Breath-holding Method Research Articles

A study of gas analysis for measurement of pulmonary diffusing capacity for carbon monoxide by chromatographic techniques.

A study was made of a chromatographic technique for the analysis of gases used to measure pulmonary diffusing capacity by the breath-holding method. No difference was observed in the calculated pulmonary diffusing capacity for carbon monoxide if neon was substituted for helium as the insoluble gas. Analyses of samples of 8 ml and 3.5 ml with helium as the carrier gas yielded the same results for neon and carbon monoxide. Samples of 0.25 ml and argon as carrier gas were used for analysis of helium and oxygen. A two-loop sampling valve in the chromatograph permitted analysis of helium, oxygen, and carbon monoxide in a single analysis and permitted the use of gas chromatography for analysis of diffusing capacity for carbon monoxide without requiring helium as carrier; it also facilitated the analysis of oxygen without interference from atmospheric argon when the membrane component of pulmonary diffusing capacity was measured.

呼気中一酸化炭素濃度測定による血液中一酸化炭素ヘモグロビン濃度の推定

It is customary to measure the percentage of carbon monoxide hemoglobin (CO-Hb) in studying CO poisoning. There are a number of techniques for measuring CO-Hb, however, of which the procedures are usually very cumbersome, time-consuming and necessitating the preparation of blood samples. In the population survey, those methods are, therefore, thought to be inadequate. Ringold et al. developed a method to estimate the percentage of CO-Hb by measuring the concentration of CO in the expired air. In the present study the authors collected samples of expired air in polyvinyl bags (18 cm × 24 cm 0.1∼0.15 mm thick) which had shown no significant CO losses for 2 days, according to Jone's 20 second breath-holding method, and analyzed samples using a commercially available nondispersive infrared analyzer, Horiba Model LIA-2. Interferences by carbon dioxide and water vapor were avoided by means of soda lime and silica gel respectively. Blood CO-Hb percentage which was measured by Conway microdiffusion method well correlated to the expired air CO concentration in the range of lower concentrations. Medical students (119) were examined in relation to their cigarette smoking habits and the result showed that number of cigarettes smoked in a day had significant correlation with the CO concentration of the expired air. Average expired air CO concentrations of 276 school children in Tokyo on very fine days in autumn were 1.5-2.0 ppm in the ambient air with CO at about 1.0 ppm. On the other hand, school children (1383) in rural Japan in winter showed a little higher average expired air CO (3.0-5.5 ppm) regardless of the presence of heaters in the class room (ambient air CO at 0.5-3.0 ppm). This expired air CO is thought to be accumulated CO emitted from traditional rural Japanese heating. But a small amount of expired CO concentration which was higher than that of the ambient CO might be due to endogenous CO.

Bronchospirometric studies of lung volumes, ventilation/perfusion ratios and diffusion

Bilateral bronchospirometric nitrogen washout studies were used for the first time to calculate ventilation/perfusion ratios for the well and poorly ventilated areas in individual lungs. Results were compared with washout studies on both lungs measured together. Data suitable for analysis were obtained from seven patients with chronic lung disease. It was demonstrated that this technique for determining simultaneous ventilation/perfusion ratios for each lung gave accurate and detailed physiological changes. Comparison of the sum of average values for pulmonary capillary blood flow when both lungs were measured together by the same nitrogen washout technique showed a variation within the accepted 10% error for cardiac output. Diffusion for the separate lungs, measured by the carbon monoxide breath-holding method, gave values which correlated with lung volumes. bronchospirometry; nitrogen washout; diffusing capacity Submitted on November 22, 1963

Change in diffusing capacity with blood flow in an improved isolated lung preparation.

The isolated blood-perfused cat lung preparation has been improved by using large cannulas placed so as to minimize kinking of large vessels and by reducing the pressure produced by the perfusing pump by placing resistances between it and the lung. This improved preparation was capable of accepting blood flows up to 500 ml/min for 5–10 min and could be studied for 3–5 hr before deteriorating. The diffusing capacity for carbon monoxide, Dl, was measured at various blood flows up to 500 ml/min in seven isolated lung preparations improved as indicated. A breath-holding method using a gas mixture containing 2% SF6 and 0.3% CO was employed for measuring Dl. The test gas was analyzed on a gas chromatograph. Dl increased with blood flow in all the lungs studied. In four of them which were studied at constant left atrial pressure, Dl increased steadily by 10%/100 ml increase in blood flow throughout the range studied. Pulmonary vascular resistance decreased as Dl increased. Submitted on July 12, 1962

Estimating recent carbon monoxide exposures. A rapid method.

