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Biomedical subjects

B Bake

Publications and source records attributed to B Bake.

At least 109 records · Page 6Linked to original sources
PubMed1982

Respiratory symptoms and lung function in oil mist-exposed workers.

The prevalence of respiratory symptoms was registered and ventilatory function was determined in 164 men exposed to oil mist. The average exposure time was 16.2 years. One hundred fifty-nine office workers served as controls. The exposed men reported more respiratory symptoms: 14% of the exposed nonsmokers v. 2% of the non-smoking controls having cough at least three months a year. There were no significant differences between spirometric measurements and chest roentgenograms of the men exposed to oil mist and those of the office workers. The lung function of 25 nonsmoking exposed men was further examined with other lung function tests. The mean values for closing volume, slope of the alveolar plateau, total lung capacity, residual volume, elastic recoil at various lung volumes, and diffusion capacity did not differ significantly.

Adult↗
PubMed1980

Effects of preinspiratory volume on the nitrogen closing volume test.

The effect of varying the preinspiratory volume (VIair; range: 0-75% vital capacity, VC) on the nitrogen closing volume (CV) test was studied in twelve seated subjects, aged 24-62 years. When VIair was increased from 0 to about 12% VC, the height of phase IV, the amplitude of the cardiogenic oscillations, CV and the slope of phase III increased. The height of phase IV and the amplitude of the cardiogenic oscillations showed a maximum at VIair = 12% VC, although the average CV was about 18% VC. While the height of phase IV and the amplitude of the cardiogenic oscillations decreased when VIair was increased above 12% VC, CV did not change and the slope of phase III increased consistently. These results cannot be explained solely by the regional lung volume model of Sutherland et al. (1968). However, if that model is extended to include the assumption that within a region alveoli behind closed airways may be differently expanded, we predict CV to be underestimated at low VIair, independently of the upper to lower nitrogen concentration difference, in agreement with present findings. This assumption would also explain why the maximal height of phase IV can be obtained at a VIair lower than CV.

Adult↗
PubMed1980

Lung volumes and pulmonary gas exchange after coarctectomy.

Ventilatory lung function and pulmonary gas exchange were assessed during rest and exercise up to the maximal level in nineteen males aged 16-28 years, eleven years after surgery for coarctation of the aorta. Compared to the normal Swedish standards, the lung volumes indicated a restrictive impairment of lung function. However, the age range in this series of patients is outside the age range of reference values for both children and adults. When the effect of age on the lung volumes was allowed for they were found to be less restrictive. Pulmonary gas exchange was normal at rest and during maximal exercise. Thus, the aortic malformation and the thoracotomy did not lead to any marked impairment of lung function.

Adolescent↗
PubMed1980

Nitrogen single breath test, flow-volume curves and spirometry in healthy children, 7-18 years of age.

One hundred and forty school children, 75 boys and 65 girls, aged 7-18 years, underwent the following lung function tests: closing volume, slope of the alveolar plateau, maximal expiratory and inspiratory flows at 75, 50 and 25% of vital capacity, static and dynamic lung volumes. Lung volumes and maximal flows increase with height in an exponential way, the exponents varying between 2.6 and 3.1, while closing volume in per cent of vital capacity and the slope of the alveolar plateau decrease linearily with increasing height. Regression equations are given for each sex with height as determinant.

Adolescent↗
PubMed1980

Ventilatory dysfunction and respiratory rehabilitation in post-traumatic quadriplegia.

Lung volumes and maximum static respiratory pressures were examined in 35 patients rendered quadriplegic by traumatic transection of the cervical spinal cord at levels between C:IV and C:VIII. Twelve of these patients were treated 15 min a day for about 6 weeks by insufflation of air using a manually operated pump and by performing forced voluntary expirations and inspirations against a resistance. The markedly reduced total lung capacity, vital capacity, expiratory reserve volume and maximum static respiratory pressures all improved significantly upon treatment. The lung volumes remained improved in the 11 patients who were restudied after about 1 year and in the five patients who were restudied after about 5 years. However, maximum static respiratory pressures appeared to have decreased at the last follow-up study compared with those immediately after treatment.

Adolescent↗
PubMed1979

Prediction of postoperative hypoxemia in smokers and non-smokers.

Age, weight, spirometric variables, peak expiratory flow and airway closure assessments were correlated to postoperative gas exchange in 40 cholecystectomized subjects grouped according to smoking history. Pao2 was significantly lower in the smoking group both pre- and postoperatively, but the decrease in Pao2 following operation was of the same magnitude irrespective of smoking history. In non-smokers, the preoperative relationship between expiratory reserve volume and closing volume (ERV-CV) showed the highest correlation to postoperative alveolar-arterial oxygen difference P(A-a)o2 (r = -0.88, P less than 0.001) and to the increase of P(A-a)o2 following operation (r = -0.67, P less than 0.001), whereas age was found to be the best preoperative predictor of postoperative gas exchange in smokers.

