory s…
A methodology to assess the energetic valorization of bio-based polymers from the packaging industry: pyrolysis of reprocessed polylactide
2012
The energetic valorization process of bio-based polymers is addressed in this study, taking polylactide (PLA) as model. The pyrolysis of virgin and multiple-injected PLA was simulated by means of multi-rate linear-non-isothermal thermogravimetric experiments. A complete methodology, involving control of gases, thermal stability and thermal decomposition kinetics was proposed. The release of gases was monitored by Evolved Gas Analysis of the fumes of pyrolysis, by in-line FT-IR, with the aid of 2D-correlation IR characterization. A novel model to establish the thermal stability of PLAs under any linear heating profile was proposed. A kinetic strategy was methodically applied to assess the th…
Infrared evolved gas analysis during thermal investigation of lanthanum, europium and samarium carbonates
2003
Abstract The characterisation of rare earth elements carbonates (REECs) was performed by thermal analysis (TG–DTG) combined with simultaneous infrared evolved gas analysis–Fourier transform infrared (EGA–FTIR) spectroscopy. The TG–DTG curves were obtained using the Perkin-Elmer PC series TGA-7 thermogravimetric analyser in the temperature range 25–800 °C both in dynamic air and nitrogen atmosphere. La 2 (CO 3 ) 3 · n H 2 O, Eu 2 (CO 3 ) 3 · n H 2 O and Sm 2 (CO 3 ) 3 · n H 2 O were analysed, the dehydration and decarbonation steps were investigated and the water content was calculated. The trace rare earth elements in lanthanum, europium and samarium carbonates were determined by Philips PU…
Der Säure-Basenstatus und die CO2-Transportfunktion des mütterlichen und fetalen Blutes zum Zeitpunkt der Geburt
1965
Als Voraussetzung fur die Analyse des Gasaustausches in der menschlichen Placenta werden die charakteristischen Daten fur den CO2-Transport und den Saure-Basenstatus im mutterlichen und fetalen Blut zum Zeitpunkt der Geburt bestimmt. Dabei ergeben sich als Mittelwerte bei 54 Fallen normaler Spontangeburt mit einzeitiger Entwicklung des Kindes, bei denen samtliche Meswerte vorliegen:
The oxygen status of arterial human blood
1990
The oxygen status of arterial human blood is described at least by four variables: Oxygen partial pressure (pO2, mmHg), oxygen saturation (sO2, %), hemoglobin content (cHb, g/dL) and oxygen content (cO2, mL/dL). Beside perfusion, however, the oxygen supply of all organs is decisively determined by the mean capillary pO2 which itself is primarily dependent on the arterial cO2. Therefore, the oxygen availability (cardiac output x caO2, mL/min) may be described by the cO2 value in arterial blood or those variables who determine the latter one. The diagnostic significance of the O2 variables of the oxygen status consequently increases in the order of pO2, sO2 (cHb) and cO2. In arterial blood, o…
Predictors of non-invasive ventilation tolerance in amyotrophic lateral sclerosis
2011
Abstract Background The most frequent cause of death in patients with Amyotrophic Lateral Sclerosis (ALS) is respiratory failure. Recently, it has been shown that non-invasive ventilation improves survival and quality of life in ALS patients with respiratory failure, but little is known about predictors of non-invasive ventilation adaptation and tolerance. In this study we evaluated the effect of a comprehensive information about non-invasive ventilation use and a prolonged and intensive monitoring on tolerance to this palliative care. Methods We prospectively monitored all consecutive ALS patients with chronic respiratory failure and indication to non-invasive ventilation between January 2…
The influence of smoking status on exhaled breath profiles in asthma and COPD patients
2021
Breath analysis using eNose technology can be used to discriminate between asthma and COPD patients, but it remains unclear whether results are influenced by smoking status. We aim to study whether eNose can discriminate between ever- vs. never-smokers and smoking <
Early albumin infusion improves global and local hemodynamics and reduces inflammatory response in hemorrhagic shock.
2002
Objective To evaluate the effects of an early, short-term albumin infusion on mesenteric microcirculation and global hemodynamics in hemorrhagic shock. Design A prospective, randomized study. Setting Animal laboratory at a university medical clinic. Subjects Seventeen Sprague-Dawley rats weighing 250–400 g. Interventions The rats underwent median laparotomy and exteriorization of an ileal loop for intravital microscopy of the mesenteric microcirculation. Volume-controlled hemorrhagic shock was provoked by arterial blood withdrawal (2.5 mL/100 g body weight for 60 mins), followed by a 4-hr reperfusion period. Albumin (20%) or 0.9% NaCl was administered intravenously as a continuous infusion …