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At least 1,153 records · Page 64Linked to original sources
PubMed2005

[Exhaled tidal volume is overestimated due to cardiogenic oscillation: effects of ventilator and mode].

BACKGROUND: We investigated effects of cardiogenic oscillation on overestimation of tidal volume using a lung model, with three ventilators and two ventilatory modes. METHODS: We simulated cardiogenic oscillation at a rate of 90 breaths x min(-1) by ventilating one bellow of a two-bellow-type lung model. The magnitude of cardiogenic oscillation was defined as peak expiratory flow fluctuation when the airway was opened to the atmosphere. The lung model was mechanically ventilated with three ventilators (Bird 8400 STi, Servo-300, and Nellcor Puritan-Bennett 840), two ventilatory modes (volume- and pressure-controlled ventilation), and two respiratory rates (5 and 10 breaths x min(-1)) in random order. We recorded tidal volume on a ventilator monitor and calculated the discrepancy from the set tidal volume. RESULTS: With Bird 8400 STi, monitored tidal volume exceeded set tidal volume, regardless of volume- or pressure-controlled ventilation. The overestimation in tidal volume was larger with smaller respiratory rate and with larger cardiogenic oscillation. In contrast, with the other ventilators, the discrepancy was small. CONCLUSIONS: Exhaled tidal volume is overestimated during mechanical ventilation when cardiogenic oscillation is large.

Models, Biological↗
PubMed2005

[From love apple to skin bouquet ... and if it also exhaled phaeromones?].

Skin exhales odours forming a bouquet which seems unique for each individual. The westernised socio-cultural behaviour tends to suppress them and to replace them by perfumes. The existence and the role of human phaeromones remain unsettled. Physiological and behavioural effects can be modulated by body odours and their putative phaeromones.

Humans↗
PubMed2005

Uranium, radium and radon exhalation studies in geological samples belonging to some areas of punjab, using track etching technique.

With a view to prospect the uranium, radium and radon concentration and related health risk assessments in areas of Muktsar and Ferozepur districts in Punjab, the fission track registration technique has been used for the analysis of water and soil samples. Uranium content in water ranged from 5.47 to 10.19 microg/l(-1) and 6.28 to 11.74 microg/l(-1) for Muktsar and Ferozepur respectively. Uranium content in soil samples of Muktsar and Ferozepur ranged from 1.14 to 1.90 mg/kg(-1) and 1.26 to 2.44 mg/kg(-1) respectively. Radium concentration in these soil samples has been found to vary from 3.97 to 15.94 bq/kg(-1) and 7.24 to 24.14 bq/kg(-1) for Muktsar and Ferozepur respectively. The radon exhalation values were calculated in terms of area (E(A)) and mass (E(M)). The values of E(M) ranged from 4.9 to 20.6 (mbqkg(-1) hr(-1)) for Muktsar and 9.4 to 31.3 (mbqkg(-1)hr(-1)) for Ferozepur and values of E(A) ranged from 173 to 728 (mbqm(-2)hr(-1)) for Muktsar and 330 to 1102 (mbqm(-2)hr(-1)) for Ferozepur district. These values in general are low and not significant from health hazard point of view. The values of uranium concentration in water samples of these areas are lower than those reported for soil and water samples of Himachal Pradesh. These values are also lower than those reported by Singh et al. for the rocks belonging to uranium and copper mines of Bihar.

Geological Phenomena↗
PubMed1990

[Indices of lipid peroxidation in the condensate of exhaled air--a simple and objective method of estimating injuries to the pulmonary surfactant system].

A method for assessing injury to the pulmonary surfactant system is suggested, based on studies of lipid peroxidation parameters in exhaled air condensate. Free-radical processes in pulmonary surfactants were examined in normal subjects and in patients with various forms of chronic nonspecific diseases of the respiratory organs. The findings evidence that a disease essentially intensifies lipid peroxidation in the alveolar lining, this being parallelled by reduced antiradical defense. Such an approach to studies of pulmonary surfactant system injuries is marked for its simplicity and atraumatism, this recommending it for mass clinical check-ups. Use of this method is promising as regards the disease prognosis and assessment of the treatment efficacy, as well as detection of subjects at high risk of developing bronchopulmonary diseases.

Adult↗
PubMed1990

[Determination of the free radical processes in condensates of exhaled air in children with recurrent bronchitis].

Free-radical processes were assessed in exhaled air condensates of healthy children and of those suffering from recurrent bronchitis during remission and at the onset of exacerbation. 3 percent hydrogen peroxide-induced chemiluminescence technique was employed with the results recorded by chemiluminometer, manufactured in this country. The data evidence an increase of the total induced chemiluminescence in the patients during exacerbation vs. that in healthy children; such measurements may become a valuable test in the diagnosis of chronic and recurrent pulmonary disease in children.

Breath Tests↗
PubMed2006

[Hydrogen peroxide is increased after sleep in exhaled breath condensate of patients with obstructive sleep apnea-hypopnea syndrome].