Adult↗
PubMed1979

Alpha1-antitrypsin deficiency: genetic, clinical and functional correlations in a three generation family.

alpha1-antitrypsin (alpha1-AT) deficiency is a hereditary condition transmitted as an autosomal codominant trait. Fully deficient homozygotes develop chronic obstructive pulmonary disease at an early age. It remains controversial whether heterozygotes develop some degree of airway disease at an early age which results in severe obstructive disease later in life. We studied 12 alpha1-AT-deficient members of a family spanning three generations by extensive pulmonary function tests, clinical history and genetic determinations. 3 of the subjects were homozygotes and showed important clinical and lung function abnormalities by the age of 30. Two out of 9 heterozygotes, a female and a male, had decreased dynamic compliance, elevated closing volume and low PaO2. 3 showed clinical and physiological abnormalities (elevation in functional residual capacity and residual volume, low FEV1/FVC and elevated closing volume); however, these alterations could be attributed to their smoking habits or concomitant medical condition. The remaining 4 subjects were normal. None of the heterozygotes showed alterations in the static elastic recoil of the lung or static compliance.

Adolescent↗
PubMed1979

Effect of inspired volume on airway closure in relation to age.

Closing volume (CV) was measured in 64 healthy subjects aged 18--76 years, in supine position, with a bolus (helium) technique in two ways: following a maximal (CV100) and a submaximal (=50% VC; CV50) inspiration from residual volume. With increasing age CV50 increased less than CV100 according to the equation CV100(%VC)-CV50(%VC)=0.13Xage-0.6(r=0.46, P less than 0.001), e.g. at 70 years of age CV100=32(%VC) and CV50=24(%VC). Therefore, during normal breathing elderly subjects to not presumably close airways at as high a lung volume as predicted from conventional CV-measurements. A strong correlation between CV50 and CV100 was found, CV50(%VC)=0.55XCV100(%VC)+5.3(r=0.90; P less than 0.001), thus allowing a more accurate prediction of CV50 from CV100 than from age. Neither smoking habits nor body position affected the decrease of CV with reduced inspired volume.

Adolescent↗
PubMed1978

Effect of the slope of the alveolar plateau on determination of closing volume.

Repeated closing volume (CV) determinations were obtained simultaneously with the nitrogen method (CV-N2) and with a helium bolus method (CV-He) in 19 selected subjects with normal routine spirometry. Ten subjects had normal slopes of phase III and nine had abnormally steep slopes of phase III obtained with the nitrogen method. No systematic difference was found between CV-N2 and CV-He irrespective of the steepness of phase III, which seems to indicate that at least in spirometrically normal subjects airway closure is adequately assessed by the nitrogen method - even in the presence of a steep slope of phase III.

Closing Volume↗
PubMed1977

A modified forced oscillation technique for measurements of respiratory resistance.

We present a modification of forced oscillation technique for automated determination of total respiratory resistance during inspiration. The modifications consist of a computerized signal averaging and an optimization technique in the assessment of the resistance value. Thereby a favorable signal-to-noise ratio is obtained, allowing very low superimposed pressure oscillations. The method is validated by comparison with a conventional esophageal balloon method, by estimating added mechanical resistances in healthy subjects and by measuring the effect of bronchodilation in asthmatic children. The coefficient of variation as obtained from day-to-day measurements was about 7%. Mechanical resistances, estimated as the difference in total resistance with and without external resistance, were within 7% of their values determined for the resistances alone. A significant decrease in resistance was obtained in each of the asthmatic children following bronchodilation.

Adolescent↗
PubMed1977

Validity of the "airflometer"--a simple device for assessment of forced expiration.

The device is basically a plastic turbine with a reduction gear (approximately 1:300) driving an indicator. Following a forced expiration on the indicator comes to rest after about 30 s, when it is read. The reading appears to be generated by the expired flow versus time pattern, and during a forced expiration, close to maximum speed for the turbine is reached within 0.5 s. In a given subject repeated measurements with the same apparatus varied within a few per cent, whereas the variation was considerable among different apparatuses. Readings correlated about equally well with FEV0.5 and FEV1.

Forced Expiratory Flow Rates↗
PubMed1977

Ventilatory lung function following two years of tobacco abstinence.

Spirometry, maximal expiratory flows and the nitrogen closing volume test were studied in 59 subjects following their attempt to give up smoking. Seventeen subjects were tobacco abstinent for at least 5 months. This group showed significant improvement of vital capacity (VC), forced expiratory volume in 1 sec (FEV1) and the slope of phase III. Nine of these subjects remained ex-smokers for at least 24 months. However, no significant improvement of any of the measured variables could be established in this group. This may be due to the small number in the group and the circumstance that they were older and had worse lung function before smoking cessation compared with those who resumed smoking.

Adult↗