A valid method for determining the carboxyhemoglobin level in the body has been developed. The method is based on the 20-second breath-holding method. Our work shows that a polyvinyl bag can be used for collection of samples in the field. An application of this method is reported. This confirms the fact that cigarette smoking is a major factor in determining the carboxyhemoglobin level in a population. Pipe and cigar smokers appear not to have much increase in carboxyhemoglobin. The method should be suitable for studying the relationship of carboxyhemoglobin to occupational and to ambient air pollution exposures. 11 references, 7 figures, 4 tables.

The Reliability of the Pulmonary Diffusing Capacity Determination

The test-retest reliability of the ten second breath-holding method for the determination of pulmonary diffusing capacity of carbon monoxide was studied in a series of 151 men and women, including patients, normal subjects and athletes.The mean and standard deviation of the DLCO was 28.2 ± 10.09 ml × min−1 × mmHg−1. The standard deviation of the difference of duplicate determinations made on the same day (32 pairs) was 1.260, of those made at an interval of 10–99 days (98 pairs) 2.915, and of those made at an interval of 100–999 days (74 pairs) 2.637. The intra-individual variation was correspondingly 12, 29 and 26 per cent of that between individuals. It is concluded that “physiological” factors cause variations in the diffusing capacity over periods longer than a day; even so the tendency to individual constancy is marked.The results are compared with those of other investigators.The authors express their thanks to Dr. J. E. Cotes, of the Medical Research Council Pneumoconiosis Research Unit at Cardiff,...

Pulmonary diffusing capacity: a comparison of breath-holding and steady state methods using carbon monoxide.

ing the diffusing capacity of the lungs for carbon monoxide (DL). Two of these are steady state methods, and they differ in the methods used to calculate the mean alveolar carbon monoxide tension. Filley, MacIntosh and Wright (1) calculate the alveolar Pco indirectly, assuming the physiological dead space for carbon dioxide to be the same as that for carbon monoxide, while Bates, Boucot and Dormer (2) use the end-tidal Pco as the mean alveolar Pco. The third method is the single breath method of Krogh and Krogh (3) as modified by Ogilvie, Forster, Blakemore and Morton (4). Each method in theory measures the total resistance to gas diffusion offered by the structures that lie between the gas in the alveoli and the hemoglobin within the red cells of the pulmonary capillaries. The results obtained by each method differ in normal subjects; and in disease states, such as emphysema, the differences may be great. While the different results obtained in similar subjects by the two steady state methods can largely be explained by the different methods of estimating the mean alveolar Pco (5), the breath-holding method consistently gives higher results than either of the steady state methods (6). Marshall (7) has recently compared the breath-holding method of

Determination of oxygenated, mixed venous blood carbon dioxide tension by a breath-holding method.

At the end of a normal expiration the subject inhaled a given volume of gas mixtures containing different concentrations of CO2 in O2 from 5 to 17%. These were held in the lung for 3 and then again for 12 seconds and were then expired and analyzed. Analyses were made with an infrared analyzer and times were obtained from the graphical record. If the rate of change of CO2 tension is plotted against the mean CO2 tension a straight line results which passes through zero rate at the tension which equals the tension of CO2 in the mixed oxygenated venous blood. From the slope of this straight line it is possible to calculate the cardiac output if the lung volume and slope of the CO2 dissociation curve of the blood are known. Data are presented from 37 experiments on 10 subjects. The method is believed to be theoretically sound but has not been validated as a practical clinical method. Occasional erratic points were obtained, especially in untrained subjects. The standard error of the mean value for venous CO2 tension was 1.9 mm Hg. Submitted on July 13, 1959

Uniformity of pulmonary diffusion: effect of lung volume

In two normal subjects, the effect of changing lung volume on the uniformity of pulmonary diffusion (uniformity of Dl/Vl) was studied using the breath-holding and equilibration methods. Nonuniformity of diffusion, as indicated by deviation from a true exponential in the disappearance of carbon monoxide from alveolar gas, was seen to increase with increasing lung volume. Over-all Dl increased significantly with increasing lung volume. When lung volume was controlled, equilibration and breath-holding diffusion methods yielded similar over-all Dl and similar variation in Dl/Vl throughout the lung. Submitted on January 29, 1959