OBJECTIVE: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is characterized by recurrent hypoxia/reoxygenation during sleep that may cause oxidative stress. The aim of the study was to explore whether obstructive sleep apnea-hypopnea syndrome could induce higher production of hydrogen peroxide in exhaled breath condensate (EBC). METHODS: Thirty-two patients with OSAHS (18 smokers and 14 non-smokers) and 10 age matched controls were enrolled in the study. EBC was collected before and after sleep at the same night from both groups. H2O2 was tested in EBC fluorimetrically. RESULTS: There was no difference of pre-sleep H2O2 level among OSAHS smoker group, OSAHS non-smoker group and the control subjects [(0.88 +/- 0.36) micromol/L, (0.87 +/- 0.45) micromol/L and (0.86 +/- 0.46) micromol/L, F = 0.01, P = 0.99]. There was a significantly increased level of H2O2 after sleep for both smoking or no-smoking OSAHS patients [post-sleep: smoker: (1.65 +/- 0.89) micromol/L, t = 3.43, P = 0.001; non smoker: (1.82 +/- 1.12) micromol/L, t = 2.95, 0.007]. The control group did not show such a change [post-sleep: (0.71 +/- 0.36) micromol/L, t = 0.81, P = 0.43]. OSAHS group, either smokers or non-smokers, showed a significantly higher post-sleep H2O2 level in EBC compared with that of controls (F = 5.11, P = 0.01). Post-sleep H2O2 level (beta = -0.36, P = 0.02) and the variation of H2O2 level (beta = -0.38, P = 0.01) correlated negatively with the minimal SpO2 during sleep period. CONCLUSIONS: Oxidative stress of respiratory tract is a characteristic change in OSAHS. Nocturnal hypoxia may be related to these changes, which may be involved in the lung injury of OSAHS.

Adult↗
PubMed1989

[Biologically active substance levels in exhaled air from patients with pre-asthma and bronchial asthma].

Acetylcholine, serotonin, and histamine levels have been measured in exhaled air humor condensate in 65 patients aged 18 to 60, 44 ones with bronchial asthma and 21 with preasthma. Nonuniform release of biogenic amines and acetylcholine in pulmonologic patients depended on the severity of the inflammatory process in the bronchi, hypoxemia, bronchial obstruction, and reactivity of the bronchi examined during cold air breathing.

Acetylcholine↗
PubMed1985

Volatile organic compounds in exhaled air from patients with lung cancer.

Using a specially developed breath collection technique and computer-assisted gas chromatography/mass spectrometry (GC/MS), we have identified in the exhaled air of lung cancer patients several volatile organic compounds that appear to be associated with the disease. The GC/MS profiles of 12 samples from lung cancer patients and 17 control samples were analyzed by using general computerized statistical procedures to distinguish lung cancer patients from controls. The selected volatile compounds had sufficient diagnostic power in the GC/MS profiles to allow almost complete differentiation between the two groups in a limited patient population.

Adenocarcinoma↗
PubMedDate not supplied

[Sedative-hypnotic compounds in the exhalation of hops, II].

Hops are told to promote sleep; manyfold efforts to detect the soporific principle have been unsuccessful so far. Preliminary pharmacological tests lead to the conclusion that the soporific activity of the exhalation of hops can be explained by its content of 2-methyl-3-butene-2-ol (1) in the volatile fraction. It was found that 1, when given to mice i.p. (0.80 g/kg) produces narcosis for about 8 h; no abnormal behaviour was observed there upon. Due to its water-solubility the concentration of 1 in the essential oil obtained by steam-distillation is low; contrary to that, 1, is enriched in the more volatile fraction of hops.

Animals↗
PubMed1980

Different actions of neomychin and metronidazole on breath hydrogen (H2) exhalation.

Purpose of this investigation was to characterize the effect of antibiotics as a possible limiting factor for the evaluation of hydrogen (H2) breath analysis tests which depend on bacterial carbohydrate fermentation. Breath H2-excretion following ingestion of the non-absorbable disaccharide lactulose was monitored in healthy subjects before and after pretreatment with the aminoglycoside neomycin or with metronidazole. Metronidazole decreased the amount of hydrogen exhaled by 39 % (p<0.05) and peak H2-excretion by 42.1 % (p<0.01), because it suppresses anaerobe H2 producing microorganisms. Neomycin intensified nonsignificantly the integrated (0-6 hours) breath hydrogen response to lactulose (+43 %) and the maximal H2-concentration by 29.8 %, probably because it interferes with intestinal bacteria which are important for H2-consumption.

Adult↗
PubMed1995

[Monitoring of endogenous carbon monoxide elimination in exhaled air of rats in hyperoxia].

The authors offer a new method for continuous monitoring of endogenic carbon monoxide elimination in expired air of rats during inhalation of different oxygen mixtures. For the real-time CO detection at a 10 ppb level and at high CO2 and H2O concentrations the adjustable diode laser spectroscopy was used. Short intense peaks of CO in exhaled air after the onset of O2 inhalation was observed. The 60 min inhalation of 100% O2, 80% O2 and 60% O2 caused 44, 37 and 27% increases of endogenic CO as compared to initial concentrations, respectively. The duration of the effect of increased CO elimination had the tendency for a decrease with reduced concentrations of O2 in the inhaled gas mixture.

Animals↗
PubMed1995

[Lipid peroxidation markers in the exhaled breath and microsomal oxidation in patients with chronic diffuse liver diseases].

Low-molecular hydrocarbons (butan, pentan) from the exhaled air as lipid peroxidation (LPO) markers were quantified in patients with chronic diffuse liver diseases. The study was also made of microsomal oxidation enzymic activity by antipirin metabolism. The above parameters were followed up in the course of antioxidant treatment. As shown by total butan and pentan levels, LPO activity varied with the disease, being high in hepatic cirrhosis and primary biliary cirrhosis, but low in chronic active hepatitis and fat dystrophy. Increased levels of butan and pentan occurred in association with inhibited activity of P450-dependent monooxygenases. This was determined by antipirin biotransformation and confirmed by a strong inverse correlation between the amount of hydrocarbons and antipirin metabolites (4-hydroxy- and norantipirin) clearance. In the course of antioxidant therapy the most pronounced inhibiting action on formation of low-molecular hydrocarbons was distinctive of essenciale, pikamilon and copmplivit. Relevant efficacy of carsil was weaker. Similar regularity for these drugs takes place in relation to activation of microsomal oxidation.

Adult↗
PubMed1994

[Diagnostic value of investigating exhaled air condensate in lung cancer].

Parameters of lipid peroxidation and the levels of calcium ions in blood plasma and exhaled air condensate (EAC) were studied in 47 patients with lung cancer. The changes in EAC turned out to be more specific than those of blood plasma. The level of lipoperoxidation in condensate in cancer patients was lower than in healthy subjects. However, calcium cations concentrations in both blood and EAC were relatively higher, the latter difference being significant. The investigation pointed to a greater diagnostic value of EAC measurements, as compared with blood plasma, in lung cancer patients.

Adult↗
PubMedDate not supplied

[Diagnostic value of gas chromatographic study of exhaled air].

The authors analyze the problem of collection and concentration of exhaled air samples and its gas chromatographic measurement. A simple method for collection, transportation, and gas chromatographic analysis of alveolar air is suggested. The results indicate changes in the alveolar air composition during various diseases.

Alcoholism↗
PubMed1993

[Excessive nitrous oxide exhalation by postoperative patients in the recovery room].

Expired nitrous oxide from patients in the recovery room is considered to be the major source of air pollution. We measured expired concentrations of nitrous oxide in three patients and three volunteers. After only 5 minute inhalation of 50% nitrous oxide, it took over 2 hours for exhaled N2O concentration to decrease to 25 ppm in volunteers and after 30 minute inhalation, it took over 4 hours. The patients inhaled 50% nitrous oxide for 60, 165, 150 minutes, respectively and all patients expired nitrous oxide, the concentrations of which exceed 100 ppm over 3 hours. As to the patient who inhaled nitrous oxide for 150 minutes, expired nitrous oxide over 25 ppm was detected 10 hours after the end of anesthesia, and it was 4 ppm even after 20 hours. Any personnel including anesthesiologists and nurses working in the operating room can be exposed to high concentrations of nitrous oxide exceeding the permissible limit of 25 ppm, whenever they take care closely of their patients. We do not have any effective measures to protect us from this kind of air pollution except employing total intravenous anesthesia.

Adult↗
PubMedDate not supplied

[Methods of measuring lipid peroxidation products in exhaled air condensate and their clinical significance].

The authors propose simple, sufficiently sensitive, and reproducible methods for measuring lipid peroxidation products in exhaled air condensate. The content of diene conjugates, ketodienes, and conjugated trienes in the isopropanol phase of lipid extract is recommended to be measured. The methods were tried in patients with chronic nonspecific pulmonary diseases and lung cancer and proved to be valuable for the differential diagnosis of malignant and nontumorous processes in the respiratory organs.

1-Propanol↗
PubMedDate not supplied

[Lipids in the exhaled air condensate of pneumonia patients].

Lipid composition of exhaled air condensate (EAC) was assessed by thin layer chromatography in patients with pneumonia and normal subjects. In parallel with this, diene conjugates and diene ketones were assessed by spectrophotometry. Berhan's principle was for the first time used for noninvasive obtaining of EAC from each lung separately. Decreased percentage of phospholipids and increased level of free fatty acids in EAC of patients with massive pneumonia may be an evidence of disordered pulmonary surfactant, and an increase of the intermediate products of lipid peroxidation indicate the cause of these changes.

Breath Tests↗